The serum concentration of the third component of complement 131 C / 13 iA in liver disease

Serum C3 (P1C/PIA) has been measured in normal individuals and the range found is in agreement with findings of other authors (85-370 mg/100 ml). In 18 patients with acute hepatitis and massive necrosis serum C3 was consistently reduced to below 50% of normal. In other patients with acute hepatitis the serum C3 concentration was normal. In the majority of the 150 patients with chronic liver disease serum C3 concentration was normal. However, 10 patients (six with active chronic hepatitis, four with cryptogenic cirrhosis) had hypocomplementaemia. The reason for the depression is not clear but could reflect either decreased synthesis or increased consumption, or a combination of the two.