Changes in the phagocytic cells in children treated with continuous ambulatory peritoneal dialysis.

Children on continuous ambulatory peritoneal dialysis (CAPD) in endstage renal failure are highly exposed to peritonitis. Peritoneal macrophages (PM) and blood neutrophils (PMNC) are the first line of defense against invading microbes. This study was undertaken for assessing surface receptors expression on PM and PMNC and to check their ability to phagocytosis and killing of bacteria. We have found that in spite of the decreased number of PM in dialysate fluid their viability and activity significantly increased during CAPD. Moreover, higher number of PM expressed CD16 and CD35 antigens (FcRIII and C3bR, respectively) in comparison with the results observed at CAPD onset. The number of PMNC expressed of these two antigens in uremic children blood were significantly lower in comparison with healthy control. The number of CD16 positive cells increased under influence of CAPD only temporarily. CAPD caused improvement of phagocytosis and intracellular killing of bacteria by PM but not by PMNC. There is discussed here influence of uremia and CAPD on surface antigens, function of phagocytes as well as renewal of PM during CAPD.