Characterization of Incident Hepatitis C Virus Infection among People Living with HIV in a HIV Clinic in Korea

Background: Coinfection with human immunodeficiency virus (HIV) and hepatitis C virus (HCV) can cause more rapid progression to cirrhosis than HCV-monoinfection. In this study, incident HCV case (IHCV)s were investigated in a HIV clinic in Korea.

Materials and methods: A retrospective HIV cohort was constructed who visited National Medical Center in Korea from 2013 to 2022 and performed ≥ 1 anti-HCV antibody tests (anti-HCV) during the study period. IHCV was defined as newly confirmed HCV infection by PCR with a prior negative anti-HCV and factors associated with IHCV were investigated among alanine aminotransferase (ALT) >150 IU/mL sub-cohort without plausible reasons for ALT elevation.

Results: Overall, 2,567 HIV clinic visitors were recruited during the study period and 42 (1.63%) were confirmed as HIV/HCV co-infection. Fifteen IHCVs were identified during the study period. While no IHCV was observed in 2013-2015, incidence of 2016-2019 and 2020-2022 were 0.84 and 1.48 per 1000 person-year, respectively. Subtype 1a were more common among IHCVs in 2020-2022 (8/9) while subtype 2 dominated in 2016-2019 (5/6, P=0.003). Most IHCVs were identified during the evaluation of de novo liver enzyme elevation which was identified through the regularly performed blood tests (86.7%, 13/15). Comparing twelve IHCVs with ALT>150 IU/mL with 58 HIV mono-infection comparators whose peak ALT exceeded 150 IU/mL during the study period, age, sex, HIV/HCV infection risk factor, CD4 cell count, and HIV-RNA viral load were not different between two groups. However, mean peak ALT of IHCVs was higher than comparators (776 vs. 237, P<0.001) and syphilis treatment within prior 24 months of ALT elevation was more common in IHCV group (41.7% vs. 12.7%, P=0.026).

Conclusion: Incidence rate of HCV among PLH revealed increasing trend between 2013 and 2022 among visitors at a HIV clinic in Korea. Subtype 1a dominated among IHCVs after 2020 and recent syphilis treatment was associated with IHCVs.