Decrease of Membrane B7-H5 on CD14+ Cells in Severe Acute Pancreatitis Is Related to RANSON Scores and APACHE II Scores.

Background: B7-H5 is an important ligand which is deeply involved in the immune response in various diseases. However, its clinical usefulness as an early indicator in acute pancreatitis (AP) remains unclear.

Aims: To determine the role of B7-H5 in severe acute pancreatitis (SAP).

Methods: Whole blood samples from patients with SAP (n = 20) and healthy donors (n = 20) were collected. Expression of soluble B7-H5 (sB7-H5) in plasma was determined by ELISA and membrane B7-H5 (mB7-H5) on the peripheral CD14+ cells was determined by flow cytometry. Peripheral blood mononuclear cells (PBMCs) were isolated from healthy donors and stimulated with serum from SAP patients, lipopolysaccharide (LPS), TNF-α, or IFN-γ, then, sB7-H5 and mB7-H5 were measured. The relationship between expression levels of mB7-H5 and clinical features of SAP patients were analyzed.

Results: The expression levels of sB7-H5 in plasma were increased and the expression levels of mB7-H5 on the peripheral CD14+ cells were decreased in SAP patients. These changes of B7-H5 expression pattern in cultured PBMCs could be induced by stimulation with serum from SAP patients, LPS, TNF-α, or IFN-γ. Expression levels of mB7-H5 were negatively related to levels of hematocrit, urea nitrogen, creatinine, lactic acid, RANSON scores, and APACHE II scores.

Conclusion: Changes of B7-H5 expression pattern were involved in immune response of SAP. Innate immunity activation-induced decrease of mB7-H5 might be related to poor prognosis of SAP patients.