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The aim of the study was to analyze genotype I hepatitis A virus (HAV) 5' nontranslated region (NTR) sequences from a recent outbreak in South Korea and compare them with reported sequences from Japan. We collected a total of 54 acute hepatitis A patients' sera from HAV genotype I [27 severe disease (prothrombin time INR≥1.50) and 27 mild hepatitis (prothrombin time INR <1.00)], performed nested RT-PCR of 5' NTR of HAV directly sequenced from PCR products (~300 bp), and compared them with each other. We could detect HAV 5'NTR sequences in 19 of the 54 (35.1%) cases [12 of 27 severe cases (44.4%) and 7 of 27 self-limited cases (25.9%)], all of which were subgenotype IA. Sequence analysis revealed that sequences of severe disease had 93.6%-99.0% homology and of self-limited disease 94.3%-98.6% homology, compared to subgenotype IA HAV GBM wild-type IA sequence. In this study, confirmation of the 5'NTR sequence differences between severe disease and mild disease was not carried out. Comparison with Japanese HAV A10 revealed 222C to G or T substitution in 8/12 cases of severe disease and 222C to G or T and 392G to A substitutions in 5/7 and 4/7 cases of mild disease, respectively, although the nucleotide sequences in this study showed high homology (93.6%-100%). In conclusion, HAV 5'NTR subgenotype IA from Korea had relatively high homology to Japanese sequences previously reported from Japan, and this region would be considered one of the antiviral targets. Further studies will be needed. [ABSTRACT FROM AUTHOR]

Hepatic fibrosis is characterized by excessive accumulation of extracellular matrix. Matrix metalloproteinases (MMPs) play an important role in the remodeling of the extracellular matrix during hepatic fibrosis. Lipocalin-2 (LCN2) forms complexes with MMP-9 and can be detected in the urine of patients with several types of cancers. The objective of this study was to examine the relationship between urinary LCN2 levels and MMP-9 activity with respect to the stage of liver fibrosis in patients with chronic hepatitis C (CHC), and to assess the utility of urine LCN2 as a non-invasive marker of hepatic fibrosis. Fresh spot urine samples were prospectively collected from forty-two interferon-naive CHC patients who underwent liver biopsy. The stage of hepatic fibrosis was assessed according to the METAVIR fibrosis score; 18 patients had no or mild fibrosis (stages F0 and F1) and 24 patients showed significant fibrosis (stages F2-F4). Immunoblot analyses demonstrated co-migration of urine LCN2 and MMP-9. Gelatin zymography showed that urinary MMP-9/MMP-2 activity ratios were higher in patients with significant fibrosis (F2-F4) than in patients no or mild fibrosis (F0-F1). Urine LCN2 levels which were normalized to urine creatinine concentration (urine LCN2-to-creatinine ratio; ULCR) were higher in F2-F4 patients compared to F0-F1 patients. There was a positive correlation between ULCR and urine MMP-9/MMP-2 activity ratios ( r = 0.735). ULCR and AST-to-platelet ratio index were independent predictors of significant fibrosis by multivariate analysis. The present study suggests that urinary LCN2 is a novel marker of hepatic fibrosis by reflecting urine MMP-9 activity in CHC. [ABSTRACT FROM AUTHOR]

Hepatitis E virus (HEV) was originally identified as the etiological agent of non-HAV enterically transmitted hepatitis. One HEV strain (FJ763142) was identified from an acute viral hepatitis E patient with IgM anti-HEV in Korea. The complete genome sequence consisted of 7,238 nucleotides (nt) plus a 22-nt poly(A) tail. The strain belongs to genotype IV, with 91% homology compared with AB197674, which was found in a Japanese patient who had traveled to China. This finding suggests that HEV genotype IV already circulates in Korea, and this HEV might be the first example of an indigenous strain. [ABSTRACT FROM AUTHOR]

Background and Aims: The eradication rate of proton-pump inhibitor-based triple therapy for Helicobacter pylori infection is low due to increasing antibiotics resistance, especially clarithromycin. Recently, it was reported in Europe that a 10-day sequential strategy produced good outcomes. The aim of this study was to assess the efficacy of sequential therapy as first-line treatment for eradication of H. pylori in clinical practice in Korea. Materials and Methods: A total of 98 patients (mean age 55.2 years and male 47, female 51) with proven H. pylori infection received 10-day sequential therapy (20 mg of rabeprazole, and 1 g of amoxicillin, twice daily for the first 5 days, followed by 20 mg of rabeprazole, 500 mg of clarithromycin, and 500 mg of metronidazole, twice daily for the remaining 5 days). Eradication was evaluated 4 weeks later, after completion of treatment by 13C-urea breath testing. Eradication rates were calculated by intention-to-treat (ITT) and by per protocol (PP). Compliance and adverse events were also assessed in study group. Results: The eradication rate of sequential therapy was 91.8% (90/98) by ITT and same result was reported by PP analysis (89/97). The study group consisted of 66 H. pylori associated gastritis, 7 gastric ulcer, and 25 duodenal ulcer patients (67.3%, 7.1%, 25.5%, respectively). Mild adverse events happened frequently (21.4%) but the treatment was well tolerable. The most common adverse event was a bitter taste (9.2%) followed by nausea and diarrhea (4.1%). Conclusions: Ten-day sequential therapy is found to effectively eradicate H. pylori infection as first-line treatment in Korea. [ABSTRACT FROM AUTHOR]

