Most studies have evaluated TPE use in specific patient population such as in ABO incompatible transplantations5 and GBS.6 Kaynar et al.7 in his retrospective multi-centre study in neurologic diseases observed that the mean number of sessions of TPE per patient was 5, and the mean processed plasma volume was 3,075 mL for each cycle. This evidence concerns the gene ABO and Guillain-Barre syndrome.