Latest Advances in Ultrasound Assessment of Salivary Glands in Sjögren Syndrome

Sjogren's Syndrome and Pulmonary Disease

Sjogren's syndrome is an autoimmune connective tissue disease targeting the exocrine glands and frequently affecting the respiratory system. The pulmonary disease is the most important extra-glandular manifestation as it carries most of the morbidity and mortality. Typically, it affects the small airways ranging from mild to severe respiratory symptoms. The upper airways are also commonly involved, predisposing sinusitis to occur more frequently than in the normal population. Lymphocytic interstitial pneumonia was initially thought to be the prevailing parenchymal disease; however, multiple cohorts report non-interstitial pneumonia to be the most frequent subtype of interstitial lung disease. In the review of high-resolution computed tomography scans, cystic lesions are commonly found and associate with both the small airways and parenchymal disease. Under their presence, amyloidosis or lymphomas should be considered in the differential. Overall, Sjogren's syndrome has a higher risk for lymphoma, and in lungs this condition should be thought of, especially when the images reveal pulmonary nodularity, lymphocytic interstitial pneumonia and lymphadenopathy. Although, pulmonary artery hypertension was traditionally and exceptionally linked with Sjogren's syndrome, together with systemic lupus erythematosus, they are now acknowledged to be the most common pulmonary vascular disease in east Asian populations, even over patients with systemic sclerosis. Although there are no controlled prospective trials to treat pulmonary disease in Sjogren's syndrome, the mainstay treatment modality still falls on glucocorticoid therapy (systemic and inhaled), combined with immune modulators or alone. Most of the evidence sustains successful outcomes based on reported cases or case series.

Dry mouth diagnosis and saliva substitutes-A review from a textural perspective

The aim of this review is to assess the objective and subjective diagnosis, as well as symptomatic topical treatment of dry mouth conditions with a clear focus on textural perspective. We critically examine both the current practices as well as outline emerging possibilities in dry mouth diagnosis and treatment, including a patent scan for saliva substitutes. For diagnosis, salivary flow rates and patient-completed questionnaires have proven to be useful tools in clinical practice. To date, objective measurements of changes in mechanical properties of saliva via rheological, adsorption, and tribological measurements and biochemical properties of saliva such as assessing protein, mucins (MUC5B) are seldom incorporated into clinical diagnostics; these robust diagnostic tools have been largely restricted to application in non-clinical settings. As for symptomatic treatments of dry mouth, four key agents including lubricating, thickening, adhesive, and moisturizing agents have been identified covering the overall landscape of commercial saliva substitutes. Although thickening agents such as modified celluloses, polysaccharide gum, polyethylene glycol, and so forth are most commonly employed saliva substitutes, they offer short-lived relief from dry mouth and generally do not provide boundary lubrication properties of real human saliva. Innovative technologies such as self-assembly, emulsion, liposomes, and microgels are emerging as novel saliva substitutes hold promise for alternative approaches for efficient moistening and lubrication of the oral mucosa. Their adoption into clinical practice will depend on their efficacies, duration of relief, and ease of application by the practitioners and patient compliance.

Ultra-high frequency ultrasound (UHFUS) applications in Sjogren syndrome: narrative review and current concepts

Primary Sjogren's syndrome (SS) is a systemic autoimmune chronic inflammatory disease with predominant involvement of the exocrine glands, particularly the salivary glands (SGs). The role of salivary glands ultrasound (SGUS) in the work-up of patients with primary Sjogren syndrome (SS) is progressively increasing due to its useful support in diagnosis and follow-up as a widely available, repeatable, non-invasive and safe technique. Although SGUS is not yet included in the dominant primary SS classification, several studies supported its inclusion in the American College of Rheumatology/European League Against Rheumatism criteria. In this context, a novel imaging technique, ultra-high frequency ultrasound (UHFUS), is being explored. Compared to the frequencies used in conventional ultrasound (US) (up to 22 MHz), UHFUS operates with higher frequencies (30-100 MHz) allowing for outstanding image resolution, up to 30 µm. UHFUS permits the scan of both major and minor SGs, opening new avenues for the integration of tissue and imaging biomarkers. Although further studies are needed to confirm its role, this novel imaging technique might lead to several potential improvements, including earlier diagnosis, reduction of unnecessary and inadequate biopsies and better management and follow-up of patients with primary SS.

