Therapeutic apheresis exchange in two patients with prolidase deficiency

Background Prolidase deficiency is a rare genetic disorder for which a cure has not yet been found. Objectives To assess the effectiveness of apheresis exchange as a new therapeutic approach. Methods Apheresis exchanges were repeated monthly for four consecutive months, in parallel, on two patients, replacing prolidase-deficient red blood cells with normal filtered cells. Prolidase activity and urinary dipeptides were determined at regular intervals. Results The constant presence of active prolidase inside cells allowed a continuous, although partial, degradation of imidodipeptides, with a concomitant improvement of skin ulceration. Conclusions Apheresis exchange could be a reasonable way of obtaining a clinical improvement in these patients.