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The human N-acetyltransferase 2 enzyme, encoded by the NAT2 gene, plays an important role in the metabolism of isoniazid, the main drug used to treat tuberculosis. The interindividual variation in the response of patients to drug treatment for tuberculosis may be responsible for the occurrence of unfavorable outcomes. The presence of polymorphisms in genes associated with the metabolism and transport of drugs, receptors, and therapeutic targets has been identified as a major determinant of this variability. The objective of this study was to identify the genetic profile of NAT2 in the study population. Using the obtained genomic DNA followed by PCR amplification and sequencing, the frequency of nine SNPs as well as alleles associated with slow (47.9%), intermediate (38.7%), and fast acetylation phenotypes (11.3%), in addition to those whose phenotype has not yet been characterized (2.1%), was estimated. The NAT2*5B allele was identified more frequently (31.3%). The description of SNPs in pharmacogenes and the establishment of their relationship with the pharmacokinetics of an individual offer an individualized approach that allows us to reduce the unfavorable outcomes of a therapy, ensure better adherence to treatment, prevent the emergence of MDR strains, reduce the cost of treatment, and improve the quality of patients' lives. [ABSTRACT FROM AUTHOR]

Rationale: Standardized dosing of antitubercular drugs leads to variable plasma drug levels, which are associated with adverse drug reactions, delayed treatment response, and relapse. Mutations in genes affecting drug metabolism explain considerable interindividual pharmacokinetic variability; however, pharmacogenomic assays that predict metabolism of antitubercular drugs have been lacking. Objectives: We sought to develop a Nanopore sequencing panel and validate its performance in patients with active tuberculosis (TB) to personalize treatment dosing. Methods: We developed a Nanopore sequencing panel targeting 15 SNPs in five genes affecting the metabolism of antitubercular drugs. For validation, we sequenced DNA samples (n = 48) from the 1,000 Genomes Project and compared the variant calling accuracy with that of Illumina genome sequencing. We then sequenced DNA samples from patients with active TB (n = 100) from South Africa on a MinION Mk1C and evaluated the relationship between genotypes and pharmacokinetic parameters for isoniazid (INH) and rifampin (RIF). Measurements and Main Results: The pharmacogenomic panel achieved 100% concordance with Illumina sequencing in variant identification for the samples from the 1,000 Genomes Project. In the clinical cohort, coverage was more than 100× for 1,498 of 1,500 (99.8%) amplicons across the 100 samples. Thirty-three percent, 47%, and 20% of participants were identified as slow, intermediate, and rapid INH acetylators, respectively. INH clearance was 2.2 times higher among intermediate acetylators and 3.8 times higher among rapid acetylators, compared with slow acetylators (P < 0.0001). RIF clearance was 17.3% (2.50–29.9) lower in individuals with homozygous AADAC rs1803155 G→A substitutions (P = 0.0015). Conclusions: Targeted sequencing can enable the detection of polymorphisms that influence TB drug metabolism on a low-cost, portable instrument to personalize dosing for TB treatment or prevention. [ABSTRACT FROM AUTHOR]

Objectives: Isoniazid is a key drug in the chemotherapy of tuberculosis (TB), however, interindividual variability in pharmacokinetic parameters and drug plasma levels may affect drug responses including drug induced hepatotoxicity. The current study investigated the relationships between isoniazid exposure and isoniazid metabolism-related genetic factors in the context of occurrence of drug induced hepatotoxicity and TB treatment outcomes. Methods: Demographic characteristics and clinical information were collected in a prospective TB cohort study in Latvia (N = 34). Time to sputum culture conversion (tSCC) was used as a treatment response marker. Blood plasma concentrations of isoniazid (INH) and its metabolites acetylisoniazid (AcINH) and isonicotinic acid (INA) were determined at three time points (pre-dose (0 h), 2 h and 6 h after drug intake) using liquid chromatography-tandem mass spectrometry. Genetic variations of three key INH-metabolizing enzymes (NAT2, CYP2E1, and GSTM1) were investigated by application PCR- and Next-generation sequencing-based methods. Depending on variables, group comparisons were performed by Student's t-test, one-way ANOVA, Mann-Whitney-Wilcoxon, and Kruskal-Wallis tests. Pearson correlation coefficient was calculated for the pairs of normally distributed variables; model with rank transformations were used for non-normally distributed variables. Time-to-event analysis was performed to analyze the tSCC data. The cumulative probability of tSCC was obtained using Kaplan-Meier estimators. Cox proportional hazards models were fitted to estimate hazard rate ratios of successful tSCC. Results: High TB treatment success rate (94.1%) was achieved despite the variability in INH exposure. Clinical and demographic factors were not associated with either tSCC, hepatotoxicity, or INH pharmacokinetics parameters. Correlations between plasma concentrations of INH and its metabolites were NAT2 phenotypedependent, while GSTM1 genetic variants did not showed any effects. CYP2E1*6 (T > A) allelic variant was associated with INH pharmacokinetic parameters. Decreased level of AcINH was associated with hepatotoxicity, while decreased values of INA/INH and AcINH/INH were associated with month two sputum culture positivity. Conclusion: Our findings suggest that CYP2E1, but not GSTM1, significantly affects the INH pharmacokinetics along with NAT2. AcINH plasma level could serve as a biomarker for INH-related hepatotoxicity, and the inclusion of INH metabolite screening in TB therapeutic drug monitoring could be beneficial in clinical studies for determination of optimal dosing strategies. [ABSTRACT FROM AUTHOR]

Objectives Head and neck cancer (HNC) is one of the most common cancers. Most exogenous HNC is head and neck squamous cell carcinomas. Scientists are striving to develop diagnostic tests that will allow the prognosis of HNC. The aim of the study was to determine the risk of HNC. The research concerned changes caused by polymorphisms in genes encoding proteins responsible for the metabolism of xenobiotics. Material and Methods In group of 280 patients with HNC, the occurrence of polymorphic variants in NAT1 (rs72554606), NAT2 (rs1799930), CYP1A (rs1799814), CYP2D (rs3892097) were studied with TaqMan technique. The control group consisted of 260 cancer free people. The TNM scale was analyzed. Gene interactions of genotyped polymorphisms were investigated. The effects of smoking and alcohol consumption on HNC were assessed. Results The results indicated an increased risk of HNC in NAT1 polymorphisms in the GC genotype (OR = 1.772, 95% CI: 1.184–2.651, p = 0.005) and NAT2 polymorphism in the GA genotype (OR = 1.506, 95% CI: 1.023–2.216, p = 0.037). The protective phenomenon in the CYP1A polymorphism the GT genotype (OR = 0.587, 95% CI: 0.381–0.903, p = 0.015) and the TT genotype (OR = 0.268, 95% CI: 0.159–0.452, p = 0.001). The coexistence of GA-GC polymorphisms (OR = 2.687, 95% CI: 1.387–5.205, p = 0.003) in NAT2-NAT1 genes increases the risk of HNC. Risk-reducing effect in the polymorphism GG-GT (OR = 0.340, 95% CI: 0.149–0.800, p = 0.011), GG-TT (OR = 0.077, 95% CI: 0.028–0.215, p < 0.0001), GA-TT (OR = 0.250, 95% CI: 0.100–0.622, p = 0.002), AA-GT (OR = 0.276, 95% CI: 0.112–0.676, p = 0.002) in NAT2-CYP1A genes. In the CYP2D-CYP1A genes in the polymorphisms CT-CC (OR = 0.338, 95% CI: 0.132–0.870, p = 0.020), TT-GG (OR = 0.100, 95% CI: 0.027–0.359, p = 0.001), TT-GC (OR = 0.190, 95% CI: 0.072–0.502, p = 0.0004), TT-CC (OR = 0.305, 95% CI: 0.107–0.868, p = 0.024). Correlation was noted between cigarette smoking and HNC (OR = 7.297, 95% CI: 4.989–10.674, p < 0.0001) and consuming alcohol (OR = 1.572, 95% CI: 1.003–2.464, p = 0.047). Conclusions The CYP1A polymorphism shows a protective association with HNC. On the other hand, NAT2 , NAT1 polymorphism influence the susceptibility to developing HNC. The coexistence of the NAT2-NAT1 genotypes increases the risk of HNC. In contrast, NAT1-CYP1A and CYP1A-CYP2D reduce this risk. Smoking and alcohol consumption increase the incidence of HNC. Int J Occup Med Environ Health. 2023;36(6):812–24

Tobacco smoking is the most important risk factor for bladder cancer. Previous studies have identified the N‐acetyltransferase (NAT2) gene in association with bladder cancer risk. The NAT2 gene encodes an enzyme that metabolizes aromatic amines, carcinogens commonly found in tobacco smoke. In our study, we evaluated potential interactions of tobacco smoking with NAT2 genotypes and polygenic risk score (PRS) for bladder cancer, using data from the UK Biobank, a large prospective cohort study. We used Cox proportional hazards models to measure the strength of the association. The PRS was derived using genetic risk variants identified by genome‐wide association studies for bladder cancer. With an average of 10.1 years of follow‐up of 390 678 eligible participants of European descent, 769 incident bladder cancer cases were identified. Current smokers with a PRS in the highest tertile had a higher risk of developing bladder cancer (HR: 6.45, 95% CI: 4.51‐9.24) than current smokers with a PRS in the lowest tertile (HR: 2.41, 95% CI: 1.52‐3.84; P for additive interaction = <.001). A similar interaction was found for genetically predicted metabolizing NAT2 phenotype and tobacco smoking where current smokers with the slow NAT2 phenotype had an increased risk of developing bladder cancer (HR: 5.70, 95% CI: 2.64‐12.30) than current smokers with the fast NAT2 phenotype (HR: 3.61, 95% CI: 1.14‐11.37; P for additive interaction =.100). Our study provides support for considering both genetic and lifestyle risk factors in developing prevention measures for bladder cancer. [ABSTRACT FROM AUTHOR]