Background: The eradication rate of first-line Helicobacter pylori treatment is only 70–85% and has been decreasing due to the increase in antibiotic resistance. The aim of this study was to evaluate the efficacy of bismuth-containing quadruple therapy as second-line treatment for H. pylori infection based on treatment duration. Methods: We prospectively enrolled 227 patients that were found to have persistent H. pylori infection after first-line proton-pump inhibitor-clarithromycin-amoxicillin triple therapy. Patients were randomized to 1-week (112 patients) and 2-week (115 patients) quadruple therapy with tripotassium dicitrate bismuthate 300 mg q.i.d., meteronidazole 500 mg t.i.d., and tetracycline 500 mg q.i.d. and esomeprazole 20 mg b.i.d. The eradication rate, drug compliance, and adverse events were compared based on treatment duration. Results: The eradication rates were 72/112 (64.3%, 95% CI: 0.504–0.830) and 71/92 (77.2%, 0.440–0.749) with 1-week group, and 95/115 (82.6%, 1.165–2.449) an 88/94 (93.6%, 1.213–5.113) with 2-week group by intention-to-treat therapy ( p = .002) and per-protocol analysis ( p = .001), respectively. The adverse events increased as the treatment durations increased from 7 to 14 days (20.0 and 42.5%, respectively, p < .001). However, there was no significant difference in the patient compliance or the rate of major adverse events between the 1- and 2-week groups (6.3 and 12.5%, respectively, p = .133). Conclusion: Two-week bismuth-containing quadruple therapy was more effective than the 1-week treatment, and should be considered for second-line treatment in Korea. [ABSTRACT FROM AUTHOR]

Background and Aims: To evaluate the validity of the biopsy-based tests (histology, culture, and urease test) and serology in detecting current Helicobacter pylori infection against a background of atrophic gastritis (AG) or intestinal metaplasia (IM). Methods: Helicobacter pylori infection was diagnosed in 651 subjects, using the predefined gold standard for H. pylori tests. The sensitivity, specificity, and positive and negative predictive values of culture, CLOtest, histology (Giemsa stain), and serology were calculated with regard to the histological grade of AG and IM. The level of serum pepsinogen (PG) I and II was also measured as a marker for the presence of AG. Results: In the study population (n = 651), sensitivity and specificity, respectively, were as follows: culture, 56.2 and 100%; histology, 93.0 and 94.0%; CLOtest, 80.4 and 96.7%; serology, 96.0 and 67.5%. If the analysis is limited to those without AG or IM (n = 158) or to those younger than 40 years (n = 69), all tests, except for culture, had a sensitivity and specificity >90%. The sensitivity of CLOtest and the specificity of serology markedly decreased with progression of AG and IM, and serology was less specific in the presence of AG, as determined by a PG I/II ratio ≤4.1 (specificity, 83.7% vs 40.7% in PG I/II >4.1 and ≤4.1, respectively). Conclusions: Any one of biopsy-based tests or serology was found to be excellent for identifying current H. pylori infection among individuals without AG or IM and/or younger patients (<40 years). However, a combination of at least two tests is necessary in the clinical setting of AG or IM. [ABSTRACT FROM AUTHOR]

Background: Ciprofloxacin is commonly used and considered to be relatively safe in patients with cirrhosis, especially in the treatment of enteric and urinary tract infections. Among the adverse effects of ciprofloxacin, neurologic complications are rare. Methods/Results: We report a case of hemiballism and altered mental status after prolonged administration of ciprofloxacin for a renal abscess in a 59-year-old patient with cirrhosis. Hemiballism accompanied by mental changes imposed a diagnostic challenge in the differentiation between hepatic encephalopathy and stroke. Conclusion: Careful dosing and a high index of suspicion of the neurological adverse effects of ciprofloxacin including movement disorders are warranted especially in cirrhotic patients. Copyright © 2009 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Abstract  The aim of this study was to investigate HFE gene mutations, blood iron indices, and their clinical correlates in a Korean population. In 484 prospectively enrolled health-check examinees, HFE gene mutations and iron indices with clinical and laboratory variables were analyzed. Although neither the C282Y nor S65C gene mutation were found, the H63D heterozygote was detected in 41 subjects (8.5%). The mean serum ferritin and transferrin saturation (TS) were 136.2 ± 129.8 μg/dl and 39.2 ± 15.7%, respectively. The H63D genotype was not significantly associated with iron indices. High serum ferritin was associated with old age, the male gender, high body mass index (BMI), and the presence of nonalcoholic fatty liver disease (NAFLD). High TS was associated with the male gender and alcohol drinking. HFE gene mutation is rare; however, TS seems to be higher in Koreans compared to Caucasians or other ethnic groups. Serum ferritin reflects iron store as well as the presence of NAFLD. [ABSTRACT FROM AUTHOR]

Background: This study was performed to evaluate whether the addition of probiotics to proton pump inhibitor (PPI)-based triple therapy increases the likelihood of successful Helicobacter pylori eradication. Materials and Methods: Three hundred and forty-seven H. pylori-infected patients were randomized into a triple-plus-yogurt group (yogurt group, n = 168) or a triple-only group (control group, n = 179). Triple therapy consisted of PPI b.i.d., clarithromycin 500 mg b.i.d., and amoxicillin 1 g b.i.d. for 7 days. Yogurt group received triple therapy for 1 week and one bottle of Will yogurt per day for at 3 weeks, starting on the first day of triple therapy. Will yogurt (a Korean brand) contains Lactobacillus acidophilus HY2177, Lactobacillus casei HY2743, Bifidobacterium longum HY8001, and Streptococcus thermophilus B-1. 13C-urea breath test was performed at least 4 weeks after completion of triple therapy. Eradication rates, compliances, and adverse events were compared. Results: By intention-to treat analysis the H. pylori eradication rates in the yogurt group 79.2% (133 of 168) was similar to that in the control group 72.1% (129 of 179) ( p = .124). However, by per-protocol (PP) analysis, the eradication rate in the yogurt group, 87.5% (133 of 152) was higher than that in the control group, 78.7% (129 of 164) ( p = .037). Common adverse events were metallic taste (11.8%) and diarrhea (8.6%). The frequency of adverse effects in the yogurt group 41.1% (69/168) were higher than in the control group, 26.3% (47 of 179) ( p = .003). However, most adverse events were mild to moderate in intensity, and the severities of adverse effects were similar in both groups ( p = .401). Conclusions: The addition of Will yogurt to triple therapy did not reduce the side-effects of triple therapy. But it increased the H. pylori eradication rate by PP analysis, encouraging more research in this field. [ABSTRACT FROM AUTHOR]

