We investigated the risk factors for radiographic bone damage to foot joints in patients with chronic gout among various patient characteristics and serum inflammatory cytokines such as interleukin 1ß (IL-1ß), IL-6, soluble IL-6 receptor (sIL-6R), osteoprotegerin (OPG), and receptor activator of nuclear factor-κB ligand (RANKL).
Fifty consecutive male patients with gout and 54 age-matched healthy male controls were enrolled. Serum levels of cytokines including IL-1ß, IL-6, sIL-6R, OPG, and RANKL were measured using ELISA. Radiographic damage indices including erosion scores, narrowing scores, and total scores for foot joints were assessed according to a modified Sharp-van der Heijde system.
There were significant differences in serum IL-1ß, IL-6, sIL-6R, OPG, and RANKL levels between patients with gout and the controls, after adjustment for confounding factors such as age, body mass index, blood urea nitrogen, creatinine, triglyceride, and fasting blood glucose (p = 0.034 for IL-1ß, p < 0.001 for IL-6, p = 0.040 for sIL-6R, p = 0.002 for OPG, and p = 0.018 for RANKL). Radiographic damage indices (erosion, narrowing, and total scores) were negatively associated with serum sIL-6R and OPG levels in multivariable-adjusted regression analysis. Serum sIL-6R levels in patients without radiographic damage were higher than in those with damage (p = 0.006).
Radiographic damage in patients with chronic gouty arthritis was negatively associated with serum sIL-6R and OPG. Further study on the role of inflammatory cytokines in the pathogenesis of radiographic damage in gout is needed.