Rifampicin-induced immune thrombocytopenia.

Rifampicin-induced thrombocytopenia is reported in three patients with pulmonary tuberculosis. All three patients gave a definite history of having had prior exposure to rifampicin. Immunological studies in all three patients showed the presence of antiplatelet antibodies, resulting in thrombocytopenia. Moreover, binding of these antibodies to the platelet membrane was more avid in the presence of rifampicin, thereby implicating the drug. The avidity of the rifampicin-dependent antibodies was demonstrated by platelet aggregation inhibition test, and estimation of the rifampicin-dependent antibody was done by studying the platelet-associated immunoglobulin [PAlgG] by ELISA which was also used to quantitate antiplatelet antibodies. Immunofluorescence test was also performed to detect antiplatelet antibodies.