Correlates of Spontaneous Clearance of Hepatitis C Virus among HIV-Infected Persons with Hemophilia.

Up to the late 1980s, hepatitis C virus (HCV) infected the majority of people with hemophilia (PWH) in the United States (US), via contaminated plasma clotting factor therapy. Approximately two-thirds of the HCV-infected PWH in the US also were infected with human immunodeficiency virus (HIV). The Second Multicenter Hemophilia Cohort Study (MHCS-II) investigated complications of HCV and HIV infections in people with hemophilia. From 2001 - 2005, data and specimens were collected from 2561 anti-HCV positive participants, including 763 who were co-infected with HIV. These data were analyzed for correlates of spontaneous HCV clearance.

Results. Of the 763 HIV-positive, anti-HCV-positive participants, 285 were eliminated from the analysis because they had received interferon treatment to clear HCV, lacked HCV treatment data, or lacked sufficient specimens to determine HCV clearance status. Of the remaining 478 interferon-untreated participants, 61 (12.8%) had cleared HCV RNA from plasma. HCV had cleared in 8.6% of the 116 who were never infected with hepatitis B virus (HBV), 11.6% of 207 with resolved HBV infection, and 8.9% of 124 with missing HBV status (P≥ 0.41). In contrast, HCV had cleared in 16 (51.6%) of the 31 participants with chronic HBV surface antigen (HBsAg) in serum. Adjusted for gender and race, HCV clearance was increased 7.4-fold (95% CI 3.7 - 15.0) for those with chronic HBsAg. In the HBsAg negative group, HCV clearance was significantly lower among participants of African ancestry (1.6%, p=0.01) and was significantly lower in PWH with severe compared to mild or moderate coagulopathy (8.2% vs 15.9%, p=0.02). Clearance was unrelated to type of initial clotting factor replacement therapy, year of birth, year of primary HCV infection, age at primary HCV infection, age at HIV infection, and year of enrollment in the cohort. HCV clearance occurred in 2 (12.5%) of the 14 participants in whom primary HCV infection occurred after or within one year of HIV infection, compared to 9.1% when HCV infection occurred more than one year before HIV (p=0.65). HCV clearance was unrelated to CD4 count at cohort enrollment, history of immunologically or clinically defined AIDS, and detection of HIV RNA in plasma at cohort enrollment. HCV clearance tended to be higher among the 231 participants on HAART (12.6%) than in those on less intensive (9.1%), anomalous (6.7%) or no anti-HIV therapy (6.5%, P_trend=0.07), although when restricted to non-African ancestry males, HIV therapy was not associated with clearance (P_trend=0.26).

Conclusion. Unlike in HIV-negative people with hemophilia, HCV clearance in the current study was unrelated to age at or year of primary HCV infection. We were unable to evaluate repeated exposure to and likely re-infection with HCV, although the lower clearance in patients with severe hemophilia, who would have been treated, and thus exposed more frequently, supports the hypothesis of lower clearance with re-infection. While reduced overall, spontaneous HCV clearance was markedly increased by the presence of chronic HBsAg carriage. These findings will increase our understanding of interactions between these viruses and may lead to improved approaches to treatment of co-infected patients.