Negative serology for hepatitis A and B viruses in 18 cases of neonatal cholestasis.

Serologic evidence of hepatitis A virus (HAV) or hepatitis B virus (HBV) infection was sought in 14 patients with biliary atresia and in four patients with neonatal hepatitis; maternal serum was also analyzed. Specific sensitive radioimmunoassays were used to detect HBV surface antigen (HBsAg) and antibody (anti-HBs); complement fixation was used to detect antibody to HBV core antigen (anti-HBc). Antibody to HAV (anti-HAV) was assayed by radioimmunoassay, as well as by immune adherence hemagglutination. There was no evidence of active or past HBV infection in any infant or mother studied. All three infants with detectable anti-HAV were born to mothers similarly anti-HAV positive; serial testing of sera from two of these infants documented disappearance of detectable anti-HAV by 9 months of age. It is unlikely, therefore, that either HAV or HBV had an etiologic role in neonatal cholestasis in these patients. The role of other (non-A, non-B) hepatitis viruses or nonviral etiologies must be investigated.