Prospective Follow-Up of Patients with Acute Hepatitis C Virus Infection in Brazil

Background. The natural outcome of infection with hepatitis C virus (HCV) varies substantially among individuals. However, little is known about host and viral factors associated with a self-limiting or chronic evolution of HCV infection. Methods. From 1 January 2001 through 31 December 2008, a consecutive series of 65 patients from Rio de Janeiro, Brazil, with a well-documented diagnosis of acute HCV infection, acquired via various routes, were enrolled in this study. Patients were prospectively followed up for a median of 40 months after the estimated date of HCV infection with serial measurements of serum alanine aminotransferase, HCV RNA, and anti-HCV antibodies. Spontaneous viral clearance (SVC) was defined as undetectable levels of HCV RNA in serum, in the absence of treatment, for 3 consecutive HCV polymerase chain reaction tests within the first 6 months of follow-up. Cox proportional hazards regression was used to identify host and viral predictors of SVC. Results. The cumulative rate of SVC was 44.6% (95% confidence interval, 32.3%–57.5%). Compared with chronic HCV evolution, patients with self-limiting disease had significantly lower peak levels of anti-HCV antibodies (median, 109.0 vs 86.7 optical density-to-cutoff ratio [od/co]; P < .02), experienced disease symptoms more frequently (69.4% vs 100%; P < .001), and had lower viral load at first clinical presentation (median, 4.3 vs 0.0 log copies; P = .01). In multivariate analyses, low peak anti-HCV level (