Diminished Non-Classical Monocytes in the Blood Associate with Disease Severity in Alcoholic Hepatitis

Elisabeth Busk Rasmussen,1 Lotte Lindgreen Eriksen,2 Stinne Ravn Greisen,1 Anne Louise Hansen,1 Mikkel Carstensen,1 Thomas Damgaard Sandahl,2 Sidsel Støy,2 Tue Wenzel Kragstrup1,3 1Department of Biomedicine, Aarhus University, Aarhus, Denmark; 2Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus, Denmark; 3Diagnostic Center, Silkeborg Regional Hospital, Silkeborg, DenmarkCorrespondence: Tue Wenzel KragstrupDepartment of Biomedicine, Aarhus University, Wilhelm Meyers Allé 4, Aarhus C, DK-8000, DenmarkTel +4587167265Email kragstrup@biomed.au.dkObjective: Alcoholic hepatitis (AH) holds a high mortality, and vast macrophage infiltration of the liver is involved in the progressive liver injury. No efficient medical treatment exists, and macrophages may be a future treatment target. Here, we examine associations between non-classical monocyte subsets and cell surface markers of migration with disease activity in patients with severe AH.Methods: We analyzed samples from two cohorts of patients with AH. Cohort 1 included 15 AH patients, followed for 30 days, and 8 healthy controls (HCs). Cohort 2 included 23 AH patients, followed for 90 days, and 9 HCs. Peripheral blood mononuclear cells (PBMCs) from both cohorts were analyzed by flow cytometry. Liver biopsies from cohort 2 were analyzed by RNA sequencing.Results: Circulating non-classical monocytes in all but absent in patients with AH compared to HC in both cohorts (both p< 0.0001). The frequency of non-classical monocytes was significantly associated with Maddrey’s discriminant function (mDF) (r=− 0.79, p=0.0008, cohort 1), Child–Pugh score (CP) (r=− 0.56, p=0.03, cohort 1), Model for End-Stage Liver Disease (MELD) (r=− 0.54, p=0.02, cohort 2) and C-reactive protein (CRP) (r=− 0.51, p=0.027, cohort 2). The surface expression of CD11b was increased on non-classical monocytes in patients with AH compared to HC (p< 0.0001) (cohort 1). The mRNA expression of CD11b was increased in liver biopsies in patients with AH compared to HC (cohort 2) (p< 0.0001).Conclusion: In this study, we describe an almost complete depletion of circulating non-classical monocytes in the blood in two independent cohorts of patients with AH, which may be associated with a possible harmful recruitment of these cells to the liver. These results contribute to a better understanding of the disease, which hopefully can lead to therapies that target the acute inflammatory response leading to severe AH.Keywords: monocytes, non-classical, alcoholic hepatitis, CD11b, CCR2, CX3CR1