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HLA-DQA1*05:75 differs from DQA1*05:05:01:01 by a single substitution at nucleotide 701 (G/A) in exon 4., (© 2023 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

HLA-B*15:656 differs from B*15:27:01:01 by two nucleotide substitutions in codon 163 (CTG > GAG)., (© 2023 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: In Korea, during the early phase of the coronavirus disease 2019 (COVID-19) pandemic, we responded to the uncertainty of treatments under various conditions, consistently playing catch up with the speed of evidence updates. Therefore, there was high demand for national-level evidence-based clinical practice guidelines for clinicians in a timely manner. We developed evidence-based and updated living recommendations for clinicians through a transparent development process and multidisciplinary expert collaboration., Methods: The National Evidence-based Healthcare Collaborating Agency (NECA) and the Korean Academy of Medical Sciences (KAMS) collaborated to develop trustworthy Korean living guidelines. The NECA-supported methodological sections and 8 professional medical societies of the KAMS worked with clinical experts, and 31 clinicians were involved annually. We developed a total of 35 clinical questions, including medications, respiratory/critical care, pediatric care, emergency care, diagnostic tests, and radiological examinations., Results: An evidence-based search for treatments began in March 2021 and monthly updates were performed. It was expanded to other areas, and the search interval was organized by a steering committee owing to priority changes. Evidence synthesis and recommendation review was performed by researchers, and living recommendations were updated within 3-4 months., Conclusion: We provided timely recommendations on living schemes and disseminated them to the public, policymakers and various stakeholders using webpages and social media. Although the output was successful, there were some limitations. The rigor of development issues, urgent timelines for public dissemination, education for new developers, and spread of several new COVID-19 variants have worked as barriers. Therefore, we must prepare systematic processes and funding for future pandemics., (© 2023 The Korean Academy of Medical Sciences.)

Background: We aimed to identify changes in the diagnosis and subtype classification of Korean patients with BCR-ABL1-negative MPN related to the revision of the WHO classification in 2016., Methods: We evaluated 76 Korean patients with BCR-ABL1-negative MPN who underwent diagnostic work-ups, including bone marrow (BM) examinations and JAK2 V617F mutation analysis, from January 2013 to June 2018. Additionally, we reclassified the subtype of 43 patients who were diagnosed based on the WHO 2008 classification., Results: From January 2013 to April 2016, 43 patients were diagnosed with BCR-ABL1-negative MPN (12 PV, 17 ET, 14 PMF) according to the 2008 WHO classification, and from May 2016 to June 2018, 33 patients were diagnosed according to the 2016 classification (15 PV, 11 ET, 7 PMF). With the application of 2016 classification, 3 cases of ET were reclassified as pre-PMF, and the proportion of PV increased from 27.9% to 45.5%. There were significant differences in CBC between pre-PMF and overt PMF, between ET and overt-PMF, but no difference between ET and pre-PMF., Conclusions: The overall characteristics of BCR-ABL1-negative MPN patients were not significantly different from those of previous reports. 'Masked PV', which could not be diagnosed according to the WHO 2008 classification, may have been diagnosed as PV since 2016 due to the increase in the diagnostic value of the BM findings and the lowering of the hemoglobin (Hb) threshold.

Background: There have been reports of increases in the incidence and prevalence of nontuberculous mycobacterial pulmonary disease (NTM-PD) in several countries, but no studies have analyzed claims data using laboratory tests. This study aimed to estimate the nationwide epidemiology and medical treatments of NTM-PD according to laboratory tests run in Korea., Methods: Using claims data from the Health Insurance Review and Assessment Service, we analyzed patients with nontuberculous mycobacterium (ICD-10: A31) who were diagnosed from Jan 2007 to Jun 2019. The incidence and prevalence of NTM-PD and whether related laboratory tests were performed were analyzed. Diagnostic code-based NTM-PD patients were defined as patients who had NTM as a diagnosis on at least 2 occasions within 180 days. Clinically refined NTM-PD patients were defined as those excluding hospital-diagnosed patients with acid-fast bacilli (AFB) culture rates less than 5%. Laboratory tests included AFB smears, AFB culture, NTM identification, and drug susceptibility tests (DSTs)., Results: A total of 60,071 diagnostic code-based NTM-PD patients were evaluated. Clinically refined NTM-PD included 45,321 patients, excluding 14,750 (24.6%) patients diagnosed in hospitals with low AFB culture rates. The annual incidence per 100,000 population increased from 2.9 cases in 2008 to 12.3 cases in 2018. The annual prevalence per 100,000 population increased from 5.3 cases in 2008 to 41.7 cases in 2018. After removing outliers according to the AFB culture rate, a significant decrease in incidence was observed in women younger than 50 years. Among patients with clinically refined NTM-PD, the test rates for AFB culture, NTM identification, and DST were 84.3%, 59.1%, and 40.4%, respectively. From the outpatient clinic, 17,977 (39.7%) patients were prescribed drugs related to NTM treatment, with a median number of prescriptions of 7 (interquartile range (IQR) 3-11) and a median duration from the diagnosis to end of treatment of 330 (IQR 118-578) days., Conclusions: Although the incidence and prevalence of NTM-PD are on the rise, the recent surge in women 50 years of age is overestimated in patients not adequately tested. In claim-based studies, there may be limitations in estimating the epidemiological data with only the diagnostic codes., (© 2022. The Author(s).)

