Different Profile of Cytokine Production in Patients with Systemic Sclerosis and Association with Clinical Manifestations

Immune dysregulation is a central process in the pathogenesis of systemic sclerosis (SSc). Cytokines produced by lymphocytes and monocytes are important mediators and induce tissue damage, recruit additional inflammatory cells, and promote extracellular matrix production and fibrosis. In the present research, we aimed to study the associations between levels of cytokines in serum and culture supernatants from peripheral blood mononuclear cells (PBMCs) and clinical manifestations in SSc patients. Serum samples were obtained from 56 SSc patients and 56 unrelated age- and gender-matched healthy individuals. Resting and anti-CD3/CD28-stimulated PBMC cultures were obtained from 19 SSc patients and 8 healthy controls. IL-2, IL-4, IL-6, IL-10, IL-17A, TNF, and IFN-γ levels were measured by ELISA or CBA. Serum cytokines, except IL-17A, were below the kit detection limit in most of the patients and controls. In unstimulated PBMC, the production of TNF(p = 0.004), IL-10(p = .048), IL-2(p < 0.001), and IL-6 (p = 0.01) was higher in SSc patients than in healthy controls. After anti-CD3/CD28 stimulation, scleroderma PBMCs had lower concentrations of TNF(p = 0.009), IL-10(p = .018), and IL-2(p = .002) than HC. In unstimulated PBMC, IL-2 concentration was higher in patients with esophageal dysmotility (p = 0.04), and IL-10 levels had a positive correlation with modified Rodnan score (p = 0.03). After anti-CD3/CD28 stimulation, higher levels of IL-2 and IL-4 were observed in SSc patients with lung fibrosis (p = 0.01 and 0.006, respectively), and higher levels of IL-10 (p = 0.04) and IL-4 (p = 0.04) in patients with digital ulcers. In conclusion, SSc patients have a different profile of cytokine production and this was associated with clinical manifestations.