[Effect of leukapheresis on gene expression profiles of donor's peripheral blood mononuclear cells]

Leukapheresis has commonly been used to obtain the cell products intended for clinical cell therapy. Hypocalcemia related to citrate toxicity and some circulatory effects such as hypovolemia and hypotension are well-known complications of leukapheresis. In this study, we analyzed the gene expression profiles of peripheral blood mononuclear cells (PBMCs) obtained before and after leukapheresis to determine if the hemodynamic changes can affect the gene expression profiles of leukocytes.

PBMCs were isolated from EDTA blood from 5 healthy donors collected before and immediately after apheresis. RNA was isolated, amplified, and analyzed using a cDNA microarray with 17,500 genes. Hierarchical clustering analysis was performed to evaluate the differences of gene expression profiling.

Hierarchical clustering separated PBMCs from different donors with each other, but did not separate PBMCs collected before and after leukapheresis. Comparison of gene expression by PBMCs collected before and after leukapheresis found only 25 genes were differentially expressed (15 were up-regulated and 10 were down-regulated after leukapheresis) (F-test, P<0.005). Stress induced apoptosis-related genes, ANXA3, DEDD, and ATXN2L, and cytokine-related genes, IL13RA1 and IK, which were also related to stress, were up-regulated after leukapheresis. Genes involved in DNA and protein binding, such as CLSTN3, LRBA, SATB2, and HSPA8, were down-regulated.

Leukapheresis had little effect on gene expression of PBMCs. Some genes showing differences between before and after leukapheresis were mainly involved in stress-related reactions.