Background: We aimed to define the maternal lipid profiles that are associated with fetal growth and cord blood (CB) hematopoietic cells in healthy Korean full-term newborns., Methods: A total of 608 fetal-maternal pairs were enrolled; mothers voluntarily donated CB with informed consent. We analyzed birth weight (BW) as a marker of fetal growth, and we examined total nucleated cells (TNCs) and CD34 + cell concentrations of CB as markers of hematopoietic progenitor cell (HPC) contents. We also analyzed maternal lipid levels and investigated their associations with BW, TNCs and CD34 + cells., Results: Maternal triglycerides (TG) showed a significant positive association with BW and CD34 + cells, and low-density lipoprotein (LDL) showed a negative association with BW and CD34 + cells. Though not statistically significant, higher maternal TG showed a tendency toward higher levels of TNCs. Maternal TG was independently and positively correlated with BW, and maternal LDL was independently and negatively correlated with CD34 + cells, although the impacts were not as strong, as indicated by small beta coefficients (0.157 and -0.226, respectively)., Conclusions: We were able to investigate the association of maternal lipid profiles with BW and CB HPCs in healthy Korean newborn-mother pairs in this study. Both BW and the HPC contents showed independent associations with maternal TG and LDL, although the effect of maternal lipid levels on fetal growth and HPCs was not strong in the normal healthy population. Because maternal lipid levels were assessed once in the healthy fetal-maternal pairs, we could not investigate those associations across pregnancy.

Background: Associations between IgA nephropathy (IgAN) and HLA-DRB1 and -DQB1 alleles have been reported in several ethnic groups. We investigated the association of HLA-DRB1 and -DQB1 alleles with the predisposition for IgAN and disease progression to end-stage kidney disease (ESKD) in Korean patients., Methods: We analyzed HLA-DRB1 and -DQB1 genotypes in 399 IgAN patients between January 2000 and January 2019 using a LIFECODES sequence-specific oligonucleotide (SSO) typing kit (Immucor, Stamford, CT, USA) or a LABType SSO Typing Test (One Lambda, Canoga Park, CA, USA). Alleles with a significant difference in two-digit resolution were further analyzed using in-house sequence-based typing and sequence-specific primer PCR. As controls, 613 healthy hematopoietic stem cell donors were included. Kidney survival was analyzed in 281 IgAN patients with available clinical and laboratory data using Cox regression analysis. Where needed, P-values were adjusted using Bonferroni correction., Results: The allele frequencies of HLA-DRB1*04:05 (corrected P [ Pc ]<0.001), -DQB1 *04:01 ( Pc =0.048), and -DQB1*03:02 ( Pc =0.021) were significantly higher in IgAN patients than in controls, whereas those of HLA-DRB1*07:01, -DRB1*15:01, -DQB1*02:02, and -DQB1*06:02 ( Pc <0.001 for all) were significantly lower in IgAN patients than in controls. The allele frequency of HLA-DQB1*05:03 ( Pc =0.016) was significantly lower in the ESKD group than in the non-ESKD group; however, there was no significant difference for ESKD progression between these groups., Conclusions: We report novel associations of HLA-DRB1*15:01, DQB1*02:02, -DQB1*03:02, and -DQB1*04:01 with IgAN. Further studies of HLA alleles associated with IgAN progression in a larger cohort and in various ethnic groups are needed.

Background: In the coronavirus disease 2019 (COVID-19) pandemic era, the simultaneous detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), influenza virus (Flu), and respiratory syncytial virus (RSV) is important in the rapid differential diagnosis in patients with respiratory symptoms. Three multiplex real-time reverse transcription polymerase chain reaction (rRT-PCR) assays have been recently developed commercially in Korea: PowerChek™ SARS-CoV-2, Influenza A&B Multiplex Real-time PCR Kit (PowerChek; KogeneBiotech); STANDARD™ M Flu/SARS-CoV-2 Real-time Detection Kit (STANDARD M; SD BioSensor); and Allplex™ SARS-CoV-2/FluA/FluB/RSV Assay (Allplex; Seegene). We evaluated the analytical and clinical performances of these kits., Methods: A limit of detection tests were performed and cross-reactivity analysis was executed using clinical respiratory samples. Ninety-seven SARS-CoV-2-positive, 201 SARS-CoV-2-negative, 71 influenza A-positive, 50 influenza B-positive, 78 RSV-positive, and 207 other respiratory virus-positive nasopharyngeal swabs were tested using the three assays. The AdvanSure™ respiratory viruses rRT-PCR assay (AdvanSure; LG Life Sciences) was used as a comparator assay for RSV., Results: Except in influenza B, in SARS-CoV-2 and influenza A, there were no significant differences in detecting specific genes of the viruses among the three assays. All three kits did not cross-react with common respiratory viruses. All three kits had greater than 92% positive percent agreement and negative percent agreement and ≥ 0.95 kappa value in the detection of SARS-CoV-2 and flu A/B. Allplex detected RSV more sensitively than AdvanSure., Conclusion: The overall performance of three multiplex rRT-PCR assays for the concurrent detection of SARS-CoV-2, influenza A/B, and RSV was comparable. These kits will promote prompt differential diagnosis of COVID-19, influenza, and RSV infection in the COVID-19 pandemic era., Competing Interests: The authors have no potential conflicts of interest to disclose., (© 2021 The Korean Academy of Medical Sciences.)

