Elevated serum levels of interleukin 4 (IL-4), IL-10, and IL-13 in patients with systemic sclerosis.

To determine whether serum interleukin 4 (IL-4), IL-10, and IL-13 levels in patients with systemic sclerosis (SSc) are elevated and whether they correlate with the clinical or serologic features of this disease. Serum samples from patients with limited cutaneous SSc (ISSc) (n = 45), diffuse cutaneous SSc (dSSc) (n = 28), and control subjects (n = 30) were examined by ELISA. Serum IL-4 and IL-13 levels were significantly higher in patients with ISSc and dSSc than in the controls. Serum IL-10 levels were significantly higher in the patients with dSSc compared with controls. Elevated IL-10 levels were detected frequently in patients with arthralgia. Serum IL-13 levels correlated with erythrocyte sedimentation rates and C-reactive protein levels in patients. We suggest that IL-4, IL-10, and IL-13 may be some of the cytokines that contribute to the disease process, and that IL-13 may be a serologic indicator of systemic inflammation in patients with SSc.