Serum KL-6, CA19-9, CA125 and CEA are Diagnostic Biomarkers for Rheumatoid Arthritis-Associated Interstitial Lung Disease in the Chinese Population
Muhan Zheng, Aiju Lou, Haoru Zhang, Shijie Zhu, Min Yang, Weinan Lai
Abstract
This study aimed to evaluate the role of tumor marker carbohydrate antigen (CA) 125 (CA125), CA19-9, carcinoembryonic antigen (CEA) and Krebs von den Lungen-6 (KL-6) in the diagnosis and determination of the severity of interstitial lung disease (ILD) in rheumatoid arthritis (RA) patients. A retrospective analysis was performed. Fifty RA patients (24 patients with ILD and 26 patients without ILD), 10 healthy subjects and 14 patients with other connective tissue disease-associated interstitial lung disease were included. Serum levels of KL-6 and tumor markers CA19-9, CA125 and CEA were measured. Chest HRCT of patients with ILD was scored quantitatively according to the degree of fibrosis. Data on the C-reactive protein, erythrocyte sedimentation rate, rheumatoid factors and anti-cyclic peptide containing citrulline (anti-CCP) were also collected. Serum levels of KL-6, CA19-9, CA125 and CEA in the RA-ILD group were significantly higher than those in the RA-no-ILD group. The serum KL-6 level was positively correlated with the HRCT fibrosis score (r = 0.63, p = 0.002). The logistic regression analysis showed that CA19-9 and smoking were associated with RA-ILD [OR = 1.118, 95% CI = (1.038, 1.204), p = 0.003 for CA19-9, OR = 14.969, 95% CI = (1.750, 128.043), p = 0.013 for smoking]. KL-6 level and tumor markers were elevated in RA-ILD, and strongly associated with the severity of ILD, supporting their value as pathogenically relevant biomarkers, which can contribute to noninvasive detection of this extra-articular disease complication. Interstitial lung disease (ILD) is a common pulmonary manifestation of RA associated with high morbidity and mortality. Our retrospective study was performed to investigate the clinical utility of tumor marker carbohydrate antigen (CA) 125 (CA125), CA19-9, carcinoembryonic antigen (CEA) and Krebs von den Lungen-6 (KL-6) in the diagnosis and determining the severity of RA-ILD. Fifty RA patients (24 patients with ILD and 26 patients without ILD), 10 healthy subjects and 14 patients with other connective tissue disease-associated interstitial lung disease (CTD-ILD) were included. The results showed KL-6 level and tumor markers were elevated in RA-ILD, and strongly associated with the severity of ILD, which meant KL-6 and tumor markers might be useful pathogenically relevant biomarkers and could be predictors for the diagnosis and determination of severity of ILD in RA.