Expression of transferrin receptors by monocytes and peritoneal macrophages from renal failure patients treated by continuous ambulatory peritoneal dialysis (CAPD)

Abstract

Approximately 20% of monocytes and peritoneal macrophages from renal failure patients undergoing continuous ambulatory peritoneal dialysis (CAPD) were transferrin-receptor (TfR) positive by immunofluorescence, whereas cells from normal controls were generally TfR negative, as were monocytes from rheumatoid arthritis patients and from renal failure patients treated by haemodialysis. There was a significant correlation between the length of time on CAPD and the proportion of TfR-positive blood monocytes. CAPD peritoneal macrophages possessed 6.7-37.1 x 10(3) transferrin binding sites per cell, with a Ka of 3-25 x 10(7) mol l-1. In culture, monocytes from CAPD patients showed a progressive decrease in TfR expression, while in contrast about 20% of monocytes from normal controls which were originally 100% TfR negative expressed TfR after 3 days in culture. These findings indicate that regulation of TfR in monocytes/macrophages is complex, and that frequent removal of peritoneal cells during dialysate exchange may place a strain on the bone marrow, resulting in the release of an increasingly immature population of TfR positive monocytes to the circulation in CAPD patients.

Automated Peritoneal Dialysis Symposium: Host Defenses in APD

“…Several authors have reported that PMOs from CAPD patients appear to be in a state of chronic activation (16,17). Other authors have described an increased expression of transferrin receptors on peripheral monocytes and on PMOs from PD patients (18,19). It was stated that, due to the repeated removal of peritoneal cells during dialysis, relatively immature monocytes are constantly invading the peritoneal cavity from the blood.…”

Peritoneal Defenses Against Infection: Winning the Battle but Losing the War?

“…A number of studies indicate that peritoneal macrophages in peritoneal dialysis patients are relatively immature, and that the immaturity becomes more pronounced with time on dialysis (12)(13)(14)(15). They also have an activated phenotype, possibly as a result of exposure to the dialysate (10,16,17).…”

Impact of Terminal Heat Sterilization on the Quality of Peritoneal Dialysis Solutions

“…Several researchers have reported that peritoneal macrophages and lymphocytes ap pear to be in a state of chronic activation as evidenced by the enhanced expression of sur face antigens such as HLA-DR. CD25 (the IL-2 receptor), and CD71 (transferrin receptor) [27][28][29]. Theoretically, chronic activation of peritoneal leukocytes could result in chronic production of fibrogcnic cytokines and oxida tive free radicals, which, in turn, could lead to mesothelial cell toxicity and membrane fibro sis [30,31], Bos et al [32] have demonstrated in a rat model that current peritoneal dialysis solutions could induce peritoneal mononu clear cell activation.…”