Tumor necrosis factor–α and interleukin-10 contribute to immunoparalysis in patients with acute pancreatitis

Immunoparalysis, defined as downregulation of human leukocyte antigen–DR (HLA-DR) expression on monocytes, is strongly associated with septic complications of acute pancreatitis. However, the possible causes of this immunoparalysis have been largely unknown. A prospective case control study was performed in 54 patients with acute pancreatitis and 24 normal volunteers. HLA-DR expression on monocytes and serum cytokine levels were measured. In addition, monocytes from normal volunteers treated with tumor necrosis factor (TNF)–α in vitro were evaluated for HLA-DR expression and cytokine release. HLA-DR expression was significantly lower in patients with severe pancreatitis than in those with mild acute pancreatitis and healthy volunteers (42.28% ± 11.49% vs. 86.85% ± 14.56% vs. 93.92% ± 7.40%, p < 0.0001). Pearson correlation analysis showed that serum TNF-α and serum interleukin-10 levels were both correlated with HLA-DR expression. In addition, exogenous TNF-α could enhance IL-10 secretion from normal monocytes in a dose–response manner. In addition, TNF-α could downregulate the HLA-DR expression on monocytes even in the presence of anti-IL-10 antibodies. Therefore, both TNF-α and IL-10 contributed to the development of immunoparalysis in patients with acute pancreatitis.