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.