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.

Methylene blue-photoinactivated plasma versus quarantine fresh frozen plasma in thrombotic thrombocytopenic purpura: a multicentric, prospective cohort study.

Plasma exchange (PE) with plasma infusion is the treatment of choice for thrombotic thrombocytopenic purpura (TTP) but doubts remain as to whether all kinds of plasma are equally effective. A multicentric cohort study was conducted to compare methylene blue-photoinactivated plasma (MBPIP) with quarantine fresh frozen plasma (qFFP) in the treatment of TTP. One hundred and two episodes of idiopathic TTP were included; MBPIP was used in 63 and qFFP in 39. The treatment schedule consisted of daily PE and costicosteroids, and the main end-point was remission status on day 8. Patients treated with MBPIP required more PEs (median: 11 vs. 5, P = 0.002) and a larger volume of plasma (median: 485 ml/kg vs. 216 ml/kg, P = 0.007) to achieve a remission, and presented more recrudescences while on PE therapy (29 of 63 vs. 8 of 39, P = 0.02) than those receiving qFFP. After adjustment for possible confounding factors, the use of MBPIP was associated with a lower likelihood of remission on day 8 [Odds ratio (OR): 0.17; 95% confidence interval (CI): 0.06-0.47] and a higher risk of recrudescence while on treatment (OR: 4.2; 95% CI: 1.6-10.8). In conclusion, MBPIP is less effective than qFFP in the treatment of TTP.