Risk Factors for Hepatitis C Virus Reinfection After Sustained Virologic Response in Patients Coinfected With HIV

Abstract

Background: Highly effective hepatitis C virus (HCV) therapies have spurred a scale-up of treatment to populations at greater risk of reinfection after sustained virologic response (SVR). Reinfection may be higher in HIV-HCV coinfection, but prior studies have considered small selected populations. We assessed risk factors for reinfection after SVR in a representative cohort of Canadian coinfected patients in clinical care.

Methods: All patients achieving SVR after HCV treatment were followed with HCV RNA measurements every 6 months in a prospective cohort study. We used Bayesian Cox regression to estimate reinfection rates according to patient reported injection drug use (IDU) and sexual activity among men who have sex with men (MSM).

Results: Of 497 patients treated for HCV, 257 achieved SVR and had at least 1 subsequent RNA measurement. During 589 person-years of follow-up (PYFU) after SVR, 18 (7%) became HCV RNA positive. The adjusted reinfection rate (per 1000 PYFU) in the first year after SVR was highest in those who reported high-frequency IDU (58; 95% credible interval [CrI], 18-134) followed by MSM reporting high-risk sexual activity (26; 95% CrI, 6-66) and low-frequency IDU (22; 95% CrI, 4-68). The rate in low-risk MSM (16; 95% CrI, 4-38) was similar to that in reference patients (10; 95% CrI, 4-20). Reinfection rates did not diminish with time.

Conclusions: HCV reinfection rates varied according to risk. Measures are needed to reduce risk behaviors and increase monitoring in high-risk IDU and MSM if HCV elimination targets are to be realized.

Keywords: HIV; hepatitis C virus; reinfection; sustained virologic response; hepatitis C treatment.

Figure 1.

Patient flow diagram. As of July 2016, 497 coinfected patients initiated hepatitis C virus (HCV) treatment, of whom 319 achieved sustained virologic response (SVR). Of these, 257 patients had at least 1 post-SVR HCV RNA measurement available and were included in the analysis. Patients excluded from the analysis (n = 62) were older (median age 52 years), more likely to be Aboriginal (15%), and less likely to be former (65%) or current (8%) injection drug users than those included. Abbreviations: HCV, hepatitis C virus; SVR, sustained virologic response.

Figure 2.

Hepatitis C reinfection rates and 95% credible intervals per 1000 person-years for up to 1 year, 1 to 3 years, and more than 3 years after a sustained virologic response (Canadian Co-infection Cohort, n = 257). Reference patients are those with no risk factors. Abbreviations: HCV, hepatitis C virus; IDU, injection drug use; MSM, men who have sex with men.