Diagnostic accuracy of salivary gland ultrasound in Sjögren's syndrome: A systematic review and meta-analysis

BACKGROUND

To systematically review the diagnostic accuracy of salivary gland ultrasound in primary Sjögren's syndrome (pSS).

METHODS

PubMed, Embase, CINAHL, Cochrane Central and Scopus and ClinicalTrials.gov were searched to identify diagnostic or validation studies in patients with pSS meeting the diagnostic criteria. A diagnostic test meta-analysis was performed using a bivariate model to calculate the pooled sensitivity, specificity, positive/negative likelihood ratios, and the diagnostic odds ratio. Meta-regression analyses were done for several pSS covariates.

RESULTS

Sixty-five studies met our criteria for the qualitative review. Fifty-four studies with a total of 6087 patients were included in the meta-analysis. Pooled sensitivity for salivary gland ultrasound was 80% [95% confidence interval (CI): 77-83%; I 2 = 78%], and specificity was 90% (95% CI: 87-92%; I 2 = 76%). The pooled positive and negative likelihood ratios were 8 (95% CI: 6.4-10) and 0.22 (95% CI: 0.19-0.25), respectively. The corresponding pooled diagnostic odds ratio (DOR) was 37 (95% CI: 28-48). Separate meta-regression models resulted in similar diagnostic estimates: (a) adjusted for mean age: sensitivity 81% (95% CI:77-84%; I 2 = 99%) and specificity 90% (95% CI: 87-93%; I2 = 99%); (b) adjusted for mean disease duration, sensitivity 79% (95% CI:72-84%; I 2 = 99%), and specificity 90% (89-94%; I 2 = 99%). The diagnostic estimates were robust to sensitivity analyses by quality criteria, pSS diagnostic criteria and ultrasound scoring systems.

CONCLUSION

Salivary gland ultrasound is a valuable modality for the diagnosis of Sjögren's syndrome. It is plausible that salivary gland ultrasound can be used as an important criterion for the diagnosis of pSS.

CLINICAL AND LABORATORY FEATURES OF ANTICENTROMERE ANTIBODY-POSITIVE SJö GREN’S SYNDROME

Objective: to study the clinical and laboratory features of patients with anticentromere antibody (ACA) positive Sjö gren’s syndrome (SjS); to assess the spectrum of autoantibodies in patients of this group; to determine the frequency with which the SjS patients who are highly positive for ACA, meet the international classification criteria for SjS and systemic sclerosis (SS); to reveal the incidence of MALT lymphomas in this patient group; to estimate the incidence of primary biliary cirrhosis (PBC)/biliary lesions as part of autoimmune epithelitis in SjS in this patient group.

Material and methods. A total of 83 patients with ACA positive SjS were comprehensively examined at the V.A. Nasonova Research Institute of Rheumatology during the period 2012 to 2018. The inclusion criteria were con formity to the 2001 Russian SjS criteria and a high ACA level. MALT lymphomas were diagnosed on the basis of histological and immunohistochemical studies and polymerase chain reaction-based determination of B-cell clonality in the biopsy samples of affected organs according to the World Health Organization classification of Hematopoietic Tumors. The diagnosis of PBC/biliary lesions was made on the basis of histological and immunohistochemical studies of liver biopsy specimens.

Results and discussion. The investigation revealed low detection rates for anti-Ro antibodies (32.5%), anti-La antibodies (7.2%) and rheumatoid factor (RF) (21.7%), which were typical for the classical SjS immunophenotype), increased ESR (14%), leukopenia (7%), hypergammaglobulinemia (17.6%), elevated levels of IgG (9.5%) and IgA (18.7%), and hypocomplementemia (16.1%) in the ACA positive SjS patients. Despite the low detection rate of RF, 15 (18%) patients in this group developed MALT lymphomas: 14 patients had salivary gland MALT lymphoma and one patient had tonsil MALT lymphoma with peripheral lymph node involvement (generalized marginal zone lymphoma). Also, the patients of this group showed high detection rates for AMA antibodies (34.6%), increased IgM level (29.7%) and a higher risk for PBC/biliary lesions as a manifestation of autoimmune epithelitis in SjS (14.5%). AMA-antibodies were absent in only two patients who were diagnosed with liver disease according to biopsy specimens. Nervous system and renal lesions, antiphospholipid syndrome, rheumatoid arthritis, hypergammaglobulinemic purpura, and cryoglobulinemic vasculitis were much less common and sporadic. Also ACA-positive SjS patients often have Raynaud’s phenomenon (54.9%) with scleroderma-type capillaroscopic changes (68%) and a limited form of SS (24%) according to the 2013 ACR criteria.

