Study on the Correlations among Disease Activity Index and Salivary Transforming Growth Factor-β1 and Nitric Oxide in Ulcerative Colitis Patients

摘要

Growth factors and nitric oxide (NO) play a major role in dysregulated immune response in ulcerative colitis (DC). Recent evidence has shown increased levels of transforming growth factor-β_1 (TGF-β_1) in UC and suggested an anti-inflammatory effect for this factor. Based on our recent study, dysfunctional immunoregulation is present in saliva of UC patients, we hypothesized that salivary level of NO and TGF-β_1 may differ by severity of UC and be useful to determine the activity of the disease. Thirty-seven UC patients and 15 healthy controls were enrolled and saliva samples were obtained. Truelove-Witts severity index and modified Truelove-Witts severity index were used to determine the severity of the disease. NO and TGF-β_1 levels were detected in saliva of all patients and control subjects using enzyme-linked immunosorbent assay. A total of 21 patients had mild disease while 8 had moderate and 8 had severe colitis. Adjusted for baseline characteristics, the levels of NO and TGF-β_1 in different groups were compared. Salivary NO and TGF-β_1 levels were higher in UC patients comparing to controls (P ＜ 0.00005 and P = 0.005, respectively). The levels of NO and TGF-β1 showed no significant differences among the severity groups (P = 0.46 and P = 0.23, respectively). NO levels linearly increased by age (Coeff = 1.5, r = 0.38, P = 0.02). Gender, extension of disease, and medical treatment did not affect NO and TGF-β_1 levels. Although UC patients have abnormal amounts of NO and TGF-β_1 in their saliva, their disease activity cannot be predicted by these factors, which may indicate a pathophysiologic role rather than being nonspecific inflammatory markers for TGF-β_1 and NO.