Analysis of the Clinical Application Value of Immune Function Markers and Cytokines in the Recurrent Aphthous Ulcer

ABSTRACT Background This study aimed to analyze the alterations in cellular and humoral immune functions, alongside cytokine profiles, in patients with recurrent aphthous ulcer (RAU) compared to those with other oral mucosal diseases and healthy controls (HC), and to investigate their clinical significance. Methods Anticoagulated whole blood and serum samples were collected from 101 cases of the RAU group, the “Others” group, and the HC group. The percentages of lymphocyte subsets, including NKT, NK, CD4 + T, CD8 + T, and CD3 − CD19 + B cells, were detected by flow cytometry. The concentrations of IgG, IgA, IgM, IgE, C3, and C4 were measured using immunoturbidimetry. Additionally, the levels of cytokines IL‐6, IL‐8, and TNF‐α were quantified by chemiluminescence. Statistical analyses were performed to compare the clinical value of these functional markers across the different groups. Results Non‐parametric tests revealed that the percentage of NKT cells in the RAU group was significantly higher than those in both the “Others” and HC groups; furthermore, the “Others” group showed significantly higher levels than the HC group. The content of IgE in the RAU group was significantly elevated compared to the “Others” and HC groups. The levels of IL‐6, IL‐8, and TNF‐α in the RAU group were significantly higher than those in the HC group. ROC analysis revealed that NKT cells, IgE, IL‐6, and IL‐8 showed AUC values greater than 0.7 in the diagnosis of RAU. Conclusion This study demonstrates that the combined detection of NKT cells, IgE, and cytokines (IL‐6, IL‐8, and TNF‐α) may potentially hold significant clinical application value in the assessment of RAU and other oral mucosal diseases.