Purpose: Granular corneal dystrophy type 2 (GCD2) is an autosomal dominant disorder and is associated with the arginine to histidine substitution at codon 124 (p.R124H) of the TGFBI gene. Although TGFBI p.R124H is known to be the most common corneal dystrophy-related pathogenic variant, there are few data on the frequency of this variant in the South Korean population., Methods: In total, 2,060 anonymous DNA samples from a public umbilical cord blood bank were tested for the TFGBI p.R124H variant using real-time PCR., Results: Six of the 2,060 samples [0.29%; 95% confidence interval (CI), 0.12-0.67%] were heterozygous for the TGFBI p.R124H variant. The prevalence of the GCD2-related TGFBI p.R124H variant in this population was estimated to be 291.3 per 100,000 [95% confidence interval (CI), 118.5-667.0]., Conclusions: To our knowledge, this is the largest study that has estimated the prevalence of the GCD2-related TGFBI p.R124H variant in South Korea., (Copyright © 2021 Molecular Vision.)

Spinal muscular atrophy (SMA) is an autosomal recessive disease characterized by progressive proximal muscle weakness and atrophy. Given the recent introduction of gene therapies, knowledge of the SMA carrier frequency in various populations has become important for developing screening programs for this disease. In total, 1,581 anonymous DNA samples from an umbilical cord blood bank were tested for SMN1 and SMN2 gene copies using a multiplex ligation-dependent probe amplification assay. Twenty-nine of the 1,581 newborns [1.83%; 95% confidence interval (CI), 1.25-2.66%] were SMA carriers with one copy of SMN1 , and no homozygous SMN1 deletion was detected. The carrier frequency in this population was estimated to be 1,834 per 100,000 (95% CI, 1,254-2,659) or 1 in 55 (95% CI, 1/79-1/38). Our data indicate that SMA carriers are not uncommon in the Korean population and may serve as a reference for designing a population screening program in Korea., Competing Interests: No potential conflicts of interest relevant to this article were reported., (© The Korean Society for Laboratory Medicine.)

High-risk human papillomavirus (HPV) infection is an essential factor for the development of cervical cancer. HPV18 is the second most common carcinogenic HPV type following HPV16, but the lineages of HPV18 have been less well studied than those of HPV 16. The purpose of this study was to analyze the nucleotide variants in the E6, E7, and L1 genes of HPV18, to assess the prevalence of HPV18 variants in Korea and to explore the relationship between HPV18 genetic variants and the risk for cervical cancer.A total of 170 DNA samples from HPV18-positive cervical specimens were collected from women admitted to a secondary referral hospital located in Seoul. Among them, the lineages of the 97 samples could be successfully determined by historical nomenclature.All the studied HPV 18 variants were lineage A. Sublineages A1 and A4 comprised 91.7% (89/97) and 1.0% (1/97), respectively. Sublineages other than A1 or A4 comprised 7.2% (7/97). We identified 15 new nucleotide substitutions among 44 nucleotide substitutions: C158T, T317G, T443G, A560G, A5467G, A5560C, A5678C, A6155G, G6462A, T6650G, G6701A, T6809C, A6823G, T6941C and T6953C. Among them, 6 substitutions at positions 317, 443, 5467, 5560, 6462, and 6823 resulted in amino acid changes (E6: F71L and N113K; L1: H13R, H44P, A345T, and N465S, respectively). The pathologic results were classified as normal in 25.8% (25/97) of the women, atypical squamous cells of undermined significance (ASCUS) in 7.2% (7/97), cervical intraepithelial neoplasia (CIN) 1 in 36.1% (35/97), CIN2/3 in 19.6% (18/97), and carcinoma in 12.4% (12/97). There was no significant association between the HPV18 sublineages and the severity of pathologic lesion or the disease progression.This study is the first to analyze the distribution of HPV18 variants in Korean and to associate the results with pathologic findings. Although the HPV18 variants had no significant effect on the degree and progression of the disease, the newly discovered nonsynonymous mutation in L1 might serve as a database to determine vaccine efficacy in Korean women.

Long-term observation of the prevalence of sexually transmitted infections (STIs) is unclear in sexual assault victims (SAVs).We aimed to identify the trends in the prevalence of STIs in SAVs and factors correlated with STIs. Between January 2010 and May 2019, a retrospective observational study was conducted in a regional sexual assault center in Seoul. Data were collected from sexual assault questionnaires and laboratory results. PCR for STIs, including Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), Mycoplasma genitalium (MG), Mycoplasma hominis (MH), Ureaplasma urealyticum (UU), Trichomonas vaginalis (TV) and cytomegalovirus (CMV), was performed via vaginal swab. Associations between STIs and covariates were examined by logistic regression. A total of 1843 SAVs were included, and 60.2% were positive for at least one STI. UU was the dominant agent (32.6%), followed by MH (27.7%) and CT (17.4%). The annual positivity rate ofMH showed a significant decreasing trend (tau = -0.600, P value = 0.020). The highest positivity rate of STI by age group was 68.0% (282/415) in the 15-19 years of age group. Age (OR = 0.951, 95% confidence interval [CI] = 0.934-0.968) and pyuria (OR = 1.898, 95% CI = 1.543-2.329) were associated with clinically important STIs (NG, CT and TV). The prevalence of STIs in SAVs was consistently high over 10 years, and most STIs were more prevalent in SAVs than in the general population. Presumptive treatment is still needed, especially for young SAVs with pyuria., Competing Interests: Declaration of competing interest I declare that authors listed have no competing financial, professional or personal interests that might have influenced the outcomes of this study., (Copyright © 2020 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.)

