Yeast opsonisation and complement in children with liver disease. Analysis of 69 cases

Opsonisation of heat-killed bakers yeast and C3 and C4 concentrations were determined in sera from 69 children with liver disease and 39 controls as simple screening procedures for abnormalities in the complement system. Where significant defects in these moieties were encountered, the activity of the following was measured: total haemolytic complement, C4, C5, total alternative pathway, factor B and D activities were measured. Complement activation was detected by the presence of C3d in EDTA plasma samples. Yeast opsonisation, C3 and C4 concentrations and activities of all complement components measured were significantly (P less than 0.001) reduced in all of 10 children with fulminant hepatic failure (FHF) and six with chronic active hepatitis (CAH). There was no consistent relationship between complement deficiency and standard tests of liver function. C3 breakdown products were identified in plasma from five patients with CAH and complement deficiency but not in three patients with complement deficiencies associated with FHF. Complement concentration and activity improved in children recovering from FHF and in CAH treated by immunosuppressants. Yeast opsonisation index was raised significantly without parallel increase in C3 or C4 concentration in eight of nine children with biliary atresia before surgery and 11 of 13 with alpha-1-antitrypsin deficiency regardless of age or the presence of active liver disease. Yeast opsonisation indices became normal after successful surgery in patients with biliary atresia.