Immune responses in patients with obstructive jaundice of infancy. Anti-LSP and Clq binding in sera

To investigate possible involvement of immune responses in the pathogenesis of obstructive jaundice in infancy we measured antibody to liver specific lipoprotein (LSP) by radio immunoassay and immune complexes by their ability to bind C1q in sera from 16 patients with extrahepatic biliary atresia and 16 with neonatal hepatitis and 13 age matched controls. Anti-LSP was present in 6 of 16 with preoperative biliary atresia and 6 of 16 with hepatitis. Mean percentage C1q bound was higher in hepatitis (22 SD 15%) than preoperative biliary atresia (11.1 SD 2.3%). Nine of 16 hepatitis patients had elevated C1q binding as compared with 1 of 16 with biliary atresia. The highest value for anti-LSP and C1q binding were found in sera from patients with histologically severe hepatitis and hepatitis associated with specific viral or bacterial causes. Anti-LSP was significantly raised 5 months post-operatively in all of 6 patients with biliary atresia and poor biliary drainage but only 2 of 5 survivors. Elevated C1q binding was detected in 6 of 7 with poor drainage and 1 of 7 survivors at the same stage. Anti-LSP and C1q binding fell in 4 patients with neonatal hepatitis on recovery. These findings suggest that immunological mechanisms, possibly involving antibody to hepatocyte membrane components and immune complexes, may be involved in the pathogenesis of progressive liver disease in biliary atresia.