The role of gender on clearance of hepatitis C virus: a different story in an area endemic for hepatitis B and C

HBsAg stimulates NKG2D receptor expression on natural killer cells and inhibits hepatitis C virus replication

BACKGROUND

Higher hepatitis B surface antigen (HBsAg) facilitates hepatitis C virus (HCV) clearance in patients with hepatitis B virus (HBV)/HCV co-infection. We investigated the effect of exogenous HBsAg on the inhibition of HCV replication mediated by natural killer (NK) cells.

METHODS

After isolated from peripheral blood of 42 chronic hepatitis B (CHB) patients and 16 healthy individuals, NK cells were co-cultured with HCV-infected Huh7 cells, respectively, with or without HBsAg. Three days later, the co-cultured supernatants were collected and HCV RNA levels were measured by real-time quantitative PCR. NKG2D, NKp46 and NKG2A expression levels were measured by flow cytometry. NKG2D on NK cells from CHB responsive subgroup was blocked and HCV RNA levels were examined again.

RESULTS

HCV RNA levels in the co-cultured system were significantly reduced by NK cells isolated from healthy donors (P < 0.01) but not from CHB patients. However, HCV RNA levels in CHB cultures were significantly decreased following HBsAg addition (P < 0.05), whereas no such effect was seen in control cultures. No significant difference was observed in basic NKG2D expression between the CHB patients and healthy donors. On NK cells from CHB patients, the expression of NKG2D was increased significantly by HBsAg stimulation (P < 0.01), and higher than that from healthy controls (P < 0.05). HCV RNA levels were increased significantly after the blockage of NKG2D on NK cells from responsive CHB patients in the co-cultured system (P < 0.05).

CONCLUSION

Exogenous HBsAg stimulated NKG2D expression on NK cells from CHB patients which inhibit HCV replication, suggesting that HBsAg may facilitate the clearance of HCV in patients with HBV/HCV co-infection.

Seroprevalence and clinical characteristics of viral hepatitis in transfusion-dependent thalassemia and hemophilia patients

BACKGROUND/AIMS

Transfusion dependent subjects are at a great risk of viral hepatitis infection. We aimed to evaluate the prevalence and factors associated with hepatitis B virus (HBV) and hepatitis C virus (HCV) infection among transfusion-dependent patients in Taiwan.

METHODS

A total of 140 patients (67 thalassemic patients, 70 hemophilic patients, two patients with hereditary spherocytosis and one patient with von Willebrand disease) were prospectively enrolled to evaluate the prevalence and factors associated with viral hepatitis and spontaneous HCV clearance. All patients were tested for HBV and HCV serology and virology. Two consecutive serum samples, at least 1 year apart, were collected to clarify HCV seroclearance.

RESULTS

The seropositivity rate of hepatitis B surface antigen (HBsAg), HCV antibody (anti-HCV), and both HBsAg/anti-HCV were 6.4%, 45.7% and 5%, respectively. Logistic regression analysis of factors associated with anti-HCV seropositivity included age (odds ratio/95% confidence interval [OR/CI]: 1.12/1.07-1.18, P<0.001), serum alanine aminotransferase (ALT) (OR/CI: 1.04/1.02-1.06, P<0.001) and platelet counts (OR/CI: 0.995/0.991-0.998, P = 0.002). Age was the only factor independently associated with HBsAg seropositivity (OR/CI: 1.08/1.02-1.14.4, P = 0.007). Compared to patients born before 1992, the seroprevalence of HCV among thalassemic patients decreased dramatically in those born after 1992 (46.0% vs. 11.8%, p = 0.012). The seroprevalence of HCV among hemophilic patients also decreased significantly when comparing patients born before 1987 to those born after 1987 (79.5% vs. 11.5%, p<0.001). Similarly, the seroprevalence of HBV decreased significantly in the post-vaccination cohort compared to its counterpart (13.1%, vs. 1.3%, p = 0.005). The spontaneous clearance of HCV was observed in 25.4% (15/59) of patients, and ALT was the only factor associated with it (OR/CI 0.98/0.96-1.00, P = 0.02).

CONCLUSIONS

Both HBV and HCV infections are prevalent among transfusion-dependent thalassemic and hemophilic patients in Taiwan. Nevertheless, seroprevalence decreased significantly and dramatically for HCV after universal blood screening and for HBV after implementation of a universal mass vaccination program.

