Belated diagnosis in three patients with rifampicin-induced immune haemolytic anaemia.

We report three patients who developed haemolysis following rifampicin treatment. Initially, autoimmune haemolytic anaemia (AIHA) of the warm type and/or an acute haemolytic transfusion reaction (AHTR) was suggested. The direct antiglobulin tests (DAT) were strongly positive for IgG and C3d, and tests for rifampicin-dependent antibodies were positive in all three cases, featuring C-specificity in one case. The outcome was fatal in two out of the three cases, presumably due to belated diagnosis. This shows that rifampicin may stimulate the production of autoantibodies (aab) and/or drug-dependent antibodies (ddab), and that the resulting haemolytic syndrome bears similarities with AIHA and AHTR.