The interleukin-17 pathway is involved in human alcoholic liver disease.
Immune dysregulations in alcoholic liver diseases are still unclear, especially regarding alcoholic hepatitis inflammatory burst. Interleukin-17 (IL-17) is known to enhance neutrophil recruitment. We studied the IL-17 pathway in alcoholic cirrhosis and alcoholic hepatitis. Patients with alcoholic liver disease were compared with patients with chronic hepatitis C virus (HCV) infection or autoimmune liver disease and with healthy controls. IL-17 plasma levels and peripheral blood mononuclear cell secretion were assessed by enzyme-linked immunosorbent assay (ELISA) and T cell phenotype by flow cytometry. IL-17 staining and co-staining with CD3 and myeloperoxidase were performed on liver biopsy specimens. IL-17 receptor expression was studied on liver biopsies and in human hepatic stellate cells as well as their response to recombinant IL-17 by chemotaxis assays. IL-17 plasma levels were dramatically increased in alcoholic liver disease patients. Peripheral blood mononuclear cells of patients with alcoholic liver disease produced higher amounts of IL-17, and their CD4(+) T lymphocytes disclosed an IL-17-secreting phenotype. In the liver, IL-17-secreting cells contributed to inflammatory infiltrates in alcoholic cirrhosis, and alcoholic hepatitis foci disclosed many IL-17(+) cells, including T lymphocytes and neutrophils. In alcoholic liver disease, liver IL-17(+) cells infiltrates correlated to model for end-stage liver disease score, and in alcoholic hepatitis to modified discriminant function. IL-17 receptor was expressed in alcoholic liver disease by hepatic stellate cells, and these cells recruited neutrophils after IL-17 stimulation in a dose-dependent manner through IL-8 and growth related oncogen alpha (GRO-alpha) secretion in vitro.


CONCLUSIONS
Human alcoholic liver disease is characterized by the activation of the IL-17 pathway. In alcoholic hepatitis, liver infiltration with IL-17-secreting cell infiltrates is a key feature that might contribute to liver neutrophil recruitment. (Clinical trials number NCT00610597).
Lemmers
Arnaud
A
Department of Gastroenterology and Hepato-Pancreatology, Erasme Hospital, Université Libre de Bruxelles, Brussels, Belgium. arnaud.lemmers@erasme.ulb.ac.be
Moreno
Christophe
C
Gustot
Thierry
T
Maréchal
Raphaël
R
Degré
Delphine
D
Demetter
Pieter
P
de Nadai
Patricia
P
Geerts
Albert
A
Quertinmont
Eric
E
Vercruysse
Vincent
V
Le Moine
Olivier
O
Devière
Jacques
J
D000410:Alanine Transaminase / Q000097:blood; D001219:Aspartate Aminotransferases / Q000097:blood; D002097:C-Reactive Protein / Q000378:metabolism; D005260:Female; D055166:Hepatic Stellate Cells / Q000166:cytology / Q000502:physiology; D019698:Hepatitis C, Chronic / Q000097:blood / Q000473:pathology / Q000503:physiopathology; D006519:Hepatitis, Alcoholic / Q000097:blood / Q000503:physiopathology; D006801:Humans; D020381:Interleukin-17 / Q000097:blood* / Q000378:metabolism; D008103:Liver Cirrhosis / Q000097:blood / Q000473:pathology / Q000503:physiopathology; D008104:Liver Cirrhosis, Alcoholic / Q000097:blood / Q000473:pathology / Q000503:physiopathology*; D008297:Male; D009504:Neutrophils / Q000502:physiology; D012016:Reference Values
D020381:Interleukin-17; D002097:C-Reactive Protein; D001219:Aspartate Aminotransferases; D000410:Alanine Transaminase