Prevalence and characterization of hepatitis B and C virus infections in a needle-sharing population in Northern China

BACKGROUND

The epidemiologies of hepatitis C virus (HCV) and hepatitis B virus (HBV) infections in specific populations in certain areas of China are poorly understood. A pilot survey of HCV/HBV infections was carried out in villages in Kuancheng County, Heben Province, where injection of sodium benzoate or amphetamines using shared needles has been a common practice. The aims of this study were to analyze the endemicity and characterize HCV/HBV infections in this population.

METHODS

Data on demographic characteristics and drug abuse were collected from individuals who signed informed consent forms. Serum HCV antibody (anti-HCV), hepatitis B surface antigen (HBsAg), and hepatitis B core antibody (anti-HBc) were measured in all participants. HCV RNA was measured in samples positive for anti-HCV using real-time polymerase chain reaction.

RESULTS

Among 852 participants from 11 villages, 49.9% had used sodium benzoate or amphetamine at least once, by intravenous injection. The overall prevalence of anti-HCV, HCV RNA, anti-HBc, HBsAg, and HCV/HBV co-infection was 37.1%, 26.6%, 67.7%, 10.7%, and 30.0%, respectively. Two-hundred-twenty-three of 227 (98.2%) participants positive for HCV RNA were aged >40 years. Co-infection was related to sex, age, number of injections, and time from first injection. The rate of spontaneous HCV RNA clearance was 28.2% (89/316), and was related to the number of injections, time from first injection, and HBsAg positivity. However, HBsAg was related to the anti-HBc signal/cut-off ratio rather than to the above parameters. Trend tests demonstrated that the prevalence of anti-HCV, HCV RNA, and anti-HBc was related to the number of injections (P < 0.001), while HBsAg prevalence was not (P = 0.347).

CONCLUSIONS

The prevalence of HCV and HBV infection is likely to be high among individuals older than 40 years in areas of needle sharing, and one-time screening for HCV infection should be offered to these populations.

Hepatitis C virus infection among injection drug users with and without human immunodeficiency virus co-infection

The aim of this study is to explore the prevalence of hepatitis C virus (HCV) infection among injection drug users (IDUs) with and without human immunodeficiency virus (HIV) infection in southern Taiwan. For 562 IDUs (265 anti-HIV negative, 297 anti-HIV positive), we analyzed liver function, anti-HIV antibody, anti-HCV antibody, HCV viral loads, and hepatitis B surface antigen (HBsAg). HIV RNA viral loads and CD4 cell count for anti-HIV-seropositive IDUs and the HCV genotype for HCV RNA-seropositive IDUs were measured. The seroprevalence rates of anti-HIV, anti-HCV, and HBsAg were 52.8%, 91.3%, and 15.3%, respectively. All the anti-HIV-seropositive IDUs were positive for HIV RNA. Anti-HCV seropositivity was the most important factor associated with HIV infection (odds ratio [OR], 25.06; 95% confidence intervals [CI], 8.97-74.9), followed by male gender (OR, 6.12; 95% CI, 4.05-9.39) and HBsAg seropositivity (OR, 1.90; 95% CI, 1.11-3.34). Among IDUs positive for anti-HCV, 80.7% had detectable HCV RNA. HCV viremia after HCV exposure was strongly related to HIV infection (OR, 6.262; 95% CI, 1.515-18.28), but negatively correlated to HBsAg seropositivity (OR, 0.161; 95% CI, 0.082-0.317). HCV genotype 6 was the most prevalent genotype among all IDUs (41.0%), followed by genotypes 1 (32.3%), 3 (12.8%), and 2 (5.6%). In conclusion, about half IDUs were infected with HIV and >90% with HCV infection. Male and seropositivity for HBsAg and anti-HCV were factors related to HIV infection among our IDUs. HIV was positively correlated, whereas hepatitis B co-infection was negatively correlated with HCV viremia among IDUs with HCV exposure. Different HCV molecular epidemiology was noted among IDUs.

High hepatitis B virus surface antigen levels and favorable interleukin 28B genotype predict spontaneous hepatitis C virus clearance in uremic patients

BACKGROUND & AIMS

Host and viral factors interplay in the spontaneous clearance of hepatitis C virus (HCV) infection. We aimed to explore the roles of IL28B genotypes and hepatitis B virus (HBV) infections in spontaneous HCV seroclearance.

METHODS

IL28B rs8099917 genotypes, HCV and HBV markers were determined in 290 patients who were seropositive for HCV antibodies from 1681 total uremic patients on maintenance hemodialysis.