Recently, HLA class II loci, including HLA-DPB1, have been reported to be associated with interindividual variance in the hepatitis B (HB) vaccine response. In this study, we investigated significant single nucleotide polymorphisms (SNPs) for anti-HBs antibody levels in 6867 healthy Koreans using a genome-wide association study (GWAS). In GWAS, the top 20 SNPs that showed significant association with anti-HBs levels (P < 1.0 × 10 -29 ) all resided in HLA-DPB1. Utilizing PCR sequencing, we verified the relationship of the top 3 most significant SNPs (rs1042169, rs9277355 and rs9277356) from the GWAS and genotypes of HLA-DPB1 with the HB vaccine response in Korean infants who received a scheduled vaccination. The DPB1*04:02 allele has G, C and A nucleotides for the 3SNP sites, and was significantly more frequent in responders than in nonresponders (10.9% vs 1.0%, P c  = 0.018). DPB1*05:01 was significantly more frequent in nonresponders than in responders (49.0% vs 31.1%, P c  = 0.018). In multivariate logistic regression, DPB1*04:02 showed a significant association with both vaccine response (P = 0.037, OR = 8.465) and high-titre response (P = 0.027, OR = 9.860). The haplotypes rs1042169 G - rs9277355 C - rs9277356 A showed a significant association with a high-titre response only (P = 0.002, OR = 2.941). In conclusion, DPB1*04:02 possessing rs1042169 G - rs9277355 C - rs9277356 A is an independent predictor of the HB vaccine response in Koreans., (© 2019 John Wiley & Sons Ltd.)

The present study investigated risk factors for iron deficiency (ID) and iron deficiency anemia (IDA) during late infancy, including feeding type and complementary feeding (CF) practice. Healthy term Korean infants (8-15 months) were weighed, and questionnaires regarding delivery, feeding, and weaning were completed by their caregivers. We also examined levels of hemoglobin, serum iron/total iron-binding capacity, serum ferritin, and mean corpuscular volume (MCV). Among 619 infants, ID and IDA were present in 174 infants (28.1%) and 87 infants (14.0%), respectively. The 288 infants with exclusively/mostly breastfeeding until late infancy (BFL) were most likely to exhibit ID (53.1%) and IDA (28.1%). The risk of ID was independently associated with BFL (adjusted odds ratio [aOR], 47.5; 95% confidence interval [CI], 18.3-122.9), male sex (aOR, 1.9; 95% CI, 1.2-2.9), fold weight gain (aOR, 2.6; 95% CI, 1.5-4.6), and perceived inadequacy of red meat intake (aOR, 1.7; 95% CI, 1.0-2.7). In addition to the risk factors for ID, Cesarean section delivery (aOR, 1.9; 95% CI, 1.1-3.2) and low parental CF-related knowledge (aOR, 2.8; 95% CI, 1.5-5.2) were risk factors for IDA. In conclusion, prolonged breastfeeding and perceived inadequacy of red meat intake may be among the important feeding-related risk factors of ID and IDA. Therefore, more meticulous education and monitoring of iron-rich food intake, such as red meat, with iron supplementation or iron status testing during late infancy if necessary, should be considered for breastfed Korean infants, especially for those with additional risk factors for ID or IDA., Competing Interests: The authors have no potential conflicts of interest to disclose., (© 2017 The Korean Academy of Medical Sciences.)

Even low levels of toxic metal exposure (As, Cd, Hg, and Pb) in infancy might be harmful to children's development. This study investigated toxic metal exposure on healthy weaning-age infants and its relationship with growth, diet, and iron/anemia status. The weight, height, head circumference, whole blood levels of four toxic metals, hemoglobin, and serum ferritin of healthy infants was measured. Among 210 infants with a median age of 11.4 months (interquartile range: 10.5-12.0), the median levels of As, Cd, Hg, and Pb were 1.2 μg/L, 0.05 μg/L, 0.8 μg/L, and 0.83 μg/dL, respectively. In adjusted linear regression models, post-birth weight gain (Pb) and current head circumference (As, Pb) were negatively associated with toxic metal levels. In multiple linear regression or logistic regression analysis, the duration of breastfeeding (all four metals), perceived adequacy of rice-based food intake (As), regular fish intake (As, Hg), and iron deficiency with/without anemia (Cd, Pb) were associated with increased toxic metal levels. Although levels of toxic metals may not usually be high in this population, individual exposure risk may need to be assessed after considering the type of feeding or intake of complementary foods and the iron/anemia status while evaluating growth status during late infancy.

