Hemodialysis-induced degranulation of polymorphonuclear cells: No correlation between membrane markers and degranulation products

Background/Aims: Degranulation of polymorphonuclear leukocytes (PMN) during hemodialysis (HD) is usually assessed by measuring degranulation products. However, this process might also be estimated by the assessment of cell su rface markers. In this study, the relationship between the expression of PM N degranulation markers (CD63 and CD66b) and the release of degranulation p roducts [myeloperoxidase (MPO) and lactoferrin (LF)] was investigated durin g clinical HD in order to evaluate cell surface markers as a useful index o f PMN degranulation. Methods: The expression of CD63 and CD66b on PMN and t he release of MPO and LF were investigated in 10 chronic HD patients, durin g both heparin (HDhep) and trisodium citrate anticoagulation (HDcit), in a randomized order. Samples were drawn from both the efferent and afferent li nes of the dialyzer at 0, 7.5, a nd 180 min. Results: During HDhep at first passage, a major increase in MPO (from 158 +/- 32 to 448 +/- 177 mu g/l, p = 0.001) and LF (from 134 +/- 52 to 260 +/- 120 mu g/l, p = 0.01) was foun d across the dialyzer, whereas marked changes were not observed during HDci t. The expression of CD63 and CD66b increased across the dialyzer during bo th anticoagulation modalities, but was only significant in the case of HDhe p (CD63: mean fluorescence intensity from 247 +/- 61 to 331 +/- 118, p < 0. 01; CD66b: mean fluorescence intensity from 340 +/- 76 to 434 +/- 103, p = 0.01). During HDhep a correlation was noted between the degranulation produ cts and markers of both azurophilic and specific granules (MPO and CD63: r = 0.35; p < 0.01; LF and CD66b: r = 0.39, p < 0.01). Significant difference s in the expression of CD63 and CD66b between HDhep and HDcit were not obse rved. When analyzing the combined data for both HDhep and HDcit no correlat ion was observed between degranulation products and markers. Conclusion: Ou r data suggest that the measurements of cell surface markers may not be a r eliable indicator of the degree of HD-induced PMN degranulation. Copyright (C) 2000 S. Karger AG, Basel.