Objectives: Head and neck cancer (HNC) is one of the most common cancers. Most exogenous HNC is head and neck squamous cell carcinomas. Scientists are striving to develop diagnostic tests that will allow the prognosis of HNC. The aim of the study was to determine the risk of HNC. The research concerned changes caused by polymorphisms in genes encoding proteins responsible for the metabolism of xenobiotics. Material and Methods: In group of 280 patients with HNC, the occurrence of polymorphic variants in NAT1(rs72554606), NAT2(rs1799930), CYP1A(rs1799814), CYP2D(rs3892097) were studied with TaqMan technique. The control group consisted of 260 cancer free people. The TNM scale was analyzed. Gene interactions of genotyped polymorphisms were investigated. The effects of smoking and alcohol consumption on HNC were assessed. Results: The results indicated an increased risk of HNC in NAT1 polymorphisms in the GC genotype (OR = 1.772, 95% CI: 1.184-2.651, p = 0.005) and NAT2 polymorphism in the GA genotype (OR = 1.506, 95% CI: 1.023-2.216, p = 0.037). The protective phenomenon in the CYP1A polymorphism the GT genotype (OR = 0.587, 95% CI: 0.381-0.903, p = 0.015) and the TT genotype (OR = 0.268, 95% CI: 0.159-0.452, p = 0.001). The coexistence of GA-GC polymorphisms (OR = 2.687, 95% CI: 1.387-5.205, p = 0.003) in NAT2-NAT1 genes increases the risk of HNC. Risk-reducing effect in the polymorphism GG-GT (OR = 0.340, 95% CI: 0.149-0.800, p = 0.011), GG-TT (OR = 0.077, 95% CI: 0.028-0.215, p < 0.0001), GA-TT (OR = 0.250, 95% CI: 0.100-0.622, p = 0.002), AA-GT (OR = 0.276, 95% CI: 0.112-0.676, p = 0.002) in NAT2- CYP1A genes. In the CYP2D-CYP1A genes in the polymorphisms CT-CC (OR = 0.338, 95% CI: 0.132-0.870, p = 0.020), TT-GG (OR = 0.100, 95% CI: 0.027-0.359, p = 0.001, TT-GC (OR = 0.190, 95% CI: 0.072-0.502, p = 0.0004), TT-CC (OR = 0.305, 95% CI: 0.107-0.868, p = 0.024). Correlation was noted between cigarette smoking and HNC (OR = 7.297, 95% CI: 4.989-10.674, p < 0.0001) and consuming alcohol (OR = 1.572, 95% CI: 1.003-2.464, p = 0.047). Conclusions: The CYP1A polymorphism shows a protective association with HNC. On the other hand, NAT2, NAT1 polymorphism influence the susceptibility to developing HNC. The coexistence of the NAT2-NAT1 genotypes increases the risk of HNC. In contrast, NAT1-CYP1A and CYP1A-CYP2D reduce this risk. Smoking and alcohol consumption increase the incidence of HNC. [ABSTRACT FROM AUTHOR]

Objectives: Isoniazid is a key drug in the chemotherapy of tuberculosis (TB), however, interindividual variability in pharmacokinetic parameters and drug plasma levels may affect drug responses including drug induced hepatotoxicity. The current study investigated the relationships between isoniazid exposure and isoniazid metabolism-related genetic factors in the context of occurrence of drug induced hepatotoxicity and TB treatment outcomes.Methods: Demographic characteristics and clinical information were collected in a prospective TB cohort study in Latvia (N = 34). Time to sputum culture conversion (tSCC) was used as a treatment response marker. Blood plasma concentrations of isoniazid (INH) and its metabolites acetylisoniazid (AcINH) and isonicotinic acid (INA) were determined at three time points (pre-dose (0 h), 2 h and 6 h after drug intake) using liquid chromatography-tandem mass spectrometry. Genetic variations of three key INH-metabolizing enzymes (NAT2, CYP2E1, and GSTM1) were investigated by application PCR- and Next-generation sequencing-based methods. Depending on variables, group comparisons were performed by Student’s t-test, one-way ANOVA, Mann-Whitney-Wilcoxon, and Kruskal-Wallis tests. Pearson correlation coefficient was calculated for the pairs of normally distributed variables; model with rank transformations were used for non-normally distributed variables. Time-to-event analysis was performed to analyze the tSCC data. The cumulative probability of tSCC was obtained using Kaplan-Meier estimators. Cox proportional hazards models were fitted to estimate hazard rate ratios of successful tSCC.Results: High TB treatment success rate (94.1%) was achieved despite the variability in INH exposure. Clinical and demographic factors were not associated with either tSCC, hepatotoxicity, or INH pharmacokinetics parameters. Correlations between plasma concentrations of INH and its metabolites were NAT2 phenotype-dependent, while GSTM1 genetic variants did not showed any effects. CYP2E1*6 (T > A) allelic variant was associated with INH pharmacokinetic parameters. Decreased level of AcINH was associated with hepatotoxicity, while decreased values of INA/INH and AcINH/INH were associated with month two sputum culture positivity.Conclusion: Our findings suggest that CYP2E1, but not GSTM1, significantly affects the INH pharmacokinetics along with NAT2. AcINH plasma level could serve as a biomarker for INH-related hepatotoxicity, and the inclusion of INH metabolite screening in TB therapeutic drug monitoring could be beneficial in clinical studies for determination of optimal dosing strategies.

Background: Anti-tuberculosis drug-induced hepatotoxicity can result from genetic polymorphism of the isoniazid (INH) metabolizing enzyme. This study aimed to determine the effect of genetic polymorphism of N-acetyltransferase 2 (NAT2) and cytochrome P450 2E1 (CYP2E1) genes on serum isoniazid level and drug-induced hepatotoxicity. Methods: A cross-sectional study was conducted on 120 patients (with and without hepatotoxicity) with pulmonary tuberculosis from June 2019 to April 2022 in Tehran (Iran). High-performance liquid chromatography was used to measure the serum concentration of INH and acetylisoniazid (AcINH). NAT2 and CYP2E1 genotypes were determined using polymerase chain reaction and restriction fragment length polymorphism methods. Data were analyzed using SPSS software (version 22.0) with independent two-sample t test, Chi square test, or Fisher’s exact test. P

Yazun Jarrar,1 Sara Abudahab,2 Ghasaq Abdul-Wahab,3 Dana Zaiter,4 Abdalla Madani,4 Sara J Abaalkhail,4 Dina Abulebdah,4 Hussam Alhawari,5 Rami Musleh,6 Su-Jun Lee7 1Department of Basic Medical Sciences, Faculty of Medicine, Al-Balqa Applied University, Al-Salt, Jordan; 2Department of Pharmacotherapy and Outcomes Science, School of Pharmacy, Virginia Commonwealth University, Richmond, VA, USA; 3Department of Oral Surgery and Periodontology, College of Dentistry, Al-Mustansiriya University, Baghdad, Iraq; 4Department of Pharmacy, Faculty of Pharmacy, Al-Zaytoonah University of Jordan, Amman, Jordan; 5Department of Internal Medicine, School of Medicine, The University of Jordan, Amman, Jordan; 6Department of Pharmacy, Faculty of Medicine and Health Sciences, An-Najah National University, Nablus, Palestine; 7Department of Pharmacology, Pharmacogenomics Research Center, College of Medicine, Inje University, Busan, KoreaCorrespondence: Yazun Jarrar, Department of Basic Medical Sciences, Faculty of Medicine, Al-Balqa Applied University, Al-Salt, 19117, Jordan, Email yazan.jarrar@bau.edu.joBackground: N-acetyltransferase 2 (NAT2) enzyme is a Phase II drug-metabolizing enzyme that metabolizes different compounds. Genetic variations in NAT2 can influence the enzyme’s activity and potentially lead to the development of certain diseases.Aim: This study aimed to investigate the association of NAT2 variants with the risk of Type II diabetes mellitus (T2DM) and the lipid profile among Jordanian patients.Methods: We sequenced the whole protein-coding region in NAT2 using Sanger’s method among a sample of 45 Jordanian T2DM patients and 50 control subjects. Moreover, we analyzed the lipid profiles of the patients and examined any potential associations with NAT2 variants.Results: This study revealed that the heterozygous NAT2&ast;13 C/T genotype is significantly (P = 0.03) more common among T2DM (44%) than non-T2DM subjects (23.5%). Furthermore, the frequency of homozygous NAT2&ast;13 T/T genotype was found to be significantly higher (P = 0.03) among T2DM patients (26.7%) compared to that of non-T2DM subjects (11%). The heterozygous NAT2&ast;7 G/A genotype was exclusively observed in T2DM patients (11.1%) and absent in the control non-T2DM group. Moreover, among T2DM patients, those with a homozygous NAT2&ast;11 T/T genotype exhibited significantly higher levels of triglycerides (381.50 ± 9.19 ng/dL) with a P value of 0.01 compared to those with heterozygous NAT2&ast;11 C/T (136.23 ± 51.12 ng/dL) or wild-type NAT2&ast;11 C/C (193.65 ± 109.89 ng/dL) genotypes. T2DM patients with homozygous NAT2&ast;12 G/G genotype had a significantly (P = 0.04) higher triglyceride levels (275.67 ± 183.42 ng/dL) than the heterozygous NAT2&ast;12 A/G (140.02 ± 49.53 ng/dL) and the wild NAT2&ast;12 A/A (193.65 ± 109.89 ng/dL).Conclusion: The finding in this study suggests that the NAT2 gene is a potential biomarker for the development of T2DM and changes in triglyceride levels among Jordanians. However, it is important to note that our sample size was limited; therefore, further clinical studies with a larger cohort are necessary to validate these findings.Keywords: type II diabetes mellitus, N-acetyltransferase 2, NAT2, triglyceride, genetic variants, Jordanian population

The human N-acetyltransferase 2 enzyme, encoded by the NAT2 gene, plays an important role in the metabolism of isoniazid, the main drug used to treat tuberculosis. The interindividual variation in the response of patients to drug treatment for tuberculosis may be responsible for the occurrence of unfavorable outcomes. The presence of polymorphisms in genes associated with the metabolism and transport of drugs, receptors, and therapeutic targets has been identified as a major determinant of this variability. The objective of this study was to identify the genetic profile of NAT2 in the study population. Using the obtained genomic DNA followed by PCR amplification and sequencing, the frequency of nine SNPs as well as alleles associated with slow (47.9%), intermediate (38.7%), and fast acetylation phenotypes (11.3%), in addition to those whose phenotype has not yet been characterized (2.1%), was estimated. The NAT2*5B allele was identified more frequently (31.3%). The description of SNPs in pharmacogenes and the establishment of their relationship with the pharmacokinetics of an individual offer an individualized approach that allows us to reduce the unfavorable outcomes of a therapy, ensure better adherence to treatment, prevent the emergence of MDR strains, reduce the cost of treatment, and improve the quality of patients’ lives.

