A case of oxaliplatin-induced immune-mediated thrombocytopenia
A 53-year-old man with type 2 diabetes mellitus and hypertension was diagnosed with stage IIIB transverse colon cancer in February 2011. He underwent a right hemicolectomy and subsequently received 10 cycles of adjuvant chemotherapy with oxaliplatin and 24-hour infusions of fluorouracil (5FU) and leucovorin (FOLFOX). Before starting the 11th FOLFOX cycle, a complete blood count (CBC) showed the following values: neutrophils, 3.38×109/L, platelets, 113×109/L, and hemoglobin, 14.8 g/dL. During the 11th FOLFOX cycle, he experienced mild fever (37.6℃) and pain in his injected arm. Gum bleeding and petechiae on his legs also developed. The CBC showed: platelets, 3×109/L, neutrophils, 4.18×109/L, and hemoglobin, 13.8 g/dL. The patient's prothrombin time (PT, 10.5 seconds) and activated partial thromboplastin time (APTT, 25.5 seconds) were within normal range. There were no relevant abnormalities in total bilirubin, aminotransferase, blood urea nitrogen (BUN), creatinine and complement factors (C3 and C4). He was hospitalized and treated with platelet transfusion, immunoglobulin 55 g/day for 2 days and corticosteroids. His platelet count recovered to 83×109/L, and his gum bleeding and petechiae resolved (). The liver and spleen were not palpable. Human immunodeficiency virus testing, hepatitis B and C screening, viral marker of Epstein-Barr virus early antigen (EBV-EA) IgM and cytomegalovirus (CMV) antigen (Ag), antinuclear antibody analysis and thyroid function tests were all negative. The results of bone marrow aspiration and biopsy were unremarkable. Because all other causes of thrombocytopenia were excluded, we concluded that oxaliplatin was the only cause of his thrombocytopenia. He was discharged with oral prednisone, and his platelet count recovered completely without further treatment in 2 months.