PHAGOCYTOSIS IN UREMIC AND HEMODIALYSIS-PATIENTS - A PROSPECTIVE AND CROSS-SECTIONAL STUDY

Leukocyte response to phagocytic challenge was assessed in uremic and hemodialysis patients in a prospective and cross sectional study. Using latex, zymosan and staphylococcus as phagocytic challenge, the utilization of glucose-1-C-14 and the generation of reactive oxygen species was measured in these patients. In uremic, non-dialysis dependent patients, the response to phagocytosis was significantly reduced when creatinine exceeded 6 mg/dl and prior to initiation of dialysis (mean serum creatinine 9.3 +/- 0.3 mg/dl) was less than half that of patients with normal renal function (P < 0.01). In a prospective study of 15 patients initiated on dialysis, the metabolic response of their leukocytes was assessed sequentially. In eight patients, initiation of dialysis with cuprophane (Cu) membrane lead to a further decline (60%) in their metabolic response to phagocytosis at the end of four weeks of dialysis compared to pre-initiation of dialysis (P < 0.01), whereas in seven other patients, dialysis with non-complement activating membranes did not result in a significant decline. Prospective cross-over studies of chronic hemodialysis patients corroborated these findings: eight patients dialyzed with new CU membranes had a significant decline of their metabolic response to phagocytic challenge acutely at the end of each dialysis and in pre-dialysis samples after two weeks of Cu dialysis, whereas their response returned back to baseline after two weeks of dialysis with non-complement activating membrane. In prospective and cross sectional studies, a decreased response to phagocytic stimulus was a predictor of hospitalization, primarily for infectious reasons. We conclude that both uremia and the type of dialysis membrane affect the ability of leukocytes to respond to phagocytic challenge, and that the risk of infections increases with advancing uremia and is worsened with the use of Cu membrane.