Measuring ADAMTS13 activity in patients with suspected thrombotic thrombocytopenic purpura: when, how, and why?

Abstract

During the past 17 years, thrombotic thrombocytopenic purpura (TTP) has become defined by a severe deficiency of ADAMTS13.1 However this definition is not equivalent to a diagnosis of TTP. ADAMTS13 measurements have become common in our evaluation and management of patients with suspected TTP, but there are still uncertainties about the interpretation of these measurements. To address these uncertainties, we need to consider three questions. Addressing these questions is something that clinicians do whenever seeing a patient for whom the question is, “Does she have TTP?”