Background: Serology is widely used for epidemiologic research of Helicobacter pylori. However, there is limited information on the long-term follow up of H. pylori titers after eradication. In addition, it is presumed that the reinfection rate decreases as the H. pylori infection rate decreases. The aim of this study was to investigate the long-term follow up of H. pylori IgG, and to evaluate the reinfection rate of H. pylori in Korea. Methods: Among 247 patients, who were enrolled during 2003–07, 185 patients with invasive H. pylori test positive received proton pump inhibitor-based triple therapy, and follow-up H. pylori testing, including histology, CLOtest, culture, and serology, were evaluated 2, 10, and 18 months after H. pylori eradication. Results: The initial H. pylori IgG optical density (OD450nm), 2.06, gradually decreased to 0.63 (67% reduction) at 18 months after H. pylori eradication. The seroreversion rate was 5, 10, and 45% at 2, 10, and 18 months after H. pylori eradication, respectively. The recrudescence of H. pylori was 3.49%, and the annual reinfection rate was 2.94% per year. H. pylori IgG titers abruptly increased in cases with recrudescence and reinfection, and correlated with the results of the invasive H. pylori tests. Conclusion: The results of this study showed that H. pylori IgG serology could be used for the determination of reinfection of H. pylori, but not for the diagnosis of H. pylori eradication. The reinfection rate of H. pylori, in Korea, was found to be very low, 2.94% per year. [ABSTRACT FROM AUTHOR]

Objective: The number of adult hepatitis A cases has progressively been increasing during the last several years in Korea. The aim of the present study was to describe the recent clinical features of hepatitis A and the seroprevalence of hepatitis A virus (HAV), and to discuss HAV vaccine strategy in Korea. Methods: Retrospective analysis of clinical characteristics of hepatitis A from 109 patients consecutively enrolled at a community hospital between 2003 and 2006 as well as cross-sectional study of seroprevalence of HAV from 307 patients of hospital population group during the same period were performed. Results: Most hepatitis A cases were young adults in their twenties or thirties, and the severity of the disease was related to the age of patients. The seroprevalence of HAV was 62%, which was dependent on the age of patients. HAV seroepidemiology in Korea is rapidly changing and a growing number of young adults are susceptible to HAV infection. Conclusions: The clinical features and the epidemiological shift of HAV urge Korea, as well as other countries which are experiencing similar issues, to promote childhood vaccination and consider catch-up vaccination for adolescents and young adults. Copyright © 2008 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Recombinant hepatitis C virus (HCV)-like particles (HCV-LPs) containing HCV structural proteins (core, E1, and E2) produced in insect cells resemble the putative HCV virions and are capable of inducing strong and broad humoral and cellular immune responses in mice and baboons. Here, we present evidence on the immunogenicity and induction of protective immunity by HCV-LPs in chimpanzees. Chimpanzees (two in each group), were immunized with HCV-LPs or HCV-LPs plus AS01B adjuvant. After immunizations, all animals developed an HCV-specific immune response including IFN-γ+, lL-2+, CD4+, and CD8+ T cell and proliferative lymphocyte responses against core, E1, and E2. Upon challenge with an infectious HCV inoculum, one chimpanzee developed transient viremia with low HCV RNA titers (10³ to 104 copies per ml) in the third and fourth weeks after the challenge. The three other chimpanzees became infected with higher levels of viremia (104 to 105 copies per ml), but their viral levels became unquantifiable (<10³ copies per ml) 10 weeks after the challenge. After the HCV challenge, all four chimpanzees demonstrated a significant increase in peripheral and intrahepatic T cell and proliferative responses against the HCV structural proteins. These T cell responses coincided with the fall in HCV RNA levels. Four naïve chimpanzees were infected with the same HCV inoculum, and three developed persistent infection with higher viremia in the range of 105 to 106 copies per ml. Our study suggests that HCV-LP immunization induces HCV-specific cellular immune responses that can control HCV challenge in the chimpanzee model. [ABSTRACT FROM AUTHOR]

OBJECTIVES: Osteopontin (OPN) is a secreted glycoprotein, frequently associated with various tumors. We investigated the usefulness of plasma OPN level as a biomarker for hepatocellular carcinoma (HCC). METHODS: We determined plasma levels of OPN, α-fetoprotein (AFP), and prothrombin induced by vitamin K absence II (PIVKA II) in a group of 62 HCC patients, in 60 patients with chronic liver diseases, and in 60 healthy control individuals using a standardized ELISA kit. To determine the source of elevated plasma level of OPN, immunohistochemical analysis of 285 HCC samples on tissue microarray was performed. RESULTS: Plasma OPN levels in the HCC patients (median 954 ng/mL, range 168–5,742) were significantly higher ( p-value < 0.001) than those patients with chronic liver diseases (381 ng/mL, 29–1,688) or of a healthy control group (155 ng/mL, 10–766). Within the HCC patient group, plasma OPN level increased significantly with advancing degree of Child-Pugh class and of tumor stage. Diagnostic sensitivity and specificity of OPN for HCC was 87% and 82%, respectively (cut-off value: 617.6 ng/mL). OPN had a greater area under curve value (0.898) than AFP (0.745) or PIVKA II (0.578), suggesting superior diagnostic accuracy of OPN. Immunohistochemistry of 285 samples of HCC showed that OPN was expressed in 92 of 285 tumors (32.3%). OPN expression was found in the malignant hepatocytes and cancer-infiltrating macrophages, not in the noncancerous hepatocytes or Kupffer cells. CONCLUSIONS: These data propose elevated plasma OPN levels as a potential biomarker for HCC. [ABSTRACT FROM AUTHOR]

