Circulating T helper 17 and IFN-γ positive Th17 cells in Major Depressive Disorder

Animal models of depression have reported elevated levels of T helper 17 (Th17) and T helper 1 (Th1) cells along with a decrease in T regulatory (Treg) cell percentage. However, there is ambiguity in the results of clinical studies investigating Th17 cells in Major Depressive Disorder (MDD). No studies have investigated the role of Interferon gamma positive Th17 cells (IFNγ+ Th17) in MDD yet. The study population included 53 patients of first episode, drug naïve MDD patients, and 53 non-psychiatric healthy volunteers as healthy controls. Th17, Th1, IFNγ+ Th17 and Treg cell percentages were assessed by flow cytometry. The mean (±SD) percentage of Th17 cells in cases (1.87 ± 1.03) was significantly higher than the mean in controls (1.1 ± 0.94) (p