Evaluation of thrombotic thrombocytopenic purpura and other thrombotic microangiopathies: Lessons learned from a 14-year retrospective study

Abstract

Introduction: Thrombotic thrombocytopenic purpura (TTP) is a clinical thrombotic microangiopathy (TMA) syndrome defined by the pentad of symptoms. Therapeutic plasma exchange with plasma replacement is an ASFA Category I modality that can reduce morbidity and mortality if initiated early. We describe a 14-year review of patients referred for plasma exchange with a suspected diagnosis of TTP.

Methods: For 70 patients referred for urgent plasma exchange, clinical, therapeutic, and laboratory data were retrospectively analyzed, and the diagnosis was determined.

Results: Fifteen of the patients were diagnosed with TTP based upon ADAMTS-13 activity with the other 51 patients having other non-TTP TMA diagnoses. The mortality rate was significant for both TTP and non-TTP TMAs. PLASMIC scores were also calculated retrospectively and were noted to have limited value. TMA is a diagnostic challenge and encompasses different syndromes with similar presentations.

Conclusion: Determining an accurate diagnosis, including prompt ADAMTS-13 testing, makes it possible to initiate appropriate therapy for the multiple different TMAs that can be seen in clinical practice.

Keywords: HUS; TMA; TTP; atypical; plasma exchange.