Conclusion. ACA-positive SjS is a subtype of the disease, which is significantly different from the classic one in a number of clinical and laboratory signs and characterized by an increased risk for SS, MALT lymphomas, and PBC/biliary lesions as a manifestation of autoimmune epithelitis in SjS which in some cases leads to the underdiagnosis of SjS. ACA should be considered as pathogenetically related to SjS autoantibodies; and all patients who are seropositive for ACA should be examined for SjS and PBC/biliary lesions as a manifestation of autoimmune epithelitis in SjS regardless of whether they have SS or not, as well as complaints of dry mouth and eyes. Patients with significantly enlarged salivary glands should undergo biopsy to rule out or confirm MALT lymphoma before initiating hormonal, antilymphoproliferative, and anti-B-cell therapy.

Clair EW. Recent advances in the search for a targeted immunomodulatory therapy for primary Sjögren's syndrome

Primary Sjögren's syndrome is a chronic autoimmune disease characterized by salivary and lacrimal gland dysfunction, leading to substantial morbidity and reduced quality of life. Many patients with primary Sjögren's syndrome also have extraglandular systemic complications, some of which can be organ- or life-threatening. Over the last decade, numerous targeted immunomodulatory therapies for primary Sjögren's syndrome have failed to show a benefit in clinical trials, and as yet no disease-modifying therapy has been approved for this disease. Herein, we provide an updated review of the clinical trial landscape for primary Sjögren's syndrome and the numerous efforts to move the field forward, including the development of new classification criteria and outcome measures, the results of recent clinical trials in this field, the challenges faced in the search for effective therapies, and the expanding pipeline of novel therapies under development.

Minimally invasive ultrasound-guided parotid gland biopsy in cadavers performed by rheumatologists

Introduction: Surgical biopsy of minor salivary glands is routinely performed for the diagnosis of Sjögren syndrome. However, surgical biopsies of the minor labial glands may result in various complications in up to 6% of patients. On the other hand, adverse events following core needle biopsies of the parotid gland in non-rheumatological settings have been reported as very rare. Aim: The objective of this study was to assess the feasibility and determine the presence of parotid gland tissue in ultrasound-guided parotid gland biopsies performed by rheumatologists in cadavers. Material and method: Two senior rheumatologists obtained, under direct ultrasound visualization in in-plane technique, biopsies of 8 parotid glands from 4 different cadavers using a core biopsy needle. One biopsy per gland was taken. Results: All histological exams showed typical parotid gland tissue without any neuronal or vascular tissue. Conclusion: In conclusion, we demonstrated that minimally invasive, ultrasound-guided core needle biopsy of the parotid gland is a highly precise and easy method to obtain salivary gland tissue.

Introduction: Surgical biopsy of minor salivary glands is routinely performed for the diagnosis of Sjögren syndrome. However, surgical biopsies of the minor labial glands may result in various complications in up to 6% of patients. On the other hand, adverse events following core needle biopsies of the parotid gland in non-rheumatological settings have been reported as very rare. Aim: The objective of this study was to assess the feasibility and determine the presence of parotid gland tissue in ultrasound-guided parotid gland biopsies performed by rheumatologists in cadavers. Material and method: Two senior rheumatologists obtained, under direct ultrasound visualization in in-plane technique, biopsies of 8 parotid glands from 4 different cadavers using a core biopsy needle. One biopsy per gland was taken. Results: All histological exams showed typical parotid gland tissue without any neuronal or vascular tissue. Conclusion: In conclusion, we demonstrated that minimally invasive, ultrasound-guided core needle biopsy of the parotid gland is a highly precise and easy method to obtain salivary gland tissue.