Decreased levels of regulatory B cells in patients with acute pancreatitis: association with the severity of the disease

Early stratification of the severity of acute pancreatitis (AP) is clinically important. Regulatory B cells have been found to be associated with disease activity of autoimmune diseases. However, the role of Regulatory B cells in AP remains unknown. We investigate the dynamic longitudinal changes in circulating IL-10-producing B cells (B10) and memory CD19(+)CD24(hi)CD27(hi) cells in patients with AP to evaluate their prediction utility for AP severity. B10, CD19(+)CD24(hi)CD27(hi) cells, inflammatory markers and cytokines were detected in patients with AP immediately after admission to the hospital (day 1), then on the third and seventh days. We observed decreases in lymphocytes, CD19(+), B10, CD19(+)CD24(hi)CD27(hi) cells and lower mean fluorescence intensity (MFI) of CD80 and CD86 on B10 or CD19(+)CD24(hi)CD27(hi) cells in patients with AP, especially in those with severe acute pancreatitis (SAP). CD19(+)CD24(hi)CD27(hi) cells from patients with AP suppressed the cytokine productions of CD4(+) T cells and CD14(+) monocytes, but had impaired ability to induce regulatory T cells response. B10 and CD19(+)CD24(hi)CD27(hi) cells significantly increased in patients with mild acute pancreatitis (MAP) from day 1 to day 7, whereas these indexes remained stable in patients with SAP. B10 or CD19(+)CD24(hi)CD27(hi) cells were negatively correlated with the severity index (APACHE II score), inflammatory markers (C-reactive protein, CD64 index), and cytokines (IL-6, IL-17, TNF-α). Furthermore, receiver operating characteristic (ROC) curve analysis revealed that B10 and CD19(+)CD24(hi)CD27(hi) cells could predict the development of SAP. Thus, the detection of B10 and CD19(+)CD24(hi)CD27(hi) cells may be a practical way to improve the early assessment of AP severity.