Ultrasonographic Changes of Major Salivary Glands in Primary Sjögren's Syndrome

Performance of salivary glands ultrasonography, shear wave elastography and their combined use for the diagnosis of primary and secondary Sjögren's syndrome

BACKGROUND

Sjögren's syndrome (SS) is a common rheumatic disease for which finding the right imaging tool remains a challenge.

PURPOSE

This study aimed to evaluate the performance of salivary gland ultrasonography (SGUS), shear wave elastography (SWE) and their combined use for the diagnosis of primary and secondary SS (pSS and sSS).

METHODS

This retrospective study included patients with dry symptoms who underwent routine examinations between May 2019 and December 2023. Patients were categorized into the pSS (n = 41), sSS (n = 26), and control (n = 27) groups based on the American College of Rheumatology/European League Against Rheumatism classification criteria (2016). A comparison of SGUS and shear wave velocity (SWV) results was conducted among the three groups. The diagnostic capabilities of different ultrasound methods for SS were evaluated using receiver operating characteristic (ROC) curves and the area under the curve (AUC) for specificity.

RESULTS

Compared to the control group, both the pSS (1.80 ± 1.03 vs. 0.67 ± 0.48, p < 0.001) and the sSS (1.85 ± 0.88 vs. 0.67 ± 0.48, p < 0.001) groups exhibited significantly elevated SGUS scores. However, there was no statistically significant difference between the pSS and sSS groups (p = 0.849). The SWV values in both the pSS and sSS groups were significantly higher than those in the control group (all p < 0.001). The AUC for diagnosing SS using only SGUS scores was 0.823 (95% confidence interval [CI]: 0.731-0.894). Combining SGUS scores and SWV values resulted in improved diagnostic accuracy (AUC: 0.883, 95% CI: 0.801-0.940).

CONCLUSIONS

SGUS and SWE are pivotal in the diagnosis of Sjögren's syndrome, with their synergistic application poised to bolster diagnostic precision. This combined approach also furnishes substantial backing for the clinical assessment and management of Sjögren's syndrome.

Case Series of Changes in Greyscale and Power Doppler Signals on Salivary Gland Ultrasonography after Treatment in Patients with Sjögren's Syndrome

The usefulness of greyscale (GS) in salivary gland ultrasonography for Sjögren's syndrome (SS) has been established; however, limited information is currently available on power Doppler signals (PDs), and changes after treatment remain unknown. PDs are considered to represent glandular inflammation, which indicates the worsening of GS in later years. We examined the changes in PDs in three immunosuppressant-treated SS patients. PDs decreased, along with GS and markers of disease activity, after treatment. PDs have the potential to provide insights into glandular inflammation in real time; however, large-scale studies on their clinical usefulness are needed.

Value of High-Frequency Ultrasonography in the Qualitative and Semi-Quantitative Assessment of Immunoglobulin G4-Related Submandibular Sialadenitis

OBJECTIVE

To assess the value of high-frequency ultrasonography in the evaluation of immunoglobulin G4-related submandibular sialadenitis (IgG4-SS).

METHODS

Thirty-four submandibular glands in 17 patients with IgG4-SS were retrospectively enrolled, as well as 34 submandibular glands in 17 healthy control subjects. Qualitative ultrasonic features including submandibular gland size, border, echogenicity, and vascularity were reviewed. Two different scoring systems (0-16 and 0-48, respectively) were used for semi-quantitative analysis of imaging features. Comparison of both qualitative and semi-quantitative ultrasonic analysis were made between patients with IgG4-SS and healthy controls. Spearman correlation was used to explore relationships between variables.

RESULTS

The submandibular glands with IgG4-SS presented with enlarged size, rough border, increased vascularity, and abnormal echogenicity (All P < .05). The most common echogenicity pattern for IgG-SS was diffuse hypoechoic foci pattern (44.1%), followed by superficial hypoechoic pattern (20.6%), tumor-like pattern (14.7%), and diffuse hypoechogenicity pattern (11.8%). Most IgG4-SS glands presented linear hyperechogenicity in parenchyma (91.2%). Based on both scoring system, scores of IgG4-SS were significantly higher than those of the controls (All P < .05). Association analysis of both scoring systems showed positive correlation of scores with vascularity in the gland parenchyma (All P < .05).

