Lymphocyte subsets in dialyser eluates: a new parameter of bioincompatibility?

Abstract

Only with CU was a significant leukocyte decrease observed in peripheral blood at 30 min (P<0.001). Neither the total number of lymphocytes nor the proportion of T(CD3+) and B(CD19+) cells had markedly changed after HD with either membrane. Meanwhile, all membranes induced a relative decline in natural killer cells -NK(CD3-/CD16+/56+)- at the end of dialysis, although this was only significant for CTA (P=0.04). As for the T-lymphocyte subsets, the proportion of CD4+ cells had markedly increased after three hours of HD with all three dialysers, CTA and PS being significant (P<0.05). Dialyser eluates contained 33.8-82.2 x 10(6) cells, CTA yielding the highest cell counts. The majority (81-91%) of the eluted cells consisted of PMN dialyser eluates versus peripheral blood: P<0.05), whereas only few lymphocytes were found (4-13%, absolute 2.6 x 10(6)). Lymphocyte subpopulations in dialyser eluates were comparable to peripheral blood at t 180 in case of CTA and CU. In contrast PS eluates contained significantly fewer T-cells (37%), but more B-cells (22%) and NK-cells (30%) in comparison with peripheral blood at 180 min (peripheral blood: 79, 6 and 16% respectively; P<0.05). The expression of activation markers on T-cells (HLA-DR, CD25) in dialyser eluates was comparable with peripheral blood. Conclusions. The absolute number of lymphocytes in dialyser eluates of CTA, CU, and PS dialysers was low (mean 2.6 x 10(6)) in comparison with peripheral blood (mean 1.4 x 10(9)/l). Whereas non-selective adhesion occurred in CU and CTA dialysers, a selective adhesion pattern of lymphocyte subpopulations was observed in case of PS, suggesting a difference in bioincompatibility. Apparent T-cell activation was not noted, either in peripheral blood or in dialyser eluates. Because PMN in the dialyser eluates of three different membranes showed similar activation patterns in a previous study, we hypothesize that eluted lymphocyte, rather than PMN, represent a preferable parameter of bioincompatibility.

Lymphocyte adhesion and interactions with biomaterial adherent macrophages and foreign body giant cells

“…PET showed greater selectivity for CD8+ T lymphocyte interactions. In previous studies involving column cell separation and dialysis, various material surfaces were also capable of selectively retaining lymphocyte subpopulations 13, 15. Again, this could be the result of differences in adherent macrophage responses on the different biomaterial surfaces.…”

“…Lymphocytes are capable of adhering onto surfaces composed of synthetic materials and are affected by surface properties. The use of hemodialysers composed of different synthetic polymers showed differential lymphocyte elution profiles after hemodialysis 12, 13. Similarly, various polymers have shown the capability to retain specific subtypes of lymphocytes in the context of in vitro column separation methods 14, 15.…”

Hepatitis C virus screening and clinical monitoring of biomarkers in patients undergoing hemodialysis

“…Decreased numbers of circulating CD4 þ T cells have been reported in hemodialysis patients [Ankersmit et al, 2001;Litjens et al, 2006;Urbani et al, 2006;Costa et al, 2008]. Some studies have also demonstrated that CD4 þ T-cells can increase in the first 30 min/3 hr from the beginning of hemodialysis, but with significant decreases at the end of the hemodialysis session [Grooteman et al, 1996;Rasic et al, 2001]. In this study, it was demonstrated that HCV seronegative patients presented lower percentages of circulating CD3 þ , mainly due to the decreased percentage of circulating CD4 þ T-cells as compared to both seropositive patients and the control group.…”

The immunological effects of continuous veno-venous haemodiafiltration in critically ill patients

“…The absence of significant changes in the other lymphocyte subpopulations and in the number of natural killer cells is in contrast to findings with haemodialysis. During haemodialysis a decline in the number of natural killer cells and an increase in the proportion of CD4 + lymphocytes have been observed [17]. …”