Sonographic findings of immunoglobulin G₄-related sialadenitis and differences from Sjögren’s syndrome

Abstract

Objective

To evaluate ultrasonic features of the major salivary glands in patients with immunoglobulin G₄-related sialadenitis (IgG₄-RS) and to explore the differences between IgG₄-RS and Sjögren’s syndrome (SS).

Method

We conducted the study in 150 patients with IgG₄-RS and 100 patients with SS. Ultrasonographic variables of the static images of major salivary glands were analysed. An experienced radiologist scored the confidence rating regarding the presence of the characteristic imaging findings using a five-grade rating system. Ultrasonography scores between IgG₄-RS and SS were compared.

Results

The major salivary glands were significantly larger in patients with IgG₄-RS than in the SS group. The main features of ultrasonography of the salivary glands in IgG₄-RS were various hypoechoic lesions and increased colour Doppler signalling. In contrast, the major salivary glands in SS exhibited hyperechoic lines and/or spots and obscuration of the gland configuration. The scores of the summarized sonographic characteristics also showed statistically significant differences between the IgG₄-RS and SS groups.

Conclusion

This study revealed different ultrasonic features of the major salivary glands in patients with IgG₄-RS and SS. The scored sonographic features were helpful in differentiating IgG₄-RS from SS. Consequently, we suggest that ultrasonography of major salivary glands could be a useful imaging procedure in the evaluation of patients suspected of having IgG₄-RS.

Authorship

All named authors meet the International Committee of Medical Journal Editors (ICJME) criteria for authorship of this manuscript, take responsibility for the integrity of the whole work, and have given approval for the publication of this version of the manuscript.

Compliance with ethical guidelines

Ethical approval was granted by the medical ethics committee of the Institute of Peking University People’s Hospital (2020PHB164-01), and the study was conducted according to the Declaration of Helsinki.

Data availability statement

The datasets used and/or analysed during the current study are available from the corresponding author upon reasonable request.

Disclosure statement

The authors declare no competing interests.

Supporting information

Additional Supporting Information may be found in the online version of this article.

Supplementary figure S1: Representative images showing the presence of patchy hypoechoic areas of grade 2–5 in major salivary glands.

Supplementary figure S2: Representative images showing the presence of large flaky hypoechoic area of grade 2–5 in major salivary glands.

Supplementary figure S3: Representative images showing the presence of diffuse hypoechoic pattern of grade 2–5 in major salivary glands.

Supplementary figure S4: Representative images showing the presence of hyperechoic lines and/or spots of grade 2–5 in major salivary glands.

Supplementary figure S5: Representative images showing the homogeneity of the parenchyma of grade 2–5 in major salivary glands.

Supplementary figure S6: Representative images showing the colour Doppler signalling of grade 2–5 in major salivary glands.

Supplementary figure S7: Representative images showing the clearness of salivary gland borders of grade 2–5 in major salivary glands.

Supplementary figure S8: Images of normal parotid and submandibular glands represented grade 1 for all seven parameters.

Please note that the editors are not responsible for the content or functionality of any supplementary material supplied by the authors. Any queries should be directed to the corresponding author.

Additional information

Funding

This work was supported by National Key R&D Program of China [2017YFA0105802], Peking University People’s Hospital Research and Development Funds [RDH2020-03][RDY2017-35].