Favorable role of interleukin 10 in patients with polymyalgia rheumatica.

OBJECTIVE

To determine the relationship between the antiinflammatory molecule interleukin 10 (IL-10) and disease symptoms, IL-1beta, tumor necrosis factor (TNF), and IL-1 receptor antagonist (IL-1ra) in patients with polymyalgia rheumatica (PMR).

METHODS

In 102 patients with PMR, we determined the severity of the disease by the presence of typical clinical symptoms (symptom score with a maximum of 10 points). IL-10, IL-1beta, TNF, and IL-1ra were measured in all patients and 31 age matched healthy controls by enzyme immunometric assays.

RESULTS

Compared to patients with elevated serum levels, patients with normal serum levels of IL-10 (below the mean + 3 SD of controls, 7.79 pg/ml) more often had adynamia (p = 0.045), bilateral muscular pain in shoulders, upper 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 higher symptom score (5.5+/-0.4 vs 3.7+/-0.3; p < 0.001). The overall symptom score correlated negatively with IL-10 serum levels (Rrank = -0.421, p < 0.001). IL-10 correlated negatively with IL-1beta (p = 0.013) and TNF-alpha (p = 0.039). The association between elevated serum levels of IL-10 and low serum levels of IL-1beta and TNF was observed only in patients with corticosteroid treatment. In these patients, elevated serum levels of IL-10 were positively associated with an increased ratio of IL-1ra to IL-1beta.

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 with PMR.