Natural history of vertically acquired HCV infection and associated autoimmune phenomena.

The natural history of vertically acquired HCV infection is ill defined. The aim of this study was to outline the natural course of vertical HCV infection in a cohort of untreated children, including rate of spontaneous viral clearance, frequency and features of HCV-related autoimmune disorders. Children with vertical HCV infection were prospectively followed from the first month of life with regular clinical and laboratory assessments. Statistical analysis was performed using Prism 5.0. Forty-five children (median age 12 years, interquartile range 6.9-15.5) were studied. Genotype 1 was predominant (53.3 %). Spontaneous viral clearance was achieved by 12 patients (26.7 %) and associated with genotype 3. Alanine-amino-transferase levels were increased in most children in the first 2 years of life with higher values in those who later cleared the infection. All children were asymptomatic for liver disease. Transient elastography (32 patients) showed mild or moderate fibrosis in nine and two cases, respectively. Non-organ-specific autoantibodies were detected in 24 children (53.3 %) independently of viremia; of these, one developed type-1 diabetes. Cryoglobulinemia was associated with genotype 1 infection and found in 15 subjects (33.3 %): two had low C4 levels and persistent proteinuria. Conclusions: Vertically acquired HCV infection may result in spontaneous clearance in up to 27 % of children. Resolution of infection is higher with genotype 3, usually occurs in preschool age and persists over time. Chronic infection is generally asymptomatic, although hepatomegaly and mild fibrosis may develop. Autoantibodies and cryoglobulins are frequent, whereas the associated clinical manifestations are rare.