Abstract

 Background and Objectives

 White blood cells (WBCs) in blood products are the major stimulus for a number of detrirmental biological reactions including febrile nonhemolytic transfusion reactions, alloimmunization against HLA antigens, and cytomegalovirus transmission. In this study, our objective was to study the effect of storage time on the filtration of platelet concentrates (PCs). The total number of white blood cells as well as the distribution of WBC subsets in PC units filtered before and after storage was compared.

 Materials and Methods

 In this experimental study, platelet-rich plasma-derived PCs (5 pooled units) were filtered both fresh and after 5 days of storage then, the total number of WBCs was calculated by flow cytometry and cell counting. WBC subsets were analyzed by flow cytometry with three-color fluorescence. In this study, the third genaration bags and filters were used.

 Results

 Before filtration, the total number of WBC was significantly higher in fresh units compared with stored units, whereas in postfiltration samples the number of white blood cells was significantly lower in the fresh compared with the stored units. Although the absolute number of WBCs significantly reduced, filtration induced significant changes in proportion in subsets in both fresh and stored units the percentage of B cells and monocytes increased after filtration.

 Conclusions

 Both pre- and post-storage WBC filtration affect the proportions of WBCs in the final product but pre-storage WBC filtration of platelet concentrates is superior than post-storage WBC filtration.

 Key words : White blood cells, Platelet concentrates, Blood, Filtration