Favorable role of interleukin 10 in patients with polymyalgia rheumatica

Objective. To determine the relationship between the antiinflammatory molec ule interleukin 10 (IL-10) and disease symptoms, IL-1 beta, tumor necrosis factor (TNF), and IL-1 receptor antagonist (IL-1ra) in patients with polymy algia rheumatica (PMR). Methods. In 102 patients with PMR, we determined the severity of the diseas e by the presence of typical clinical symptoms (symptom score with a maximu m of 10 points). IL-10, IL-1 beta, TNF, and IL-1ra were measured in all pat ients and 31 age matched healthy controls by enzyme immunometric assays. Results. Compared to patients with elevated serum levels, patients with nor mal serum levels of IL-10 (below the mean +3 SD of controls, 7.79 pg/ml) mo re often had adynamia (p = 0.045), bilateral muscular pain in shoulders, up per arms or neck (p = 0.045), bilateral muscular pain in the pelvic girdle (p < 0.001), headache (p = 0.014), morning stiffness (p < 0.001), symptoms of depression (p = 0.013), and initial weight loss (p = 0.011), and had a h igher symptom score (5.5 +/- 0.4 vs 3.7 +/- 0.3; p < 0.001). The overall sy mptom score correlated negatively with IL-10 serum levels (R-rank = -0.421, p < 0.001). IL-10 correlated negatively with IL-1 beta (p = 0.013) and TNF -alpha (p = 0.039). The association between elevated serum levels of IL-10 and low serum levels of IL-1 beta and TNF was observed only in patients wit h corticosteroid treatment. In these patients, elevated serum levels of IL- 10 were positively associated with an increased ratio of IL-1ra to IL-1 bet a. Conclusion. Elevated serum levels of IL-10 were associated with a more mild form of PMR. This study indicates a favorable role of IL-10 in patients wi th PMR.