Sammanfattning
Thrombotic microangiopathy can be caused by several conditions, which are difficult to discriminate on the basis of clinical presentation alone. Deficient enzyme activity of ADAMTS13 can lead to thrombotic thrombocytopenic purpura (TTP). ADAMTS13 cleaves high molecular weight forms of von Willebrand factor in plasma; a key protein in primary haemostasis. Lack of ADAMTS13 activity leads to increased concentrations of high molecular weight von Willebrand factor forms and increased platelet aggregation. Measurement of ADAMTS13 activity is useful for the diagnosis of TTP and may also be relevant as a prognostic test for recurrent TTP.