Background: Considering the genetic characteristics of people with antituberculosis (TB)-drug-induced liver injury (ATDILI), genetic factors and their consequences for treatment need to be studied. Objective: The correlation between N-acetyltransferase 2 (NAT2) genetic polymorphisms and ATDILI was analysed. Methods: In this study, the liver and coagulation functions of 120 patients with TB were monitored dynamically for at least 3 months. The genetic polymorphisms of patients were detected by pyrosequencing, and the acetylation types of liver damage and the distribution of NAT2 genetic polymorphisms were compared and analysed. Results: The results showed that there were significant differences in the distribution of alleles and acetylation types among different groups (p < 0.05). In patients with grade 4 liver injury (liver failure), any two alleles were included, i.e., *6 and *7. Specifically, patients with fast acetylation genotypes accounted for 42.4% (14/33), those with intermediate acetylated genotypes accounted for 55.2% (32/58), and patients with slow acetylation genotypes accounted for 65.5% (19/29). Conclusion: Patients with slow acetylation genotypes had higher rates of liver failure and liver injury than those with intermediate and fast acetylation genotypes, and patients with slow acetylation genotypes containing any two alleles (*6 and *7) had a higher rate of liver failure than those with other alleles. In summary, the time of liver injury in patients with slow acetylation genotypes was earlier than the total average time, and the time of liver function recovery in patients with fast acetylation genotypes was shorter than the total average time. [ABSTRACT FROM AUTHOR]

Background: Anti-tuberculosis drug-induced hepatotoxicity can result from genetic polymorphism of the isoniazid (INH) metabolizing enzyme. This study aimed to determine the effect of genetic polymorphism of N-acetyltransferase 2 (NAT2) and cytochrome P450 2E1 (CYP2E1) genes on serum isoniazid level and drug-induced hepatotoxicity. Methods: A cross-sectional study was conducted on 120 patients (with and without hepatotoxicity) with pulmonary tuberculosis from June 2019 to April 2022 in Tehran (Iran). High-performance liquid chromatography was used to measure the serum concentration of INH and acetylisoniazid (AcINH). NAT2 and CYP2E1 genotypes were determined using polymerase chain reaction and restriction fragment length polymorphism methods. Data were analyzed using SPSS software (version 22.0) with independent two-sample t test, Chi square test, or Fisher's exact test. P<0.05 was considered statistically significant. Results: A total of 40 patients showed hepatotoxicity. The risk of anti-tuberculosis drug-induced hepatotoxicity was significantly higher in patients who are slow acetylator (SA) phenotype than in rapid or intermediate acetylator (P<0.001). NAT2*4/*4 genotypes were not found in patients with hepatotoxicity. The frequency of NAT2*5 and NAT2*6 haplotypes and serum INH concentration was significantly higher in patients with hepatotoxicity than in those without (P=0.003, P<0.001, and P<0.001, respectively). NAT2*4 haplotype was correlated with protection against hepatotoxicity. A combination of SA and CYP2E1 C1/C1 genotype was significantly associated with hepatotoxicity (P<0.001). Conclusion: Hepatotoxicity in Iranian patients with tuberculosis was confirmed due to the presence of NAT2 SA polymorphism. Determining NAT2 and CYP2E1 genotypes and/or INH concentration can be a valuable tool to identify patients susceptible to hepatotoxicity. [ABSTRACT FROM AUTHOR]

Rivaroxaban is a direct inhibitor of factor Xa, a member of direct oral anticoagulant group of drugs (DOACs). Despite being a widely extended alternative to vitamin K antagonists (i.e., acenocoumarol, warfarin) the interindividual variability of DOACs is significant, and may be related to adverse drug reaction occurrence or drug inefficacy, namely hemorrhagic or thromboembolic events. Since there is not a consistent analytic practice to monitor the anticoagulant activity of DOACs, previously reported polymorphisms in genes coding for proteins responsible for the activation, transport, or metabolism of DOACs were studied. The study population comprised 60 healthy volunteers, who completed two randomized, crossover bioequivalence clinical trials between two different rivaroxaban formulations. The effect of food, sex, biogeographical origin and 55 variants (8 phenotypes and 47 single nucleotide polymorphisms) in drug metabolizing enzyme genes (such as CYP2D6, CYP2C9, NAT2) and transporters (namely, ABCB1, ABCG2) on rivaroxaban pharmacokinetics was tested. Individuals dosed under fasting conditions presented lower tmax (2.21 h vs 2.88 h, β = 1.19, R2 =0.342, p = 0.012) compared to fed volunteers. NAT2 slow acetylators presented higher AUC∞ corrected by dose/weight (AUC∞/DW; 8243.90 vs 7698.20 and 7161.25 h*ng*mg /ml*kg, β = 0.154, R2 =0.250, p = 0.044), higher Cmax/DW (1070.99 vs 834.81 and 803.36 ng*mg /ml*kg, β = 0.245, R2 =0.320, p = 0.002), and lower tmax (2.63 vs 3.19 and 4.15 h, β = −0.346, R2 =0.282, p = 0.047) than NAT2 rapid and intermediate acetylators. No other association was statistically significant. Thus, slow NAT2 appear to have altered rivaroxaban pharmacokinetics, increasing AUC∞ and Cmax. Nonetheless, further research should be conducted to verify NAT2 involvement on rivaroxaban pharmacokinetics and to determine its clinical significance.

Paracetamol (acetaminophen, APAP) is the most common non-prescription analgesic drug used during pregnancy. The aim of this study was to investigate the effect of vitamin E on acute APAP toxicity in pregnant rats. Toxicity in the liver, kidney, and brain (hippocampus, cerebellum, and olfactory bulb) was examined. Twenty pregnant female Wistar rats at gestational day 18 were used. Pregnant rats were divided into four groups: Control, APAP, E + APAP, and APAP + E. The Control group was treated with 0.5 mL p.o. corn oil. The APAP group received 3000 mg/kg p.o. APAP. The E + APAP group received 300 mg/kg p.o. vitamin E one hour before 3000 mg/kg APAP. The APAP + E group received 3000 mg/kg paracetamol one hour before 300 mg/kg p.o. vitamin E. Twenty-four hours after the last treatment administration, rats were euthanized and blood, brain, liver, and kidney samples were collected. Alanine aminotransferase (ALT), aspartate aminotransferase (AST), blood urea nitrogen (BUN), creatinine levels, uric acid (UA), and superoxide dismutase (SOD) levels, as well as the relative mRNA expression of Cyp1a4, Cyp2d6, and Nat2, were determined. Acute APAP treatment upregulated ALT, AST, BUN, and creatinine levels. APAP treatment downregulated UA and SOD levels. APAP treatment upregulated the relative mRNA expression of Cyp1a4 and Cyp2d6, but downregulated Nat2 expression. Vitamin E treatment, either before or after APAP administration, attenuated the toxic effects of APAP. In conclusion, the results showed that an acute toxic APAP dose in late pregnancy can cause oxidative stress and dysregulation in Cyp isoform expression, and that vitamin E treatment attenuates these effects. [ABSTRACT FROM AUTHOR]

Procainamide is a useful agent for management of ventricular arrhythmia, however its disposition and appropriate dosing during extracorporeal membrane oxygenation (ECMO) is unknown. We report experience with continuous procainamide infusion in a critically ill adult requiring venoarterial ECMO for incessant ventricular tachycardia. Pharmacokinetic analysis of procainamide and its metabolite, N-acetylprocainamide (NAPA), was performed using serum and urine specimens. Kidney function was preserved, and sequencing of the N-acetyltransferase 2 gene revealed the patient was a phenotypic slow acetylator. Procainamide volume of distribution and half-life were calculated and found to be similar to healthy individuals. However, despite elevated serum procainamide concentrations, NAPA concentrations remained far lower in the serum and urine. The magnitude of procainamide and NAPA discordance suggested alternative contributors to the deranged pharmacokinetic profile, and we hypothesized NAPA sequestration by the ECMO circuit. Ultimately, the patient received orthotopic cardiac transplantation and was discharged home in stable condition. Procainamide should be used cautiously during ECMO, with close therapeutic drug monitoring of serum procainamide and NAPA concentrations. The achievement of therapeutic NAPA concentrations while maintaining safe serum procainamide concentrations during ECMO support may be challenging. [ABSTRACT FROM AUTHOR]

Purpose: N-acetyltransferase 2 is an enzyme that is involved in the detoxification of carcinogens in the human body, so any damage to this protein may lead to the emergence of several metabolic dysfunctions. This work was conducted to determine the association between NAT2 polymorphism and non-small cell lung carcinoma (NSCLC) that is increasingly reported in the Iraqi population. Methods: PCR sequencing was conducted to assess the possible association between genetic variants and NSCLC. Several in silico tools were implemented to investigate the effect of the observed SNPs on the structure, function, and stability of the altered NAT2. Results: Five SNPS of NAT2 (rs1208, rs1041983, rs1799929, rs1799930, and rs1801280) were identified in high frequencies in the amplified fragment. These SNPs showed variable distributions of haplotypes between cases and controls. No significant association of rs1208, rs1041983, rs1799929, and rs1799930 with NSCLC was shown in the investigated population. In contrast, rs1801280: CC genotype showed a highly significant (P = 0.009) association with the NSCLC, and individuals with this genotype had 2.19 more chances for developing NSCLC (OR 2.19; Cl95% 1.21–3.94). Association analysis of rs1801280 SNP distribution among the investigated patients showed that patients with CC genotype showed a significant (P = 0.02, OR 2.65) association with family history, which entailed a high hereditary possibility of this genotype among Iraqi patients. It was predicted that this SNP showed high damaging effects on the activity of NAT2 enzyme, with various deleterious outcomes on enzyme structure, function, and stability. Conclusion: Data indicated that rs1801280 SNP exerted a tight association with NSCLC since individuals with CC genotype exhibited the most damaging effects on the NAT2 that may be behind the low acetylation rates of this enzyme in patients with NSCLC. [ABSTRACT FROM AUTHOR]

Isoniazid and its metabolites are potentially associated with hepatotoxicity and treatment outcomes in patients who receive antituberculosis (TB) therapy. To further understand the pharmacokinetic profiles of these molecules, a method based on LC-MS/MS was developed to determine the concentration of these compounds in human plasma. Isoniazid, acetylisoniazid, and isonicotinic acid were directly analyzed, whereas hydrazine and acetylhydrazine were determined after derivatization using p-tolualdehyde. Chromatographic separation was conducted on reversed-phase C18 columns with gradient elution, and detection was carried out in multiple reaction monitoring mode. The calibration curves were linear with correlation coefficients (r) greater than 0.9947 for all analytes. The intra- and inter-day precision was less than 13.43%, and the accuracy ranged between 91.63 and 114.00%. The recovery and matrix effect of the analytes were also consistent (coefficient of variation was less than 9.36%). The developed method successfully quantified isoniazid and its metabolites in TB patients. The method has broad applications in clinical research, including isoniazid one-point-based therapeutic drug monitoring, genotype–phenotype association studies of isoniazid metabolic profile and isoniazid-induced hepatotoxicity, and the initial dose prediction of isoniazid using population pharmacokinetic modeling. [ABSTRACT FROM AUTHOR]

