The present study aimed to investigate the salivary chemokine levels in patients with primary SS (pSS) and compare them with those in patients with non-SS sicca symptoms or non-sicca controls.
Unstimulated and stimulated whole saliva samples were obtained from pSS patients (n = 30) and age- and gender-matched patients with non-SS sicca (n = 30) and non-sicca healthy controls (n = 25). Salivary CCL2, CCL3, CCL4, CXCL8 and CXCL10 levels were measured using a Luminex bead-based multiplex assay.
Patients with pSS had significantly different distributions of salivary CCL3 (P = 0.0001 by the Kruskal-Wallis test), CCL4 (P < 0.00001), CXLC8 (P < 0.0001) and CXCL10 (P < 0.05) levels in unstimulated saliva and all chemokine levels in stimulated saliva when compared with non-SS sicca and non-sicca controls. In comparison with chemokine production rate, the CXCL8 and CXCL10 production rates were significantly higher in pSS than in non-SS sicca controls (P < 0.01 by the Mann-Whitney test). Logistic regression analyses revealed that salivary CXCL8 (P < 0.05) and CXCL10 (P < 0.05) were the significant discriminating chemokines between the pSS and non-SS sicca groups. Although CXCL8 and CXCL10 levels were not correlated with the focus scores, CXCL8 and CXCL10 levels were significantly associated with salivary gland dysfunction.
These results support the notion that CXCL8 or CXCL10 chemokine plays a role in the pathogenesis of pSS.