Enhanced Th17 phenotype in individuals with generalized anxiety disorder

The generalized anxiety disorder (GAD) is often a debilitating chronic condition, characterized by long-lasting anxiety that is not focused on any object or situation. Besides being clearly linked to increased susceptibility to infectious diseases, anxiety is also known to contribute to the pathogenesis of many inflammatory/autoimmune disorders. The present work aimed to explore the T cell profile following in vitro activation in cultures obtained from a group of individuals with GAD, comparing them with healthy control individuals. Our results demonstrated that cell cultures from GAD group proliferated less following T cell activation as compared with the control group. The analysis of the cytokine profile revealed Th1 and Th2 cytokine deficiencies in the anxious group, as compared with the control subjects. On the other hand, this cellular and humoral immune damage was followed by enhanced production of Th17-derived cytokines. In particular, the levels of TNF-α and IL-17 were significantly higher in cell cultures containing activated T cells from GAD individuals. Therefore, besides a deficiency on Th1 phenotype, an elevated proinflammatory status of these individuals might be related to both glucocorticoid immune resistance and lower IL-10 levels produced by activated T cells. In conclusion, our results demonstrated a T cell functional dysregulation in individuals with GAD, and can help to explain the mechanisms of immune impairment in these subjects and their relationship with increased susceptibility to infections and autoimmune diseases.