Coagulation abnormalities and thrombotic microangiopathy following bone marrow transplantation from HLA-matched unrelated donors in patients with hematological malignancies.

Thrombotic microangiopathy is a well-known heterogeneous disorder that occurs as a complication of allogenic bone marrow transplantation (BMT). We evaluated 12 consecutive patients receiving HLA-matched unrelated BMT and 12 consecutive recipients of HLA-identical related BMT for the development of bone marrow transplantation-associated thrombotic microangiopathy (BMT-TM) on days 30 and 60 following BMT. A diagnosis was made in four of 12 (33.3%) unrelated compared to none of 12 (0%) HLA-identical cases. Levels of serum lactic dehydrogenase (LDH), fibrin degraded products (FDP) and de novo thrombocytopenia were elevated in eight of 12 patients (66.7%) receiving unrelated donor BMT, and none of the patients receiving related donor BMT. Our findings suggest clinical or subclinical microangiopathic changes may occur frequently in unrelated donor BMT. FDP elevation is possibly an important marker of microangiopathic changes as early complications of BMT.