Chronic liver disease, including liver cirrhosis and hepatocellular carcinoma (HCC), has been a major cause of mortality in Korea. The prevalence rates of hepatitis C virus (HCV) and hepatitis B virus (HBV) infections in the general population of Korea are approximately 1 and 5%, respectively. The most common genotypes of HCV in Korea are 1b and 2a. The sustained virological response rates after antiviral therapies, including combined interferon-α and ribavirin, have been reported to be 38–59%. The annual incidence of HCC among HCV-related liver cirrhosis has been estimated at 5%, and approximately 12% of HCC is attributable to HCV and 68% to HBV in Korea. The mean age of patients with HCV-related HCC at the time of diagnosis was consistently 10 years older than that of patients with HBV-related HCC. Moreover, HCV-related HCC was accompanied by more advanced liver cirrhosis than HBV-related HCC. Coinfection with HBV seemed to increase the risk of developing HCC in chronic HCV infection. After the successful program of hepatitis B vaccination, HCV infection is now emerging as an important etiology of chronic liver disease in Korea, which warrants more detailed and large-scale studies. Copyright © 2006 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background/Aims The combination of glecaprevir and pibrentasvir (G/P) is the first pan-genotypic direct-acting antiviral agent therapy approved in South Korea. It is estimated that there are 300 thousand individuals with hepatitis C virus (HCV) antibody- positive in South Korea. Among chronic hepatitis C (CHC) patients, virus genotype (GT) 1 and 2 combined account for the vast majority (~99%) of CHC. We evaluated the efficacy and safety of G/P in South Korean CHC GT1 or 2 patients with or without compensated cirrhosis. Methods We pooled the data from five Phase II/III trials for sub-analysis of patients from South Korea who received G/P for either 8 or 12 weeks. Efficacy was evaluated as the rate of sustained virologic response at 12 weeks posttreatment (SVR12). Results The analysis included 265 patients (intention-to-treat population); 179 (67.5%) were HCV treatment-naïve, and 5 (1.9%) and 81 (30.6%) had previously received sofosbuvir or interferon-based treatment, respectively. A total of 262 of 265 patients (98.9%) achieved SVR12. There was one virologic failure (relapse at 12 weeks after treatment), one patient discontinued treatment due to adverse event (AE), which was assessed as not related to the treatment, and one patient had missing SVR12 result. G/P was safe and well-tolerated, with most of the AEs being grade 1 (mild) and eight of 265 patients (3.0%) reporting at least one AE of severity grade 3 or higher. Only two patients experienced grade 3 hepatic laboratory abnormalities; one hyperbilirubinemia and one alanine aminotransferase elevation. Conclusions G/P combination therapy for 8 or 12 weeks achieved a high efficacy with SVR12 rate of 98.9% among patients with CHC GT1 or 2 infection from South Korea. G/P was safe and had a favorable safety profile, comparable to that observed in the G/P global clinical trials. [ABSTRACT FROM AUTHOR]

Background/Aims To eliminate hepatitis C virus (HCV) infection by 2030, improving the public knowledge of and accessibility to HCV screening and treatment is essential. The aim of this study was to evaluate the knowledge and testing rate of HCV and the opinions about the inclusion of the HCV test in the Nation Health Examination among the general population of South Korea. Methods A telephone interview survey was conducted by an independent research company using a 16 item-questionnaire (demographic, knowledge on HCV, testing rate and its result, necessity of screening) during May 2019. The sample population consisted of 1,003 Korean adult residents adjusted by age, gender and area according to the standard Korean population in 2019. Results Among the 1,003 participants (498 men and 505 women, mean age of 47.9 years), 56.4% recognized HCV; 44.4% understood HCV is transmittable; and 56.4% thought HCV is curable by medication. Testing for anti-HCV was reported by 91 people (9.1%); among them, 10 people (11.0%) reported a positive result, and eight people were treated. The common reasons for HCV testing were a health check-up (58.5%), a physician's recommendation (11.0%) and elevated liver enzymes (10.7%). The HCV testing rate was significantly low in the young age group with those in their 20s (2.3%), but the people in their 30s and above had a similar testing rate from 9% to 12.9% according to increasing age. The majority (75.1%) agreed to HCV screening by integration into the National Health Examination System. Conclusions The level of knowledge on HCV is suboptimal, and the self-reported testing rate of HCV is less than 10%, but once diagnosed, the treatment rate seems to be high in South Korea. More active campaigns and effective screening are urgently needed. [ABSTRACT FROM AUTHOR]