RESULTS

Persistent HCV viremia was observed in 74.6% (214/287) of patients. Logistic regression revealed that the strongest factors associated with spontaneous HCV seroclearance were carriage of rs8099917 TT-type (odds ratio/95% confidence intervals [OR/CI]: 6.22/1.41-27.35, p=0.016), followed by concurrent hepatitis B surface antigen (HBsAg) seropositivity (OR/CI: 2.37/1.06-5.26, p=0.035). The clearance rate was highest among patients with both positive HBsAg/rs8099917 TT-type (44.8%, OR/CI: 20.88/3.5-402.5), followed by positive HBsAg/rs8099917 non-TT-type (28.6%, OR/CI: 8.86/1.8-160.8), and negative HBsAg/rs8099917 TT-type (26.7%, OR/CI: 12.75/1.0-319.4), compared to 4% of negative HBsAg/rs8099917 non-TT-type (trend p=0.0002). HBsAg levels, but not HBV DNA levels, were significantly associated with spontaneous HCV seroclearance. Spontaneous HCV seroclearance rate was 58.3% in patients with HBsAg>200IU/ml/rs8099917 TT-type (OR/CI: 42.54/5.7-908.4), 28.0% in patients with HBsAg<200IU/ml/rs8099917 TT-type or HBsAg>200IU/ml/rs8099917 non-TT-type (OR/CI: 11.12/2.3-201.0), compared to only 3.3% in those with HBsAg<200IU/ml/rs8099917 non-TT-type (trend p=0.0004). Five of 214 (2.3%) HCV viremic patients at enrollment had spontaneous HCV seroclearance during one-year follow-up, which was associated with baseline HCV RNA and HBsAg levels.

CONCLUSIONS

High HBsAg levels and favorable IL28B genotype were additively associated with spontaneous HCV seroclearance in uremic patients.

Low viraemia at enrollment in children with chronic hepatitis C favours spontaneous viral clearance

The significance of hepatitis C viral (HCV)-RNA levels in long-term clinical outcomes of children with chronic HCV infection is not well understood. We conducted a long-term follow-up study of 42 children with chronic HCV infection that included clinical evaluation, biochemical tests, HCV genotyping and repeated quantitative HCV-RNA detection. Patients were divided into low and high viraemia groups according to RNA levels at enrollment (below/above 4.5 x 10(4) IU/mL), and clinical, biochemical and virological factors were evaluated. Overall, 14.3% (6/42) of patients developed spontaneous viral clearance during a median 10.1 years of follow-up. HCV-RNA levels at enrollment and mean RNA levels during follow-up for each patient were significantly correlated (R = 0.9018, 95% CI: 0.6637-0.9038, P < or = 0.001). HCV-RNA level fluctuation was within two log units in 76% of patients. Cumulative viraemia probability during follow-up could be predicted by viraemia levels at enrollment (P = 0.0092). Chronic HCV-infected children, with an RNA level below 4.5 x 10(4) IU/mL at enrollment, have a higher spontaneous viral clearance rate.

Associations between hepatitis C viremia and low serum triglyceride and cholesterol levels: a community-based study

BACKGROUND/AIMS

To evaluate the association of virologic status with serum cholesterol and triglyceride levels in individuals with hepatitis C virus (HCV) infection.

METHODS

We conducted a large scale community-based study enrolling 11,239 residents in an area endemic for hepatitis B virus (HBV) and HCV infection in southern Taiwan. Overall, 703 (6.3%), 1,536 (13.7%), 84 (0.7%) and 9,084 (80.8%) subjects were sero-positive for anti-HCV antibody (anti-HCV), hepatitis B surface antigen (HBsAg), and both anti-HCV and HBsAg, and negative for anti-HCV and HBsAg, respectively.

RESULTS

By multivariate logistic analyses, the independent factors significantly associated with elevated serum cholesterol level were older age, female, negative for diabetes, anti-HCV or HBsAg and elevated triglyceride levels. The independent factors significantly associated with elevated serum triglyceride level were male, positive for diabetes, negative for anti-HCV or HBsAg, higher body mass index (BMI) and elevated cholesterol levels. Of 642 anti-HCV-positive subjects that have HCV RNA tested by standardized automated qualitative PCR assay, 478 (74.5%) were positive for HCV RNA. By multivariate logistic analyses, the independent factors associated with elevated serum cholesterol level were female, elevated serum triglyceride levels, negative for diabetes or HCV RNA. The independent factors associated with elevated serum triglyceride levels were elevated serum cholesterol levels, positive for diabetes, higher BMI and negative for HCV RNA. Diabetes, lower cholesterol and triglyceride levels were independent factors associated with positive HCV RNA.

CONCLUSIONS

Based on the result of this large scale community study, HCV viremia appears to be associated with lower serum cholesterol and triglyceride levels which implies that HCV itself might play a significant role on serum lipid profile of patients with chronic HCV infection.