Operational characteristics of ultrasound in the diagnosis of Sjögren’s syndrome

Background and objective

To determine the operational characteristics of salivary gland ultrasound (SGU) in the diagnosis of Sjögren’s syndrome (SS) in a population of colombian patients with dry symptoms.

Materials and methods

Study of diagnostic tests in patients with dry symptoms who consecutively attended the rheumatology consultation (2018–2020). Sociodemographic and clinical data were obtained through a survey, paraclinical and ophthalmological tests, minor salivary gland biopsy, unstimulated salivary flow and SGU (score 0–6 based on De Vita) were done. Sensitivity, specificity, positive (PPV) and negative (NPV) predictive values (Stata 15®) were calculated. The receiver operating characteristics (ROC) curve was developed.

Results

102 patients were included (34 SS and 68 non-SS), mean age 55.69 (±11.93) years, 94% women. Positive ultrasound (score of 2 or more) was more frequent in the SS group, (70.6% vs. 22.1%, P < 0.0001). The sensitivity was the same for grade 2 and 3 (70.59%), with a higher specificity (89.71%) for grade 3 (PPV 77.42% NPV 85.92). The ROC curve from the sum of the glands by means of ultrasound was better than those of the independent glands. The ROC curve of the ultrasound presented a greater area under the curve (0.72 [0.61−0.82]) than that of the histological analysis (focus score) (0.68 [0.59−0.78]), P = 0.0252.

Conclusion

Salivary gland ultrasound is a useful and reliable method for the classification of SS. Its use could be considered in the future within the SS classification criteria.