Role of methylene blue‐treated or fresh‐frozen plasma in the response to plasma exchange in patients with thrombotic thrombocytopenic purpura

Summary. Twenty patients with thrombotic thrombocytopenic purpura (TTP) underwent plasma exchange using either standard fresh-frozen plasma (Group A, na 13) or methylene blue-treated plasma (Group B, na 7). Both groups presented similar characteristics except that bilirubin values were higher in Group A (P , 0·05). The complete remission rate was higher in Group A than B (69% versus 57%). The mean number of procedures was higher in Group B (21 ^ 7 versus 11 ^ 3, P , 0·01) and the mean duration of hospitalization was also longer (37 ^ 12 d versus 22 ^ 11 d; P , 0·01). Our study shows that the use of methylene blue-treated fresh-frozen plasma to treat TTP is associated with a higher number of plasma exchanges and greater transfusion requirements without improving clinical results.