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 x 10(9)/L to less than 5 x 10(9)/L within a 3-hour period and her white blood cells (WBCs) decreased from 5 x 10(9) to 1.5 x 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.