Interleukin-1β, -6 and Interferon-γ Productions in Patients Undergoing Continuous Ambulatory Peritoneal Dialysis

In order to investigate cytokine productions in patients undergoing continuous ambulatory peritoneal dialysis (CAPD), we studied the production of interleukin (IL)-1β, -6, and interferon (IFN)-γ by cultured peripheral blood mononuclear cells (PBMC) in peritonitis-free CAPD patients. The correlation of cytokine production with plasma parathyroid hormone (PTH) and albumin levels was also evaluated. While the release of IL-1β was not markedly different from controls, the release of IL-6 from 24-hour cultured PBMCs was significantly greater than that of controls (Mean±S.D., IL-6: 2186.8±1217.9 pg/ml, vs 1516.3±767.9, p<0.05). The addition of lipopolysaccahride (LPS, 10 μg/ml) significantly stimulated IL-1β and -6 production of PBMCs in CAPD patients and controls, compared to an unstimulated condition. The LPS-induced IL-1β production was also not markedly different from controls, whereas LPS-induced IL-6 production was significantly higher than controls (IL-6: 13220.7±7177.4 vs 7411.4±1236.9, p<0.05). However, the percentage increases of IL-6 production stimulated with LPS in CAPD patients were not significantly different from controls (p>0.05). No difference of baseline IFN-γ was detected between CAPD patients and controls, but phytohemagglutinin (PHA, 10 μg/ml)-stimulated IFN-γ release was significantly higher in CAPD patients than controls (2425.9±1565.0 pg/ml vs 1364.0±755.1, p<0.05). There was no significant correlation between PTH and, IL-1β, -6, or IFN-γ production. On the other hand, a significant correlation was observed between the serum albumin level and LPS-stimulated IL-6 production (r=0.54, p<0.05). In conclusion, CAPD seems to partly induce activation of PBMCs with an enhanced release of IL-6 and IFN-γ, and CAPD patients with higher serum albumin levels tend to show higher IL-6 production in immune response.