Acute hepatitis C in Korea: different modes of infection, high rate of spontaneous recovery, and low rate of seroconversion

Epidemiological and Clinical History of Viral Hepatitis in Korea

Viral hepatitis is the most important cause of acute and chronic liver disease in Korea. Particularly, hepatitis B virus (HBV) is the leading cause of liver-related mortality. Because of the nationwide vaccinations in the 1980s, hepatitis B surface antigen positive rates substantially decreased from 8% to 3%. Moreover, the introduction of potent nucleoside or nucleotide analogs led to the effective treatment of patients who had already been infected by HBV. The remaining issue has been to develop novel drugs that can cure HBV infection. Hepatitis C virus (HCV), on the other hand, is a hepatotropic virus that is parenterally transmitted. In Korea, the prevalence of HCV is estimated to be approximately 1%. Although no effective vaccine for HCV has been developed yet, highly effective and safe direct-acting antiviral therapy, which has a short treatment duration of 8 - 12 weeks, has made HCV eradication possible globally. Currently, the unsolved issue regarding HCV management is low disease awareness among patients and health care providers. Therefore, nationwide testing for anti-HCV would be a solution to identify patients infected with HCV but with no symptoms. Lastly, the Hepatitis A virus (HAV) is orally transmitted and results in acute hepatitis. In Korea, the young adult population is a high-risk group since this group is not vaccinated against HAV. More active vaccination and improved hygiene would be necessary to prevent HAV infection.

Increased levels of circulating IL-10 in persons recovered from hepatitis C virus (HCV) infection compared with persons with active HCV infection

OBJECTIVE

Approximately 70% of all hepatitis C (HCV) infections develop chronic disease. Active or exacerbated chronic hepatitis C infection subsequently progress to liver disease. The role of T-cells secretions in achieving viral clearance is still not well understood. Thus, the current study was set to determine the relationship between the T cell cytokine profiles, biochemical parameters and persistent HCV infection or spontaneous recovery.

RESULTS

Twenty-five percent (41/163) of the anti-HCV positive participants had recovered from HCV and had significantly higher concentration of IL-10 compared to those with active HCV infection (P < 0.012). Other circulating cytokines measured; IL-2, IFN gamma, TNF alpha, IL-5 and IL-17 were similar in both groups. Participants with active HCV infection had significantly higher aspartate transaminase (AST) (35 units) and alanine transaminase (46 units) compared to those in the recovered state (P < 0.001). Thus, serum levels of IL10 could be explored in larger prospective cohort study as a predictive marker of recovering from an active HCV infection.

Prevalence, Awareness, and Treatment of Hepatitis C Virus Infection in South Korea: Evidence from the Korea National Health and Nutrition Examination Survey

Background/Aims

This study aimed to investigate the epidemiology of hepatitis C virus (HCV) infection in the Korean general population and the awareness and treatment status of HCV infection among anti-HCV-positive persons.

Methods

We used data from the Korea National Health and Nutrition Examination Survey (KNHNES) collected between 2012 and 2016. All the participants aged ≥10 years in the KNHNES were tested for the anti-HCV antibody. Anti-HCV-positive persons were tested for HCV RNA and assessed for their awareness and treatment experience regarding HCV infection.

Results

The prevalence of anti-HCV was 0.66% (95% confidence interval, 0.56% to 0.78%) among Koreans aged ≥10 years, representing an estimated 278,819 anti-HCV-positive persons, and 0.71% (95% confidence interval, 0.60% to 0.84%) among Koreans aged ≥20 years. The prevalence of anti-HCV increased with age and had significant geographic variation. The positive rate of HCV RNA in anti-HCV-positive persons was 33.5% and increased with age. The rate of HCV infection awareness was 15.2% (35/250) among anti- HCV-positive persons and 30.5% (18/59) among HCV RNApositive persons. Among the participants, 13.5% of HCV RNA-positive persons had been treated for HCV infection.

Conclusions

The prevalence of anti-HCV among Koreans aged ≥20 years was 0.71%; one-third of anti-HCV-positive persons tested HCV RNA-positive. The awareness and treatment rates of HCV infection were low among HCV-infected persons. Therefore, active measures should be taken to diagnose and treat persons unaware of HCV infection.

Role of interleukin-28B genetic polymorphisms in Korean patients with hepatitis C virus infection

BACKGROUND/AIMS

This study investigated the role of single nucleotide polymorphisms (SNPs) near the interleukin-28B (IL28B) gene with respect to clinical outcomes and the antiviral response in hepatitis C virus (HCV) infection to suggest the practical utility of IL28B genotyping in Korea.

METHODS

Two SNPs near IL28B, rs12979860 and rs8099917, were analyzed using an allelic discrimination assay in a total of 454 individuals, including 147 health-check examinees and 307 patients with HCV infection.

