There is a mild-to-moderate positive and negative correlation between active innate and adaptive immune indexes secreted by gastric mucosa in patients with peptic ulcer.10 Immunosuppression was reported to be detected in the cellular immunity of patients with peptic ulcer.11 In our study, the levels of CD3+, CD4+, and CD4+/CD8+ ratio in children with peptic ulcer were lower than those in healthy children, which were consistent with previous reports. Here, CD8A is linked to peptic ulcer disease.