부산대학교 도서관

In peripheral blood the majority of circulating monocytes present a CD14 CD16 (CD14 ) phenotype, while a subpopulation shows a CD14 CD16 (CD14 CD16 ) surface expression. During haemodialysis (HD) using cellulosic membranes transient leukopenia occurs. In contrast, synthetic biocompatible membranes do not induce this effect. We compared the sequestration kinetics for the CD14 CD16 and CD14 monocyte subsets during haemodialysis using biocompatible dialysers. Significant monocytopenia, as measured by the leucocyte count, occurred only during the first 30 min. However, remarkable differences were observed between the different monocyte subsets. CD14 monocyte numbers dropped to 77 ± 13% of the predialysis level after 15 min, increasing to ≥ 93% after 60 min. In contrast, the CD14 CD16 subset decreased to 33 ± 15% at 30 min and remained suppressed for the course of dialysis (67 ± 11% at 240 min). Approximately 6 h after the end of HD the CD14 CD16 cells returned to basal levels. Interestingly, the CD14 CD16 monocytes did not show rebound monocytosis while a slight monocytosis of CD14 monocytes was occasionally observed during HD. A decline in CD11c surface density paralleled the sequestration of CD14 CD16 monocytes. Basal surface densities of important adhesion receptors differed significantly between the CD14 CD16 and CD14 subsets. In conclusion, during HD the CD14 CD16 subset revealed different sequestration kinetics, with a more pronounced and longer disappearance from the blood circulation, compared with CD14 monocytes. This sequestration kinetics may be due to a distinct surface expression of major adhesion receptors which facilitate leucocyte–leucocyte, as well as leucocyte–endothelial, interactions.