A population of atypical CD56−CD16+ natural killer cells is expanded in PTSD and is associated with symptom severity

This study is the first to characterize NK cell subsets in individuals with PTSD. The results suggest that combat-exposed men with PTSD exhibit an aberrant profile of NK cells with significantly higher frequencies of an atypical population of CD56−CD16+ cells and possibly lower frequencies of the functional CD56brightCD16− NK cell subsets. Higher proportions of dysfunctional CD56−CD16+ cells have been reported in certain chronic viral infections and in senescent individuals. It is possible that this could contribute to immune dysfunctions and prematurely senescent phenotypes seen in PTSD.