ABSTRACT
Lymphocyte subsets were determined in 20 packed red blood cell units (PRC) before and after filtration (FPRC) with the Pall Leukotrap RC inline filter system; 10 units were prepared by low spin and platelet rich plasma (PRP) removal (Group A) and 10 with high spin, plasma and buffy-coat (BC) removal (Group B). Flow cytometry was employed for white blood cell (WBC) enumeration and phenotype analysis. Median WBCs in prefiltered units was 2.08 x 10(9) (Group A) vs. 0.8 x 10(9) (Group B) (p < 0.0001). Five Group A and three Group B filtered units had WBC counts above the limit of detection (LD), median values being 25.59 and 3.08 x 10(3), respectively. Whereas CD3+, CD3+CD4+ and CD3+CD8+ lymphocyte subsets were assessable in 20-40% of Group A units, inline filtration of Group B units lowered lymphocytes below the LD of the present study. Post-filtration CD19+ lymphocytes were below the LD in all the 20 units.
