[Drug-induced immune thrombocytopenia: When both oxaliplatin and methylprednisolone are the culprits].

Abstract

Introduction: Drug-induced immune thrombocytopenia (DIIT) is a rare cause of immune thrombocytopenia, characterized by the formation of drug-dependent antiplatelet antibodies. DIIT can lead to life-threatening hemorrhage. The diagnosis is difficult, relying on the detection of antiplatelet antibodies in patient's serum exclusively in the presence of the implicated drug. The gold standard test is the monoclonal antibody immobilization of platelet antigens (MAIPA), although other techniques (flow cytometry and Luminex®) can be used.

Patients: We report two cases of DIIT induced by both oxaliplatin and methylprednisolone.

Results: The two patients were undergoing chemotherapy for colon malignancy, receiving a regimen including oxaliplatin following premedication with methylprednisolone. Thrombocytopenia occurred within hours after one infusion (both patients had received prior courses with this regimen). Immunological tests for both patients revealed antiplatelet antibodies in the presence of oxaliplatin (anti-GPIIbIIIa in the first observation, and polytypic in the second one) and methylprednisolone (anti-GPIbV in the first observation and GPIIbIIIa in the second one). After the discontinuation of the implicated drugs (and treatment with prednisone plus intravenous immunoglobulin for the first patient), both patients showed rapid improvement in a few days. Both patients continued chemotherapy without oxaliplatin and methylprednisolone. No relapse was observed during the follow up.

Conclusion: DIIT are a rare cause of secondary immune thrombocytopenia. Diagnosis is complex, and the detection of drug-dependent antiplatelet antibodies in reference laboratories is essential. Oxaliplatin is a classical cause of DIIT. However, associated drugs like methylprednisolone can also be responsible for DIIT.