Case Report: Oxaliplatin-Induced Immune-Mediated Thrombocytopenia.

Thrombocytopenia is a frequent complication of cancer may be due to a variety of causes including malignancy itself, acute disease processes, or cancer therapy. Systemic cancer therapy is the most common cause of thrombocytopenia in cancer patients observed nearly two-thirds of patients with solid tumors. Thrombocytopenia with traditional chemotherapy agents is most frequently the result of megakaryocyte cytotoxicity. Oxaliplatin is a platinum derivative commonly used in gastrointestinal malignancies and is associated with drug-induced immune thrombocytopenia.

Case Presentation

A 36 year-old woman with Her-2 negative metastatic gastric adenocarcinoma currently on capecitabine and oxaliplatin presented for oxaliplatin infusion. Laboratory testing one day prior showed a platelet count of 237 × 109 and ahemoglobin of 10.9 g/dL with an MCV of 81.9 attributed to iron deficiency anemia, She had previously received 5-fluorouracil/leucovorin/oxaliplatin for 14 months and then was switched to single agent capecitabine for 2 months in the setting of stable disease. At progression of disease, oxaliplatin was added to capecitabine, which the patient had been on for the past 9 months.

Thirty minutes after the oxaliplatin infusion was started, the patient developed significant bleeding from her gums, epistaxis, and had 150 to 200 mL of bloody oral secretions. Laboratory testing showed a platelet count of < 5 × 109, white blood cell count of 2.6 × 109, hemoglobin 6.2 g/dL, PT 16.4, INR 1.4, total bilirubin 0.5 mg/dL, LDH 211 U/L. Peripheral smear showed few platelets and no schistocytes. The patient was admitted and received intravenous immunoglobulin 1 g/kg, dexamethasone 40 mg IV for 4 days, and oral aminocaproic acid, with resolution of bleeding after one day. No platelet transfusions were given. She received 1 unit of packed red blood cells. The platelet count improved to 77 × 109 after 4 days and normalized to 341 × 109 one month later. Oxaliplatin was definitively discontinued.

Discussion

Although myelosuppression is the most common cause of thrombocytopenia in cancer patients receiving oxaliplatin, there are several other recognized mechanisms of oxaliplatin-induced thrombocytopenia [1, 2, 3, 4, 5]. With myelosuppression, thrombocytopenia is usually asymptomatic and is accompanied by anemia and neutropenia [6]. Management includes observation and the occasional need for dose reductions or delays [7]. Oxaliplatin-induced ITP is a well-recognized but uncommon etiology of thrombocytopenia. The mechanism is platelet destruction mediated by oxaliplatin-dependent antibodies to platelet antigens, leading to a sudden drop in platelet count to < 10 × 109 and bleeding manifestations within several hours of oxaliplatin infusion. This typically occurs after > 12 cycles of oxaliplatin and may be preceded by hypersensitivity reaction [7, 8]. Management includes platelet transfusion, corticosteroid therapy, and IV immunoglobulin therapy with resolution of thrombocytopenia within approximately 2 weeks. Definitive discontinuation of oxaliplatin is recommended [1, 9, 10].

Statement of Ethics

The authors have no ethical conflicts to disclose

Disclosure Statement

The authors have no conflicts of interest to declare.