Increased frequency of circulating Tfh cells in patients with acute pancreatitis

Considered as true helper cells for B cells in antibody response, Tfh cells are associated with inflammation and immune abnormality. Acute pancreatitis is an acute abdominal disease characterized by inflammatory response and immune disorder. Thus, our objective was to study the frequency of circulating Tfh cells, together with the Tfh cell-related CD4⁺ T cells and inflammatory factors in patients with acute pancreatitis. We first examined the frequency of circulating Tfh cell subsets by detecting the expression of CXCR5, PD-1, ICOS and IL-21 by flow cytometry analysis. Then we investigated the abundance of helper T cells and Treg cells. In addition, the plasma level of IgA, IgM, and Tfh cell-related inflammatory factor were detected by cytometric bead array. We showed that the frequency of circulating Tfh cells increased significantly in patients of acute pancreatitis, including CD4⁺CXCR5⁺ cells, CD4⁺CXCR5⁺PD-1⁺ cells, CD4⁺CXCR5⁺ICOS⁺ cells, and CD4⁺CXCR5⁺IL-21⁺ cells. Also, increases in plasma IL-1, IL-6, IL-8, IL-17, IL-21 and IgA were observed in patients with acute pancreatitis compared to HCs. This finding indicates that Tfh cells play a vital role in the development and progression of acute pancreatitis that is dependent on IL-6 and IL-21.