Primary Sjögren's syndrome: The diagnostic and prognostic value of salivary gland ultrasonography using a simplified scoring system.

Objective: To determine the usefulness and prognostic value of a simplified salivary gland ultrasonography (SGUS) scoring system in primary Sjögren's syndrome (pSS). Methods: Patients with pSS (n=105) and controls (n=57) were evaluated using a simplified SGUS scoring system. Parenchymal homogeneity in salivary glands was graded from 0 to 3, grades 0 (normal) and 1 (mild inhomogeneity) being interpreted as normal or unspecific, and grades 2 (several rounded) and 3 (numerous or confluent hypoechoic lesions) as pSS-typical. Associations between SGUS and clinical, histological and laboratory disease characteristics were analyzed. Results: The characteristic hypoechoic lesions (score 2 or 3) were found in 52% of pSS patients and in 1 (1.8%) of controls, p<0.001. Specificity and positive predictive value of abnormal SGUS for pSS were both 98%, sensitivity and negative predictive value were 52 and 53%. Age or disease duration did not influence the SGUS result. Dryness did not differ between normal or abnormal SGUS. However, patients with pathological SGUS had significantly more often signs and symptoms of systemic complications, higher disease activity and more frequently markers of lymphoma development, such as salivary gland swelling, skin vasculitis, germinal center-like structures in salivary gland biopsy and CD4(+) T-lymphocytopenia. Conclusion: SGUS using a simplified score for assessment of parenchyma dyshomogeneity is highly specific for pSS and offers the advantage of identifying patients with severe disease or at lymphoma risk. Early disease may however be missed. It is easy and rapidly performed and may be considered as an item in future modified classification criteria. © 2013 American College of Rheumatology.