TMA: beware of complements.

摘要

In this issue of Blood, Jodele and colleagues1 report that defective complement regulation contributes to the development of thrombotic microangiopathy (TMA) after hematopoietic stem cell transplantation (HSCT) with important implications for diagnosis and management of this severe clinical complication.Approximately 10% to 25% of the 11 000 autologous, 3000 sibling donor, and 4000 unrelated HSCTs performed annually in the United States are complicated by TMA.2 TMA is associated with a high rate of renal failure and significant mortality. Older age, advanced underlying disease, unrelated donors, high-dose radiation for conditioning, calcineurin inhibitors, cytomegalovirus, and possibly mutations in thrombomodulin and diacylglycerol kinase-e, human herpesvirus 6, and graft-versus-host disease are putative risk factors, but the lack of consensus diagnostic criteria precludes precise estimates of incidence, outcome, or effectiveness of intervention with rituximab and plasma exchange. TMA is undoubtedly a multifactorial syndrome, but this study delineates a subset of patients for whom early diagnosis and treatment that restores physiological complement activity may be helpful.