Distinct Subpopulations of Elicited Human Macrophages in Peritoneal Dialysis Patients and Women Undergoing Laparoscopy: A Study on Peroxidatic Activity

The endogenous peroxidatic activity (PA) pattern of peritoneal macrophages from 24 continuous ambulatory peritoneal dialysis (CAPD) patients and from five healthy women undergoing laparoscopy was studied. In general, the macrophages showed two different PA patterns in vivo: exudate and negative macrophages. However, two of 24 CAPD patients showed resident macrophages, the first described in vivo in man. Since, in general, the examined human peritoneal macrophages are exudate and PA-negative, this suggests, in accordance with the animal model system, that a chronic sterile inflammation exists in the peritoneal cavity of CAPD patients and healthy women undergoing laparoscopy. After 2 hr culture, blood monocytes and peritoneal macro-phages transformed into cells with the characteristics of exudate-resident and resident macrophages, so isolation procedures that include short periods of culture can change the developmental stage of human monocytes and macrophages. Key words: endogenous peroxidatic activity, continuous ambulatory peritoneal dialysis (CAPD) patients, peritoneal macrophage