Abstract: Objective To investigate the relationship between CD3⁺T, CD4⁺T, CD8⁺T cells, Th1/Th2 cytokines IL-2, IL-4, IL-6, sIL-2R and the pathogenesis as well as disease activity in patients with cutaneous nodular vasculitis (NV). Methods Cytokines IL-2, IL-6, sIL-2R and cell surface markers CD3⁺, CD4⁺ and CD8⁺ were detected by flow cytometry and ELISA with peripheral blood mononuclear cells from patients and controls. Expressions of IL-2, IL-4 and CD3⁺, CD4⁺, CD8⁺ were determined by immunohistochemistry in patients' lesions in situ. Results Serum levels of IL-2, IL-6 and sIL-2R were significantly increased in patients with active NV compared with those in inactive stage(P<0.01) and in controls(P<0.01). There were no significant differences of the percentage of CD3⁺T, CD4⁺ and CD8⁺T in peripheral blood between patients with active NV and patients in stable stage, as well as controls. The numbers of CD3⁺T, CD4⁺T cells and IL-2-positive cells, except IL-4 positive cells, were significantly increased in biopsy tissues from NV patients compared with those from normal controls (P<0.01). Conclusions Th1 immune response, as indicated by the predominance of IL-2, may be involved in the pathogenesis of nodular vasculitis. It is suggested that IL-2 in both sera and tissue infiltration be associated with the disease activity.

Key words: Vasculitis, Nodular, Cytokine