Diagnostic Value of Salivary Gland Ultrasonographic Scoring System in Primary Sjögren’s Syndrome: A Comparison with Scintigraphy and Biopsy

Abstract

To compare an ultrasonographic (US) scoring system of salivary glands with scintigraphy and salivary gland biopsy, in order to evaluate its diagnostic value in primary Sjögren's syndrome (SS). In 135 patients with suspected SS, the grades of 5 US measures of both parotid and submandibular salivary glands were scored (0-48 scale). Diagnosis of primary SS was established following the American-European Consensus Group criteria of 2002. The patients' total scintigraphic score (0-12 scale) was determined and the histopathological changes of minor salivary glands graded. Area under the receiver-operating characteristic (ROC) curve was employed to evaluate the diagnostic value of the US scoring system. Primary SS was diagnosed in 107 (79.2%) patients and the remaining 28 subjects (20.8%) constituted the control group. US changes of salivary glands were established in 98/107 patients with SS and in 14/28 controls. Mean US score was 26 in SS patients and 6 in controls. Through ROC curves, US arose as the best performer (0.95 +/- 0.01), followed by scintigraphy (0.86 +/- 0.31). Setting the cutoff score for US at 19 resulted in the best ratio of specificity (90.8%) to sensitivity (87.1%), while setting the cutoff scintigraphic score at 6 resulted in specificity of 86.1% and sensitivity of 67.1%. Among 70 patients with US score >or= 19, a scintigraphic score > 6 was recorded in 54/70 (77.1%) and positive biopsy findings in 62/70 (88.5%) patients. We show high diagnostic accuracy of a novel US scoring system of salivary glands (0-48) in patients with primary SS comparable to invasive methods, i.e., scintigraphy and salivary gland biopsy.