Expression and Clinical Significance of Serum CTHRC1,LCN2,and FABP4 in Patients with Knee Osteoarthritis

Cui Shubei; Wang Taoxia; Jia Haidong; Zhao Jianlong; Jiang Liqiang; Zhang Weili; Yan Jiying

Abstract：Objective To investigate the expression and clinical significance of serum collagen triple helix repeat-containing protein 1(CTHRC1),lipoprotein 2(LCN2),and fatty acid-binding protein 4(FABP4)in patients with knee osteoarthritis(KOA).Methods Between July 2023 and July 2024,152 patients diagnosed with KOA at Handan Central Hospital were enrolled as the study group,while 148 age-matched healthy volunteers undergoing routine health examinations during the same period served as controls.The study group comprised 85 males and 67 females,aged 52～82 years[mean age(67.69±9.85)years[.The control group included 78 males and 70 females,aged 53～81 years[mean age(67.41±9.69)years].Patients were categorized into mild,moderate,and severe groups based on the Kellgren-Lawrence(K-L)grading system and X-ray findings.Serum levels of CTHRC1,LCN2,and FABP4 were measured using enzyme-linked immunosorbent assay(ELISA).Pearson correlation analysis was used to assess the relationships between serum CTHRC1,LCN2,FABP4 levels,Western Ontario and McMaster Universities(WOMAC)scores,and serum inflammatory factors.Multivariate logistic regression analysis was performed to identify risk factors for severe KO A,and receiver operating characteristic(ROC)curve analysis was used to evaluate the diagnostic value of serum CTHRC1,LCN2,and FABP4 levels for severe KOA.Results Compared with the control group,serum levels of CTHRC1,LCN2,and FABP4 were significantly elevated in the study group(P＜0.05).Serum levels of these proteins were higher in the moderate and severe groups than in the mild group,with the severe group showing the highest levels(P＜0.05).Serum CTHRC1,LCN2,and FABP4 levels were positively correlated with C-reactive protein(CRP),cartilage oligomeric matrix protein(COMP),and WOMAC scores(P＜0.05).Elevated serum CTHRC1,LCN2,FABP4 levels and increased WOMAC scores were identified as independent risk factors for severe KOA(P＜0.05).The area under the curve(AUC)for the combined diagnosis of serum CTHRC1,LCN2,and FABP4 levels in severe KOA patients was 0.932,which was superior to individual diagnoses(Z=3.214,2.439,2.168;P＜0.05).Conclusion Serum levels of CTHRC1,LCN2,and FABP4 are significantly upregulated in KOA patients and correlate with disease severity.The combined measurement of these proteins offers diagnostic value for severe KOA and may serve as serum biomarkers for assessing disease status in KOA patients.