Background Adipose tissue is a source of factors stimulating the pro-oxidative-antioxidant system, such as adipokines, whose functions are closely associated with metabolic abnormalities and damage by oxidative stress. There are only few reports in literature about the correlation between body mass index (BMI), serum levels of adipokines and clinical manifestations of SSc.
Objectives We evaluated serum levels of adipokines (leptin, resistin, visfatin, adiponectin) and cytokines (TNFα, IFNγ, IL-2, IL-10, IL-17) in SSc and controls (HD) and their pattern according the clinical and laboratory SSc features.
Methods 89 SSc pts satisfying ACR EULAR criteria (age 52 ± 14.4 years and disease duration of 8.14 ± 6.6) and 26 HD were enrolled. Serum levels of Adiponectin, Leptin, Resistin, Visfatin, TNFα, IFNγ, IL-2, IL-10, IL-17A were measured using Bio-Rad kits and Multiplex Immunoassay tool. In all participants we collected clinical and laboratory features, such as visceral involvement, BMI, WHR (Waist to Hip Ratio), index of cardiovascular risk, acute phase reactants, cholesterol, triglycerides, smoking status, comorbidity and therapy. Data were analysed using IBM-SPSS Statistics 20 software. Mann-Whitney U-test or t-Student for unpaired data or Kruskal-Wallis test or ANOVA were used for comparison between groups. Spearman's or Pearson's test were used for correlations. A p-value ≤0.05 was considered statistically significant.
Results The weight of SSc and HD differed (p<0,05) which was higher in HD. Serum levels of Leptin, Resistin, Visfatin and IL-10, IL-17 were increased in SSc compared to HD (p<0.05). In SSc, TNFα serum levels were not different from HD. Leptin levels positively correlated with body weight and BMI that in turn correlated with the values of ESR, CRP, WHR, triglycerides and cholesterol serum levels. Increased levels of IL-2, IL-10, IL-17, IFNγ, Leptin and Visfatin were found in overweight/obese SSc pateints (p<0.05) in respect to HD. TNFα was significantly increased in underweight patients (p=0.03) and there was a significant difference compared with normal weight (p=0.018). TNFα levels correlated with IL-2, IL-10, IL-17 and IFNγ levels and with esophageal involvement. There were no differences in cytokine levels between groups when correlated to skin subset, disease duration (Early/Late) and different class of cardiovascular risk. In HD, no statistically significant correlation between weight, TNFα and Leptin levels was detected.
Conclusions Adipokines may play a role in inflammatory and immune pathways in SSc pathogenesis. The present data suggest a role for Leptin and TNFα as new potential SSc related circulating biomarker. Categories of modified BMI (underweight and obesity) seem to be associated to a different and a significant organ involvement in SSc. In underweight subjects, the increase of TNFα may be involved in the cachectic status, thus the role of TNFα needs be confirmed in further prospective longitudinal studies investigating also its correlation with disease severity and activity.
Pehlivan Y et al. Serum leptin, resistin and TNFa levels in patients with systemic sclerosis: the role of adipokines in scleroderma, Int J of Rheum Dis 15, 374–379, 2012
Disclosure of Interest None declared