Potential role for interleukin-1 in fibrosis associated with chronic ambulatory peritoneal dialysis.

Cytokines released by inflammatory cells can modify migration, proliferation and matrix protein synthesis by mesenchymal cells. Interleukin-1 (IL-1) produced by monocytes is one cytokine which could play a role in inducing peritoneal fibrosis in patients undergoing chronic peritoneal dialysis. IL-1 increases collagen synthesis associated with increased levels of procollagen mRNAs in fibroblasts. In some fibroblasts, this increase may be masked by the inhibitory effects of prostaglandins and revealed in the presence of cyclooxygenase inhibitors. Other known cytokines act similarly to IL-1 and may be synergistic with IL-1. The lymphokine interferon-gamma inhibits collagen synthesis. These mediators function in a complex network of feedback and amplification loops to regulate collagen deposition in inflammatory conditions.