Deficiencies of Circulating Mucosal-associated Invariant T Cells and Natural Killer T Cells in Patients with Acute Cholecystitis.

Mucosal-associated invariant T (MAIT) cells and natural killer T (NKT) cells are known to play crucial roles in a variety of diseases, including autoimmunity, infectious diseases, and cancers. However, little is known about the roles of these invariant T cells in acute cholecystitis. The purposes of this study were to examine the levels of MAIT cells and NKT cells in patients with acute cholecystitis and to investigate potential relationships between clinical parameters and these cell levels. Thirty patients with pathologically proven acute cholecystitis and 47 age- and sex-matched healthy controls were enrolled. Disease grades were classified according to the revised Tokyo guidelines (TG13) for the severity assessment for acute cholecystitis. Levels of MAIT and NKT cells in peripheral blood were measured by flow cytometry. Circulating MAIT and NKT cell numbers were significantly lower in acute cholecystitis patients than in healthy controls, and these deficiencies in MAIT cells and NKT cell numbers were associated with aging in acute cholecystitis patients. Notably, a reduction in NKT cell numbers was found to be associated with severe TG13 grade, death, and high blood urea nitrogen levels. The study shows numerical deficiencies of circulating MAIT and NKT cells and age-related decline of these invariant T cells. In addition, NKT cell deficiency was associated with acute cholecystitis severity and outcome. These findings provide an information regarding the monitoring of these changes in circulating MAIT and NKT cell numbers during the course of acute cholecystitis and predicting prognosis.