CONCLUSION

The ultrasonic features of IgG4-SS comprise enlarged gland, rough border, increased vascularity, and abnormal echogenicity, which correlate with its pathological characteristics. The most common echogenicity pattern for IgG4-SS was diffuse hypoechoic foci pattern. Semi-quantitative analysis systems could be useful in the assessment of IgG4-SS. Ultrasound is a potential, valuable, and non-invasive tool for the diagnosis and evaluation of IgG4-SS.

Ultrasonographic characteristics of major salivary glands in anti-centromere antibody-positive primary Sjögren's syndrome

Purpose

To investigate salivary gland ultrasonography (SGUS) findings in primary Sjögren’s syndrome (pSS) patients positive for the anti-centromere antibody (ACA) and compare these with those in ACA-negative pSS patients.

Methods

We analyzed demographic, clinical, laboratory, and SGUS data of pSS patients who fulfilled the 2002 American-European Consensus Group classification criteria for pSS. SGUS findings of four major salivary glands (bilateral parotid and submandibular glands) were scored in five categories and compared between ACA-positive and ACA-negative pSS patients. Linear regression analysis was performed to elucidate the factors associated with SGUS score.

Results

In total, 121 pSS patients were enrolled (19, ACA-positive). The ACA-positive patients were older (67.0 vs 58.0 years, P = 0.028), whereas anti-Ro/SSA and anti-La/SSB positivity was more prevalent in the ACA-negative group (89.2% vs 21.1%, P < 0.001, and 47.1% vs 10.5%, P = 0.007, respectively). The total SGUS and hypoechoic area scores were lower in ACA-positive patients (16.0 vs 23.0, P = 0.027, and 4.0 vs 7.0, P = 0.004, respectively). In univariate regression analysis, being positive for unstimulated salivary flow rate (USFR < 1.5 ml/15 min), anti-Ro/SSA, and rheumatoid factor were positively associated whereas ACA positivity was negatively associated with the SGUS score. In multivariate regression analysis, being positive for USFR, anti-Ro/SSA, and rheumatoid factor showed significant association with the SGUS score.

Conclusions

ACA-positive pSS patients showed a lower SGUS score than ACA-negative patients, which was especially prominent in the hypoechoic area component.

Elderly-onset primary Sjögren's syndrome focused on clinical and salivary gland ultrasonographic features

OBJECTIVE

To assess the clinical, laboratory, and salivary gland ultrasound (SGUS) characteristics of elderly-onset of primary Sjögren's syndrome (EopSS).

METHODS

We included pSS patient from two referral hospitals over a 4-year period. The SGUS scores (0-48) and SG volumes were assessed. Clinical, laboratory, and SGUS data were compared according to age at onset: EopSS (≥65 years), adult-onset (AopSS) (≥40 and <65 years), and young-onset (YopSS) (<40 years).

RESULTS

This cross-sectional study included a total of 221 patients, 43 (19.5%) of which had EopSS. Subjective sicca symptoms, results of the Schirmer's test, and unstimulated salivary flow rate revealed no significant differences between the groups. EopSS patients presented a significantly higher frequency of interstitial lung disease (ILD) (EopSS: 51.2% vs. AopSS: 13.5% vs. YopSS: 8.7%, P<0.001) and lower frequency of arthritis (7% vs. 22.6% vs. 39.1%, P<0.01). They also had significantly lower positivity of anti-Ro/SSA (51.2%) and anti-La/SSB (7.0%) and lower levels of rheumatoid factor, C4, and IgG. The EopSS group had significantly lower SGUS positivity (defined as total scores ≥14) (44.2% vs. 64.5% vs. 78.3%, P<0.05), lower SGUS scores, and smaller submandibular gland volume.

CONCLUSION

We report a specific phenotype of EopSS, characterised by high prevalence of ILD, less involvement of the peripheral joint, and low biological activity. SGUS evaluation showed less parenchymal abnormalities but more atrophic changes in major SGs in EopSS patients. Considering the low positivity of anti-Ro/SSA and SGUS in EopSS, SG biopsy remains the only way to confirm the diagnosis of pSS, especially in elderly patients.