Serum YKL-40 and Serum Krebs von den Lungen-6 as Potential Predictive Biomarkers for Rheumatoid Arthritis-Associated Interstitial Lung Disease

ABSTRACT

Background

Interstitial lung disease (ILD) is a common pulmonary manifestation of rheumatoid arthritis (RA) and is associated with a poor prognosis. However, the role of blood biomarkers in RA-associated interstitial lung disease (RA-ILD) is ill-defined. We aim to evaluate the role of YKL-40 and Krebs von den Lungen-6 (KL-6) in the diagnosis and severity evaluation of RA-ILD.

Methods

45 RA-non-ILD patients and 38 RA-ILD patients were included. The clinical data and the levels of YKL-40 and KL-6 were measured and collected for all patients. The risk factors for RA-ILD were analyzed and their correlation with relevant indicators and predictive value for RA-ILD was explored.

Results

The levels of YKL-40 and KL-6 in RA-ILD patients were higher than RA-non-ILD patients (p < .001). Both YKL-40 and KL-6 were correlated with the incidence of RA-ILD. The predictive power of combined KL-6 and YKL-40 for the presence of ILD was 0.789, with a sensitivity and specificity at 73.7% and 73.3%, respectively. In RA-ILD patients, both YKL-40 and KL-6 were positively correlated with the Scleroderma Lung Study (SLS) I score and negatively correlated with pulmonary function.

Conclusions

KL-6 and YKL-40 might be a useful biomarker in the diagnosis and severity evaluation of RA-ILD.

KEYWORDS:

• Biomarker
• interstitial lung disease
• KL-6
• rheumatoid arthritis
• YKL-40

Authors’ contributions

All authors who participated in this study contributed significantly to the research results, which included all aspects of the conception, design, implementation, data collection, processing, and interpretation of the study. In addition, they participated in writing, revising, and reviewing the paper and agreed with the final published manuscript. All authors have agreed to submit the paper to a designated journal and assume overall responsibility for the research work.

Ethics approval and consent to participate

This study was conducted in accordance with theDeclaration of Helsinki and approved by the Research Ethics Committee of Beijing Shunyi Hospital (ethical batch number: 2022-K-015-01), and informed consent was obtained from all participants. All methods were carried out in accordance with relevant guidelines and regulations.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Availability of data and materials

The datasets used and analyzed during the current study are available from the corresponding author on reasonable request.