Purpose: Significant pharmacokinetic variabilities have been reported for isoniazid across various populations. We aimed to summarize population pharmacokinetic studies of isoniazid in tuberculosis (TB) patients with a specific focus on the influence of N-acetyltransferase 2 (NAT2) genotype/single-nucleotide polymorphism (SNP) on clearance of isoniazid. Methods: A systematic search was conducted in PubMed and Embase for articles published in the English language from inception till February 2022 to identify population pharmacokinetic (PopPK) studies of isoniazid. Studies were included if patient population had TB and received isoniazid therapy, non-linear mixed effects modelling, and parametric approach was used for building isoniazid PopPK model and NAT2 genotype/SNP was tested as a covariate for model development. Results: A total of 12 articles were identified from PubMed, Embase, and hand searching of articles. Isoniazid disposition was described using a two-compartment model with first-order absorption and linear elimination in most of the studies. Significant covariates influencing the pharmacokinetics of isoniazid were NAT2 genotype, body weight, lean body weight, body mass index, fat-free mass, efavirenz, formulation, CD4 cell count, and gender. Majority of studies conducted in adult TB population have reported a twofold or threefold increase in isoniazid clearance for NAT2 rapid acetylators compared to slow acetylators. Conclusion: The variability in disposition of isoniazid can be majorly attributed to NAT2 genotype. This results in a trimodal clearance pattern with a multi-fold increase in clearance of NAT2 rapid acetylators compared to slow acetylators. Further studies exploring the generalizability/adaptability of developed PopPK models in different clinical settings are required. [ABSTRACT FROM AUTHOR]

Aim: Our study aimed to screen the genotype frequencies of very important pharmacogenomic (VIP) mutations and identify their differences between Bai and other populations. Materials & methods: We selected 66 VIP variants from PharmGKB (www.pharmgkb.org/) for genotyping. χ2 test was used to identify differences in loci between these populations and FST values of Bai and the other 26 populations were analyzed. Results: Our study showed that the frequencies of SNPs of CYP3A5, ACE, PTGS2 and NAT2 differed significantly from those of the other 26 populations. At the same time, we found that some VIP variants may affect the metabolism of drugs and the genetic relationship between the Bai population and East Asian populations was found to be the closest. Conclusion: By comparing the genotype frequencies of different populations, the loci with significant differences were identified and discussed, providing a theoretical basis for individualized drug use in the Bai ethnic population. [ABSTRACT FROM AUTHOR]

Background: In Peru, 32,970 people were diagnosed with tuberculosis (TB) in 2019. Although TB treatment is effective, 3.4%–13% is associated with significant adverse drug reactions (ADR), considering drug‐induced liver injury (DILI) as the most prevalent. Among the first‐line anti‐TB drugs, isoniazid (INH) is primarily responsible for the occurrence of DILI. INH is metabolized in the liver by the enzymes N‐acetyltransferase‐2 (NAT2) and Cytochrome P450 2E1 (CYP2E1). Based on the previous studies, we hypothesized that the interactions between slow CYP2E1 genotype and NAT2 slow acetylators will induce DILI in TB patients. Methods: In this cross‐sectional study, all 377 participants completed their anti‐TB treatment, and we genotyped SNPs: rs1041983, rs1801280, rs1799929, rs1799930, rs1208, and rs1799931 for NAT2 and rs3813867 and rs2031920 for CYP2E1. Results: We found that rapid, intermediate, and slow NAT2 acetylator were 15%, 38%, and 47%, respectively, in the general population. Intermediate NAT2 acetylator is the least prevalent among patients with adverse reactions (p = 0.024). We did not confirm our hypothesis, however, we found that the combination of intermediate NAT2 acetylators and CYP2E1 c1/c1 genotype significantly protected (OR = 0.16; p = 0.049) against the development of DILI in our population. Conclusion: We propose that the presence of NAT2 intermediate and CYP2E1 c1/c1 genotype could help in therapeutic drug monitoring, and optimize its therapeutic benefits while minimizing its risk for side effects or toxicity. [ABSTRACT FROM AUTHOR]

Drug acetylation plays an important role in the medical practice. Modern methods of acetylation phenotype prediction are based on genotyping of polymorphisms in the second exon of the gene NAT2. Some disadvantages of these methods limit their application in the clinical practice. We developed a method of human genotyping based on identification of NAT2 gene polymorphism rs1495741 by real-time PCR. This method of genotype determination has a number of advantages: high sensitivity, simplicity, possibility of automated interpretation of the results, and feasibility in clinical laboratories. [ABSTRACT FROM AUTHOR]

Abstract Background In Peru, 32,970 people were diagnosed with tuberculosis (TB) in 2019. Although TB treatment is effective, 3.4%–13% is associated with significant adverse drug reactions (ADR), considering drug‐induced liver injury (DILI) as the most prevalent. Among the first‐line anti‐TB drugs, isoniazid (INH) is primarily responsible for the occurrence of DILI. INH is metabolized in the liver by the enzymes N‐acetyltransferase‐2 (NAT2) and Cytochrome P450 2E1 (CYP2E1). Based on the previous studies, we hypothesized that the interactions between slow CYP2E1 genotype and NAT2 slow acetylators will induce DILI in TB patients. Methods In this cross‐sectional study, all 377 participants completed their anti‐TB treatment, and we genotyped SNPs: rs1041983, rs1801280, rs1799929, rs1799930, rs1208, and rs1799931 for NAT2 and rs3813867 and rs2031920 for CYP2E1. Results We found that rapid, intermediate, and slow NAT2 acetylator were 15%, 38%, and 47%, respectively, in the general population. Intermediate NAT2 acetylator is the least prevalent among patients with adverse reactions (p = 0.024). We did not confirm our hypothesis, however, we found that the combination of intermediate NAT2 acetylators and CYP2E1 c1/c1 genotype significantly protected (OR = 0.16; p = 0.049) against the development of DILI in our population. Conclusion We propose that the presence of NAT2 intermediate and CYP2E1 c1/c1 genotype could help in therapeutic drug monitoring, and optimize its therapeutic benefits while minimizing its risk for side effects or toxicity.

Drug-induced liver injury (DILI) is an unpredictable and feared side effect of antituberculosis treatment (AT). The present study aimed to identify clinical and genetic variables associated with susceptibility to AT-associated hepatotoxicity in patients with pulmonary tuberculosis treated with a standard protocol. Of 233 patients enrolled, 90% prospectively, 103 developed liver injury: 37 with mild and 66 with severe phenotype (DILI). All patients with mild hepatitis had a RUCAM score ≥4 and all patients with DILI had a RUCAM score ≥ 6. Eight clinical variables and variants in six candidate genes were assessed. A logistic multivariate regression analysis identified four risk factors for AT-DILI: age ≥ 55 years (OR:3.67; 95% CI:1.82–7.41; p < 0.001), concomitant medication with other hepatotoxic drugs (OR:2.54; 95% CI:1.23–5.26; p = 0.012), NAT2 slow acetylator status (OR:2.46; 95% CI:1.25–4.84; p = 0.009), and carriers of p.Val444Ala variant for ABCB11 gene (OR:2.06; 95%CI:1.02–4.17; p = 0.044). The statistical model explains 24.9% of the susceptibility to AT-DILI, with an 8.9 times difference between patients in the highest and in the lowest quartiles of risk scores. This study sustains the complex architecture of AT-DILI. Prospective studies should evaluate the benefit of NAT2 and ABCB11 genotyping in AT personalization, particularly in patients over 55 years. [ABSTRACT FROM AUTHOR]

Edhyana Sahiratmadja,1 Ika Agus Rini,2 Simeon Penggoam,3 Afandi Charles,2 Ani Melani Maskoen,1,2 Ida Parwati4 1Division of Biochemistry and Molecular Biology, Department of Biomedical Sciences, Faculty of Medicine, Universitas Padjadjaran, Bandung, Indonesia; 2Health Research Unit, Faculty of Medicine, Universitas Padjadjaran, Bandung, Indonesia; 3Laboratorium Mikrobiologi, RSUD Prof. Dr. WZ Johannes, Kupang, Indonesia; 4Department of Clinical Pathology, Faculty of Medicine, Universitas Padjadjaran, Bandung, IndonesiaCorrespondence: Edhyana SahiratmadjaDivision of Biochemistry and Molecular Biology, Department of Biomedical Sciences, Faculty of Medicine, Universitas Padjadjaran, Jl. Raya Bandung – Sumedang KM 21, Jatinangor, Sumedang, Jawa Barat, 45363, IndonesiaTel +62 22 779 5594Fax +62 22 779 5595Email e.sahiratmadja@unpad.ac.idPurpose: N-acetyltransferase-2 enzyme in the liver, encoded by NAT2 gene, plays a central role in metabolizing tuberculosis (TB) drug isoniazid (INH). Low compliance of patients toward six-month TB therapy and internal host factors, ie comorbid diseases, immune status, and genetic profiles, are factors leading to treatment failure and recurrence of pulmonary TB infection. This study aimed to explore the NAT2 acetylator status among newly diagnosed and recurrent pulmonary TB patients in eastern part of Indonesia.Patients and Methods: Archived DNA of TB patients (n=124) and healthy controls (n=124) were sequenced, and NAT2 acetylator status was determined, then categorized as fast, intermediate, or slow acetylators. Pulmonary TB patients who had no previous TB treatment history were designated as newly diagnosed pulmonary TB, whereas patients with a history of TB treatment were designated as recurrent pulmonary TB. The demographic, clinical, and microbiological data between pulmonary TB groups were compared, and acetylator status was described among groups.Results: Male was more significantly prevalent in the recurrent pulmonary TB group (p=0.025), and anemia was more prevalent in new pulmonary TB (p=0.003). The acetylator status in pulmonary TB patients compared to healthy controls were rapid (33.9% vs 48.1%), intermediate (57.8% vs 33.0%), and slow acetylators (8.3% vs 18.9%), respectively. Interestingly, the rapid and intermediate acetylator were significantly more prevalent in pulmonary TB patients than in healthy controls (p=0.023, OR=2.58 (1.12– 5.97). Furthermore, no differences were found in acetylator status between new and recurrent pulmonary (p=0.776).Conclusion: Rapid and intermediate acetylators status predominated the pulmonary TB patients in Kupang, eastern part of Indonesia, postulating different genetic makeup in this area. As the pulmonary TB patients in Kupang exhibit more rapid acetylator phenotype, the acetylator status might be relevant to be checked before TB therapy for adjusting treatment dose to prevent drug resistances.Keywords: acetylator status, NAT2, Indonesia, tuberculosis, recurrence