Recently, HLA-DP single nucleotide polymorphisms (SNPs) have been reported to be related to responsiveness to hepatitis B virus (HBV) vaccination. The aim of this study was to investigate associations between HLA-DP SNPs and responsiveness to HBV vaccine in Korean infants. A total of 290 healthy Korean infants who were registered to Seoul Metropolitan Public Cord Blood Bank during the period of February 2007 to December 2011 were enrolled. Anti-HBs antibody level was analyzed after three doses of HBV vaccination. Genotyping of HLA-DPA1 SNPs (rs3077 and rs3830066) and HLA-DPB1 SNPs (rs7770370, rs7770501, rs3128961, and rs9277535) were performed by PCR-sequencing. HLA-A, -B, and -DRB1 genotyping was also performed by PCR-sequence-specific oligonucleotide probe kits. HLA-DPB1 SNPs (rs7770370, rs7770501, rs3128961, and rs9277535) were associated with HBV vaccine response. Allele frequencies of rs7770370 A, rs7770501 C, rs3128961 G, and rs9277535 A were significantly higher in responders than in non-responders (all p<0.01). Anti-HBs antibody levels were different according to genotypes of DPB1 rs7770370, rs7770501, rs3128961, and rs9277535 (all p<0.01). In multivariate analysis, HLA-DPB1 rs7770370 AA genotype was significantly associated with HBV vaccine response (relative risk, RR=2.5, p=0.033) and high-titer vaccine response (RR=2.7, p<0.001). In conclusion, HLA-DPB1 SNPs were significantly associated with responses to HBV vaccination in Korean infants., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Background: Data on allele frequencies (AFs) and haplotype frequencies (HFs) of HLA-C and -DQB1 are limited in Koreans. We investigated AFs and HFs of HLA-A, -B, -C, -DRB1, and -DQB1 in Koreans by high-resolution sequence-based typing (SBT)., Methods: Hematopoietic stem cells were obtained from 613 healthy, unrelated donors to analyze HLA-A, -B, -C, -DRB1, and -DQB1 genotypes by using AlleleSEQR HLA-A, -B, -C, -DRB1, and -DQB1 SBT kits (Abbott Molecular, USA), respectively. Alleles belonging to HLA-C*07:01/07:06 group were further discriminated by using PCR-sequence specific primer analysis. AFs and HFs were calculated by direct counting and maximum likelihood method, respectively., Results: In all, 24 HLA-A, 46 HLA-B, 24 HLA-C, 29 HLA-DRB1, and 15 HLA-DQB1 alleles were identified. AFs and HFs of HLA-A, -B, and -DRB1 were similar to those reported previously. For the HLA-C locus, C*01:02 was the most common allele, followed by C*03:03, C*03:04, C*14:02, C*03:02, and C*07:02 (AF ≥7%). AFs of C*07:01 and C*07:06 were 0.16% and 3.18%, respectively. For the HLA-DQB1 locus, DQB1*03:01 was the most common allele, followed by DQB1*03:03, *03:02, *06:01, *05:01, *04:01, and *06:02 (AF ≥7%). AFs of DQB1*02:01 and DQB1*02:02 were 2.12% and 6.69%, respectively. HFs of A*33:03-C*07:06 and C*07:06-B*44:03 were 3.09% and 3.10%, respectively, while those of DRB1*07:01-DQB1*02:02 and DRB1*03:01-DQB1*02:01 were 6.61% and 2.04%, respectively., Conclusions: This study reported AFs and HFs of HLA, including HLA-C and -DQB1, in Koreans by using high-resolution SBT. These data can be used to resolve ambiguous results of HLA typing for organ and hematopoietic stem cell transplantations.

Background: Recently, molecular detection of Mycobacterium tuberculosis in a respiratory specimens is accepted as one of the standard procedures for diagnosis of tuberculosis in Korea. When detecting tuberculosis using a real-time polymerase chain reaction (PCR), results showed the repeated near-cutoff values in a specimen make it difficult for the laboratory to give definitive reports as positive or negative., Methods: We retrospectively evaluated clinical state of ninety-eight patients who were not currently taking antituberculosis medications and had near-cutoff values of respiratory specimens using a real-time PCR test., Results: Sixty-eight percent of the patients had clinical tuberculosis. In subgroup analysis, patients less than the age of 50, 94.3% had tuberculosis while only 55.6% of the patients with the age of equal and over 50 had tuberculosis (p < 0.001)., Conclusions: Setting a gray zone for real-time PCR result and give additional tailored information onto the interpretative report would be suggested for the clinical practice in an intermediate burden of tuberculosis country.

Background: Recently, CC chemokine ligand28 (CCL28) has been reported as a severity marker in atopic dermatitis. We studied the association between objectively observed lesions and the level of CCL28 in children patients., Methods: A total of 105 children patients were grouped by the objective Scoring Atopic Dermatitis index (SCORAD). Total IgE, specific IgE, complete blood count, and serum level of CCL28 were evaluated., Results: The mean age of the subjects was 5.3 (range, 0 - 12 years). The median SCORAD was 21.4 and consisted of mild 70%, moderate 25%, and severe 6% disease. There were no statistical differences among severity groups for CCL28 or for total IgE. Total IgE showed positive correlation with eosinophil count (r = 0.429, p < 0.01), and SCORAD (r = 0.210, p < 0.05)., Conclusions: The disease severity of atopic dermatitis in children is not correlated to the level of CCL28, but rather related to that of total IgE.

