Increases in tumor markers are associated with primary Sjögren's syndrome-associated interstitial lung disease

Interstitial lung disease (ILD) is the most common type of pulmonary involvement of extraglandular complication in patients with primary Sjögren's syndrome (pSS), but the diagnosis of pSS-associated ILD (pSS-ILD) is still challenging. This study aimed to investigate the levels of serum tumor markers in pSS patients with or without ILD (pSS-non-ILD) and explore its diagnostic value for pSS-ILD.

A total of 168 pSS-ILD patients and age- and sex-matched 538 pSS-non-ILD were recruited. The levels of peripheral tumor markers, including carbohydrate antigen (CA)153, CA125, CA19-9, carcinoembryonic antigen (CEA), neuron-specific enolase (NSE), β-human chorionic gonadotropin, alpha fetoprotein, CA724, and complexed prostate specific antigen, the clinical manifestations, and general laboratory indicators were measured and collected.

Compared with pSS-non-ILD, pSS-ILD patients had higher levels of disease activity indicators, such as EULAR Sjögren's syndrome disease activity index, ESR, and CRP, and elevated serum levels of tumor markers: NSE, CEA, CA125, and CA153. The serum levels of CA153 [odds ratio (OR) = 4.521, 95% confidence interval (CI) = [1.871, 10.928)] and CEA [OR = 2.879, 95% CI = (1.305, 6.353)] were significantly correlated with the onset of SS-ILD. CA153 was the only tumor marker with area under receiver operating characteristic curve (AUC) over 0.7 [AUC = 0.743, 95% CI = (0.70, 0.79)].

Tumor markers increased in serum of pSS-ILD patients. Higher CA153 levels are significantly correlated to the increased risk of ILD in patients with pSS and may be directly involved in the pathogenesis of pSS-ILD. Serum CA153 had the best diagnostic value in those tumor markers for pSS-ILD without malignancy.