Thrombotic thrombocytopenic purpura-like syndromes following bone marrow transplantation: an analysis of associated conditions and clinical outcomes

The diagnosis acid treatment of thrombotic thrombocytopenic purpura (TTP) i n patients following BMT are often uncertain and unsuccessful. To better un derstand the evaluation and management of these patients, we describe 17 pa tients treated with plasma exchange for a presumptive diagnosis of TTP foll owing BMT during a 10 year period, 1989-1998, Because of the uncertainty of the diagnosis, these patients are described as having a 'TTP-like syndrome '. All 17 patients had received an allogeneic BMT, Comparison with the othe r 245 patients who had an allogeneic BR IT during the same period demonstra ted that patients with a TTP-like syndrome more frequently had unrelated an d/or HLA-mismatched donors, and had also experienced more serious complicat ions: grade III-IV acute GVHD and systemic bacterial, fungal, and viral inf ections. Three months after the diagnosis of the TTP-like syndrome, only fo ur of 17 patients (24%) were alive; currently only one patient survives. Th ese data emphasize: (1) the diagnosis of TTP following BMT is uncertain bec ause of the presence of multiple BMT-associated complications. (2) The outc ome of patients with TTP-like syndromes following BMT is poor. (3) Urgent i ntervention with plasma exchange when TTP is suspected following BMT may no t always be appropriate. Alternative explanations for the signs and symptom s should be considered and treated aggressively.