Thrombotic microangiopathies and their distinction from ttp

Abstract

Thrombotic microangiopathies (TMAs) comprise a number of distinct disorders with shared findings of platelet thrombi within small arterioles with resultant thrombocytopenia and mechanical destruction of red blood cells within small vessels. For many forms of TMA, including thrombotic thrombocytopenic purpura (TTP), effective treatment exists but must be instituted without undue delay, and the treatment itself may be costly and not without risk. This chapter will highlight distinguishing characteristics of TTP, with an emphasis on efficient and accurate diagnosis through appropriate laboratory testing and early recognition of clinical features. Differentiating TTP from hemolytic-uremic syndrome (HUS) poses a particular challenge and will be discussed in some detail. Other forms of TMA will be reviewed more briefly, and a suggested diagnostic algorithm is presented.