Researchers evaluated the incidence of spontaneous clearance among 632 patients with acute HCV infection during a median follow-up of 0.63 years to 9.42 years across nine international cohorts.
Spontaneous clearance was defined as two consecutive test results, 4 or more weeks apart, indicating undetectable HCV RNA levels. Forty-nine percent of 542 patients with evaluable genotype data had IL28B CC genotype, while 55% of 537 evaluable patients were infected with HCV genotype 1.
During follow-up, spontaneous clearance occurred in 173 participants with 25% of the full cohort having cleared the virus at 1 year after infection. Clearance occurred within a median of 16.5 weeks, in 34% of patients at 3 months, 67% at 6 months and 83% at 12 months.
Factors associated with time to spontaneous clearance included IL28B CC genotype (adjusted HR=2.26; 95% CI, 1.52-3.34 vs. CT/TT genotypes), female sex (aHR=2.16; 95% CI, 1.48-3.18) and HCV genotype 1 (aHR=1.56; 95% CI, 1.06-2.3).
Investigators said associations with IL28B CC and HCV genotypes were more pronounced and had the highest clearance rates in females with IL28B CC genotype and HCV genotype 1. IL28B CC (aHR=2.89; 95% CI, 1.6-5.22) and HCV genotype 1 (aHR=1.78; 95% CI, 1-3.17) were independently predictive of clearance among females, while only IL28B CC genotype was among males (aHR=1.79; 95% CI, 1.05-3.06).
