LAUSR

T cells, or CD56 NK cells expressing NKG2D. We collected blood samples 4 times, and the FACS analysis was also performed by dividing into 4 times. Therefore, final data were represented as a fold change of each cells expressing NKG2D over the healthy control (control set to 1). The patients were segregated into 2 or 3 subgroups according to AA severity, activity, type, and treatment modalities for subgroup analysis. Statistical analysis was performed using the ManneWhitney U test and KruskaleWallis analysis. Double-labeling immunofluorescence microscopy in 2 representative cases using freshly frozen specimens was also performed. The results showed that the levels of NKG2DCD8 T cells and NKG2DCD56 NK cells were higher in the AA group compared with the control group (P \ .05). Interestingly, a 2.49-fold increase in the CD4 T cells subset expressing NKG2D was detected in the peripheral blood from patients with AA compared with healthy controls (P \ .05; Fig 1). Although not statistically significant, the proportion of NKG2DCD4 T cells was lower in patients who had mild severity AA and in those who received systemic immunosuppressive therapy. Double label immunofluorescence revealed NKG2D cells coexpressed CD4 around the hair follicles of the AA lesion (Fig 2). Recently, the role of NKG2DCD4 T cells in other chronic autoimmune diseases, such as Crohn’s disease and rheumatoid arthritis, was highlighted. A subset of CD4 T cells expressing NKG2D was higher in the lamina propria of patients with Crohn’s disease. These NKG2DCD4 T cell clones were functionally active through major histocompatibility complex class I-related chain A (MICA) eNKG2D interactions, producing IFNand killing targets expressing MICA. We hypothesize that NKG2DCD4 T cells might exhibit a TH1 cytokine profile in patients with AA. Our results suggest that IFNeproducing NKG2DCD4 T cells have the potential to become therapeutic targets and biologic markers of disease activity in AA. However, additional studies are needed to characterize the functional properties of NKG2DCD4 T cells in patients with AA.