Elevated interleukin-6 expression in keloid fibroblasts

Keloids are characterized by a net accumulation of collagen, To date, the r ole of growth factors and various cytokines in the pathogenesis of these le sions has not been fully characterized, Interleukin-6 (IL-6) is an importan t immunoregulatory cytokine that has keen implicated in a number of fibroti c autoimmune diseases such as scleroderma, interstitial nephritis, and pulm onary interstitial fibrosis. However, the role of IL-6 in the development o f keloids has yet to be defined. This study demonstrates increased expressi on of the IL-6 gene in fibroblasts isolated from patients with keloids when compared with control fibroblasts using the ribonuclease protection assay. Subsequent detection of increased levels of IL-6 secretion by keloid fibro blasts is also demonstrated under unstimulated and stimulated conditions us ing serum and interferon gamma (IFN-gamma) (unstimulated: 0.3694 + 0.2499 p g/cell vs 0.0662 + 0.0786 pg/cell, P = 0.0137; serum: 1.066 + 0.513 pg/cell vs 0.233 + 0.231 pg/cell, P = 0.0027; serum and IFN-gamma: 1.286 + 0.395 p g/cell vs 0.244 + 0.199 pg/cell, P < 0.0001). These results suggest that IL -6 may play a significant role in the pathogenesis of keloids. (C) 2000 Aca demic Press.