Cytokines and Effector/Regulatory Cells Characterization in the Physiopathology of Cutaneous Lupus Erythematous: A Cross-Sectional Study

Abstract

We compared the presence of diverse cytokines and regulatory T and B cells in skin biopsies of discoid lupus erythematosus (DLE) and subacute cutaneous lupus erythematosus (SCLE). We included 19 patients with DLE, 13 with SCLE, 8 healthy controls, and 5 patients with hypertrophic scars. We assessed the CLASI activity score. To determine IL-22-producing cells and the subpopulation of CD4+/IL-17A+-, CD4+/IL-4+-, and CD4+/IFN-γ+-expressing T cells, CD123+/IDO+ pDCs, CD25+/Foxp3+ Tregs, and CD20+/IL-10+-producing B cells, an immunostaining procedure was performed. Also intracellular IL-22, IL-17, IL-4, IFN-γ, and Foxp3 in CD4 T cells, IL-10 in B cells, and IDO in pDCs were analyzed by flow cytometry in peripheral blood. The main cellular participation in both lupus groups was IL-17- and IL-22-producing cell responses both at skin and at peripheral blood but prevailed in DLE. The CLASI activity scores negatively correlated with Th22 subpopulation and positively correlated with CD25+/Foxp3+ Treg cells. In conclusion a proinflammatory and regulatory imbalance coexists in cutaneous lupus, both responses being more intense in DLE.