Pro-inflammatory adipokine profile in psoriatic arthritis: results from a cross-sectional study comparing PsA subset with evident cutaneous involvement and subset “sine psoriasis”

Objective Adipokines have been considered in the pathogenesis of the inflammatory processes of psoriatic arthritis (PsA). The main aim of the current study is to investigate possible differences and correlations between adipokines and clinical expression in PsA patients with and without clinical evident psoriasis. Methods Serum levels of TNF-α, IL-6, leptin, resistin, visfatin, and ghrelin were measured in 80 consecutive PsA patients, 42 PsA patients with clinically evident psoriasis (group 1) and 38 PsA patients sine psoriasis (group 2), fulfilling the CASPAR criteria. Results Patients of the two groups were not significantly different for levels of TNF-α, IL-6, leptin, resistin, visfatin, and ghrelin. In the entire cohort, a positive association has been shown between leptin levels and female gender ( β = 0.3, p = 0.001), BMI ( β = 0.8, p < 0.0001), tender joint count ( β = 0.23, p = 0.05), and patient pain-VAS score ( β = 0.4, p = 0.049). In group 1, serum concentration of leptin was associated with female gender ( β = 0.41, p < 0.0001) and BMI ( β = 0.6, p = 0.012), whereas in group 2, a positive association was shown between leptin levels and BMI ( β = 0.7, p = 0.003) and CRP ( β = 0.35, p = 0.012). With regard to resistin, in the multivariate model, only the association between resistin and IL-6 was found ( β = 0.33, p = 0.002). The association between resistin and IL-6 was confirmed in group 1 ( β = 0.46, p = 0.004) but not in group 2. Conclusions Until today, the present study represents the first investigating difference in the adipokine pattern between PsA patients with psoriasis and sine psoriasis. We report a strict interplay between leptin, female gender, BMI, and inflammatory activity in overall PsA patients. In PsA patients with clinical evident psoriasis, leptin was associated with female gender and BMI, and a close association between resistin and IL-6 was found. Further, a positive association between leptin levels and BMI and CRP was found in PsA sine psoriasis patients. Further studies are also advocated for clarifying the possible role of these adipokines as laboratory findings or as disease mediators in addressing the different phenotypes of the disease. Key Points • Levels of TNF-α, IL-6, leptin, resistin, visfatin, and ghrelin did not differ between PsA patients with clinical evident psoriasis and PsA sine psoriasis. • There is a strict interplay between leptin, female gender, BMI, and inflammatory activity in PsA. • There is a close association between resistin and IL-6 in PsA patients with clinical evident psoriasis.