In abortion patients, the number of Treg cells (p = .010) was decreased compared to no abortion patients, leading to a significant imbalance in the CD8+ T/Treg (p = .044), Th2/Treg (p < .001), Th17/Treg (p = .004), and B/Treg (p = .023) ratios. Here, CD8A is linked to abortion.