Cytotoxic NK cells phenotype and activated lymphocytes are the main characteristics of patients with alcohol-associated liver disease

T cells, natural killer (NK) and NKT cells have opposing actions in the development of alcohol-associated liver fibrosis. We aimed to evaluate the phenotype of NK cells, NKT cells and activated T cells in patients with alcohol use disorder (AUD) according to the presence of advanced liver fibrosis (ALF). Totally, 79 patients (51-years, 71% males) were admitted to treatment of AUD. ALF was defined as FIB4-score > 2.67. Immunophenotyping of NK cells (CD3(−)CD56(+)CD16(+), CD3(−)CD56(+)CD16(−), CD3(−)CD56(−)CD16(+)), NKT-like (CD3(+)CD56(+)), and the activation status of CD4(+), CD8(+) and regulatory T cells (Tregs) were evaluated according to the HLA-DR expression. Patients had an AUD duration of 18 ± 11 years with a daily alcohol consumption of 155 ± 77 gr/day prior to hospital admission. The values of absolute cells were 2 ± 0.9 cells/L for total lymphocytes, 1054 ± 501 cells/µL for CD4(+), 540 ± 335 cells/µL for CD8(+), 49.3 ± 24.8 cells/µL for Tregs, 150.3 ± 97.5 cells/µL for NK cells and 69.8 ± 78.3 cells/µL for NKT-like. The percentage of total NK cells (11.3 ± 5.5% vs. 7 ± 4.3%, p < 0.01), CD3(−)CD56(+)CD16(+) regarding total lymphocytes (9.7 ± 5.1% vs. 5.8 ± 3.9%, p < 0.01), activated CD4(+) cells (5.2 ± 3.2% vs. 3.9 ± 3%, p = 0.04) and activated CD8(+) cells (15.7 ± 9.1% vs. 12.2 ± 9%, p = 0.05) were significantly higher in patients with ALF. The percentage of CD3(−)CD56(+)CD16(−) regarding NK cells (5.1 ± 3.4% vs. 7.6 ± 6.2%, p = 0.03) was significantly lower in patients with ALF. Activated Tregs (39.9 ± 11.5 vs. 32.4 ± 9.2, p = 0.06) showed a tendency to be higher in patients with ALF. The proportion of activated CD4(+) cells (r = 0.40, p < 0.01) and activated CD8(+) cells (r = 0.51, p < 0.01) was correlated with the proportion of NKT-like in patients without ALF. Patients with ALF presented an increased NK cytotoxic phenotype and activated T cells concomitant with a decreased NK cytokine-secreting phenotype.