First Case of Immune-mediated Haemolytic Anaemia Associated to Imatinib Mesylate

Imatinib mesylate is a specific inhibitor of protein tyrosine kinase activity secondary to bcr-abl, mostly indicated for the treatment of patients with Philadelphia chromosome positive chronic myeloid leukaemia (CML). Generally, the undesirable effects of imatinib administration observed in clinical trials were of mild-to-moderate degree, and no haemolysis has been associated with this drug. We report here a case of immune-mediated haemolytic anaemia associated to imatinib mesylate successfully treated with prednisone in a patient with CML. Laboratory investigation showed anaemia [haemoglobin (Hb) of 59 g/L], reticulocyte of 61 x 10(9)/L and a positive direct antiglobulin test. Anti-drug in vitro studies revealed a positive result with gel microcolumn assay by an adsorption mechanism. Seventy-four days after prednisone therapy, the patient's Hb level was of 110 g/L with negative direct antiglobulin test and drug in vitro studies. This case demonstrated that patients treated with imatinib mesylate can present immune-mediated haemolysis and adequate management of this event can be done maintaining the drug and associating corticosteroids.