The role of Th1 and Th2 cells in the severity of acute pancreatitis

Objective To investigate the relationship between the levels of Th1 and Th2 cells and their cytokines IFN-γ, TNF-α, IL-2, IL-4, IL -5 and IL-13 in peripheral blood of patients with acute pancreatitis and the clinical severity of acute pancreatitis, and to evaluate the diagnostic value and significance for the severity of acute pancreatitis. Methods This study enrolled 72 patients with acute pancreatitis and 30 healthy controls admitted to the Emergency Surgery Department of the First Affiliated Hospital of Zengzhou University from January 2015 to June 2017. The patients were divided into the mild MAP group, moderate MSAP group, and severe SAP group according to the 2012 Atlanta classification criteria. Whole blood and serum samples were taken on the day of admission for all confirmed cases, the number of Th1 and Th2 cells was detected by flow cytometry, the expression levels of IFN-γ, TNF-α, IL-2, IL-4, IL-5 and IL-13 were determined by ELISA. The total length of hospital stay and length of hospital stay in ICU of each group were recorded. The number of Th1 and Th2 cells and the expression of related cytokines in patients with mild, moderate and severe acute pancreatitis were compared by one-way analysis of variance. Pearson linear correlation was used to analyze the correlation between Th1and Th2 cytokines and the length of hospital stay and the length of hospital stay in ICU. A P<0.05 was considered statistically significant. Results Compared with the healthy controls, the number of Th1 and Th2 cells, the levels of Th1 cytokine IFN-γ, TNF-α, IL-2 and Th2 cytokine IL-4 were significantly increased in acute pancreatitis. Th1 cells in the SAP group were significantly higher than those in the MAP and MSAP groups (F=11.137, P<0.01), while Th2 cells in the SAP group were significantly lower than those in the MAP and MSAP groups (F=9.493, P<0.01), and there was no significant difference between the MAP group and MSAP group. The expression level of IFN-γ was higher in the SAP and MSAP groups than that in the MAP group (F=8.605, P=0.001). The expression level of TNF-α was higher in the SAP group than those in the MSAP and MAP groups (F=11.847, P<0.01), and the IL-4 expression level was significantly lower in the SAP group than those in the MAP and MSAP groups (F=8.042, P=0.001). The expression level of IFN-γ was positively correlated with the length of hospital stay and the length of hospital stay in ICU (r=0.569, P=0.014; r=0.538, P=0.021). The expression level of TNF-α was positively correlated with the length of hospital stay (r=0.475, P=0.046). The expression level of IL-4 was negatively correlated with the length of hospital stay and the length of hospital stay in ICU (r=-0.577, P=0.012; r=-0.657, P=0.003). Conclusions Th1 and Th2 cells and their associated inflammatory factors IFN-γ, TNF-α, IL-2 and IL-4 are elevated in patients with acute pancreatitis.The increase in the number of Th1 proinflammatory cytokines IFN-γ, TNF-α and Th1 cells tends to aggravate the development of acute pancreatitis, and the increase in the number of Th2 cells and the anti-inflammatory cytokine IL-4 are associated with a better prognosis. Key words: Acute pancreatitis; Th1 cells; Th2 cells; Cytokine; Lymphocyte