Background Previous studies have demonstrated typical findings in the ultrasound of salivary glands (USG) in patients with primary Sjögren syndrome (pSS) compared with healthy controls. However, it is unknown, if these findings are only seen in patients with pSS but also in patients with secondary Sjögren syndrome (sSS) or other connective tissue diseases with positive Ro-SSA/La-SSB antibodies.
Methods We used an ultrasound score developed by Zhang  to investigate salivary glands with a score ranging from 0–48. We compared the score from patients with pSS according the criteria of the American-European Consensus Group (group 1) with patients who fulfilled the clinical criteria (1–4), but were Ro-SSA/La-SSB negative (group 2), with patients who had another rheumatic disease, but had sicca symptoms and were Ro-SSA and/or La-SSB positive (sSS) (group 3), with patients with other rheumatic disease without Ro-SSA or La-SSB antibodies (group 4), with patients with other rheumatic disease with Ro-SSA antibodies but no sicca symptoms (group 5) and with patients with no rheumatic disease (group 6), respectively. We investigated the parotid and the submandibular salivary glands bilaterally. The USG was assessed with a score from 0–48 points with a maximum of 12 points for 4 items each (hyoechoic areas, hyperechoic reflexes, inhomogeneity and distinct organ border). If available the score was correlated with the scintigraphically measured function of the salivary glands.
Results We included USG of 92 patients in our study. Group 1 (n=33) had a score of 16.6±11.6; group 2 (n=7) 2.4±3.5; group 3 (n=16) 8.6±9.5; group 4 (n=16) 5.3±7.8; group 5 (n=11) 4.5±6.7 and group 6 (n=9) 1.5±2.3, respectively. The score between group 1 and all other groups was significantly different (p<0.01), with no significant differences between all other groups. In 25 patients a scintigraphy of the salivary glands was available. The excretory function in the scintigraphy highly significantly correlated with the ultrasound score (r=0.53, p<0.001).
Conclusions USG showed significantly higher scores in patients with pSS, than in patients with sSS or other rheumatic disease. USG as a non invasive investigation might be similarly helpful for the diagnosis of pSS like salivary gland functional tests. USG findings can reliable distinguish between pSS and sSS associated with other rheumatic disease, also if they are positive for Ro-SSA/La-SSB.
Zhang X, Zhang S, He J, Hu F, Liu H, Li J, Zhu J, Li Z. Ultrasonographic evaluation of major salivary glands in primary Sjögren's syndrome: comparison of two scoring systems. Rheumatology (Oxford). 2015 Sep;54(9):1680–7.
Disclosure of Interest None declared