Ultrasonography of the salivary glands in Sjögren's disease: own data analysis

Objective : to investigate feasibility of using ultrasonography (US) to evaluate structural changes of salivary glands (SG) in patients with Sjögren's disease (SD). Material and methods . The study included 159 patients who were examined in V.A. Nasonova Research Institute of Rheumatology from 2016 to 2022 who met V.A. Nasonova Research Institute of Rheumatology 2001, and/or ACR 2012, and/or ACR/EULAR 2016 criteria for SD, and who had not previously received immunosuppressive therapy. All patients underwent a comprehensive classical examination (ophthalmological, dental, immunological) to diagnose SD. Disease activity was determined using ESSDAI index. US of the parotid gland (PG) and submandibular SGs was performed using a GE LOGIQ 9 device, and the images obtained were scored according to the OMERACT SGUS scoring system (SGUS SS). Results and discussion . All SGUS SS scores statistically significantly correlated (p<0.05) with mouth sicca symptoms, enlargement of PG, ESSDAI activity index, presence of lymphohistiocytic infiltrate and focus score in labial SG biopsy, and parenchymatous parotitis according to sialography. No significant correlation was found with the results of sialometry. There was a significant correlation between the changes detected by US and sialography (r=0.422; p=0.001). Considering the data obtained, the consistency of the results of the different examination methods was analyzed. Bland-Altman diagrams were created to reflect the dependence of the differences between the results of US and sialography. At various stages of the comparison, not all data points were within the standardized range. In addition, 5% of the parameters were not within the interval of two standard deviations. The Bland-Altman analysis revealed a systematic discrepancy indicating a low degree of agreement between the two methods for determining structural changes in SG. According to the ROC analysis, sensitivity of ultrasound was 94% and specificity 51%. The area under the curve (AUC) was 0.787 (95% confidence interval 0.700–0.875). Conclusion . SG US and sialography are not interchangeable, but complement each other in the assessment of SG structure. SG US is a safer and non-invasive method of SG examination that does not require contrast agent administration and is likely to play an important role in the dynamic monitoring of patients during the therapy. However, sialography is a more accurate method of diagnostics and assessment of the extent of SG lesions.