Acute alcoholic hepatitis and cellular Th1 immune responses to alcohol dehydrogenase.
Keywords
Abstract
BACKGROUND
Alcoholic hepatitis is characterised by florid hepatic inflammation, liver failure, and death within 28 days in 35% of patients. We recently showed proliferative peripheral blood mononuclear cell (PBMC) responses to alcohol dehydrogenase (ADH) in patients with alcohol-related cirrhosis, associated with T-helper-type 1 (Th1) immunity and disease severity. We aimed to define whether ADH-specific cellular immunity is present in alcoholic hepatitis.
METHODS
PBMCs were collected from 15 patients with alcoholic hepatitis (modified Maddrey's discriminant function >32), nine with alcohol-related cirrhosis (long-term alcohol abstinence), and three healthy controls. 25 overlapping peptides, spanning the human ADH β1 subunit, were constructed. Proliferation to ADH peptides (1 × 10(5) cells per well, cultured with 10 mM peptides for 7 days) was assessed by (3)H-thymidine incorporation. A stimulation index (SI) of 2·5 or more was regarded as positive. ELISA measured concentrations of interferon γ (IFNγ), interleukin (IL) 17, and IL4 from supernatant.
RESULTS
PBMCs from seven of 15 patients with alcoholic hepatitis recognised one to three ADH peptides (SI ≤5·7). IFNγ (mean 390·9 pg/mL [SE 31·4]) was detected in 48% of wells, IL17 (20·1 [3 ·4]) in 15%, and IL4 (90·5 [9·3]) in 14%. PBMCs from six of the nine patients with alcohol-related cirrhosis recognised one to five peptides (SI ≤5·2). IFNγ (360·7 [58·9], p>0·05) was detected in 31% of wells, IL17 (57·7 [10·9], p=0·0006) in 19%, and IL4 (219·7 [11·2], p=0·0012) in 28%. PBMCs from two healthy controls recognised one to two peptides (SI ≤3·1); all cytokine levels were below baseline.
CONCLUSIONS
Proliferative anti-ADH immune responses in alcoholic hepatitis focused on individual epitopic regions. Predominance of proinflammatory Th1 responses was more pronounced in alcoholic hepatitis than in alcoholic-related cirrhosis. This finding requires investigation of targeted therapies to inhibit Th1 immunity in alcoholic hepatitis.
BACKGROUND
Wellcome Trust.