Intermediate-resolution HLA-DQ typing has gained importance in organ transplantation recently. We evaluated the performance of the LIFECODES HLA-DQB1 typing kit (Immucor, USA) using sequence-specific oligonucleotide (SSO) probe and Luminex platform (Luminex Corp., USA) on 100 samples tested by sequence-based typing (SBT) using the AlleleSEQR HLA-DQB1 kit (Abbott Molecular, USA) in Korean individuals. No sample showed ambiguity in the assignment of 4-digit HLA-DQB1 allele with the LIFECODES HLA-DQB1 SSO typing kit, and the results were fully concordant with those of high-resolution typing of AlleleSEQR HLA-DQB1 SBT up to 4-digit level. Three samples required adjustment of false reactions (3/100, 3.0%): two samples with DQB1(*)03:03/(*)06:01 showed false-positive result in probe 253, and 1 sample with DQB1(*)04:02/(*)05:02 showed false-negative result in probe 217. We tested an additional sample with DQB1(*)03:03/(*)06:01, which showed same false-positivity in probe 253 and 2 samples with DQB1(*)04:02/(*)05:02, which showed no false reaction. The false reactions did not result in ambiguity or change in the HLA allele assignment. We could assign HLA-DQB1 alleles to 4 digit-level without ambiguity, with 100% concordance with the SBT results. Thus, LIFECODES HLA-DQB1 SSO typing kit showed good performance for intermediate-resolution HLA-DQB1 typing in clinical laboratory for organ transplantation in Koreans.

Background: The obstetrician's role in vitalizing cord blood (CB) banking is important in both informing donors and beginning CB processing. The aim of the study was to investigate obstetricians' understanding of CB and their roles in informing donors and collection management., Study Design and Methods: Questionnaires examining the management and awareness of CB were distributed to collection centers, and we analyzed 57 respondents who had collection experience., Results: All respondents were experienced, and 82.5% had CB collection experience of at least 4 years. If patients asked for information, one-third provided information about CB themselves, and two-thirds provided CB banks' (CBBs') contact information. Less than half of the respondents knew the legal regulations and had a collection manual. Regarding the awareness of transportation and storage of CB, 58% rated their knowledge as minimal, and respondents who knew the legal regulations rated their knowledge at a higher level. One-fifth of the participants felt that CB collection distracted the labor process, and 16% were concerned about delayed bleeding control. The probability of autologous CB transplantation was overestimated, and the matching probability in public CBBs was underestimated. Approximately 82.7% of the respondents correctly rated the therapeutic use of CB, and 54% rated their knowledge level about CB usefulness as average., Conclusion: Obstetricians' understanding of CB was lower than expected, considering that they are associated with CB collection centers. Obstetricians who provide information and recognize regulations seem to collect CB in compliance with the regulations better. These results will be helpful in CB collection management and education planning for obstetricians., (© 2014 AABB.)

Cord blood (CB) has become a viable stem cell source for hematopoietic stem cell transplantation (HSCT), and public cord blood banks (CBBs) have been established to manage donated cord blood units (CBUs) for unrelated HSCT. As the potential uses for CB continue to grow, there is a global tendency to encourage public CBBs. The aim of this study was to investigate the current status of public CBBs that were designated and supported by the Korean national government. We analyzed 6,168 CBUs preserved at the 3 Government-Assigned Public CBBs during their first two years of operation (2012-2013) and the standard operating procedures for CB processing at each CBB. CBU inventories at ALLCORD, Catholic HSC Bank and Fatima Public CBB were 4,022, 1,207 and 939 units, respectively. Total nucleated cell (TNC) counts per unit were 11.0 × 10(8) at ALLCORD, 10.7 × 10(8) at Fatima and 9.8 × 10(8) at Catholic, and all far exceeded the requirement for cryopreservation under the law (7.0 × 10(8)). CD34(+) cell counts and % were as follows: 3.5 × 10(6) (0.31 %) in ALLCORD, 2.2 × 10(6) (0.20 %) in Fatima and 2.2 × 10(6) (0.22 %) in Catholic. All the three banks observed the 'CB Act' in dealing with CBUs, including collection, processing, laboratory tests and cryopreservation. Government supported and strictly law-abiding public CBBs in Korea have considerable CBU inventories of high quality in terms of efficacy and safety. Legislation and accompanying government-support will be helpful for establishing CB standardization, vitalizing CBT and improving clinical outcomes.

