Heparin-induced thrombocytopenia after bone marrow transplantation: report of two cases.

Persistent thrombocytopenia and thrombotic complications are commonly observed in bone marrow transplant (BMT) patients. We describe two incidents following BMT in which heparin may have played a contributory role. One patient developed subclavian venous thrombosis following autologous BMT in spite of the severe thrombocytopenia. The second patient, who received an HLA-matched sibling allogeneic BMT, developed thrombocytopenia after a normal platelet recovery. Because of the clinical evidence and a normocellular bone marrow biopsy result, heparin-induced thrombocytopenia was suspected and heparin was discontinued. In 2 weeks, the patient was transfusion free and her platelet count returned to normal levels. These two cases demonstrate that heparin-induced thrombocytopenia may be responsible for some cases of post-BMT thrombocytopenia and thrombosis.