Abstract: Objective To evaluate the utility of growth differentiation factor 15 (GDF15) as a biomarker in the diagnosis and therapeutic management of autoimmune hepatitis (AIH).Methods Data were retrospectively analyzed from 65 patients with AIH, 45 healthy individuals, 40 patients with hepatitis B (HB) and hepatitis C (HC), and 35 patients with primary biliary cholangitis (PBC). These individuals, admitted to our hospital from July 2020 to July 2022, were categorized as the AIH group, healthy control group, HB group, HC group and PBC group, respectively. Clinical baseline data among these diverse liver disease patient groups and the control group were compared. In particular, the serum levels of GDF15 were analyzed for both cirrhosis and non-cirrhosis patients. Additionally, in the AIH group, serum GDF15 levels in patients with cirrhosis were compared to those without cirrhosis, and multivariate regression analysis was performed to assess the correlation of GDF15 levels with the occurrence of cirrhosis and the area under the (ROC) curve for GDF15 was calculated.Results In patients with AIH, levels of ALT, AST, Fib4 index, IgG and TBil were found to be significantly elevated. These levels were meaused at(368.9±59.8)U/L, (294.6±52.7)U/L, (5.8±2.5), (2668.3±901.5)mg/dL and(49.6±11.5) μmol/L, respectively, which were higher compared to the healthy control group[(24.5±4.8 )U/L,(8.4±2.1)U/L,(1.1±0.3),(476.2±172.8)mg/dL and (3.4±1.3)μmol/L], HB group [(61.7±25.8)U/L,(50.9±18.5)U/L,(3.2±1.5),(953.6±253.4)mg/dL and (18.8±5.2)μmol/L], HC group [(48.4±12.5)U/L,(48.6±21.4)U/L,(4.1±1.6),(1868.6±539.8)mg/dL and(19.2±5.3)μmol/L] and PBC group [(59.6±11.2)U/L,(42.3±20.1)U/L,(1.5±0.8),(641.5±125.8)mg/dL and (12.3±3.7)μmol/L] (P<0.05). Additionally, GDF15 levels were(2000.9±699.2)pg/dL, which were higher compared to the control group, HB group and PBC group [(476.2±172.8)pg/dL, (953.6±253.4)pg/dL, and (641.5±125.8)pg/dL, respectively)(P<0.05). In AIH patients with liver cirrhosis, serum levels of ALT, AST, Fib4 index and GDF 15 were significantly higher at (461.7±55.8) U/L, (298.4±41.1) U/L, (6.1±2.3) and (2045.1±350.8)pg/dL, respectively, compared to non-liver cirrhosis AIH patients[(224.5±24.8) U/L, (80.9±18.5) U/L, (3.8±1.5) and (1305.2±200.2)pg/dL, P<0.05]. GDF15 was an independent risk factor for cirrhosis in AIH patients (P<0.05). Using a GDF15 threshold of 1639.0 pg/dL, the area under the curve(AUC), sensitivity and specificity of GDF15 for diagnosing AIH-related cirrhosis were 0.924, 93.3%(14/15) and 82.5%(33/40), respectively.Conclusion The levels of GDF15 in AIH patients are elevated, indicating that GDF15 measurement can aid in the diagnosis of AIH. This finding demonstrates significant potential for evaluating therapeutic efficacy, suggesting that GDF15 testing could have considerable application value and merits further clinical implementation.

Key words: Growth differentiation factor 15, Autoimmune hepatitis, Diagnosis, Therapeutic efficacy