Salivary gland ultrasonography improves the diagnostic performance of the 2012 American College of Rheumatology classification criteria for Sjögren’s syndrome

Objective. The aim of this study was to evaluate whether salivary gland ultrasonography (SGUS) improves the diagnostic performance of the 2012 ACR classification criteria for SS. Methods. We studied a cohort of 101 patients with suspected SS seen at a single centre in Brittany, France. An SGUS echostructure score 52 was considered abnormal. The reference standard was a clinical diagnosis of SS made by a group of experts blinded to SGUS findings. Results. SS was diagnosed in 45 patients. Similar proportions of patients with and without SS had an ocular staining score 53. Adding RF positivity and ANA titre 51:320 as an alternative to anti-SSA/SSB positivity increased the sensitivity of the serological item without modifying specificity compared with using anti-SSA/SSB alone. SGUS was 60.0% sensitive and 87.5% specific for SS. Adding the SGUS score to the ACR criteria increased sensitivity from 64.4% to 84.4% and only slightly decreased specificity, from 91.1% to 89.3%. Conclusion. The diagnostic performance of the ACR classification criteria for SS is notably improved by adding the SGUS score. SGUS should be included in future classification criteria for SS.