Abstract: Objective To investigate the diagnostic utility of the GLDH/ALT ratio in staging primary biliary cholangitis(PBC), by quantifying peripheral blood GLDH levels across pathological stages in PBC patients.Methods A total of 212 PBC patients with definitive pathological staging were included in the study. The peripheral blood GLDH levels of the participants were measured, and a series of non-invasive serological indicators such as FIB-4, APRI, AAR, and RPR were calculated. Spearman correlation analysis was performed to Explore the correlation between these various indicators and PBC staging. Diagnostic efficacy was evaluated by employing logistic binary regression analysis and constructing revervier operating characteristic(ROC) curves.Results There was no significant difference in GLDH and GLDH/ALT levels among patients in stage Ⅰ/Ⅱ (P>0.05); The levels of GLDH and GLDH/ALT were statistically significant between patients at stages Ⅱ/Ⅲ and stages Ⅲ/Ⅳ (P<0.05); There were no significant correlations between the pathological staging of PBC and the levels of ALT, GGT, and GPRI (r=0.006, P=0.152/r=-0.036, P=0.182/r=0.340, P=0.055); Positive correlations were observed between PBC pathologica staging and TBil (r=0.401, P=0.009), DBil (r=0.403, P=0.007), AST (r=0.217, P=0.019), RDW (r=0.422, P<0.001), FIB-4 (r=0.774, P<0.001), APRI (r=0.620, P<0.001), AAR (r=0.359, P<0.001), and RPR (r=0.742, P<0.001), whereas it was negatively correlated with PLT (r=-0.719, P<0.001); Levels of GLDH (r=0.162, P=0.007) and GLDH/ALT (r=0.203, P<0.001) in peripheral blood were positively correlated with PBC pathological staging. FIB-4 showed the best diagnostic efficacy for each stage of PBC, with AUC values of 0.821, 0.813, and 0.823, respectively; Among PBC patients at ≥ S1 stage, GLDH/ALT exhibited the highest sensitivity (93.75%), FIB-4 displayed the highest sensitivity (80.00%, 93.75%) at ≥ S2 and ≥ S3 stages, while APRI and RPR showed the best specificity at ≥ S1/≥ S2 stages (85.45%, 92.19%) and ≥ S3 stage (88.52%), respectively. Following the combination of multiple indicators, the diagnostic effectiveness (AUC=0.931/0.878) and sensitivity (82.81%/81.67%) of FIB4+APRI+AAR+GLDH+GLDH/ALT were enhanced for ≥ S2 and ≥ S3, respectively. The combination of FIB4+APRI+AAR+GLDH+GLDH/ALT demonstrated the highest specificity (92.73%) for diagnosing PBC at stage≥ S2, while FIB4+GLDH+GLDH/ALT showed the highest specificity (87.5%) for diagnosing PBC at stage ≥ S3.Conclusion The levels of GLDH and GLDH/ALT in peripheral blood present a certain diagnostic value for staging PBC, exhibiting a postive correlation. Moreover, the integration of multiple non-invasive serological indicators enhances the diagnostic efficacy.

Key words: GLDH, GLDH/ALT, Primary biliary cholangitis