Circulating Dickkof-1 as a potential biomarker associated with the prognosis of patients with rheumatoid arthritis-associated interstitial lung disease

摘要

To the Editor: Interstitial lung disease (ILD) is a common extra-articular manifestation in patients with connective tissue diseases (CTDs), including rheumatoid arthritis (RA), which contributes significantly to the disease burden and excess mortality.[1] It has been well-recognized that RA-associated ILD (RA-ILD) patients have a threefold higher risk of death than RA patients without ILD.[2] However, among approximately 30% of ILD patients, the specific diagnosis cannot be made from clinical findings and high-resolution computed tomography features, resulting in diagnostic and management uncertainty.[3] Noninvasive blood biomarkers with diagnostic and prognostic utility may, therefore, provide alternative information for identifying vulnerable patients,[4] especially in clinical settings with limited medical resources. Dickkof-1 (DKK1) protein level was found to increase in lung tissue specimens from donors and idiopathic pulmonary fibrosis (IPF) patients.[5] In this context, the DKK1 was able to alter Wnt-induced epithelial cell proliferation in a dose-dependent manner,[5] implying clinical relevance of DKK1 in both ILD and RA.