Morbidity and Mortality in Adults With “Idiopathic” Thrombotic Thrombocytopenic Purpura/Hemolytic Uremic Syndrome

Abstract

We attempt to define the morbidity and mortality of adult patients with idiopathic (i.e., absence of known co-existent factors) thrombotic thrombocytopenic purpura/hemolytic uremia syndrome (TTP/HUS) who underwent a standard program of aggressive plasma exchange therapy. We conducted a retrospective review of patients treated with a diagnosis of TTP/HUS at a single institution over 7 years. TTP/HUS diagnosis in 52 patients was based on presence of microangiopathic, hemolytic anemia, and thrombocytopenia (< 150,000/mm³), along with 1 or more of the following: neurological abnormalities, renal dysfunction, or fever (>38°. Thirteen patients with co-existent factors of systemic lupus erythematosis, pregnancy, HIV infection, and cyclosporin or mitomycin C therapy were excluded from analysis; therefore, 39 patients treated over 7 years were studied. Interventions involved therapeutic plasma exchange of 150% plasma volume, with daily plasma replacement, until remission or death. Steroid therapy, antiplatelet therapy, or splenectomy were added at the discretion of the participating physicians. We found an overall mortality of 13 (35%) in the 39 patients. Time from onset of symptoms until initiation of therapy for all patients was 17 ± 24 days (mean ± SD). Average hospital stay was 29 ± 32 days, of which 10 ± 29 days and 12 ± 26 days were spent on the ventilator and in the intensive care unit, respectively. No differences between patients who survived and those who died were found with respect to gender, age, or blood component support (i.e., platelet, red cell transfusions) required. Six (30%) of 20 patients relapsed after attaining initial remission with medical therapy. Nine (60%) of 13 patients refractory to medical management underwent splenectomy and survived. We conclude that despite aggressive medical and surgical management, idiopathic TTP/HUS remains a syndrome with significant morbidity and mortality in otherwise young and healthy adults. Our results suggest that these patients should not be considered stable and should not undergo trial therapy with steroid or plasma infusion therapy. Earlier diagnosis and treatment with daily plasma exchange, along with consideration of surgical splenectomy in patients refractory to medical management, may be necessary if outcomes are to be improved in the management of this syndrome.