Comparison of two automated mononuclear cell collection systems in patients undergoing extracorporeal photopheresis: a prospective crossover equivalence study

BACKGROUND: Extracorporeal photopheresis (ECP) is an effective cell therapy employed in several diseases, including graft versus host disease (GVHD) and organ rejection. When ECP is performed using an off-line technique, mononuclear cell (MNC) collection by leukapheresis is necessary for further manipulation (addition of 8-methoxypsoralen and ultraviolet A irradiation before reinfusion to the patient). We report the results of the first crossover equivalence study on yield and purity of MNCs collected from patients undergoing ECP with two different automated systems: MNC and CMNC (working with intermittent and continuous-flow collection, respectively), released by Terumo BCT. STUDY DESIGN AND METHODS: Fifty-one patients (15 males and 36 females) with GVHD or chronic lung allograft dysfunction were consecutively enrolled and randomly assigned to MNC collection alternatively by the CMNC or MNC system within each ECP cycle (two procedures) in two consecutive cycles. ECP procedures were performed using the off-line technique, according to our internal protocol, processing 1.5 blood volumes. RESULTS: A total of 204 ECP procedures were evaluated. The MNC system showed a higher MNC concentration capacity than the CMNC (mean difference, −13.46; 95% confidence interval, −21.05 to −5.47; p < 0.001). Collection efficiency was higher with the CMNC system as well as total MNC bag content, while MNC bag purity was equivalent for both systems. Platelet loss was higher with the CMNC. Equivalence was shown for MNC purity and anticoagulant infused to the patient. CONCLUSION: CMNC and MNC systems offer different advantages in different clinical conditions, and both are safe and efficient in collecting MNCs for ECP.