Association of TG2 from mast cells and chronic spontaneous urticaria pathogenesis

Abstract Background Mast cells and their mediators play important roles in chronic spontaneous urticaria (CSU) pathogenesis. Transglutaminase 2 (TG2) is expressed in activated mast cells and contributes to airway inflammation in allergic asthma. Objective To investigate the role of TG2 in CSU. Methods Patients with CSU (n = 72) and healthy controls (n = 51) were evaluated. Skin biopsy specimens were obtained from 5 patients with CSU and 2 healthy controls. Cord blood–derived human mast cells and peripheral blood–derived human mast cells were activated with IgE. TG2 activity and inflammatory mediators, such as histamine, leukotriene C4, and cytokines, were measured in serum or supernatant from cultured mast cells by enzyme-linked immunosorbent assay. Colocalization of mast cells and TG2 was determined in skin tissues by immunofluorescence. Results TG2 activity was significantly higher in serum samples from patients with CSU than in serum samples from healthy controls ( P P P P Conclusion Our findings suggest that TG2 expressed in and released from mast cells plays an important role in CSU pathogenesis.