Outcomes of thrombotic thrombocytopenic purpura patients submitted to therapeutic plasma exchange in a single center in Brazil

Immune thrombotic thrombocytopenic purpura (iTTP) is characterized by acute systemic microvascular thrombosis and is associated with a high morbidity and mortality, especially in delayed diagnosis (later than 6–7 days from symptoms). iTTP data in Brazil is scarce, so we aimed to characterize the clinical presentation and identify predictors of death risk in patients with this disease in Brazil. In this single-center retrospective study the patients who underwent therapeutic plasma exchange (TPE) for presumptive or confirmed iTTP were evaluated regarding the epidemiological, clinical, laboratorial characteristics and management. A total of 50 patients (90 % female), with median age (IQR) of 34.1 (27–47) years, were enrolled, of which 12 (24 %) died. The most frequent symptoms were neurological (96 %), bleeding (76 %), gastrointestinal (52 %), fever (38 %), and cardiovascular (22 %). Neurological focal deficit and cardiovascular symptoms were more frequently observed in the non-survivor group (P = 0.0019 and P = 0.007, respectively). The mean ± SD number of days from beginning of symptoms to first TPE was 12.22 ± 7.91. We identified an association regarding mortality rate with a score MITS ≥ 2 points (P = 0.04), a higher indirect bilirubin (P = 0.0006), a higher number of transfused red blood cell units (P = 0.025), and platelet transfusion (P = 0.027). Delayed diagnosis appears to be associated with a higher frequency of neurological symptoms and mortality. Intensity of hemolysis and signs of organ ischemia, such as cardiovascular symptoms and focal neurological deficit, are indicators of death risk.