Over-expression of CD8⁺ T-cell activation is associated with decreased CD4⁺ cells in patients seeking treatment of Alcohol Use Disorder

Introduction: Harmful alcohol consumption may have an impact on the adaptive immune system through an imbalance in T cell subpopulations and changes in cell activation. We aimed to analyze profiles of CD4 and CD8T cell activation in patients with alcohol use disorder (AUD).

Methods: We used a cross-sectional study with patients seeking treatment of the disorder. Blood samples for immunophenotyping were obtained at admission. Profiles of T cell activation were defined: (I) CD38⁺/HLA-DR⁺, (II) CD38⁺/HLA-DR^-, (III) CD38^-/HLA-DR⁺, (IV) CD38^-/HLA-DR^- and compared with healthy controls. We calculated a CD8⁺ T cell activation indicator (AI) that was defined as the quotient of non-activated cells (CD38^-/HLA-DR^-) and activated cells (CD38⁺/HLA-DR⁺).

Results: 60 patients were eligible (83%M); median age was 49 years [IQR: 44-54] and alcohol consumption was 145g/day [IQR: 90-205]. Mean±SD of CD38⁺/HLA-DR^- was 50.3±50.6 cells/μL in patients and 33.5±24.5 cells/μL in controls (p=0.03), for the CD38^-/HLA-DR⁺ it was 61±62.2 cells/μL in patients and 21.2±17.3 cells/μL in controls (p<0.001) and for the CD38⁺/HLA-DR⁺ it was 20.2±15.6 cells/μL in patients and 10.8±10.3 cells/μL in controls (p<0.001). In patients, an inverse correlation was observed between absolute number and percentage of CD4⁺ T cells, and the percentage of CD38⁺/HLA-DR⁺CD8⁺ T cells (r=0.37, p=0.003; r=0.2, p=0.086, respectively).

Conclusions: Patients with AUD have an increased expression of immune activation with respect to healthy individuals. This excess of activated CD8⁺ T cells correlates with the absolute CD4⁺ T cells.