Trigger factors and HL-A antigens in chronic active hepatitis.

Forty-six patients with histologically verified chronic active hepatitis (CAH) were divided into three groups according to whether the CAH was virus-induced, drug-induced, or cryptogenic. The frequency of the HL-A antigens 1 and 8 was increased in the cryptogenic group while the other groups did not differ significantly from healthy controls. Autoantibodies were often found in high titres in the drug-induced and cryptogenic groups but were infrequent in the virus-induced group.