Clinical features and prognostic factors of thrombotic thrombocytopenic purpura associated with systemic lupus erythematosus: a literature review of 105 cases from 1999 to 2011.

This study aims to review clinical features, treatments, and prognostic factors of thrombotic thrombocytopenic purpura (TTP) associated with systemic lupus erythematosus patients (sTTP). The case reports of sTTP published in world literature from 1999 to 2011 were collected, and 105 cases were divided into death group and survival group. The epidemiologic characteristics, clinical manifestations, laboratory examinations, treatments, and prognostic factors were analyzed. We found that coexistence of renal and neurological impairments were significantly frequent in the death group (100%) than in the survival group (56.5%) (P = 0.002). Type IV was predominant in 57.7% of renal pathological damage, followed by type V (11.5%), type II (5.8%), and thrombotic microangiopathy (TMA) (5.8%). TMA appeared more frequently (50%) in the death group than in the survival group (6.25%) (P = 0.042). End-stage renal disease occurred in nine cases with type IV in five (55.6%), type TMA in one (11.1%), and unspecified in three cases (33.3%). Of 32 cases, 40.6% showed severe ADAMTS13 deficiency and returned to normal or mildly deficient after remission. The total mortality rate of sTTP was 12.4 % and the mortality rate of patients with infection (27.3%) was significantly higher than those without infection (8.4%) (P = 0.028). Plasma exchange and glucocorticoids were administrated in over 80% of cases with 65.7% remission rate, while additional cytotoxics or rituximab was mostly used in refractory sTTP and achieved over 90 % of remission rate. Above all, coexistence of renal and neurological impairments, infection, and renal damage with type IV or TMA might denote a poor prognosis of sTTP.