Natural history of hepatitis C virus infection in a large national seroconversion cohort in the direct-acting antiviral agent era: Results from ERCHIVES.

Hepatitis C virus (HCV) natural history studies are limited by not knowing the time of infection, small numbers and non-representative populations. No studies are available from the direct-acting antiviral agents (DAA) era. We created the largest known cohort of persons with HCV with a known window of seroconversion in the DAA era. We compared the annual cumulative incident events and incidence rate/1000 person-years of follow-up for liver cirrhosis, hepatic decompensation, hepatocellular carcinoma (HCC) and mortality from the time of seroconversion among untreated and those treated and attaining a sustained virologic response (SVR). Among 12,881 persons in the final analyses, 10,417 had never been treated for HCV, 2464 (23.6%) were treated with a DAA regimen and 1836 (74.5%) attained SVR. After 9 years of follow-up, cirrhosis was diagnosed in 17.4% of untreated and 13.6% of the SVR group. Overall, 29.5% in the untreated versus 3.5% in the SVR group died. Incidence rates/1000 person-years of follow-up (95% CI) for untreated versus SVR group were 22.7 (21.6, 23.9) versus 19.5 (17.0, 21.9) for cirrhosis (p = 0.03), 0.1 (0.03, 0.2) versus 0.07 (-0.07, 0.2) for HCC (p = 0.74) and 35.4 (34.0, 36.8) versus 4.53 (3.4, 5.7) for mortality (p < 0.0001). After excluding those with alcohol-related diagnoses at baseline, the difference in cirrhosis was not statistically significant. Cirrhosis and mortality occur early and steadily increase over the first decade after acquiring HCV infection, while HCC is rarely observed. Those treated with a DAA regimen have sharply lower cirrhosis and mortality rates, particularly among those without alcohol abuse or dependence.