Abstract

WEAX0105 - Oral Abstract Session

HLAB57 does not fully explain the ability of HIV controllers to spontaneously clear hepatitis C virus (HCV) infection

Presented by Alice Asher (United States).

A. Asher^1,2, G.-M. Santos¹, E.K. Dokubo³, J. Martin⁴, S. Deeks⁴, L. Tobler⁵, M. Busch⁵, P. Hunt⁴, K. Page<sup>1

1</sup>University of California San Francisco, Epidemiology & Biostatistics, San Francisco, United States, ²University of California San Francisco School of Nursing, Community Health Systems, San Francisco, United States, ³University of California San Francisco, Center for AIDS Prevention Studies, San Francisco, United States, ⁴University of California San Francisco, Positive Health Program, San Francisco, United States, ⁵Blood Systems Research Institute, San Francisco, United States

Background: HIV controllers, maintaining low plasma HIV RNA levels (< 2000 copies/ml) in the absence of antiretroviral therapy, are also more likely to spontaneously clear HCV infection. HLAB57, the major histocompatibility class I gene, is highly enriched in HIV controllers and is associated with HCV spontaneous clearance. Whether HLAB57 explains the increased prevalence of spontaneous HCV clearance observed in HIV controllers remains unclear.
Methods: Patients in the Study of the Consequences of Protease Inhibitor Era (SCOPE) were tested for anti-HCV using enzyme immunoassay (EIA3) and HCV RNA using discriminatory HCV transcription-mediated amplification assay (Norvatis^®). We compared the proportion of HIV controllers and HIV non-controllers with serological evidence of HCV clearance (anti-HCV+/RNA-) by chi-square tests and assessed whether HLAB57 status explains the increased prevalence of HCV clearance in HIV controllers using adjusted prevalence ratio (APR) with Poisson regression models.
Results: Of 279 HIV/HCV seropositive subjects, 48 were HIV controllers. HIV controllers were significantly more likely to have evidence of spontaneous HCV clearance than HIV non-controllers (58% vs. 38%, p=0.01). While HIV controllers were more likely to have HLAB57 than HIV non-controllers, (33% vs. 10%, p< 0.01), HLAB57 was not significantly associated with HCV clearance among all participants (39% vs. 55% p=0.06), and there was no evidence of increased prevalence of HCV clearance among HLAB57+ vs. HLAB57- in HIV controllers (p=0.83). In multivariate analyses adjusted for HLAB57, age, gender, and race/ethnicity, HCV clearance was significantly more likely in HIV controllers than HIV non-controllers (APR 1.44; 95% CI 1.04-2.0; p=0.026).
Conclusions: HIV controllers are more likely to spontaneously clear HCV than HIV-non-controllers even when controlling for HLAB57 status. Immunologic factors other than HLAB57 must contribute to the control of HIV and HCV in HIV controllers. Identifying these factors may support the development of novel treatments for and effective vaccines against both viruses.