RESULTS

The CC genotype frequency was significantly higher in the spontaneous recovery group than in the chronic infection group and was higher in the chronic hepatitis group than in the liver cirrhosis or hepatocellular carcinoma group, suggesting its favorable role in the clinical outcome. Multivariate analysis revealed that the rs12979860 CC genotype was an independent predictor of sustained virologic response (SVR) in genotype 1 HCV infection. During the currently used response-guided therapy, IL28B genotyping was most helpful for the patients who exhibit early virologic responses without rapid virologic responses, as those patients exhibiting the non-CC type did not achieve SVR, although they represented approximately one-third of the total patients.

CONCLUSIONS

The IL28B SNP is an independent predictor of SVR. Our results may be helpful if the findings are carefully applied to select patients in Korea.

Hepatitis C virus and human immunodeficiency virus transmission routes: Differences and similarities

Bouare et al found that hepatitis C virus (HCV) infection in Malian women is mainly transmitted through medical procedures with contaminated supplies, and that human immunodeficiency virus (HIV) transmission is predominantly sexual. The results of this study confirm those of a recent case-control study in New York and Oregon which demonstrated that healthcare exposures represent an important source of new HCV infections in United States. HCV seroprevalence was only 0.2% in pregnant, young Malian women, indicating that hygiene improved in healthcare facilities over time. Heterosexual transmission of HCV is exceptional, and can occur, from males to females, in extremely rare occasions in case of vaginal mucosal damage or less rarely through anal intercourse. The Malian study did not show an association between HIV infection and hospitalization, transfusion, tattoo, dental care. Transmission by needle-stick injury occurs in 0.9%-2.2% of exposures from HCV-infected subjects and in 0.1%-0.3% of exposures from HIV-infected individuals. HCV is therefore more transmissible through percutaneous exposure.

Performance evaluation of the OraQuick hepatitis C virus rapid antibody test

Background

A reliable rapid assay for hepatitis C virus (HCV) may be helpful in various clinical settings. We evaluated the performance of the OraQuick HCV Rapid Antibody Test (OraSure Technologies Inc., Bethlehem, PA, USA).

Methods

Clinical sensitivity and specificity were evaluated with oral fluids and sera from 137 patients diagnosed with hepatitis C and 300 healthy blood donors in a multi-center collaborative study. The stored sera of 200 proven HCV-infected patients and 200 healthy subjects were also evaluated. Analytical sensitivity was estimated with 4 commercial seroconversion panels and 7 Korean reference panels. The performance of 4 laboratory-based tests (3 chemiluminescence assays and 1 enzyme immunoassay) and 4 rapid test kits was compared. We also assessed the interference due to bilirubin, hemoglobin, lipid, rheumatoid factor, multipara, and several viral infections.

Results

The clinical sensitivity and specificity of the OraQuick HCV test using oral fluid were 97.8% (95% confidence interval [CI], 93.2-99.4%) and 100% (95% CI, 98.4-100%), respectively. The clinical sensitivity using serum samples was 100%. Using the 4 seroconversion panels, the OraQuick HCV test showed results comparable to those of the laboratory-based assays; its analytical sensitivity was higher than that of the other rapid test kits. There was no cross-reactivity with common interfering factors.

Conclusions

The clinical performance of the OraQuick HCV Test is comparable to that of laboratory-based tests with both serum and oral fluid. This supports the supplementary use of rapid HCV testing using oral fluid in various medical and non-medical settings.

Case definitions for acute hepatitis C virus infection: a systematic review

BACKGROUND & AIMS

Case definitions for recent hepatitis C virus (HCV) infection vary considerably between studies. The aim of this systematic review was to characterize case definitions for recent HCV and explore the heterogeneity in studies performed to date.

METHODS

A systematic literature search of MEDLINE, SCOPUS, and ISI Web of Knowledge was performed covering all studies of recent HCV infection cited between January 2000 and June 2011. The criteria used by each study to define cases of recent HCV infection were extracted, structured, and analyzed.

RESULTS

Overall, 195 articles were included, with 87% (n=169) providing a clear case definition for recent HCV infection. The most frequently used individual criteria for defining a case included HCV antibody seroconversion (77%), alanine aminotransferase (ALT) elevation (68%), and HCV RNA detection (63%). In studies using HCV antibody seroconversion, the window period between the last negative and the first positive antibody test varied widely across studies (4 weeks to 4 years). Considerable diversity was also observed with respect to the ALT threshold used to characterize ALT elevations, ranging from 2 to 20 times the upper limit of normal. HCV antibody seroconversion was used as a single criterion in 41% of the studies, while all other studies used at least two criteria (range: 2-9). Epidemiology/surveillance studies mostly used a more sensitive case definition, whereas treatment studies, natural history studies, and diagnosis studies used more specific case definitions.

CONCLUSIONS

Marked heterogeneity in case definitions for recent HCV infection was observed. Although a single case definition for recent HCV is not warranted, a degree of standardization within specific study categories would enable improved cross-study comparison and more uniform evaluation of HCV prevention and management strategies.