Hepatitis B virus (HBV) vaccination is the most effective means of countering HBV-related morbidity and mortality, and individuals who do not respond to vaccination (non-responders) are problematic. The aim of the present study was to investigate associations between HLA and responsiveness to HBV vaccine in Korean infants. A total of 944 healthy Korean infants 9-12 months old were enrolled, and HLA distribution was compared among subgroups in accordance with the response to HBV vaccination. The HLA distribution of the subjects was similar to known Korean population data and did not deviate from the HWE proportions. The alleles that showed positive associations with non-responsiveness (<10mIU/mL) or low antibody titer (<100mIU/mL) were HLA-A*33, B62, DRB1*04, and DRB1*07, while the alleles A*02 and DRB1*08 showed negative associations. Among these alleles, B62, DRB1*07 and DRB1*08(-) showed significant associations with a poor or decreased response to vaccination even after correction (OR=1.83, 1.99, 5.63; pc<0.05) and also showed dose effects. After stratification by other associated alleles at different loci, B62 and DRB1*07 were independently associated with non-responsiveness, but A*02(-) and DRB1*08(-) lost their individual associations. The combined association of A*02(-)-DRB1*08(-) and B62-DRB1*08(-) was significant (OR=25.2 and 24.5; pc<0.05). Although the hierarchy is not clear, we can assume the following: (i) B62 and DRB1*07 have independent effects, (ii) DRB1*08(-) has a very strong and synergic effect, and (iii) there is probability of a third factor controlling A*02(-) and DRB1*08(-) with an effect on non-responsiveness to HBV vaccination in Korean infants., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Background: The inventory size for cord blood (CB) depends on the ethnic diversity of human leukocyte antigen (HLA) and the size estimation is important for public health in each ethnicity., Study Design and Methods: We estimate the CB inventory size in Koreans with stored CB units (CBUs) and patients who underwent allogeneic hematopoietic stem cell transplantation. Two-digit HLA specificities were determined using intermediate DNA typing. From 17,508 stored Korean CBUs, 1460 haplotypes with a frequency greater than 0.001% were used for reconstitution of the HLA. A total of 1002 transplanted patients' HLA was used for matching probability calculation., Results: The best probability for 6/6 matching is 47% in 500,000 hypothetical size. Ninety-five percent probability is achieved with 51,000 CBUs in 5/6, and 2150 in 4/6 matching condition. Because 4/6 matched CB is rarely selected in the Korean situation, 51,000 units is the lowest limit of CBUs required and the number will be adjusted depending on the cell number required for patients and the resolution of HLA typing., Conclusion: Approximately 51,000 units could provide the minimum requirement for hematopoietic transplantation in Korea., (© 2013 American Association of Blood Banks.)

Recurrent respiratory papillomatosis (RRP) is characterized by frequent recurrences of papilloma of the larynx with significant morbidity. It is caused by human papillomavirus (HPV) types 6 and 11. Some associations of HLA genes with RRP have been reported, mainly in Caucasians. We performed HLA class II (DRB1 and DQB1) genotyping using Dynal RELI™ HLA-DRB1 SSO kit and PCR-single strand conformation polymorphism on 22 Korean patients with severe RRP and 207 healthy controls. The gene frequencies of HLA-DRB1*11:01 (18.2% vs 3.6%, p=0.0006, pc=0.02, odds ratio [OR]=5.9) and DQB1*03:01 (36.4% vs 14.5%, p=0.0009, pc=0.01, OR=3.4) and the haplotype frequency of DRB1*11:01-DQB1*03:01 (15.9% vs 3.6%, p=0.003, OR=5.0) was higher in RRP patients than controls. DRB1*11:01 and DRB1*11:01-DQB1*03:01 haplotype were strongly associated with disease susceptibility to severe RRP in Koreans., (Copyright © 2013 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.)

The main purpose of this report is to provide baseline gene frequencies of Knops blood group in the complement receptor 1 gene (CR1) in Korean population. In addition, possible relationship between the CR1 polymorphism and HLA specificities were studied, because the two systems had principal importance in immunity. CR1, which contains Knops antigens, was investigated by PCR-direct sequencing from 238 cord blood from Koreans. HLA data was archived from the enrolled cord blood units. Among the 7 SNPs, only 4843 (for KCAM antigen) and 4223 (for Yk(a)) nucleotide positions showed polymorphism. The genotype frequencies of KCAM were A/A (62.2%), A/G (33.2%), and G/G (4.6%); Yk(a) were C/C (29.4%), C/T (50%), and T/T (20.6%). KCAM (A/A) associated with HLA-DRB1(∗)13 (p=0.003, P(c)=0.0513); KCAM (G/G) with HLA-A(∗)30 (p<0.001, P(c)=0.0012). The Knops blood group system in Korean population has no diversity, except SNPs for KCAM and Yk(a), and the genotype of KCAM related with specific HLA alleles., (Copyright © 2012 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.)

Reverse sequence screening for syphilis (RSSS) (screening with treponemal tests, followed by confirmation with nontreponemal tests) has been increasingly adopted. CDC recommends confirmation of discordant results (reactive EIA/CIA and nonreactive nontreponemal test) with Treponema pallidum particle agglutination assay (TP-PA). We characterized sera with discordant results from RSSS with Architect Syphilis TP CIA. Among 15,713 screening tests using Architect Syphilis TP at Seoul National University Gangnam Center between October 2010 and May 2011, 260 (1.7%) showed reactive results. Rapid plasma reagin (RPR) and TP-PA were performed on 153 available sera among them. On sera with discordant results between Architect Syphilis TP and TP-PA, INNO-LIA Syphilis Score and FTA-ABS were performed. Among 153 sera, RPR was nonreactive in 126 (82.4%). Among them, TP-PA was positive in 103 (81.7%), indeterminate (±) in 7 (5.6%), and negative in 16 (12.7%). Out of 16 CIA(+)/RPR(-)/TP-PA(-) sera, INNO-LIA Syphilis Score and/or FTA-ABS were negative on 14 sera. Out of 7 CIA(+)/RPR(-)/TP-PA(±) sera, INNO-LIA Syphilis Score and FTA-ABS were positive/reactive in 6 sera. RSSS with confirmation by TP-PA on sera with discordant results between Architect Syphilis TP and RPR effectively delineated those discordant results and could be successfully adopted for routine checkup for syphilis.

