To investigate whether CCL21 and CXCL13 expression levels in the minor salivary gland are associated with the laboratory and clinical manifestations of Sjögren's syndrome (SS).
Sociodemographic data on 106 SS patients were obtained and the glandular and extraglandular manifestations of the disease were documented. In addition, minor salivary gland biopsies were performed and the patients' laboratory findings were analysed. European League Against Rheumatism SS disease activity index (ESSDAI) values of SS disease activity at the time of biopsy and the SS disease damage index (SSDDI) values were also recorded. An immunohistochemical approach was used to semiquantitatively measure the CCL21 and CXCL13 expression in the minor salivary glands.
The minor salivary glands of SS patients stained positively for CCL21 and CXCL13 in 46.2% (49/106) and 70.7% (75/106) of all cases, respectively. Higher-level expression of CCL21 and CXCL13 was associated with increases in ESR, IgG and rheumatoid factor levels, as well as anti-SS-A and -SS-B titers. A higher focus score and ESSDAI value at the time of biopsy were also associated with these chemokines. In patients with extraglandular manifestations of SS, the prevalence of lymphadenopathy increased with increasing CCL21 levels.
The expression levels of CCL21 and CXCL13 within the lymphocytic infiltrates of SS patients were associated with several laboratory features of the disease as well as lymphadenopathy and the extent of clinical disease activity. CCL21 and CXCL13 levels can therefore serve as useful markers to predict the disease activity and prognosis of patients with SS.