Abstract: Objective To explore the changes and clinical significance of OX40/OX40L in peripheral blood of patients with autoimmune hepatitis (AIH). Methods The 85 AIH patients admitted to the hospital from July 2019 to December 2020 (research group) and 62 healthy people (control group) undergoing physical examination at the same time period were selected as the research objects. The clinical characteristics and the positive expression rate of OX40/OX40L in peripheral blood were compared between the two groups, and the factors affecting the occurrence of AIH were analyzed. The area under the receiver operating characteristic (ROC) curve (AUC) was used to evaluate the diagnostic value of OX40/OX40L in predicting the occurrence of AIH. Results The two groups of T lymphocyte subsets, C-reactive protein, white blood cell count, interleukin-6, interleukin-4, interleukin-21, chemokine, and alanine aminotransferase levels were statistically significant (P< 0.05). The positive expression rates of OX40/OX40L in the peripheral blood of the study group were (12.43±2.13)% and (14.91±2.18)%, respectively, and the control group were (6.59±1.16)% and (4.82±0.73)%, respectively. The difference was statistically significant (P<0.05). Logistic multivariate analysis showed that the levels of interleukin-21 and OX40/OX40L were the influencing factors of AIH (95%CI were 1.517~6.073, 4.903~8.418, 0.844~0.985, all P<0.05). ROC curve analysis showed that the AUC of OX40/OX40L and the combination of the two in the diagnosis of AIH were 0.804 (95%CI: 0.699~0.909), 0.789 (95%CI: 0.682~0.895), 0.914 (95%CI: 0.844~0.985). Conclusion OX40/OX40L is overexpressed in the peripheral blood of patients with AIH, and the combination of OX40 and OX40L has high value in the diagnosis of AIH.

Key words: Autoimmune hepatitis, OX40/OX40L, Diagnostic value