Aplastic anemia and non-A, non-B hepatitis.

Severe aplastic anemia is a rare but important complication of hepatitis. The agent(s) responsible for the hepatitis in these cases have not been well defined. Sixteen patient with hepatitis-associated aplastic anemia were studied for evidence of recent infection with hepatitis A virus, hepatitis B virus, cytomegalovirus, Epstein-Barr virus, and Toxoplasma. Results were compared with data from 10 randomly selected patients with aplastic anemia unassociated with hepatitis. Of the 16 patients, recent acute hepatitis A infection could be excluded in at least 14 patients. Hepatitis B surface antigen (HBsAg) was present in only one patient. A diagnosis of recent hepatitis B infection could not be excluded with confidence in two others. Tests for cytomegalovirus, Epstein-Barr virus, and Toxoplasma gave negative results. No patient with aplasia unassociated with hepatitis had evidence of recent hepatitis A infection, and the frequency of hepatitis B antibodies in this group was indistinguishable from that in patients with hepatitis. These data indicate that most cases of hepatitis that preceded aplastic anemia were not caused by hepatitis A virus or hepatitis B virus; non-A, non-B agents were probably involved in at least 13 of the 16 cases studied.