Background/Aims: To investigate a reported outbreak of presumed hepatitis E virus (HEV) infection in a Korean food manufacturing facility and to explore the association between anti-HEV immunoglobulin M (IgM) positivity and coronavirus disease 2019 (COVID-19) infection or vaccination. Methods: Twenty-four cases of anti-HEV IgM positivity were reported among 646 workers at the facility in 2022. An epidemiological investigation was conducted, comprising HEV-RNA testing of blood and environmental samples, analysis of group meal records, and an association between anti-HEV IgM positivity and confirmed COVID-19 infection or vaccination. Results: All 24 patients were asymptomatic, with cases spread sporadically across the facility. HEV RNA was not detected in the serum or environmental samples. Four out of 340 meals (1.2%) showed a significantly higher proportion of anti-HEV positivity in each meal intake group than in the non-intake group on certain days. Although the cumulative rate of COVID-19 infection showed no difference, the anti-HEV IgM positive group showed significantly higher proportions of >2 doses of COVID-19 vaccination (83.3% vs 48.7%, p=0.021), vaccination within 90 days (45.8% vs 19.7%, p=0.008), and having the Moderna vaccine administered as the last vaccine (75.0% vs 14.5%, p<0.001) than those of the anti-HEV negative group. In four multivariable models, three or more COVID-19 vaccinations and the Moderna vaccine as the last vaccine were consistently associated with anti-HEV IgM positivity, while the specific day group meal intake was also a significant factor. Conclusions: This epidemiological investigation showed that anti-HEV IgM positivity may occur as a false-positive result related to COVID-vaccination over three times and use of the Moderna vaccine, although a portion of true HEV infection may not be excluded. [ABSTRACT FROM AUTHOR]

Background/Aims We used next-generation sequencing (NGS) to analyze resistance-associated substitutions (RASs) and retreatment outcomes in patients with chronic hepatitis C virus (HCV) infection who failed direct-acting antiviral agent (DAA) treatment in South Korea. Methods Using prospectively collected data from the Korean HCV cohort study, we recruited 36 patients who failed DAA treatment in 10 centers between 2007 and 2020; 29 blood samples were available from 24 patients. RASs were analyzed using NGS. Results RASs were analyzed for 13 patients with genotype 1b, 10 with genotype 2, and one with genotype 3a. The unsuccessful DAA regimens were daclatasvir+asunaprevir (n=11), sofosbuvir+ribavirin (n=9), ledipasvir/sofosbuvir (n=3), and glecaprevir/pibrentasvir (n=1). In the patients with genotype 1b, NS3, NS5A, and NS5B RASs were detected in eight, seven, and seven of 10 patients at baseline and in four, six, and two of six patients after DAA failure, respectively. Among the 10 patients with genotype 2, the only baseline RAS was NS3 Y56F, which was detected in one patient. NS5A F28C was detected after DAA failure in a patient with genotype 2 infection who was erroneously treated with daclatasvir+asunaprevir. After retreatment, 16 patients had a 100% sustained virological response rate. Conclusions NS3 and NS5A RASs were commonly present at baseline, and there was an increasing trend of NS5A RASs after failed DAA treatment in genotype 1b. However, RASs were rarely present in patients with genotype 2 who were treated with sofosbuvir+ribavirin. Despite baseline or treatment-emergent RASs, retreatment with pan-genotypic DAA was highly successful in Korea, so we encourage active retreatment after unsuccessful DAA treatment.

Background/Aims: Glecaprevir/pibrentasvir (G/P) is the first pan-genotypic direct-acting antiviral combination therapy approved in Korea. An integrated analysis of five phase II and III trials was conducted to evaluate the efficacy and safety of G/P in Korean patients with chronic hepatitis C virus (HCV) infection. Methods: The study analyzed pooled data on Korean patients with HCV infection enrolled in the ENDURANCE 1 and 2, SURVEYOR II part 4 and VOYAGE I and II trials, which evaluated the efficacy and safety of 8 or 12 weeks of G/P treatment. The patients were either treatment-naïve or had received sofosbuvir or interferon-based treatment. Efficacy was evaluated by assessing the rate of sustained virologic response at 12 weeks posttreatment (SVR12). Safety was evaluated by monitoring adverse events (AEs) and laboratory assessments. Results: The analysis included 265 patients; 179 (67.5%) were HCV treatment-naïve, and most patients were either subgenotype 1B (48.7%) or 2A (44.5%). In the intention-to-treat population, 262 patients (98.9%) achieved SVR12. Three patients did not achieve SVR12: one had virologic failure and two had non-virologic failures. Most AEs were grade 1/2; eight patients (3.0%) experienced at least one grade ≥3 AE. No serious AEs related to G/P treatment were reported, and grade ≥3 hepatic laboratory abnormalities were rare (0.8%). Conclusions: G/P therapy was highly efficacious and well tolerated in Korean patients with HCV infection, with most patients achieving SVR12. The safety profile was comparable to that observed in a pooled analysis of a global pan-genotypic population of patients with HCV infection who received G/P. [ABSTRACT FROM AUTHOR]

Background/Aims: Extrahepatic comorbidities and comedication are important to consider in the treatment of chronic hepatitis C (CHC) patients with direct-acting antivirals (DAAs) due to the risk of drug-drug interaction (DDI) and the effect of comorbidities on clinical outcomes. This study aimed to investigate the detailed profiles of comorbidities and comedication among Korean CHC patients. Methods: All adult patients (≥18 years old) with a primary diagnostic code of CHC in 2013 were selected from the National Health Insurance claims database. For each patient, all ICD-10 codes listed as primary or secondary diagnoses and all prescribed medications were collected. Results: Among 47,104 CHC patients (median age, 57 years; male, 49.3%), 84.8% had at least one comorbidity for a mean number of 2.4, which increased with age. The most prevalent comorbidities were hypertension, esophagitis, dyslipidemia, diabetes mellitus, and peptic ulcer. Overall, 96.8% of the patients took at least one prescribed medication, with a mean of 8.1 medications/ year, and the three most common drug types were analgesics, gastrointestinal agents, and antibacterials. Use of at least one drug with a DDI risk category of "contraindicated medication" or "required dose-reduction/additional monitoring" was observed in 97% of the overall patients. The proportion of prescribed medications that were contraindicated with DAAs varied from 2.0% to 38.9% depending on the hepatitis C virus regimen. Conclusions: The majority of CHC patients had comorbidities; almost all patients took multiple prescribed medications, the number of which increased with age, and significant DDI risk was present in 97% of this Korean patient cohort. Comorbidities and comedication profiles should be considered during DAA therapy. [ABSTRACT FROM AUTHOR]