Abstract Background Intervertebral disc degeneration, one of the major causes of low-back pain, results from altered biosynthesis/turnover of extracellular matrix in the disc. Previously, we reported that the analgesic drug Neurotropin® (NTP) had an anabolic effect on glycosaminoglycan synthesis in cultured nucleus pulposus (NP) cells via the stimulation of chondroitin sulfate N-acetylgalactosaminyltransferase 1. However, its effect on the aggrecan core protein was not significantly detected, because of the data variance. A microarray analysis suggested that the effect of NTP on aggrecan was correlated with N-acetyltransferase 2 (NAT2), a drug-metabolizing enzyme. Specific NAT2 alleles are known to correlate with rapid, intermediate, and slow acetylation activities and side effects of various drugs. We investigated the association between the efficacy of NTP on aggrecan expression and the NAT2 genotype in cell donors. Methods NP cells were isolated from intervertebral disc tissues donated by 31 Japanese patients (28–68 years) who underwent discectomy. NTP was added to the primary cell cultures and its effect on the aggrecan mRNA was analyzed using real-time quantitative PCR. To assess acetylator status, genotyping was performed based on the inferred NAT2 haplotypes of five common single-nucleotide polymorphisms using allele-specific PCR. Results The phenotype frequencies of NAT2 in the patients were 0%, 42.0%, and 58.0% for slow, intermediate, and rapid acetylators, respectively. The proportions of responders to NTP treatment (aggrecan upregulation, ≥ 1.1-fold) in the intermediate and rapid acetylators were 76.9% and 38.9%, respectively. The odds ratio of the comparison of the intermediate acetylator status between responders and nonresponders was 5.2 (95% CI 1.06–26.0, P = 0.036), and regarding the 19 male patients, this was 14.0 (95% CI 1.54–127.2, P = 0.012). In the 12 females, the effect was not correlated with NAT2 phenotype but seemed to become weaker along with aging. Conclusions An intermediate acetylator status significantly favored the efficacy of NTP treatment to enhance aggrecan production in NP cells. In males, this tendency was detected with higher significance. This study provides suggestive data of the association between NAT2 variants and the efficacy of NTP treatment. Given the small sample size, results should be further confirmed.

Paracetamol (acetaminophen, APAP) is the most common non-prescription analgesic drug used during pregnancy. The aim of this study was to investigate the effect of vitamin E on acute APAP toxicity in pregnant rats. Toxicity in the liver, kidney, and brain (hippocampus, cerebellum, and olfactory bulb) was examined. Twenty pregnant female Wistar rats at gestational day 18 were used. Pregnant rats were divided into four groups: Control, APAP, E + APAP, and APAP + E. The Control group was treated with 0.5 mL p.o. corn oil. The APAP group received 3000 mg/kg p.o. APAP. The E + APAP group received 300 mg/kg p.o. vitamin E one hour before 3000 mg/kg APAP. The APAP + E group received 3000 mg/kg paracetamol one hour before 300 mg/kg p.o. vitamin E. Twenty-four hours after the last treatment administration, rats were euthanized and blood, brain, liver, and kidney samples were collected. Alanine aminotransferase (ALT), aspartate aminotransferase (AST), blood urea nitrogen (BUN), creatinine levels, uric acid (UA), and superoxide dismutase (SOD) levels, as well as the relative mRNA expression of Cyp1a4, Cyp2d6, and Nat2, were determined. Acute APAP treatment upregulated ALT, AST, BUN, and creatinine levels. APAP treatment downregulated UA and SOD levels. APAP treatment upregulated the relative mRNA expression of Cyp1a4 and Cyp2d6, but downregulated Nat2 expression. Vitamin E treatment, either before or after APAP administration, attenuated the toxic effects of APAP. In conclusion, the results showed that an acute toxic APAP dose in late pregnancy can cause oxidative stress and dysregulation in Cyp isoform expression, and that vitamin E treatment attenuates these effects.

Aim. To assess the variability of the NAT2 gene and to comparatively analyze the prevalence of NAT2 polymorphisms and acetylation types among Yakut and Russian patients newly diagnosed with pulmonary tuberculosis (TB), permanently residing in the Sakha Republic (Yakutia).Materials and methods. The study included 197 patients with newly diagnosed pulmonary TB (132 Yakuts and 65 Russians) aged (43.3 ± 14.4). The following single-nucleotide polymorphisms were analyzed, using real-time polymerase chain reaction (PCR): NAT2*5 (rs1801280, Т341С), NAT2*6 (rs1799930, G590A), NAT2*7 (rs1799931, G857A), NAT2*11 (rs1799929, C481T), NAT2*12 (rs1208, A803G), and NAT2*13 (rs1041983, C282T). Genetically determined basal metabolic rates were calculated using the NATpred online tool.Results. 75% of residents, both of Yakut and Russian ethnicity, were identified as carriers of NAT2 polymorphic variants known to be related to isoniazid biotransformation. NAT2*6 and *13 allelic variants were more frequent in Yakuts (occurring in 40.9% and 64.4%, respectively); variants NAT2*5, *6, *11, *12, and *13 were more common in Russians (69.2; 55.4; 67.7; 69.2, and 64.6%, respectively). The NAT2*5, *7, *11, and *12 polymorphisms were found to be significantly ethnicity-dependent. The study established substantial prevalence of medium acetylation type (58.3%) in Yakuts and slow acetylation type in Russians (61.5%). Correlations were shown between ethnicity and different prevalence rates of rapid, medium, or slow acetylation types among patients with TB.Conclusion. The observed NAT2 polymorphism distribution patterns and isoniazid acetylation types among Yakut and Russian patients with newly diagnosed pulmonary TB demonstrated that pharmacologic responses can be significantly different between ethnic groups. Findings of pharmacogenetic studies in Yakut and Russian populations should be incorporated in clinical practice for personalized administration of isoniazid.

Many cancers, including breast cancer, have shown differential expression of human arylamine N -acetyltransferase 1 (NAT1). The exact effect this differential expression has on disease risk and progression remains unclear. While NAT1 is classically defined as a xenobiotic metabolizing enzyme, other functions and roles in endogenous metabolism have recently been described providing additional impetus for investigating the effects of varying levels of NAT1 on global gene expression. Our objective is to further evaluate the role of NAT1 in breast cancer by determining the effect of NAT1 overexpression, knockdown, and knockout on global gene expression in MDA-MB-231 cell lines. RNA-seq was utilized to interrogate differential gene expression (genes correlated with NAT1 activity) across three biological replicates of previously constructed and characterized MDA-MB-231 breast cancer cell lines expressing parental (Scrambled), increased (Up), decreased (Down, CRISPR 2–12), or knockout (CRISPR 2–19, CRISPR 5–50) levels of NAT1. 3,889 genes were significantly associated with the NAT1 N -acetylation activity of the cell lines (adjusted p ≤ 0.05); of those 3,889 genes, 1,756 were positively associated with NAT1 N -acetylation activity and 2,133 were negatively associated with NAT1 N -acetylation activity. An enrichment of genes involved in cell adhesion was observed. Additionally, human arylamine N -acetyltransferase 2 (NAT2) transcripts were observed in the complete NAT1 knockout cell lines (CRISPR 2–19 and CRISPR 5–50). This study provides further evidence that NAT1 functions as more than just a drug metabolizing enzyme given the observation that differences in NAT1 activity have significant impacts on global gene expression. Additionally, our data suggests the knockout of NAT1 results in transcription of its isozyme NAT2. [ABSTRACT FROM AUTHOR]

Rationale: Standardized dosing of antitubercular drugs contributes to a substantial incidence of toxicities, inadequate treatment response, and relapse, in part due to variable drug concentrations achieved. SNPs in the NAT2 (N-acetyltransferase-2) gene explain the majority of interindividual pharmacokinetic variability of isoniazid (INH). However, an obstacle to implementing pharmacogenomic-guided dosing is the lack of a point-of-care assay. Objectives: To develop and test a NAT2 classification algorithm, validate its performance in predicting isoniazid clearance, and develop a prototype pharmacogenomic assay. Methods: We trained random forest models to predict NAT2 acetylation genotype from unphased SNP data using a global collection of 8,561 phased genomes. We enrolled 48 patients with pulmonary tuberculosis, performed sparse pharmacokinetic sampling, and tested the acetylator prediction algorithm accuracy against estimated INH clearance. We then developed a cartridge-based multiplex quantitative PCR assay on the GeneXpert platform and assessed its analytical sensitivity on whole blood samples from healthy individuals. Measurements and Main Results: With a 5-SNP model trained on two-thirds of the data (n = 5,738), out-of-sample acetylation genotype prediction accuracy on the remaining third (n = 2,823) was 100%. Among the 48 patients with tuberculosis, predicted acetylator types were 27 (56.2%) slow, 16 (33.3%) intermediate, and 5 (10.4%) rapid. INH clearance rates were lowest in predicted slow acetylators (median 14.5 L/h), moderate in intermediate acetylators (median 40.3 L/h), and highest in fast acetylators (median 53.0 L/h). The cartridge-based assay accurately detected all allele patterns directly from 25 μl of whole blood. Conclusions: An automated pharmacogenomic assay on a platform widely used globally for tuberculosis diagnosis could enable personalized dosing of INH. [ABSTRACT FROM AUTHOR]

Many cancers, including breast cancer, have shown differential expression of human arylamine N-acetyltransferase 1 (NAT1). The exact effect this differential expression has on disease risk and progression remains unclear. While NAT1 is classically defined as a xenobiotic metabolizing enzyme, other functions and roles in endogenous metabolism have recently been described providing additional impetus for investigating the effects of varying levels of NAT1 on global gene expression. Our objective is to further evaluate the role of NAT1 in breast cancer by determining the effect of NAT1 overexpression, knockdown, and knockout on global gene expression in MDA-MB-231 cell lines. RNA-seq was utilized to interrogate differential gene expression (genes correlated with NAT1 activity) across three biological replicates of previously constructed and characterized MDA-MB-231 breast cancer cell lines expressing parental (Scrambled), increased (Up), decreased (Down, CRISPR 2–12), or knockout (CRISPR 2–19, CRISPR 5–50) levels of NAT1. 3,889 genes were significantly associated with the NAT1 N-acetylation activity of the cell lines (adjusted p ≤ 0.05); of those 3,889 genes, 1,756 were positively associated with NAT1 N-acetylation activity and 2,133 were negatively associated with NAT1 N-acetylation activity. An enrichment of genes involved in cell adhesion was observed. Additionally, human arylamine N-acetyltransferase 2 (NAT2) transcripts were observed in the complete NAT1 knockout cell lines (CRISPR 2–19 and CRISPR 5–50). This study provides further evidence that NAT1 functions as more than just a drug metabolizing enzyme given the observation that differences in NAT1 activity have significant impacts on global gene expression. Additionally, our data suggests the knockout of NAT1 results in transcription of its isozyme NAT2.

