Objectives Chemokines, which control inflammatory cell migration, have been shown to play important roles in the inflammatory processes associated with Sjögren's Syndrome (SS). CCL21 and CXCL13 within the lymphocytic infiltrate characteristic of the condition have been reported to contribute to ectopic lymphoneogenesis. In the current study, we investigated whether the laboratory and clinical manifestations of SS patients were associated with CCL21 and CXCL13 expression levels in the minor salivary gland.
Methods We obtained sociodemographic data on a total of 106 SS patients, documented glandular and extraglandular manifestations of the disease, performed minor salivary gland biopsies, and analyzed laboratory findings. EULAR index values of SS disease activity (ESSDAI values) at the time of biopsy, and SS disease damage index (SSDDI) values, were also noted. An immunohistochemical approach was used to (semiquantitatively) measure the expression levels of CCL21 and CXCL13 in the minor salivary glands.
Results 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 was associated with an elevated ESR, an increased IgG level, elevated anti-SS-A and -SS-B titers, a higher focus score, and a greater ESSDAI value at the time of biopsy. Higher-level expression of CXCL13 was associated with an elevated ESR, an increased IgG level, elevated anti-SS-A and -SS-B titers, a rise in the level of rheumatoid factor, a higher focus score, and a greater ESSDAI value at the time of biopsy. In patients with extraglandular manifestations of SS, the prevalence of lymphadenopathy tended to rise with an increase in the level of CCL21.
Conclusions The expression levels of CCL21 and CXCL13 within the lymphocytic infiltrates of SS patients were associated with several laboratory features of the disease, lymphadenopathy, and the extent of clinical disease activity. CCL21 and CXCL13 levels should serve as useful markers predicting SS disease activity and prognosis.
Disclosure of Interest None declared