Circulating adipokines and organ involvement in patients with systemic sclerosis

Background: In recent years, mediators synthesized in the adipose tissue, the so-called adipokines, have been reported to play important roles in the pathogenesis of autoimmune rheumatic diseases. Objective: To compare serum leptin, adiponectin and resistin levels in patients with systemic sclerosis (SSc) and healthy controls. To find possible relationship between serum levels of adipokines and organ involvement with focus on interstitial lung disease in SSc patients. Patients and Methods: Lung involvement was assessed functionally (body plethysmography, diffusing capacity of the lung for carbon monoxide (DLCO) and six-minute walk test) and radiologically (using average disease extent on high resolution computed tomography (HRCT) of the lungs according to the percentage of interstitial changes) in 29 SSc patients. Quantitative sandwich ELISA was used to measure resistin, leptin and adiponectin concentrations in sera of patients and 30 healthy controls. Results: We found no statistically significant differences in serum resistin, leptin and adiponectin levels between SSc patients and the controls. However, serum adiponectin concentrations were significantly lower in active than in inactive patients, they also correlated positively with vital capacity (VC) (p=0.04) and negatively with Valentini activity score (p=0.04). Serum resistin levels were significantly elevated in patients with digital ulcers (p=0.03) and serum concentrations of leptin were associated with the duration of SSc symptoms other than Raynaud’s phenomenon (p<0.01) Conclusions: Serum adiponectin should be further investigated as a candidate for SSc activity marker and resistin may play a role in ulcer development in SSc patients.