Isoniazid and its metabolites are potentially associated with hepatotoxicity and treatment outcomes in patients who receive antituberculosis (TB) therapy. To further understand the pharmacokinetic profiles of these molecules, a method based on LC-MS/MS was developed to determine the concentration of these compounds in human plasma. Isoniazid, acetylisoniazid, and isonicotinic acid were directly analyzed, whereas hydrazine and acetylhydrazine were determined after derivatization using p-tolualdehyde. Chromatographic separation was conducted on reversed-phase C18 columns with gradient elution, and detection was carried out in multiple reaction monitoring mode. The calibration curves were linear with correlation coefficients (r) greater than 0.9947 for all analytes. The intra- and inter-day precision was less than 13.43%, and the accuracy ranged between 91.63 and 114.00%. The recovery and matrix effect of the analytes were also consistent (coefficient of variation was less than 9.36%). The developed method successfully quantified isoniazid and its metabolites in TB patients. The method has broad applications in clinical research, including isoniazid one-point-based therapeutic drug monitoring, genotype–phenotype association studies of isoniazid metabolic profile and isoniazid-induced hepatotoxicity, and the initial dose prediction of isoniazid using population pharmacokinetic modeling.

Background: We determined the frequency of genetic polymorphisms in three anti‐TB drug metabolic proteins previously reported: N‐acetyltransferase 2 (NAT2), cytochrome P450 2E1 (CYP2E1), and arylacetamide deacetylase (AADAC) within a Peruvian population in a cohort of TB patients. Methods: We genotyped SNPs rs1041983, rs1801280, rs1799929, rs1799930, rs1208, and rs1799931 for NAT2; rs3813867 and rs2031920 for CYP2E1; and rs1803155 for AADAC in 395 participants completed their antituberculosis treatment. Results: Seventy‐four percent of the participants are carriers of slow metabolizer genotypes: NAT2*5, NAT2*6, and NAT2*7, which increase the sensitivity of INH at low doses and increase the risk of drug‐induced liver injuries. Sixty‐four percent are homozygous for the wild‐type CYP2E1*1A allele, which could increase the risk of hepatotoxicity. However, 16% had a NAT2 fast metabolizer phenotype which could increase the risk of acquiring resistance to INH, thereby increasing the risk of multidrug‐resistant (MDR) or treatment failure. The frequency of rs1803155 (AADAC*2 allele) was higher (99.9%) in Peruvians than in European American, African American, Japanese, and Korean populations. Conclusions: This high prevalence of slow metabolizers for isoniazid in the Peruvian population should be further studied and considered to help individualize drug regimens, especially in countries with a great genetic diversity like Peru. These data will help the Peruvian National Tuberculosis Control Program develop new strategies for therapies. [ABSTRACT FROM AUTHOR]

Abstract Background We determined the frequency of genetic polymorphisms in three anti‐TB drug metabolic proteins previously reported: N‐acetyltransferase 2 (NAT2), cytochrome P450 2E1 (CYP2E1), and arylacetamide deacetylase (AADAC) within a Peruvian population in a cohort of TB patients. Methods We genotyped SNPs rs1041983, rs1801280, rs1799929, rs1799930, rs1208, and rs1799931 for NAT2; rs3813867 and rs2031920 for CYP2E1; and rs1803155 for AADAC in 395 participants completed their antituberculosis treatment. Results Seventy‐four percent of the participants are carriers of slow metabolizer genotypes: NAT2*5, NAT2*6, and NAT2*7, which increase the sensitivity of INH at low doses and increase the risk of drug‐induced liver injuries. Sixty‐four percent are homozygous for the wild‐type CYP2E1*1A allele, which could increase the risk of hepatotoxicity. However, 16% had a NAT2 fast metabolizer phenotype which could increase the risk of acquiring resistance to INH, thereby increasing the risk of multidrug‐resistant (MDR) or treatment failure. The frequency of rs1803155 (AADAC*2 allele) was higher (99.9%) in Peruvians than in European American, African American, Japanese, and Korean populations. Conclusions This high prevalence of slow metabolizers for isoniazid in the Peruvian population should be further studied and considered to help individualize drug regimens, especially in countries with a great genetic diversity like Peru. These data will help the Peruvian National Tuberculosis Control Program develop new strategies for therapies.

Colon adenocarcinoma (COAD) is one of the most common malignant tumors and has high migration and invasion capacity. In this study, we attempted to establish a multigene signature for predicting the prognosis of COAD patients. Weighted gene co-expression network analysis and differential gene expression analysis methods were first applied to identify differentially co-expressed genes between COAD tissues and normal tissues from the Cancer Genome Atlas (TCGA)-COAD dataset and GSE39582 dataset, and a total of 309 overlapping genes were screened out. Then, our study employed TCGA-COAD cohort as the training dataset and an independent cohort by merging the GES39582 and GSE17536 datasets as the testing dataset. After univariate and multivariate Cox regression analyses were performed for these overlapping genes and overall survival (OS) of COAD patients in the training dataset, a 13-gene signature was constructed to divide COAD patients into high- and low-risk subgroups with significantly different OS. The testing dataset exhibited the same results utilizing the same predictive signature. The area under the curve of receiver operating characteristic analysis for predicting OS in the training and testing datasets were 0.789 and 0.868, respectively, which revealed the enhanced predictive power of the signature. Multivariate Cox regression analysis further suggested that the 13-gene signature could independently predict OS. Among the 13 prognostic genes, NAT1 and NAT2 were downregulated with deep deletions in tumor tissues in multiple COAD cohorts and exhibited significant correlations with poorer OS based on the GEPIA database. Notably, NAT1 and NAT2 expression levels were positively correlated with infiltrating levels of CD8+ T cells and dendritic cells, exhibiting a foundation for further research investigating the antitumor immune roles played by NAT1 and NAT2 in COAD. Taken together, the results of our study showed that the 13-gene signature could efficiently predict OS and that NAT1 and NAT2 could function as biomarkers for prognosis and the immune response in COAD.

Colon adenocarcinoma (COAD) is one of the most common malignant tumors and has high migration and invasion capacity. In this study, we attempted to establish a multigene signature for predicting the prognosis of COAD patients. Weighted gene co-expression network analysis and differential gene expression analysis methods were first applied to identify differentially co-expressed genes between COAD tissues and normal tissues from the Cancer Genome Atlas (TCGA)-COAD dataset and GSE39582 dataset, and a total of 309 overlapping genes were screened out. Then, our study employed TCGA-COAD cohort as the training dataset and an independent cohort by merging the GES39582 and GSE17536 datasets as the testing dataset. After univariate and multivariate Cox regression analyses were performed for these overlapping genes and overall survival (OS) of COAD patients in the training dataset, a 13-gene signature was constructed to divide COAD patients into high- and low-risk subgroups with significantly different OS. The testing dataset exhibited the same results utilizing the same predictive signature. The area under the curve of receiver operating characteristic analysis for predicting OS in the training and testing datasets were 0.789 and 0.868, respectively, which revealed the enhanced predictive power of the signature. Multivariate Cox regression analysis further suggested that the 13-gene signature could independently predict OS. Among the 13 prognostic genes, NAT1 and NAT2 were downregulated with deep deletions in tumor tissues in multiple COAD cohorts and exhibited significant correlations with poorer OS based on the GEPIA database. Notably, NAT1 and NAT2 expression levels were positively correlated with infiltrating levels of CD8+ T cells and dendritic cells, exhibiting a foundation for further research investigating the antitumor immune roles played by NAT1 and NAT2 in COAD. Taken together, the results of our study showed that the 13-gene signature could efficiently predict OS and that NAT1 and NAT2 could function as biomarkers for prognosis and the immune response in COAD. [ABSTRACT FROM AUTHOR]

OBJECTIVE: This study aims to explore the correlation between N-acetyltransferase 2 (NAT2) expression in colorectal cancer (CRC) tissues and the progression and prognosis of CRC. Through in vitro and in vivo experiments, the biological functions of NAT2 in the occurrence and development of CRC were explored. PATIENTS AND METHODS: Immunohistochemical (IHC) staining, reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) and Western blot were used to detect the difference of NAT2 expression in CRC tissues and normal tissues. The role of NAT2 in the cell proliferation, apoptosis, migration, invasion, and tumorigenesis and development of CRC was analyzed by cell counting kit-8 (CCK-8), colony formation, flow cytometry, transwell cell invasion, wound-healing assays and construction of nude mouse xenograft model. The correlation between the expression level of NAT2, and the overall survival and clinicopathological characteristics of CRC patients were statistically analyzed to preliminarily determine the clinical significance of NAT2 in the diagnosis and prognosis of CRC. RESULTS: The expression level of NAT2 was notably upregulated in CRC. NAT2 knockdown inhibited the proliferation, migration, invasion and in vivo tumor formation of CRC cells, and promoted cell apoptosis. High NAT2 expression was associated with TNM stage, differentiation degree, tumor size, distant metastasis, lymph node metastasis and poor prognosis in CRC patients. CONCLUSIONS: This study showed that the expression level of NAT2 in CRC tissues was increased and closely related to the metastasis and prognosis of CRC. In addition, NAT2 can be used as a new prognostic biomarker and therapeutic target for CRC. [ABSTRACT FROM AUTHOR]

Lung cancer is the leading cause of cancer-related death worldwide and has a high incidence rate. N-Acetyltransferase 2 (NAT2) is a polymorphic xenobiotic enzyme, which can catalyze N-acetylation and O-acetylation of various carcinogens such as aromatic, heterocyclic amines and hydrazines. At present, many studies have explored the effects of NAT2 polymorphism on lung cancer, but we found inconsistent results. We researched 18 published studies, involving 4,016 patients and 5,469 controls, to more accurately assess the effects of NAT2 polymorphism on lung cancer risk and to investigate whether smoking is associated. We used STATA software to analyze the extracted data and used STATA for subgroup analysis, sensitivity analysis, and to perform publication bias tests. To determine the correlation, we used the crude odds ratio (ORs) with 95% confidence interval (CIs). Our study was prospectively registered in PROSPERO (CRD42020159737). The odds ratio was 1.53 (95% CI: 1.21–1.95, I² = 45.2%, P=0.104) for the NAT2 slow + intermediate phenotype versus rapid phenotype. The results suggested that people with NAT2 non-rapid (slow + intermediate) phenotype have a significantly increased risk of lung cancer. In addition, NAT2 rapid phenotype was significantly associated with reduced risk of lung cancer, compared with slow phenotype or intermediate phenotype (slow phenotype vs. rapid phenotype: OR: 1.61, 95% CI: 1.07–2.42, I²= 50%, P= 0.075; intermediate phenotype vs. rapid phenotype: OR: 1.47, 95% CI: 1.15–1.88, I²= 40.3%, P= 0.137).

