Acute non-A, non-B hepatitis--clinical, epidemiological and histological characteristics.

Among 73 consecutive patients with biopsy documented acute non-toxic hepatitis, half of the patients (49%) had acute type B hepatitis, while 27 patients (37%) had acute type A infection. One patient had a significant rise in antibodies against cytomegalovirus. The remaining 10 patients (14%) fulfilled the criteria of hepatitis type non-A, non-B. The main type of exposure for hepatitis A was visit to endemic hepatitis areas (41%), and for type B it was drug addiction (46%). Half of the patients with hepatitis non-A, non-B had no known hepatitis exposure while some had visited endemic hepatitis areas or were drug addicts. The patients with non-A, non-B hepatitis had significantly less biochemical changes as compared to the patients with hepatitis B. In contrast, the histological findings showed the greatest activity in the biopsies from patients with hepatitis B and non-A, non-B. Follow-up liver biopsies in half of the patients with non-A, non-B hepatitis showed no signs of chronic active liver disease. It is concluded that hepatitis type non-A, non-B is a significant problem in Denmark.