Chitinase 3-like Protein 1: A Diagnostic Biomarker for Early Liver Fibrosis in Autoimmune Liver Diseases

Shafei Liu ¹ Conggao Peng ^2,3 Shijia Xia ¹ Chaonan Li ¹ Xiahong Dai ^2,3 Xingyu Liu ^4,5 Meng Zhang ⁶ Xiaoping Li ^7* Lingling Tang ^2,3*

• ¹ School of Medicine, Zhejiang Chinese Medical University,, Hangzhou, Jiangsu Province, China
• ² Department of Infectious Diseases, Shulan（Hangzhou）Hospital，Shulan International Medical College，Zhejiang Shuren University, Hangzhou, Jiangsu Province, China
• ³ Key Laboratory of Artificial Organs and Computational Medicine in Zhejiang Province，Shulan International Medical College，Zhejiang Shuren University, Hangzhou, Jiangsu Province, China
• ⁴ Collaborative Innovation Centre for Diagnosis and Treatment of Infectious Diseases, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang Province, China
• ⁵ State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Jiangsu Province, China
• ⁶ School of Medicine, Affiliated Hospital of Hangzhou Normal University, Hangzhou, Jiangsu Province, China
• ⁷ Key Laboratory of Pollution Exposure and Health Intervention of Zhejiang Province, Shulan International Medical College, Zhejiang Shuren University, Hangzhou, China

Background and Aims: Chitinase 3-like protein 1 (CHI3L1) is a marker of liver fibrosis produced mainly by hepatic macrophages. However, few studies have assessed the relationship between CHI3L1 and liver fibrosis in autoimmune liver diseases (AILDs). We aimed to explore the diagnostic value of CHI3L1 for liver fibrosis in AILDs and to compare its application differences between AILDs and chronic hepatitis B (CHB) patients.The fibrotic group was defined as liver stiffness measurement (LSM) > 9.70kPa. Serum CHI3L1 levels were measured by ELISA in 78 AILDs patients, 65 chronic hepatitis B patients. The diagnostic accuracy was evaluated by the area under the receiver operating characteristic curve (AUROC).Results: Serum CHI3L1 levels in AILDs patients were positively correlated with LSM (r=0.750, p <0.001). The AUROC for serum CHI3L1 in identifying significant liver fibrosis was 0.939 (95% CI: 0.891 -0.988), which was higher than that of other non -invasive fibrosis scores (APRI, FIB -4, GPR, AAR, NLP, and PLR). At the optimal cutoff value of 86.84 ng/mL, the sensitivity and specificity were 92.9% and 83.3%, respectively. Furthermore, in patients with no significant difference in LSM, serum CHI3L1 levels were higher in the autoimmune liver disease group than in the CHB group.Serum CHI3L1 is an effective non-invasive indicator for assessing liver fibrosis in AILDs patients and may vary in different etiologies.