Background/Purpose: Minor salivary gland biopsy is part of the diagnostic process for primary Sjögren’s syndrome (pSS), but is not suitable for repeated follow-up. Ultrasound (US) represents a non-invasive imaging method of the major salivary glands that may serve as a supplement to minor salivary gland biopsy. The aim of this study was to investigate parotid and submandibular gland ultrasound in relation to sicca symptoms, glandular function and minor salivary gland inflammation.

Methods: Patients with primary Sjögren’s syndrome were recruited from Haukeland University Hospital (n=41). The parotid and submandibular glands were examined by US using a GE LogiqE9 with a linear transducer with 6-15MHz. Glandular homogeneity and presence of hypoechogenic areas was evaluated and scored (0-3) according to Hocevar et al 2005. Scores 0-1 were considered normal and scores 2-3 pathological. Sicca symptoms of the mouth and eyes were recorded. Salivary gland functional capacity was evaluated by unstimulated and stimulated sialometry. Tear secretion was evaluated by the Schirmer I-test. Minor salivary gland inflammation was evaluated by focus score.

Results: Ultrasound was performed in 40 patients, with scores ranging 0-1 (n=22) and 2-3 (n=18). Mean age of patients with normal US findings was 63 years compared to 52 years in patients with pathological US findings (p<0.05), and correlated with ultrasound score (p<0.05, r=-0.388, n=40). Oral sicca symptoms correlated with sicca symptoms of the eyes (p<0.001, r=592, n=41), ultrasound score (p<0.05, r=0.402, n=40), and saliva levels (p<0.05, r=-0.392, n=41) and (p<0.05, r=-0.363, n=41), unstimulated and stimulated saliva respectively. In patients with normal and pathological US, mean unstimulated saliva was 2.2 ml/15 min and 0.5 ml/15 min (p<0.01), and the stimulated saliva levels were 6.1 ml/5 min and 2.5 ml/5 min (p<0.001). Levels of unstimulated and stimulated saliva correlated (p=0.001, r=0.509, n=41). Ultrasound scores correlated with unstimulated (p<0.001, r=-0.531, n=40) and stimulated saliva (p<0.01, r=-0.454, n=40). 17/27 patients with unstimulated saliva ≤ 1.5ml/15 min had pathological ultrasound changes compared to 1/13 with normal unstimulated saliva (p<0.01). 13/17 patients with stimulated saliva ≤ 3.5ml/5 min had pathological ultrasound compared to 5/23 with normal stimulated saliva (p<0.01). Tear secretion by the Schirmer I-test correlated in the right and left eye (p<0.001, r=0.749, n=39). Unstimulated saliva secretion correlated with tear secretion (p<0.001, r=0.537, n=39) and (p<0.05, r=0.343, n=39), right and left eye, respectively. Focus score was available in 31/41 patients, and correlated with ultrasound score (p<0.05, r=0.373, n=30). Mean focus score was 2.6 in patients with ultrasound pathology and 1.3 in patients with normal ultrasound (p=0.051).

Conclusion: In this cohort of patients with pSS findings from non-invasive imaging method ultrasound correlate with oral sicca symptoms, glandular function and minor salivary gland inflammation. Ultrasound of major salivary glands seems to be a useful tool for diagnostics and follow-up of patients with pSS.

ACR Meeting Abstracts - https://acrabstracts.org/abstract/ultrasonography-of-major-salivary-glands-in-primary-sjogrens-syndrome/