In the present study, we evaluated the correlation between iron deficiency (ID) and zinc deficiency (ZD) and explored the demographic, anthropometric, and feeding-related factors associated with hypozincemia and hair zinc content in weaning infants. Infants aged 6-24 months were recruited, their feeding history was recorded, and their heights and weights were measured. Hemoglobin content, serum iron/total iron-binding capacity, and ferritin and zinc concentrations of serum and hair (using inductively coupled plasma-mass spectroscopy) were assessed. Among 101 infants, 64 (63.4 %) infants exhibited ID. The median serum zinc concentration in iron-deficient infants was lower than that in non-iron-deficient infants, respectively, 73.5 μg/dL (interquartile range [IQR], 65.0-83.8) vs. 87.0 μg/dL (IQR, 77.5-97.0; p = 0.001). The frequency of hypozincemia was also significantly higher in the iron-deficient group than in the non-iron-deficient group (21 out of 64 [32.8 %] vs. 4 out of 37 [10.8 %], respectively; p = 0.014). In multiple regression analysis, the risk of hypozincemia was significantly increased in infants with ID (p = 0.026), mildly underweight infants (weight-for-age Z score < -1; p = 0.034), and infants with mild wasting (weight-for-height Z score < -1; p = 0.028). Hair zinc concentrations (n = 81) were not significantly associated with ID status (p > 0.1); however, there was an inverse relationship between hair zinc concentrations and age of infants (r = -0.250; p = 0.024). In weaning infants, ID is a risk factor for hypozincemia. Hair zinc concentrations appeared to decrease as the age of infants increased during late infancy. Further large-scale studies are needed to validate the relationship between hypozincemia and mild degrees of weight gain impairment in this age group.

HLA class II haplotypes often contain a second expressed HLA-DRB locus tightly linked to the classical HLA-DRB1 locus on the haplotype, which can be either HLA-DRB3, -DRB4 or -DRB5. These encode the HLA-DR51, -DR52 or -DR53 supertypic specificities and mark the ancestral lineages. HLA-DRB3/B4/B5 heterozygote excess in Welsh male newborns has been reported, suggesting a possibility of male-specific major histocompatibility complex (MHC)-mediated prenatal selection. However, it has not been confirmed in newborns of other ethnic groups or in adult populations. We analyzed the HLA-DRB1 and HLA-DRB3/B4/B5 genes in Korean newborns and healthy adults to examine whether MHC-mediated prenatal or postnatal selection exists. A total of 1,038 newborns (cord blood registry, 516 males and 522 females) and 2,082 healthy adults (hematopoietic stem cell donor registry, 1,111 males and 971 females) were HLA typed. HLA-DRB1/B3/B4/B5 DNA typing was performed using Dynal RELI HLA-DRB SSO Kit (Dyanl Biotech, Wirral, U.K.). Genotype frequencies and homozygosity and heterozygosity rates for DRB3/B4/B5 supertypic loci were compared between males and females in newborns and adults. There were no significant differences in the HLA-DRB3/B4/B5 homozygosity and heterozygosity rates between males and females in both newborns and adults. In the comparison between newborns and adults, homozygosity rate was significantly higher in newborn females than in adult females (31.0% vs 25.0%, p=0.01). Whether there is an age-related change from newborns toward adults has not been well studied in other populations, and further studies are warranted. In conclusion, male-specific heterozygosity excess reported in Welsh newborns has not been observed in Korean population, and there might be some ethnic differences in the gender-specific prenatal selection events.

Background: The aim of the study was to investigate the knowledge of cord blood (CB) and attitudes toward CB banking among high-potential donors (i.e., well-educated pregnant Koreans) because their voluntary donation is indispensable to the success of unrelated CB transplantation., Study Design and Methods: Questionnaires examining perspectives on CB were distributed to and completed by 1001 women attending a maternity education program from April to October 2008; 863 women answered that they had heard of CB. We analyzed the 863 questionnaires to identify the sources of information, the plan for CB, the reasons for decisions, beliefs about the potential uses of CB, and knowledge about current therapeutic uses., Results: Most subjects received information from promotional materials distributed by CB banks and the media; however, minimal information was obtained from obstetricians. More than 90% of women who planned to donate cited "altruism," and 75.0% of the "private preservation" group indicated that a desire to "safeguard for the future" was the reason for their decision. The probability of autologous CB transplantation (p = 0.001) and current usefulness were significantly overestimated in the private preservation group (p = 0.02). In addition, 56% of subjects underestimated the probability of identifying a matched CB in the public bank, and the overall rate of correct answers about current usefulness was 57.4%., Conclusions: A considerable portion of educated pregnant Korean women has more than minimal knowledge of CB, but the levels of knowledge regarding the potency of the public bank and the current usefulness and limitations of CB are generally low; in addition, obstetricians play insignificant roles in disseminating knowledge. Providing accurate and detailed information to pregnant women not only via brochures and the media and/or Internet but also by obstetricians would encourage CB donation., (© 2010 American Association of Blood Banks.)