Assessment of SS‐A and SS‐B in parotid saliva of patients with Sjögren's syndrome

BACKGROUND: The purpose of this study was to compare the sensitivity of parotid saliva to that of serum in detecting anti-SSA/Ro and anti-SSB/La autoantibodies in patients with Sjögren's syndrome. METHODS: Forty patients and 20 controls participated in the study; all patients met the 1993 European Community criteria for the diagnosis of Sjögren's syndrome. Healthy controls were age- and sex-matched individuals with no signs or symptoms of Sjögren's syndrome. Serum and saliva samples were evaluated using AffiniTech SSA/Ro and SSB/La antibodies kits (AffiniTech, Ltd. Bentonville, AR, USA). The results were also compared with serological status of SS-A and SS-B as reported by an independent clinical laboratory. RESULTS: Serum was significantly more sensitive than saliva in detecting SSA/Ro and SSB/La antibodies (P = 0.001). There was high agreement between the results with the AffiniTech kits and the independent laboratory (kappa = 0.80; P < 0.001). However, there was poor agreement between saliva and serum results (kappa = 0.174; P = 0.168). CONCLUSIONS: The overall results appear to support that serum analysis is effective method for evaluating the presence of SS-A and SS-B autoantibodies.