Effect of intra-abdominal infection on immunological function and HMGB1/TLR4/NF-κB signaling pathway in patients with severe acute pancreatitis

Abstract

The aim of this article is to investigate the effects of intra-abdominal infection on immunological function and high-mobility group box 1 protein (HMGB1)/toll-like receptor 4 (TLR4)/nuclear factor-κB (NF-κB) pathway in patients with severe acute pancreatitis (SAP). Clinical data of SAP patients were retrospectively analyzed. SAP patients were divided into intra-abdominal infection group (103 SAP patients) and control group (115 SAP patients without intra-abdominal infection). All patients were evaluated with the Acute Physiology and Chronic Health Evaluation (APACHE) II score. Enzyme-linked immunosorbent assay (ELISA) assays were used to detect the levels of serum endotoxin, d-lactate, diamine oxidase, IgG, IgM, IgA, interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF)-α, and HMGB1. Western blotting was performed to detect the levels of TLR4 and NF-κB in peripheral blood lymphocytes. Compared with control group, the APACHE II score (12.60 ± 3.81 vs 9.55 ± 3.02) and serum endotoxin (0.33 ± 0.15 vs 0.19 ± 0.09 EU/mL), d-lactate (4.33 ± 0.16 vs 4.02 ± 0.12 mg/L), and diamine oxidase (3.88 ± 0.16 vs 3.65 ± 0.13 EU/mL) levels in intra-abdominal infection group were increased significantly (all P < 0.001); serum IgG (7.33 ± 0.82 vs 9.05 ± 0.90 g/L), IgM (1.04 ± 0.49 vs 1.18 ± 0.53 g/L), and IgA (1.65 ± 0.79 vs 1.96 ± 0.88 g/L) levels in intra-abdominal infection group were decreased significantly, while serum IL-1β (118.55 ± 17.04 vs 83.61 ± 12.28 ng/L), IL-6 (12.05 ± 7.69 vs 9.89 ± 6.77 ng/L), TNF-α (25.61 ± 8.76 vs 19.20 ± 8.33 ng/L), and HMGB1 (48.91 ± 20.63 vs 32.74 ± 17.05 μg/L) levels were increased significantly (all P < 0.05); TLR4 and NF-κB in intra-abdominal infection group were increased significantly (both P < 0.001). The intra-abdominal infection can lead to intestinal barrier dysfunction, aggravated inflammatory response, and immune dysfunction in SAP patients, which may be related to the activation of HMGB1/TLR4/NF-κB pathway caused by intra-abdominal infection.