Alcohol abstinence partially restores peripheral mucosal-associated invariant T cells in patients with alcoholic hepatitis

Abstract

Abstract Alcoholic hepatitis (AH) develops in a small percentage of heavy drinkers. The adaptive immune system of AH patients is hyper-activated, yet dysregulated and ineffective against infectious diseases. Mucosal-associated invariant T (MAIT) cells are innate-like lymphocytes that are found in liver, intestinal mucosa, and peripheral blood and contribute to protection against infectious diseases. To determine whether MAIT cells were dysregulated in heavy drinkers and the effect of alcohol abstinence on MAIT cell recovery, we compared peripheral MAIT cells between AH patients and heavy drinkers without liver disease (HDC) at baseline and 6- and 12-month followup. At baseline, AH patients had severely reduced frequency of MAIT cells than HDC and healthy donor controls (HC), whereas MAIT cell frequency was not significantly different between HDC and HC. In addition, MAIT cells in AH patients expressed higher levels of the activation markers (CD69, CD38, and HLA-DR) as well as the immune checkpoint inhibitor PD-1. Multiplex immunoassays showed that plasma levels of several cytokines related to MAIT cell activation were elevated in AH patients (IFN-s, IL-7, IL-15, IL-17, IL-18, and IL-23, and TNF-a). In AH patients, the frequency MAIT cells and CD38-expressing MAIT cells correlated with levels of several cytokines and AST. At followup, AH patients had increased MAIT cell frequency and decreased MAIT cell activation with cessation of alcohol. However, abstinent AH patients still had higher levels of CD38-expressing MAIT cells than HDC at 6-month followup. Conclusion Blood MAIT cells were severely reduced and were dysregulated in AH patients and alcohol abstinence partially reversed abnormalities in MAIT cell frequency and phenotype.