UCLA

Background

The probability of spontaneous hepatitis C virus (HCV) clearance ranges from 11% to 49%. Our previous cross-sectional study suggests that mode of acquisition explains some of this heterogeneity. We performed this prospective study to determine factors associated with spontaneous HCV clearance among men who have sex with men (MSM).

Methods

A mixture-cure model was used to evaluate the probability of spontaneous HCV clearance among 101 MSM in the Multicenter AIDS Cohort Study with acute HCV infection between 1984 and 2012.

Results

Spontaneous HCV clearance occurred in 46% of MSM (49% in non-injection drug users [IDUs] and 23% in IDUs). In the multivariable analysis, age <30 years (clearance ratio [CR] = 2.43; 95% confidence interval [CI], 1.53-3.87) and being human immunodeficiency virus (HIV) uninfected (CR = 2.97; 95% CI, 1.98-4.46) were independently associated with spontaneous clearance. Among men aged ≥30 years, being HIV uninfected, not having unprotected anal intercourse, older age, and being on highly active antiretroviral therapy were independently associated with higher clearance. The interferon lambda rs12979860 single nucleotide polymorphism (SNP) was not associated with spontaneous clearance among the 88 MSM who were not active IDUs (CR = 0.74; 95% CI, .46-1.21 for CC vs CT/TT genotype).

Conclusions

The high probability of spontaneous HCV clearance together with the lack of an association between the rs12979860 SNP and spontaneous clearance among MSM who do not use injection drugs suggests that the immune mechanisms involved with a successful response to acute HCV differ by mode of virus acquisition. Understanding potential mechanistic differences could be important for HCV vaccine development.