Background/Aims: To eliminate hepatitis C virus (HCV) infection, improving public knowledge of and access to HCV screening and treatment is essential. The aim of this study was to evaluate the knowledge of and testing rate for HCV and the opinions about the inclusion of the HCV test in the National Health Examination (NHE) among the general population in South Korea. Methods: A telephone interview survey was conducted by an independent research company using a 16 item-questionnaire (demographics, knowledge of HCV, testing and results, need for screening) in May 2019. The sample population consisted of 1,003 adult Korean residents adjusted by age, sex, and area according to the standard Korean population in 2019. Results: Among the 1,003 participants (505 women, mean age of 47.9 years), 56.4% recognized HCV; 44.4% understood that HCV is transmittable, and 56.8% thought that HCV is curable by medication. The recognition rate tended to increase with an increasing level of education. Testing for anti-HCV antibodies was reported by 91 people (9.1%); among them, 10 people (11.0%) reported a positive result, and eight people received treatment. The common reasons for HCV testing were a health check-up (58.5%), a physician’s recommendation (11.0%) and elevated liver enzyme levels (10.7%). The majority of the population (75.1%) agreed with the integration of HCV into the NHE. Conclusions: The level of knowledge of HCV is suboptimal, and the self-reported testing rate for HCV is less than 10%; however, once HCV infection is diagnosed, the treatment rate seems to be high in South Korea. More active campaigns and effective screening are needed. [ABSTRACT FROM AUTHOR]

Background/Aims: Sofosbuvir (SOF)-based therapy has been used in Korean patients with chronic hepatitis C virus (HCV) infection since January 2016. This study aimed to investigate the real-life effectiveness and safety of SOF-based therapy in genotype 2 HCV infection. Methods: From January to December 2016, 458 genotype 2 HCV-infected patients who received ≥1 dose of SOF-based therapy were consecutively enrolled in seven tertiary hospitals. Sustained virologic response (SVR) rates and safety were determined by intention-to-treat (ITT) and per-protocol (PP) analyses. Results: The mean age of the patients was 61.0 years; 183 (40%) were male, and 13.1% showed a high viral load (>6,000,000 IU/ mL). Among the 378 treatment-naïve patients, the SVR rates were 94.2% (ITT) and 96.7% (PP). Among the 80 treatmentexperienced patients, the SVR rates were 96.3% (ITT) and 98.7% (PP). Patients with a relatively high fibrosis-4 index score (>3.25) had similar SVR rates to those with a relatively low score (p=0.756). A total of 314 patients (68.6%) were treated with a reduced ribavirin dose at the prescriber’s discretion, but they showed similar SVR rates to those treated with the weight-based dose (ITT: 95.5% and 92.3%, PP: 97.4% and 96.3%, respectively). Adverse events were observed in 191 patients (41.7%), including 86 (18.8%) with anemia, but only one (0.2%) discontinued antiviral therapy due to nausea. Conclusions: SOF-based therapy showed high real-life efficacy and tolerability in Korean patients with genotype 2 chronic HCV infection, regardless of previous antiviral treatment experience and fibrosis score. A reduced ribavirin dose can be considered in this patient cohort. [ABSTRACT FROM AUTHOR]

Aims: This study aimed to elucidate the epidemiological and clinical characteristics of chronic hepatitis C (CHC) patients in South Korea from 2007 to 2017 and to compare the treatment patterns between two periods before and after the first approval of direct-acting antivirals (DAA) in South Korea in 2015. Methods: This prospective, multicenter cohort enrolled 2,758 patients with hepatitis C virus (HCV) viremia at seven tertiary centers, and clinical data were prospectively collected with questionnaire surveys focused on lifetime risk factors related to HCV infection. Results: The HCV patients had a mean age of 57.3 years (50.8% male). Among them, 14.3% showed a positive history of transfusion before HCV screening and 5.6% reported intravenous drug use (IVDU), with significant differences in these risk factors between men and women. The proportions of patients with chronic hepatitis, liver cirrhosis and hepatocellular carcinoma (HCC) were 69.5%, 18.9%, and 11.5%, respectively. The mean alanine aminotransaminase level was within the upper normal limit at 49.9%, and the major genotypes were 1b (48.2%) and 2 (46.4%). The overall treatment rate was 53.8%, showing a rapid transition from interferon-based therapy to DAA therapy. In the post-DAA-approval era, the untreated group was older, had a higher prevalence of HCC, and had less education than the treated group. Conclusions: More than 90% of CHC patients were over 40 years old, the major genotypes were 1b and 2, and IVDU was observed in less than 6% of CHC patients. Approximately half of the patients underwent antiviral therapy even in the DAA era, showing an unmet need with regard to HCV elimination. [ABSTRACT FROM AUTHOR]

Background/Aims: This study aimed to describe the healthrelated quality of life (HRQoL) outcomes for Korean chronic hepatitis C patients and to investigate the impact of patient and virus-related factors on HRQoL. Methods: HRQoL was assessed in 235 hepatitis C virus (HCV)-infected patients from seven nationwide tertiary hospital, including those with liver cirrhosis and hepatocellular carcinoma (HCC), using the Shor-Form 36 (SF-36) version 2 and the European quality of life questionnaire-5 dimensions (EQ-5D-3L). Results: The SF- 36 physical (48.8±8.3) and mental (46.2±11.7) component summary scores of the HCV-infected patients were below normal limits. Of the eight domains, general health, vitality, and mental health tended to show low scores. Patients with decompensated cirrhosis had the lowest HRQoL, while HCC and chronic hepatitis patients had similar HRQoL results. The EQ-5D index was low (0.848±0.145) in the HCV infected patients. Multivariable analysis showed age ≤65 years, high monthly family income (>$2,641), low comorbidity score, and sustained virologic response (SVR) were independently associated with favorable HRQoL. Conclusions: HRQoL in Korean patients with chronic HCV infection was low and was affected by cirrhosis severity, SVR, and comorbidity as well as income, which had the strongest effect. Therefore, HRQoL may be improved by antiviral therapy with reasonable costs to prevent cirrhosis progression. [ABSTRACT FROM AUTHOR]

