Serum CCL28 as a biomarker for diagnosis and evaluation of Sjögren’s syndrome

Abstract

Objective The aim of this study was to explore the significance of serum CCL28 in Sjögren’s syndrome (SS) diagnosis and evaluation. Method The expression of CCL28 mRNA in salivary glands of SS patients from the GEO database was analysed. Serum levels of CCL28 of SS patients, rheumatoid arthritis (RA) patients, systemic lupus erythematosus (SLE) patients, and healthy controls (HCs) were measured by enzyme-linked immunosorbent assay. The serum immunoglobulin A (IgA) levels and the focus score of labial salivary gland (LSG) in patients with SS were also measured, and the correlation between serum IgA levels and serum CCL28 was explored. In addition, the level of serum CCL28 was compared between two subsets of SS patients who were classified by clinical symptoms and laboratory tests. Results SS patients displayed decreased expression of CCL28 mRNA in salivary glands, accompanying more severe pathological injury. Serum levels of CCL28 in both primary and secondary SS patients were significantly lower than those in the HC group, whereas no significant differences were observed between RA patients or SLE patients and HCs. Compared with RA and SLE patients alone, serum levels of CCL28 were dramatically lower in patients with SS secondary to RA or SLE. No remarkable correlation between serum IgA and CCL28 levels was observed, while the focus score of LSG negatively correlated with serum CCL28 levels. Serum levels of CCL28 were lower in SS patients who had dental caries and thrombocytopenia. Conclusion Serum CCL28 is a useful biomarker in the diagnosis and evaluation of SS.