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Lymphocyte subsets in dialyser eluates: a new parameter of bioincompatibility?
M P Grooteman1, M J Nube, J van Limbeek
1Medical Center Alkmaar, Departments of Nephrology and Immunohaematology, Wilhelminalaan 12, 1815 JD Alkmaar, The Netherlands.
Insights
This study investigated how different hemodialysis membranes affect lymphocytes. While lymphocyte numbers didn't change significantly, the polysulfone membrane showed selective adhesion, suggesting it may be a better indicator of bio-compatibility.
Area of Science:
- Nephrology
- Immunology
- Biomaterials Science
Background:
- Hemodialysis (HD) can cause adverse reactions due to dialyzer membrane bio-incompatibility.
- Previous studies showed polymorphonuclear cells (PMN) activate during HD with cellulose triacetate (CTA), cuprammonium (CU), and polysulfone (PS) membranes.
- This study examines the impact of these membranes on lymphocytes during HD.
Purpose of the Study:
- To investigate the influence of HD with CTA, CU, and PS membranes on lymphocyte subpopulations and activation status.
- To compare lymphocyte behavior in peripheral blood and dialyzer eluates.
- To determine if eluted lymphocytes are a better indicator of dialyzer bio-compatibility than PMN.
Main Methods:
- Eight patients underwent HD with CTA, CU, and PS dialyzers in a randomized crossover design.
- Dialyzer elution was performed after 3 hours of HD.
- Flow cytometry analyzed leukocyte counts, lymphocyte subpopulations, and activation markers in peripheral blood and dialyzer eluates.
Main Results:
- A significant decrease in leukocytes was observed with CU dialyzers.
- Natural killer (NK) cells showed a relative decline with all membranes, significant for CTA.
- Polysulfone (PS) dialyzers exhibited selective adhesion of lymphocyte subpopulations, unlike CTA and CU.
Conclusions:
- The absolute number of lymphocytes in dialyzer eluates was low compared to peripheral blood.
- Polysulfone (PS) membranes showed selective lymphocyte adhesion, indicating potential differences in bio-incompatibility.
- Eluted lymphocytes, rather than PMN, may serve as a preferable parameter for assessing dialyzer bio-compatibility.
Introduction:
During haemodialysis (HD), several adverse reactions in peripheral blood can occur, which have been attributed to the bioincompatibility of the dialyser membrane. Utilizing a dialyser elution technique, we have demonstrated that polymorphonuclear cells (PMN) manifested non-membrane dependent signs of activation during HD with cellulose triacetate (CTA), cuprammonium (CU) and polysulphone (PS) membranes. In the present study, we employed this elution technique to investigate the influence of HD with these membranes on lymphocytes.
Methods:
Eight patients were studied during HD with CTA, CU, and PS dialysers in a randomized crossover design. Dialyser elution was performed after 3 h of HD. Besides total leukocyte count and differentiation, lymphocyte subpopulations and activation status in peripheral blood and dialyser eluates were analysed by flow cytometry.
Results:
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.