Background/Aims: The introduction of direct-acting antivirals (DAA) in 2013 revolutionized hepatitis C virus (HCV) treatment, offering a cure rate >90%. However, this therapy is expensive, and estimations of the number of chronic HCVinfected (CHC) patients and their treatment costs pre-2013 are therefore essential for creating policies and expanding drug access. Herein, we aimed to investigate the number of HCV-related liver disease patients, their healthcare utilization, their annual direct medical costs, and the interferonbased antiviral treatment rates and costs from 2009 to 2013 in South Korea. Methods: The National Health Insurance database was reviewed, and patients diagnosed with CHC from 2009 to 2013 were extracted. Data regarding detailed healthcare utilization, prescribed drugs, and direct medical costs were obtained. For annual direct healthcare cost calculations, a prevalence-based approach was used. Results: Overall, 181,768 CHC patients were identified. In 2013, the annual per-patient costs for chronic hepatitis, liver cirrhosis, hepatocellular carcinoma, and the first year post-liver transplant were 895, 1,873, 6,945, and 67,359 United States dollars, respectively. Interferon-based antiviral therapeutics were prescribed to 25,223 patients (13.9%). Conclusions: Healthcare costs have increased remarkably with increasing liver disease severity. Thus, efforts to stop disease progression are needed. Moreover, the low rate of interferon-based therapy indicates an unmet need for DAA. [ABSTRACT FROM AUTHOR]

Background: Health care workers (HCWs) are at high risk for occupational blood exposures (OBEs) and transmission of bloodborne pathogens. This study elucidated the incidence rate and epidemiological characteristics of OBEs among HCWs and investigated the pathogen transmission rate for hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV).Methods: Self-reported OBEs from January 1, 2011 to December 31, 2015 were obtained from the electronic recording system. OBE incidence densities per 100 person-years and per 100 bed-years were calculated with a 5-year trend analysis. OBE characteristics and pathogen transmission rates were evaluated.Results: Among 10,452 HCWs and 1072 average yearly beds, 1076 OBEs were reported. OBE incidence rate was 5.6 cases per 100 person (full-time equivalent)-years and 20.3 per 100 bed-years. Incidence rate decreased and was significantly associated with a decrease of beds served per HCW. Housekeeping showed the highest OBE rate (14.8%) followed by doctors (8.5%) and nurses (6.2%). OBEs occurred in wards, emergency rooms, and operating rooms (38.1%, 13.3% and 12.2%, respectively) via percutaneous (86.7%) and mucocutaneous exposures (13.2%). Of OBEs associated with HBV (n = 133), HCV (n = 126), and HIV (n = 25), only one led to an infection (HCV; transmission rate of 0.8%). Neither HBV nor HIV infection occurred.Conclusions: OBE incidence rate in a Korean university hospital was 5.6 cases per 100 person-years and 20.3 per 100 bed-years and was related to HCW workload and work proficiency. Though the actual bloodborne pathogen transmission rate was low, efforts to prevent OBE should be made for hospital safety. [ABSTRACT FROM AUTHOR]

Background/Aims: To evaluate the era of direct acting antivirals (DAAs), we must understand the treatment patterns and outcomes of interferon-based therapy for hepatitis C virus (HCV) infection. We aimed to elucidate the treatment rate, factors affecting treatment decisions, and efficacy of interferonbased therapy in a real-world setting. Methods: This nationwide cohort study included 1,191 newly diagnosed patients with chronic HCV infection at seven tertiary hospitals in South Korea. Subjects were followed retrospectively until March 2015, which was just before the approval of DAA therapy. Results: In total, 48.2% and 49.3% of the patients had HCV genotypes 1 and 2, respectively. Interferon-based therapy was initiated in 541 patients (45.4%). The major reasons for no treatment included ineligibility (18.9%), concern about adverse events (22.3%), cost (21.5%), and an age >75 years (19.5%). Interferon-based therapy was discontinued (18.5%) mainly due to adverse events (n=66). The intent-to-treat analysis found that the sustained virologic response (SVR) rate was 58.3% in genotype 1 patients and 74.7% in non-genotype 1 patients. Conclusions: Approximately one-third of newly diagnosed HCV patients in South Korea received interferon-based therapy and showed a suboptimal SVR rate. Diagnosis of patients at younger ages and with a less advanced liver status and reducing the DAA therapy cost may fulfill unmet needs. [ABSTRACT FROM AUTHOR]

Background/Aims: The association between depression and chronic hepatitis C virus (HCV) infection or pegylated interferon α and ribavirin therapy (PR therapy) has not been extensively studied in Korea. We aimed to clarify the prevalence of depression and its incidence during PR therapy in chronic hepatitis C (CHC) patients. Methods: In this prospective, multicenter study, 114 CHC patients were screened for depression using two self-reported scales, the Beck Depression Inventory-I (BDI-I) and the Hospital Anxiety and Depression scale (HADS). The incidence of depression during PR therapy was evaluated in 62 patients who underwent PR therapy during the study period. Results: The prevalence of baseline depression was 17.5% according to the BDI-I score ≥10 criterion and 4.4% according to the HADS-D score ≥8 criterion in the 114 CHC patients, and it was significantly associated with an unmarried state. During PR therapy, depression developed in 34.6% according to the BDI-I scale and 29.5% according to the HADS-D, which negatively affected sustained virologic response (SVR). Conclusions: The prevalence of depression in Korean CHC patients appears to be low compared to that in Western patients; however, its incidence during PR therapy (approximately 30%) was similar to that of other populations, which led to a lower SVR rate. Active screening and multidisciplinary management of depression during PR therapy is warranted. [ABSTRACT FROM AUTHOR]

