Objective: The relationship between systemic sclerosis (SSc) and interleukin 23 (IL-23), a cytokine associated with the differentiation of T lymphocytes, is unknown. We investigated serum IL-23 levels and their clinical association in patients with SSc.
Methods: Serum IL-23 levels were examined by ELISA in 63 patients with SSc, 15 patients with systemic lupus erythematosus (SLE), and 31 healthy individuals. SSc patients comprised 25 with limited cutaneous SSc and 38 with diffuse cutaneous SSc.
Results: Serum IL-23 levels were significantly elevated in SSc patients compared to patients with SLE (p < 0.05) and controls (p < 0.005). Elevated serum IL-23 levels were associated with the disease duration (p < 0.05) and the prevalence of pulmonary fibrosis (p < 0.05), although they were not associated with other clinical features, including the extent of skin sclerosis or the severity of pulmonary fibrosis.
Conclusion: The results suggest that IL-23 is associated with induction of SSc and that blockade of IL-23 can be a potential therapeutic strategy in early SSc.