Real World Data: Delay on Symptoms and Diagnosis Recognition Associated with Relapse and Death in Thrombocytopenic Thrombotic Purpura (PTT)

Introduction: PTT is a rare disease and plasmapheresis have change the dismal and the fatal disease prognosis, increasing the survival rate to 80 -85%. Relapses can occur in 40% and are associated with a worse prognosis. Rituximab is an option for the refractory patients.

Objectives: Analyze clinical and laboratory parameters, timelines to diagnosis and plasmapheresis of PTT patients at Hospital de Clinicas de Porto Alegre and correlate these data to survival and relapse rates.

Material and Methods: Retrospective data obtained from medical records from 2007 to 2016. Were analyzed data from the first disease symptoms, diagnosis, patient admission and of the first plasmapheresis. Were collected clinical-laboratory data from the admission date and after the first week of plasmapheresis treatment to define initial response or not to treatment. The definition of initial response to treatment was as a progressive and maintain the increase in platelet counts simultaneous with a decrease in DHL blood level. Were included only patients treated with plasmapheresis and/or corticosteroids in the first week of treatment.

Results: A total of 29 patients were included in the final analyses. Median age was 37 years (21-88), and 17 (58%) responded to plasmapheresis in the first week of treatment. The laboratory exams of this group of patients (Hb, DHL, creatinine) was not different from the nonresponders ones. A median number of plasmapheresis was 12. Deaths related to PTT and relapses were significantly higher in the patients with a delay from the beginning of the symptoms and the time from diagnosis to the first plasmapheresis was significantly higher in the patients (p=0,000, p=0,001, respectively). The time from the pt admission to the beginning of treatment had no impact on survival (p=0,750). Median survival rate was 279 days (75-1210) and was different between pts groups. Death related to TTP occurred in 9 pts (31%). Initial responders to therapy presented a median survival of 1450 days (21-2880) and the non-responders 285 days (21-2880), with p=0.05. Just 5 pts were treated with rituximab, and no impact on survival was observed (p=0.390)

Conclusions: PTT is a fatal disease if not early recognized and treated. This study was done in a university hospital, a regional reference center and in 31% of patients death was the evolution. The factors associated with fatal event and relapse were the delay in recognizing the disease and late plasmapheresis treatment. With this result, we propose to increase medical awareness of PTT for emergency care team and to create a preference admission in reference hospitals with apheresis capacity installed.