Background/Aims: Because of the limited geographic distribution, there have been insufficient data regarding hepatitis C virus (HCV) genotype 6 in Korea. This study aimed to investigate the clinical characteristics and available treatment outcomes of patients with genotype 6 HCV in Korea. Methods: From 2004 to 2014, data were collected from Korean patients infected with genotype 6 HCV in eight hospitals. Results: Thirty-two patients had genotype 6 HCV. The median age was 44 years, and 6c was the most common subtype. The baseline median alanine transaminase level was 88 (21 to 1,019) IU/mL, and the HCV RNA level was 1,405,000 (96,500 to 28,844,529) IU/mL. Twenty-five patients were treated with peginterferon (PEG-IFN) and ribavirin. Three follow-up losses occurred. Additionally, 13 patients attained a sustained virologic response (SVR), seven patients relapsed, and two patients exhibited a null response. The SVR rates were 40% and 75% for the 24- and more than 48- week treatments, respectively, and five of the six patients who achieved a rapid virologic response (RVR) attained a SVR. Conclusions: Korean patients infected with genotype 6 HCV are relatively young, and 6c is the most common subtype. When treated with PEG-IFN and ribavirin, the SVR rate was 52%. Similar to other genotypes, a longer duration of treatment and attainment of RVR are important for SVR. [ABSTRACT FROM AUTHOR]

Background/Aims: Data are lacking regarding the management of chronic hepatitis B (CHB) with resistance to clevudine (CLV). This study evaluated the efficacy of different rescue therapies for CLV-resistant CHB. Methods: Patients with CLV-resistant CHB were enrolled in the cohort, and all patients developed virologic breakthrough during CLV therapy and had confirmed-genotypic resistance to CLV (rtM204I mutation) before enrollment. Results: Of the 107 patients, 12 received adefovir (ADV), 21 received a CLV plus ADV combination (CLV+ADV), 34 received a lamivudine plus ADV combination (LAM+ADV), and 40 received entecavir (ETV) therapy for 48 weeks. The CLV+ADV group had the lowest hepatitis B virus (HBV) DNA level (p<0.0001) and showed the greatest reduction of HBV DNA levels from baseline compared to all other groups (p=0.004) at week 48. HBV DNA was undetectable (<70 IU/mL) in 0%, 57.1%, 21.2%, and 27.5% (p=0.003) of the patients in each group, respectively, at week 48. At the end of the study, the mean alanine transaminase (ALT) level, rate of ALT normalization, and rate of hepatitis B envelope antigen loss or seroconversion did not differ between groups. Conclusions: CLV+ADV combination therapy in patients with CLV-resistant CHB more effectively suppresses HBV replication than ETV, ADV, or LAM+ADV therapy. [ABSTRACT FROM AUTHOR]

Background/Aims: α-Fetoprotein (AFP) is normally <10 ng/mL in adults without malignancy or liver regeneration. However, hereditary or nonhereditary persistence of AFP in healthy adults may be encountered in clinical practice. This study describes four cases of persistent AFP elevation in healthy adults and investigates mutations in key transcription regulatory regions of the AFP gene as potential drivers of AFP overexpression. Methods: Four healthy adults with persistently elevated AFP levels (12.1 to 186.1 ng/mL) for >1 year, and 20 controls with low AFP levels (<0.61 to 2.9 ng/mL) were included in the study. AFP levels were collected from the families of two of the patients. We sequenced five regions that are critical for AFP expression: a promoter, two enhancers, and two silencers. Results: One of the two cases in which family information was represented is the first case of hereditary persistence of AFP in South Korea. Mutations related to AFP overexpression were not found in the transcription regulatory regions among the four patients. Conclusions: Persistent AFP elevation is a heterogeneous condition with or without a hereditary pattern and may be caused by factors outside of transcription regulatory region changes. Further research on the mechanism of AFP elevation is needed. [ABSTRACT FROM AUTHOR]

Aim: To clarify the prevalence of occult hepatitis B virus (HBV) infection (OBI) and the association between OBI and liver disease progression, defined as development of liver cirrhosis or hepatocellular carcinoma (HCC), worsening of Child-Pugh class, or mortality in cases of chronic hepatitis C virus (HCV) infection., Methods: This prospective cohort study enrolled 174 patients with chronic HCV infection (chronic hepatitis, n = 83; cirrhosis, n = 47; HCC, n = 44), and evaluated disease progression during a mean follow-up of 38.7 mo. OBI was defined as HBV DNA positivity in 2 or more different viral genomic regions by nested polymerase chain reaction using 4 sets of primers in the S, C, P and X open reading frame of the HBV genome., Results: The overall OBI prevalence in chronic HCV patients at enrollment was 18.4%, with 16.9%, 25.5% and 13.6% in the chronic hepatitis C, liver cirrhosis and HCC groups, respectively ( P = 0.845). During follow-up, 52 patients showed disease progression, which was independently associated with aspartate aminotransferase > 40 IU/L, Child-Pugh score and sustained virologic response (SVR), but not with OBI positivity. In 136 patients who were not in the SVR state during the study period, OBI positivity was associated with neither disease progression, nor HCC development., Conclusion: The prevalence of OBI in chronic HCV patients was 18.4%, and OBI was not associated with disease progression in South Koreans., Competing Interests: Conflict-of-interest statement: There are no conflicts of interest to report.