Complement studies in severe viral hepatitis of childhood.

Complement (C) and C components were studied in 18 children with severe viral hepatitis. Results were compared to similar determinations performed in 8 patients with toxic hepatitis related to the ingestion of Amanita Phalloïdes. Hemolytic activities and serum concentrations of C and C components were markedly decreased (less than 2 SD) in both groups of patients. Sequential determinations of C components showed different patterns according to the outcome: either a rapid return to normal in patients who healed or persistence of low levels in patients who died. Such a pattern was similar to that of the prothrombin time. In patients with viral hepatitis a rapid disappearance of C4 and C3 was observed following fresh plasma or fresh blood transfusion. In addition, C4 cleavage was shown in plasma of 8/8 patients. These data suggest that the complement depression observed in fulminant viral hepatitis is related to both consumption and deficient synthesis.