Is salivary gland ultrasonography a useful tool in Sjögren's syndrome? A systematic review

Objective. Ultrasonography (US) is a sensitive tool in the diagnosis of major salivary gland abnormalities in primary Sjögren's syndrome (pSS). The aim of this systematic review was to assess the metric properties of this technique. Methods. PUBMED and EMBASE databases were searched. All publications between January 1988 and January 2013 were considered. Data were extracted from the articles meeting the inclusion criteria according to US definition of salivary gland scoring system and metric properties studied. The type and number of glands tested, study design and metric properties according to OMERACT filter (truth, discrimination, feasibility) were assessed. Results. Of 167 publications identified initially with PUBMED and EMBASE, 31 met the inclusion criteria. The number of pSS patients varied among the studies from 16 to 140. The diagnosis of pSS was in line in most of the cases with the American-European Consensus Group (AECG) classification criteria for Sjögren's syndrome. The US examination was performed in suspected pSS only in studies in which the sensitivity ranged from 45.8 to 91.6% and specificity from 73 to 98.1%. There was heterogeneity in regard to the definition of US in B-mode and few studies used US in colour Doppler. Few studies reported reliability of US and sensitivity to change in pSS. Conclusion. US is a valuable tool for detecting salivary gland abnormalities in pSS. Its reliability has been poorly investigated and there is considerable variation in the definition of US abnormalities. Further studies are required to validate and standardize the US definition of salivary gland in pSS.