Tumor necrosis factor-like weak inducer of apoptosis and its receptor fibroblast growth factor-inducible 14 are expressed in urticarial vasculitis.

Tumor necrosis factor (TNF)-like weak inducer of apoptosis (TWEAK), a member of the TNF family, has been implicated as a pro-inflammatory cytokine in many types of autoimmune and infectious diseases. However, information about TWEAK in dermatological diseases is limited. To date, no studies have investigated the roles of TWEAK in patients with urticarial vasculitis (UV). This study aimed to assess serum TWEAK levels, together with TWEAK and fibroblast growth factor-inducible 14 (Fn14) expressions of skin lesions in patients with UV. Serum TWEAK levels in patients with UV, together with patients with cutaneous leukocytoclastic angiitis (CLA) and healthy controls were detected by enzyme-linked immunosorbent assay; TWEAK and Fn14 expressions of skin lesions were analyzed by immunohistochemistry. Results showed that TWEAK and Fn14 were abundantly expressed in the dermal vessel wall of lesional skin in patients with UV but not healthy controls. Serum TWEAK levels in the acute stage in patients with UV were significantly higher than those in the convalescent stage and healthy controls. Serum TWEAK levels were elevated significantly in patients with CLA compared with those in healthy controls. Our previous study indicated that TWEAK may be an important mediator for the development of vascular inflammation in skin. In addition, we also found that TWEAK blockade substantially reduced vascular damage and perivascular leukocyte infiltrates in lipopolysaccharide-induced cutaneous vasculitis. Our study shows that TWEAK may be associated with the pathogenesis of UV; it is therefore suggested that TWEAK may be a potential therapeutic target for UV and other types of cutaneous vasculitis.