The number of T-helpers in 48 pretreatment AA patients and 10 healthy donors. (A) The absolute number of CD3⁺CD4⁺CD25^high CD27⁺ Foxp3⁺ Tregs was significantly lower in the present study cohort of AA patients than in healthy age-matched donors (HD; P = .01). (B) The absolute number of Tregs was also correlated with the severity of disease, and this number was significantly lower in severe and very severe disease (SAA) than in nonsevere disease (NSAA; P = .01) and HDs (P < .001). (C-D) The absolute number of both Th1 and Th2 cells was significantly lower in HDs than in AA patients (P = .03 and P = .006, respectively). (E-F) Although the frequency of Th17 cells was higher in AA patients (P = .04), there was no significant difference between HDs and AA patients in terms of absolute numbers of Th17.