RESUMEN
BACKGROUND: Recently, novel protocol utilizing Continuous Mononuclear Cell Collection (cMNC) have been introduced for leukapheresis. We compared the efficacy of cMNC with an older protocol - mononuclear cell collection (MNC) for CD34+ cell collection in unrelated donors with negative stem cell collection predictors. MATERIAL AND METHODS: Retrospective data from a series of 258 consecutive unrelated hematopoietic stem cell donors was included in this single-center study (80 donors collected with cMNC and 178 with MNC). The donors with poor predictors for collection such as low number of circulating CD34+ cells and/or weight disproportion were assigned to the cMNC arm. RESULTS: The cMNC protocol yielded a higher number of CD34â¯+â¯cells per donor body weight (7.63â¯×â¯106/kg vs 6.82â¯×â¯106/kg, pâ¯=â¯0.027). One apheresis was sufficient for collection of target cell number in 89% individuals from both groups despite negative predictors in the cMNC group. In donors with CD34â¯+â¯cell count <100/µL and a body weight disproportion between donor and recipient one apheresis was sufficient in 83% of donors in cMNC group and in 58% in MNC group (pâ¯=â¯0.0345) with collection efficiency CE2% values of 61% for cMNC and 62% for MNC (pâ¯=â¯0.77). CONCLUSION: cMNC protocol is more efficient in donors with low pre-apheresis CD34+ cell count and weight disproportion between donor and recipient. This suggests that the use of cMNC in unrelated donors could possibly further improve the results of HSC collections.