Factors influencing a low rate of hepatitis C viral RNA clearance in heroin users from Southern China

Abstract

INTRODUCTIONThe hepatitis C virus (HCV) epidemic now affects over 200 million people worldwide. HCV is a single-stranded RNA flavivirus that is responsible for the majority of non-A-non-B hepatitis infections [1,2] . Natural history studies have found that 15%-59% of people who are infected with HCV will undergo spontaneous viral clearance with no further liver disease due to HCV [3][4][5][6][7][8][9][10][11] . The remaining will develop chronic HCV infection that can lead to cirrhosis, hepatocellular carcinoma and the need for a liver transplant.The exact mechanism of HCV RNA clearance is not well understood although recent studies have shown that clearance is associated with strong, broad cellular immune responses [12][13][14][15][16][17][18][19] . Other factors such as younger age [3,20] , female gender [21,22] , presence of hepatitis B surface antigen (HBsAg) [3,23] , certain HLA alleles [6,[24][25][26][27][28][29] , and low viral quasispecies diversity [30] have been linked to increased HCV RNA clearance. While African American ethnicity [3,25] , HCV genotype 1 [31][32][33] and co-infections with human immunodeficiency virus-1 (HIV-1) [3] , Human T-Lymphotropic Virus-1 [34] and Schistosoma mansoni [35] have been associated with lower HCV RNA clearance and higher HCV RNA levels. Understanding why and how individuals clear HCV is the key to developing new drugs and an effective vaccine [21] .Studies of heroin users from Guangxi Zhuang Autonomous Region in southern China have attributed the appearance and spread of HIV, HCV and other infectious agents to the change in heroin using patterns from smoking to injection [36] . Abstract AIM: To s t u d y t h e v i r o l o g i c a l a n d h o s t fa c t o r s influencing hepatitis C infection outcomes in heroin users in southern China. METHODS:HCV RNA and associated factors were analyzed among 347 heroin users from Guangxi Zhuang Autonomous Region, southern China who were hepatitis C virus (HCV) EIA positive for two or more consecutive visits. RESULTS:Using the COBAS AMPLICOR HCV TEST, a remarkably low HCV RNA negative rate of 8.6% was detected. After multivariate logistic regression analysis, HCV RNA clearance was significantly associated with the presence of HBsAg (OR = 8.436, P < 0.0001), the lack of HIV-1 infection (OR = 0.256, P = 0.038) and age younger than 25 (OR = 0.400, P = 0.029). CONCLUSION:Our study suggests HCV infection among Chinese heroin users results in high levels of viral persistence even amidst factors previously found to enhance viral clearance. Prospective studies of a possible genetic component within the Chinese population and the pathogenicity of non-genotype 1 HCV infections are needed. heroin trafficking routes into the province [37,38] . It is not clear how widespread the HCV epidemic is in China. Little seroprevalence data exists, mostly from the major cities of Beijing, Shanghai and Hong Kong and to our knowledge; no studies on HCV RNA clearance in China have been done. Studies in Yunnan Province, which borders Guangxi Zhuang Autonomous...

Molecular epidemiology of HCV genotypes among injection drug users in Taiwan: Full‐length sequences of two new subtype 6w strains and a recombinant form_2b6w

“…Previously, Piyasirisilp et al [2000] and Tee et al [2008b] reported that both CRF07_BC and CRF08_BC were circulating among intravenous drug users in Baise City, a mountainous region near the Yunnan border of Guangxi Province. In addition, the prevalence of HCV infection among intravenous drug users infected with HIV-1 from Guangxi Province was more than 90% [Garten et al, 2004[Garten et al, , 2008. Although the major HIV subtypes found in the intravenous drug users in Taiwan and Guangxi are different (CRF07_BC in Taiwan and CRF08_BC in Guangxi), the association between the HCV strains from these two areas is very interesting.…”

High Prevalence and Genetic Diversity of HCV among HIV-1 Infected People from Various High-Risk Groups in China

“…HCV positive subjects in China have low viral clearance rates [32]. The high rate of co-infection with HCV among HIV-1-infected patients represents a major challenge for the treatment of HIV-1-infected people in China [10], [33].…”

Exploration of potential mechanisms of hepatitis C virus resistance in exposed uninfected intravenous drug users

“…Conversely, an ineffective early cell-mediated response may result in the development of chronic HCV infection. 24 In SRs, viral clearance is dependent on a complex set of viral-host interactions such as young age 25 ; females respond better than males, 26 host immune response and genetics, neutralizing antibodies, and viral specific factors that include genotypes, and diversity of quasispecies. 27 Partial protective immunity after spontaneous resolution of HCV infection has been reported, with lower rates of HCV reinfection than would be expected in a matched uninfected population.…”