Clinical Significance and Factors Influencing T-Lymphocyte PD-1/PD-L1, Serum Autoimmune Antibodies and Erythrocyte Distribution Width in Patients with Autoimmune Hepatitis

Abstract

Background: To investigate the clinical significance and influencing factors of programmed death factor-1 (PD-1)/programmed death factor ligand-1 (PD-L1) in T-lymphocytes, serum autoimmune antibodies, and red blood cell distribution width (RDW) in patients with autoimmune hepatitis (AIH). Methods: Clinical data of 103 patients with type 1 AIH and 119 healthy controls admitted to our hospital during the period from November 2023 to November 2024 were selected for this retrospective case-control study. General demographic data, T-lymphocyte PD-1/PD-L1, serum autoimmune antibodies, liver function tests, and RDW were compared between the two groups. Covariance analysis was performed for the indicators with significant differences, and multivariate logistic regression analysis was conducted to identify independent factors affecting the occurrence of AIH. Receiver operating characteristic (ROC) curves were plotted to analyze the predictive value of each indicator for AIH. Results: The positivity rates of anti-nuclear antibody (ANA) (53.40% vs. 5.04%, P < 0.001) and anti-smooth muscle antibody (ASMA) (47.57% vs. 0.84%, P < 0.001) were significantly higher in the AIH group compared to controls. The PD-1/CD4+ (20.17% vs. 5.41%, P < 0.001), PD-1/CD8+ (13.86% vs. 1.88%, P < 0.001), PD-L1/CD4+ (21.10% vs. 7.40%, P < 0.001), PD-L1/CD8+ (13.15% vs. 1.98%, P < 0.001), and RDW (14.65 ± 3.01% vs. 11.95 ± 3.46%, P < 0.001) were also significantly elevated in AIH patients. Multivariate analysis identified these markers as independent risk factors for AIH with odds ratios (OR) of 2.109 [95% confidence intervals (CI): 1.667 - 2.669], 2.869 (95% CI: 1.821 - 4.520), 1.512 (95% CI: 1.340 - 1.706), 2.733 (95% CI: 1.965 - 3.801), 21.580 (95% CI: 8.705 - 53.494), 107.074 (95% CI: 14.406 - 795.841), and 1.291 (95% CI: 1.175 - 1.419), respectively. The ROC analysis demonstrated good predictive value for all markers, with area under the curve (AUC) values ranging from 0.724 (95% CI: 0.656 - 0.792) to 0.967 (95% CI: 0.943 - 0.991). Conclusions: T-lymphocyte PD-1/PD-L1, serum autoimmune antibodies, and RDW show distinctive expression patterns in AIH patients and serve as independent risk factors for disease occurrence. These markers demonstrate significant diagnostic potential and could be integrated into existing diagnostic algorithms to improve early detection of AIH. Validation in larger, prospective multicenter studies is warranted to establish their clinical utility in routine practice.