Background: Several genes are associated with the etiology of cleft lip and palate (CLP) in different populations. Many nucleotide variants on genes such as GRHL3, IRF6, NAT2, SDC2, BCL3, and PVRL1 were reported in different populations, but not studied in multigenerational cases in the Indian population. Aim and Objective: The aim of this study is to evaluate whether nucleotide variants rs41268753, rs861020, rs1041983, rs1042381, rs2965169, and rs10790332 are involved in the etiology of nonsyndromic CLP (NSCLP) in multigenerational Indian families. Study Design: Retrospective genetic study. Materials and Methods: Based on inclusion and exclusion criteria, 20 multigenerational families with nonsyndromic cleft lip with or without cleft palate (NSCL/P) were selected. Blood samples from both affected and unaffected participants were collected as a source of genomic DNA. Six nucleotide variants on these genes were genotyped to test for the association with NSCL/P. Genotyping was performed with the MassArray method. Genotype distribution was used to calculate the Hardy–Weinberg equilibrium using PLINK, a whole-genome association analysis toolset. The allelic association was compared among cases and controls using Chi-square test as implemented in PLINK. P ≤ 0.05 indicates statistical differences between groups. Results: No significant associations were found between individual single-nucleotide polymorphisms and NSCL/P. The odds ratio was 1.531, 1.198, 0.8082, 1.418, 1, and 0.5929 for polymorphisms rs41268753, rs861020, rs1041983, rs1042381, rs2965169, and rs10790332, respectively. Conclusion: Our findings suggest that among the multigenerational families in our population, the high-risk nucleotide variants GRHL3 rs41268753, IRF6 rs861020, NAT2 rs1041983, SDC2 rs1042381, BCL3 rs2965169, and PVRL1 rs10790332 are not associated with increased risk of NSCL/P. [ABSTRACT FROM AUTHOR]

Lung cancer is the leading cause of cancer-related death worldwide and has a high incidence rate. N-Acetyltransferase 2 (NAT2) is a polymorphic xenobiotic enzyme, which can catalyze N-acetylation and O-acetylation of various carcinogens such as aromatic, heterocyclic amines and hydrazines. At present, many studies have explored the effects of NAT2 polymorphism on lung cancer, but we found inconsistent results. We researched 18 published studies, involving 4,016 patients and 5,469 controls, to more accurately assess the effects of NAT2 polymorphism on lung cancer risk and to investigate whether smoking is associated. We used STATA software to analyze the extracted data and used STATA for subgroup analysis, sensitivity analysis, and to perform publication bias tests. To determine the correlation, we used the crude odds ratio (ORs) with 95% confidence interval (CIs). Our study was prospectively registered in PROSPERO (CRD42020159737). The odds ratio was 1.53 (95% CI: 1.21 – 1.95, I² = 45.2%, P=0.104) for the NAT2 slow + intermediate phenotype versus rapid phenotype. The results suggested that people with NAT2 non-rapid (slow + intermediate) phenotype have a significantly increased risk of lung cancer. In addition, NAT2 rapid phenotype was significantly associated with reduced risk of lung cancer, compared with slow phenotype or intermediate phenotype (slow phenotype vs . rapid phenotype: OR: 1.61, 95% CI: 1.07–2.42, I²= 50%, P= 0.075; intermediate phenotype vs . rapid phenotype: OR: 1.47, 95% CI: 1.15–1.88, I²= 40.3%, P= 0.137). [ABSTRACT FROM AUTHOR]

Background: There is a shortage of data on the accuracy of statistical methods for the prediction of N-acetyltransferase 2 (NAT2) haplotypes in the mixed ancestry population of the Western Cape. Objective: This study aimed to identify the NAT2 haplotypes and assess the accuracy of PHASE version 2.1.1 in assigning NAT2 haplotypes to a mixed ancestry population from the Western Cape. Methods: This study was conducted between 2013 and 2016. The NAT2 gene was amplified and sequenced from the DNA of 100 self-identified mixed ancestry participants. Haplotyping was performed by molecular and computational techniques. Agreement was assessed between the two techniques. Results: Haplotypes were assigned to 93 samples, of which 67 (72%) were ambiguous. Haplotype prediction by PHASE demonstrated 94.6% agreement (kappa 0.94, p 0.001) with those assigned using molecular techniques. Five haplotype combinations (from 10 chromosomes) were incorrectly predicted, four of which were flagged as uncertain by the PHASE software. Only one resulted in the assignment of an incorrect acetylation phenotype (intermediate to slow), although the software flagged this for further analysis. The most common haplotypes were NAT2*4 (28%) followed by NAT2*5B (27.4%), NAT2*6A (21.5%) and NAT2*12A (7.5%). Four rare single nucleotide variants (c.589CT, c.622TC, c.809TC and c.387CT) were detected. Conclusion: PHASE accurately predicted the phenotype in 92 of 93 samples (99%) from genotypic data in our mixed ancestry sample population, and is therefore a suitable alternative to molecular methods to individualise isoniazid therapy in this high burden tuberculosis setting.

IntroductionFunctional polymorphisms in drug metabolizing enzymes (DMEs) may be determinants of survival in oral and oropharyngeal squamous cell carcinoma (OOSCC).MethodsOOSCC cases (N=159) with a history of either tobacco or alcohol use were genotyped for polymorphisms in eight DMEs. Overall and disease-specific survival were analyzed using Kaplan-Meier plots and the log-rank test. Cox proportional hazards regression was used to calculate hazard ratios (HR) and 95% confidence intervals (CI) in exploratory analyses of patient subgroups.ResultsKaplan-Meier analyses showed N-acteyltransferase-2 (NAT2) fast acetylators experienced a 19.7% higher 5-year survival rate than slow acetylators (P=0.03) and this association was similar in oropharyngeal and oral cancer. After multiple adjustment, including tumor site and stage, the NAT2 fast acetylator phenotype was associated with improved overall survival (vs. slow acetylators) provided chemotherapy or radiation were not used (HR, 0.26; 95% CI, 0.10-0.66). However, NAT2 phenotype was unrelated to survival in patients treated with chemoradiotherapy (HR, 1.21; 95% CI, 0.54-2.73) or radiotherapy (HR, 0.67; 95% CI, 0.31-1.59) (P-for-NAT2/treatment-interaction=0.04). Normal activity GSTP1 was associated with a 19.2% reduction in 5-year disease-specific survival relative to reduced activity GSTP1 (P=0.04) but this association was not modified by treatment.ConclusionsOur results suggest that functional polymorphisms in NAT2 and GSTP1 are associated with OOSCC survival. Confirmation of these results in larger studies is required.

Background: The hollow-fiber infection model (HFIM) is a valuable tool for evaluating pharmacokinetics/pharmacodynamics relationships and determining the optimal antibiotic dose in monotherapy or combination therapy, but the application for personalized precision medicine in tuberculosis treatment remains limited. This study aimed to evaluate the efficacy of adjusted antibiotic doses for a tuberculosis patient using HFIM., Methods: Model-based Bayesian forecasting was utilized to assess the proposed reduction of the isoniazid dose from 300 mg daily to 150 mg daily in a patient with an ultra-slow-acetylation phenotype. The efficacy of the adjusted 150-mg dose was evaluated in a time-to-kill assay performed using the bacterial isolate Mycobacterium tuberculosis ( Mtb ) H37Ra in a HFIM that mimicked the individual pharmacokinetic profile of the patient., Results: The isoniazid concentration observed in the HFIM adequately reflected the target drug exposures simulated by the model. After 7 days of repeated dose administration, isoniazid killed 4 log 10 Mtb CFU/mL in the treatment arm, while the control arm without isoniazid increased 1.6 log 10 CFU/mL., Conclusion: Our results provide an example of the utility of the HFIM for predicting the efficacy of specific recommended doses of anti-tuberculosis drugs in real clinical setting., Competing Interests: The authors have no potential conflicts of interest to disclose., (© 2024 The Korean Academy of Medical Sciences.)

Background: Single nucleotide polymorphisms (SNPs) in the N-acetyltransferase 2 ( NAT2 ) gene as well as several other clinical factors can contribute to the elevation of liver function test values in tuberculosis (TB) patients receiving antitubercular therapy (ATT)., Research Design and Methods: A prospective study involving dynamic monitoring of the liver function tests among 130 TB patients from baseline to 98 days post ATT initiation was undertaken to assess the influence of pharmacogenomic and clinical variables on the elevation of liver function test values. Genomic DNA was extracted from serum samples for the assessment of NAT2 SNPs. Further, within this study population, we conducted a case control study to identify the odds of developing ATT-induced drug-induced liver injury (DILI) based on NAT2 SNPs, genotype and phenotype, and clinical variables., Results: NAT2 slow acetylators had higher mean [90%CI] liver function test values for 8-28 days post ATT and higher odds of developing DILI (OR: 2.73, 90%CI: 1.05-7.09) than intermediate acetylators/rapid acetylators., Conclusion: The current study findings provide evidence for closer monitoring among TB patients with specific NAT2 SNPs, genotype and phenotype, and clinical variables, particularly between the period of more than a week to one-month post ATT initiation for better treatment outcomes.

