Differential expression of interleukin-2 by anti- CD3-stimulated peripheral blood mononuclear cells in patients with psoriatic arthritis and patients with cutaneous psoriasis.

The differences in systemic T-cell responses between patients with psoriatic arthritis ( Ps A) and patients with cutaneous psoriasis ( Ps) are still largely unknown. To determine differential features that could be used to distinguish Ps A from Ps, we compared the cytokine secretion profile of circulating T cells in patients with Ps A, patients with cutaneous Ps and control subjects. We determined Th1, Th2 and Th17 cytokine secretion of anti- CD3-stimulated peripheral blood mononuclear cells ( PBMCs) using a cytokine bead array. Normality of data distribution was assessed by the Shapiro- Wilk test, and statistical significance was calculated by the Mann- Whitney test. Phenotypic characterization of circulating T cells was performed by fluorescence-activated cell sorting analysis. We found that the major systemic differences distinguishing Ps A from cutaneous Ps were the increased secretion of interleukin ( IL)-2 by α- CD3-stimulated PBMCs and a higher percentage of circulating CD3+ T cells expressing the proliferation marker CD71 in Ps A. These results indicate IL-2 as a possible biomarker of Ps A, and suggest a role of circulating T cells with high proliferative capacity in the pathogenesis of Ps A. [ABSTRACT FROM AUTHOR]