Diagnostic value of serum Golgi protein 73 in liver fibrosis and inflammation in patients with autoimmune hepatitis

There is a lack of reliable serum markers to reflect the fibrosis stage and necroinflammation grade in autoimmune hepatitis (AIH) patients. In this study, we investigated the diagnostic potential of a noninvasive serum marker, Golgi protein 73 (GP73), for fibrosis and inflammation in AIH patients. Serum GP73 concentrations were measured in a retrospective cohort of 79 patients with AIH who underwent liver biopsy. The receiver operating characteristic curve was constructed to compare the diagnostic value of GP73, liver stiffness and other 2 serum diagnostic models, namely the aspartate aminotransferase to platelet ratio index and fibrosis-4, for significant liver fibrosis and advanced fibrosis. It also compared the predictive value of GP73 with alanine aminotransferase (ALT) and aspartate aminotransferase (AST) for moderate and severe liver necroinflammation. The results showed that serum GP73 level gradually increased with the stage of liver fibrosis or inflammation. The area under the curve (AUC) of GP73 for the diagnosis of significant and severe hepatic fibrosis was 0.684 (95% confidence interval [CI], 0.547-0.820; P = .027) and 0.773 (95% CI, 0.665-0.882; P < .001) respectively. Although the diagnostic efficacy of GP73 was lower than that of liver stiffness, the diagnostic efficacy for advanced fibrosis was slightly better than that of the aspartate aminotransferase to platelet ratio index (AUC, 0.698; 95% CI, 0.578-0.817; P = .003) and fibrosis-4 (AUC, 0.746; 95% CI, 0.632-0.860; P < .001). In addition, serum GP73 had high specificity for the diagnosis of moderate and severe necroinflammation, with AUC of 0.841 (95% CI, 0.738-0.943; P = .011) and 0.783 (95%CI, 0.683-0.882; P < .001), which were better than ALT and AST. Multivariate ordinal logistic regression showed that elevated serum GP73 level was an independent risk factor for necroinflammation in AIH patients (odds ratio, 1.021; 95%CI, 0.007-0.036; P = .004). In conclusion, we found that serum GP73 has good diagnostic value for advanced liver fibrosis in AIH and is a potential auxiliary serum diagnostic marker for liver fibrosis. And GP73 can be used as a reliable and simple noninvasive marker for grading hepatic inflammation with high specificity and better diagnostic efficacy than ALT and AST.