BackgroundThe countries of Central and Eastern Europe have among the highest worldwide rates of renal cell cancer (RCC). Few studies have examined whether genetic variation in xenobiotic metabolic pathway genes may modify risk for this cancer.MethodsThe Central and Eastern Europe Renal Cell Cancer study was a hospital-based case-control study conducted between 1998 and 2003 across seven centers in Central and Eastern Europe. Detailed data were collected from 874 cases and 2053 controls on demographics, work history, and occupational exposure to chemical agents. Genes [cytochrome P-450 family, N-acetyltransferases,Nad(p)hquinone oxidoreductase I (NQO1), microsomal epoxide hydrolase (mEH), catechol-O-methyltransferase (COMT), uridine diphosphate-glucuronosyltransferase (UGT)] were selected for the present analysis based on their putative role in xenobiotic metabolism. Haplotypes were calculated using fastPhase. Odds ratios and 95% confidence intervals were estimated by unconditional logistic regression adjusted for country of residence, age, sex, smoking, alcohol intake, obesity, and hypertension.ResultsWe observed an increased risk of RCC with one SNP. After adjustment for multiple comparisons it did not remain significant. Neither NAT1 nor NAT2 slow acetylation was associated with disease.ConclusionWe observed no association between this pathway and renal cell cancer.

We show that N-acetyltransferase 2 (NAT2) loss of heterozygosity can be targeted in >4% of colorectal cancers with the use of a small molecule. We identify and describe the effect of a compound that impairs the growth of colorectal tumors with slow NAT2 activity by half when compared to wild-type.

Background: Gene polymorphisms have been associated with drug-induced liver injury (DILI). This study aimed to elucidate the association between polymorphisms of NAT2, CYP2E1, GSTT1, GSTM1, and HLA genes with isoniazid plasma concentration and DILI. Methods: This study was a prospective cohort study recruiting adult newly diagnosed tuberculosis (TB) patients who met the inclusion criteria from the Public Health Centers in Yogyakarta and Lampung. Defined single-nucleotide polymorphisms were rs1799929, rs1799930, rs1799931, rs1801280, and rs1041983 of NAT2; rs2031920, rs8192775, and rs2515641 of CYP2E1; rs1041981, rs1063355, and rs6906021 of HLA. GSTT1 and GSTM1 were defined as GSTT1, GSTM1, and GSTT1 deletion and GSTM1 deletion. The DNA was taken from the patient saliva. Data of anti-TB drug plasma concentration on the weeks 4–8 of treatment were retrieved from the patients' medical report. Statistical analysis was performed using Chi-square test, Student's t-test, and multinomial logistic regression. Results: Over the 207 patients, up to 1.9% of them experienced DILI. The percentage of slow acetylators of NAT2 was 69.5%. Patients with extensive acetylator phenotype did not experience DILI (odds ratio [OR]: 0.46; 95% confidence interval [CI]: 0.23–0.94). The G carriership of HLA rs1063355 could protect the patients from the DILI (OR: 0.39; 95% CI: 0.14–0.9). Furthermore, the C carriership of HLA rs1041981 can protect the patients from DILI (OR: 0.38; 95% CI: 0.15–0.50). The genotype of HLA-DQB*0302 significantly affects the isoniazid concentration. Conclusion: The NAT2 genotype was significantly associated with DILI. Furthermore, the absence of G carriership of HLA-DQA*0102 could protect the patients from DILI without being associated with an effect on the isoniazid concentration.

What is known and objective: Anti‐tuberculosis drug‐induced liver injury (ATLI) is one of the most significant adverse reactions for this line of therapy. N‐acetyltransferase2 (NAT2) is an important metabolic enzyme involved in drug metabolism and detoxification. Genetic polymorphism and DNA methylation have been proven to be key factors that affect the expression of NAT2. Therefore, the objective of the study was to investigate the relationship between NAT2 gene polymorphism and DNA methylation in the promoter region with ATLI risk in Mongolian tuberculosis patients. Methods: Our study is a case‐control design. Chi‐square test, Mann‐Whitney U non‐parametric test and Pearson test were all used to analyse existing relationships. The association between NAT2 gene acetylation phenotype and the total methylation of the NAT2 promoter region was analysed by means of binary logistic regression analysis. The general situation of the patients was evaluated by questionnaire, and the NAT2 genotyping of the three major polymorphism loci of gene coding was carried out by a gene sequencing technique. The methylation status of the NAT2 gene promoter region was detected by bisulphite sequencing and mass spectrometry. Result and discussion: Our study found that the detection rate of ATLI in Mongolian tuberculosis patients was 27.6%. There were no significant differences in demographic characteristics and living habits amongst the two groups, while significant differences were observed in the polymorphism of the NAT2 genes 481 (rs1799929) and 590 (rs1799930) and the acetylation phenotype. Moreover, the composition and distribution of the NAT2*4/4 and NAT2*4/5 genotypes were found in the two groups. The risk of ATLI in the slow acetylation type was 3.56 times higher than that of the fast acetylation type. Compared with the control group, the CpG5, CpG10, CpG11.12 and total methylation of the NAT2 promoter region in the ATLI group showed a hypermethylated pattern (P <.05). However, on performing binary logistic regression, neither the slow acetylation, intermediate acetylation nor rapid acetylation were found to be associated with ATLI (P >.05). It was found that the total methylation of NAT2 gene promoter region was an independent influencing factor of ATLI in Mongolian tuberculosis patients. With the increase of the total methylation level of NAT2 gene promoter region, the risk of ATLI increased gradually. (OR = 8.371, 95% CI: 2.391 ~ 29.315). CpG1, CpG4, CpG9, CpG10 and CpG11.12 were positively correlated with a total methylation level in the ATLI group. What is new and conclusion: The detection rate of ATLI in Mongolian tuberculosis patients was 27.6%, and there were differences in the NAT2 genotypes and acetylated phenotypes. The slow acetylated type was the risk factor for ATLI. Methylation in the promoter region of the NAT2 gene has an effect on the risk of ATLI. After adjusting for the interference of three acetylation types, it was found that the total methylation of the promoter region of NAT2 gene in Mongolian tuberculosis patients is an independent influencing factor of ATLI. Furthermore, there is a moderate to high correlation between some sites and the overall level of methylation. [ABSTRACT FROM AUTHOR]

Background: There is a shortage of data on the accuracy of statistical methods for the prediction of N-acetyltransferase 2 (NAT2) haplotypes in the mixed ancestry population of the Western Cape. Objective: This study aimed to identify the NAT2 haplotypes and assess the accuracy of PHASE version 2.1.1 in assigning NAT2 haplotypes to a mixed ancestry population from the Western Cape. Methods: This study was conducted between 2013 and 2016. The NAT2 gene was amplified and sequenced from the DNA of 100 self-identified mixed ancestry participants. Haplotyping was performed by molecular and computational techniques. Agreement was assessed between the two techniques. Results: Haplotypes were assigned to 93 samples, of which 67 (72%) were ambiguous. Haplotype prediction by PHASE demonstrated 94.6% agreement (kappa 0.94, p < 0.001) with those assigned using molecular techniques. Five haplotype combinations (from 10 chromosomes) were incorrectly predicted, four of which were flagged as uncertain by the PHASE software. Only one resulted in the assignment of an incorrect acetylation phenotype (intermediate to slow), although the software flagged this for further analysis. The most common haplotypes were NAT2 *4 (28%) followed by NAT2 *5B (27.4%), NAT2 *6A (21.5%) and NAT2 *12A (7.5%). Four rare single nucleotide variants (c.589C>T, c.622T>C, c.809T>C and c.387C>T) were detected. Conclusion: PHASE accurately predicted the phenotype in 92 of 93 samples (99%) from genotypic data in our mixed ancestry sample population, and is therefore a suitable alternative to molecular methods to individualise isoniazid therapy in this high burden tuberculosis setting. [ABSTRACT FROM AUTHOR]

Hydralazine, an antihypertensive agent used during pregnancy, undergoes N‐acetylation primarily via N‐acetyltransferase 2 (NAT2) to form 3‐methyl‐1,2,4‐triazolo[3,4‐a]phthalazine (MTP). To characterize the steady‐state pharmacokinetics (PK) of hydralazine during pregnancy and evaluate the effects of NAT2 genotype on hydralazine and MTP PK during pregnancy, 12 pregnant subjects received oral hydralazine (5‐25 mg every 6 hours) in mid‐ (n = 5) and/or late pregnancy (n = 8). Serial blood samples were collected over 1 dosing interval, and steady‐state noncompartmental PK parameters were estimated. Subjects were classified as either (rapid acetylators, n = 6) or slow acetylators (SAs, n = 6) based on NAT2 genotype. During pregnancy, when compared with the SA group, the RA group had faster weight‐adjusted hydralazine apparent oral clearance (70.0 ± 13.6 vs 20.1 ± 6.9 L/h, P < .05), lower dose‐normalized area under the concentration‐time curve (AUC; 1.5 ± 0.8 vs 5.9 ± 3.7 ng·h/mL, P < .05), lower dose‐normalized peak concentrations (0.77 ± 0.51 vs 4.04 ± 3.18 ng/mL, P < .05), and larger weight‐adjusted apparent oral volume of distribution (302 ± 112 vs 116 ± 45 L/kg, P < .05). Furthermore, the MTP/hydralazine AUC ratio was ∼10‐fold higher in the RA group (78 ± 30 vs 8 ± 3, P < .05) than in the SA group. No gestational age or dose‐dependent effects were observed, possibly because of the small sample size. This study describes for the first time, the PK of oral hydralazine and its metabolite, MTP, during pregnancy, and confirmed that the PK of oral hydralazine is NAT2 genotype dependent during pregnancy. [ABSTRACT FROM AUTHOR]

The objective of this study was to examine associations of single nucleotide polymorphisms, rs1045642 within the MDR1 gene and rs1799930 within the NAT2 gene, with the risk of colorectal cancer (CRC) in the population of Central Russia. DNA specimens were obtained from 178 patients with CRC (87 males and 91 females) and 327 age-matched healthy controls (179 males and 148 females). Genotyping was performed using real-time PCR. Association of the studied SNPs with the risk of CRC was evaluated using logistic regression analysis. It was demonstrated that MDR1 rs1045642 polymorphism was associated with the increased risk of CRC after correction for gender, age, and smoking (OR = 1.41, 95% CI = 1.09–1.83; P = 0.008). A gender-stratified analysis showed that MDR1 rs1045642 was associated with the increased risk of CRC only in females (OR = 1.62, 95% CI = 1.11–2.35; P = 0.01). In males, no association between MDR1 rs1045642 and CRC was found. Association between MDR1 rs1045642 and the increased risk of colorectal cancer in Russian females from Central Russia was revealed. [ABSTRACT FROM AUTHOR]