Alterations in soluble and leukocyte surface L-selectin (CD 62L) in hemodialysis patients.

Hemodialysis (HD) patients can develop acute reactions during treatment as well as increased long-term susceptibility to infections and malignancy. Leukocyte-membrane interactions may contribute to these processes. The effects of a single HD session on L-selectin, a leukocyte adhesion molecule for endothelium, were examined. Serum levels of soluble L-selectin were measured in 23 patients by enzyme-linked immunosorbent assay before and after a 3-h dialysis session. There was a statistically significant increase in soluble L-selectin from 1.36 +/- 0.12 (SE) to 1.57 +/- 0.18 micrograms/mL (P < 0.001). An increase in shed L-selectin was observed for the "venous" compared with the "arterial" part of the dialyser (P < 0.01) 15 min into HD. Soluble L-selectin levels were found to remain increased at 3 h after treatment. Leukocyte-bound L-selectin and CD11b was examined by the use of flow cytometry. Neutrophil L-selectin decreased to 69 +/- 7% at 15 min (P < 0.01) and then rebounded to 98 +/- 7% at 180 min. Monocyte and lymphocyte L-selectin did not decrease. Because L-selectin is important for leukocyte attachment to endothelium at sites of inflammation, alterations of shed L-selectin and cell-surface L-selectin levels may play a role in the immunologic consequences of HD treatment.