Immune‐mediated pancytopenia induced by oxaliplatin: a case report

BACKGROUND: Drug‐induced immune pancytopenia is considered an uncommon disorder. CASE REPORT: A 76‐year‐old woman with metastatic gastric adenocarcinoma received 15 cycles of FOLFOX‐6 (oxaliplatin/folinic acid/fluorouracil) with a complete response. Upon disease progression, she was restarted on FOLFOX; during the seventh cycle of treatment, 1 hour after completing her oxaliplatin infusion, she presented oral bleeding, petechiae and generalized hematomas. Her platelet (PLT) count decreased from 164 × 10 9 /L to less than 5 × 10 9 /L within a 3‐hour period and her white blood cells (WBCs) decreased from 5 × 10 9 to 1.5 × 10 9 /L. One day later she presented a decrease in hemoglobin level (from 11.4 to 10 g/dL, reaching 8.9 g/dL after 5 days). The patient's PLT and lymphocyte count started to recover after 3 days of immunosuppressive treatment. STUDY DESIGN AND METHODS: PLT, red blood cell (RBC), and WBC antibody detection tests were performed in the presence and absence of oxaliplatin. PLT‐associated antibodies were evaluated by monoclonal antibody immobilization of PLT antigen assay and flow cytometry; WBC antibodies were tested by flow cytometry; and RBC antibodies were evaluated by gel and indirect antiglobulin test tube testing drug‐treated RBCs and untreated RBCs in the presence of drug. RESULTS: Positive reactions were obtained only in the presence of the drug (1 mg/mL) for all tests performed (PLTs, RBCs, and WBCs). CONCLUSIONS: Our case convincingly demonstrates that oxaliplatin led to the production of drug‐dependent PLT, RBC, and WBC antibodies inducing pancytopenia in the patient. The oxaliplatin was discontinued and patient's hematologic values recovered to normal levels.