[Dihydralazine-induced acute hepatitis with IgM deficiency].

Two patients with IgM-deficiency developed acute, recurrent HB3-Ag negative hepatitis with bridging necrosis following ingestion of low daily doses of dihydralazine. The association between the drug and the liver disease appears probable, as recurrence of hepatitis followed each exposure. One patient developed high titers of antimitochondrial antibodies and the other low titers of antibodies against smooth muscles. The relationship between IgM-deficiency and dihydralazine hepatitis is not clear. Investigation of patients with IgM-deficiency for drug hypersensitivity and liver disease may provide additional information.