ENDOTOXIN-STIMULATED PERITONEAL-MACROPHAGES OBTAINED FROM CONTINUOUS AMBULATORY PERITONEAL-DIALYSIS PATIENTS SHOW AN INCREASED CAPACITY TO RELEASE INTERLEUKIN-1-BETA INVITRO DURING INFECTIOUS PERITONITIS

Abstract. Interleukin‐1 (IL‐1) release by peritoneal macrophages obtained from patients on continuous ambulatory peritoneal dialysis (CAPD) was studied in nine patients during an infection‐free period and eight patients during an infectious peritonitis, using an ELISA for IL‐ 1β. Without exogenous stimulation with LPS, peritoneal macrophages from infected and unin‐fected patients released the same amounts of IL‐lβ, 183pM40 pg ml‐1 24 h‐1) per 106 cells (means + SEM) and 251 pM 6 pg ml‐1, respectively. However, in response to a dose of 5 μg ml‐1 of LPS, peritoneal macrophages released significantly more (P < 0.005) IL‐1β during peritonitis (6579 β 2793 pg ml‐1 24 h‐1 per 106 cells) compared with the infection‐free period (1040 pM 182 pg ml‐1). These findings show that after microbial invasion of the peritoneal cavity, peritoneal macrophages are primed in vivo to release an increased amount of IL‐lβin vitro after subsequent exogenous stimulation with LPS, indicating that peritoneal mac‐rophage activation for IL‐1β secretion occurs in steps., Copyright © 1990, Wiley Blackwell. All rights reserved