Increased salivary interleukin-6 levels in patients with primary Sjogren'ssyndrome

This study's purpose was to evaluate salivary interleukin-6 (IL-6) levels i n patients with primary Sjogren's syndrome (SS). Salivary and serum IL-6 co ncentrations were evaluated by ELISA in 36 patients with SS and compared wi th 19 patients complaining of dry mouth and with normal controls. Salivary IL-6 levels were significantly elevated (P<0.01) in the 36 patients with SS as compared to the 19 patients with dry mouth (200.5 +/- 43.6 and 12.6 +/- 6.8 pg/ml, respectively). No significant differences were noted in the ser um IL-6 levels between these two groups (105.8 +/- 17.1 and 84.8 +/- 17.1 p g/ml, respectively). Both salivary and serum IL-6 levels in the normal cont rols were below the level of detection of the assay. Positive correlation ( r = 0.8613, P<0.0001) was found between salivary IL-6 levels and the focus score of labial biopsies in SS patients. Elevated salivary IL-6 levels appe ar to be a consequence of local production and may reflect the component of salivary gland inflammation in SS.