Guía diagnóstica y terapéutica de las microangiopatías trombóticas del Grupo Español de Aféresis / Diagnostic and therapeutic guidelines of thrombotic microangiopathies of the Spanish Apheresis Group

Las microangiopatías trombóticas (MAT) son un grupo de entidades que se caracterizan por presentar una anemia hemolítica microangiopática (con los típicos esquistocitos en el frotis de sangre periférica), trombocitopenia y afectación de órganos de intensidad variable. La púrpura trombocitopénica trombótica y el síndrome urémico hemolítico son las formas más importantes de MAT, y sin el tratamiento adecuado se asocian a una elevada morbimortalidad. En los últimos años se han producido avances notables en el conocimiento de la fisiopatología de las MAT. Estos avances nos han permitido pasar de un diagnóstico sindrómico con un tratamiento similar en todos los casos, a buscar un diagnóstico etiológico y un tratamiento acorde a la etiología que ha conllevado una mejoría en el pronóstico de los pacientes. Este documento pretende resumir el estado actual del conocimiento de la fisiopatología y las opciones terapéuticas disponibles, y también presentar a los profesionales que tratan a este tipo de pacientes una aproximación diagnóstica y terapéutica práctica (AU)

Thrombotic microangiopathies (TMA) are disorders defined by the presence of a microangiopathic hemolytic anemia (with the characteristic hallmark of schistocytes in the peripheral blood smear), thrombocytopenia and organ malfunction of variable intensity. Thrombotic thrombocytopenic purpura and hemolytic uremic syndrome are the most important forms of TMA and, without the adequate treatment, they are associated with high morbimortality. In recent years, significant advances in the knowledge of the pathophysiology of TMA have occurred. Those advances have allowed us to move from a syndromic diagnosis with a similar treatment to all entities to the search of etiologic diagnosis which would lead to a specific treatment, finally leading to a better outcome of the patient. This document pretends to summarize the current status of knowledge of the pathophysiology of TMA and the therapeutic options available, and to offer a diagnostic and therapeutic practical tool to the professionals caring for the patients (AU)

Efficacy and safety of rituximab in adult patients with idiopathic relapsing or refractory thrombotic thrombocytopenic purpura: results of a Spanish multicenter study.

BACKGROUND: Between 30% and 60% of patients with thrombotic thrombocytopenic purpura (TTP) relapse and mortality remains at 15-20%. Limited clinical data suggest that the administration of anti-CD20 antibody (rituximab) may be useful in preventing acute refractory and chronic relapsing TTP. DESIGN AND METHODS: We studied the clinical response to rituximab in 24 adult patients (median age 42 years, range 24-72 years) from 15 Spanish centers with an acute refractory (14 patients) or acute relapsing (10 patients) episode of idiopathic TTP. On admission, every patient received daily plasma exchange (PE). Rituximab was administered at a dose of 375 mg/m(2) weekly for a median of 13 days (range 0-57 days) after starting PE for a median of 4 doses (range 1-8 doses). RESULTS: No severe acute or delayed toxicity was observed in the patients treated with rituximab. Three (12.5%) patients died because of TTP-related causes. The remaining 21 (87.5%) patients achieved complete remission in a median of 21 days (range 2-35 days) after initiating rituximab. After a median follow-up of 30 months (range 7.5-74 months), 18 patients are in remission and 3 patients have relapsed at 7, 29, and 29 months. CONCLUSIONS: Rituximab appears to be a safe, effective therapy and has a high response rate for the treatment of acute refractory or relapsing idiopathic TTP in adult patients.