Do we need new diagnostic criteria for Sjögren's syndrome?

Evaluation and management of dry mouth and its complications in rheumatology practice

INTRODUCTION

The symptom of dry mouth has multiple potential etiologies and can be a diagnostic clue to the presence of common systemic diseases encountered in rheumatology practice. The presence of decreased saliva flow (i.e. salivary hypofunction) defines a subset of dry mouth patients in whom there may be reversible drug effects, an iatrogenic insult such as head and neck irradiation, or a disease that directly involves the salivary glands (e.g. Sjögren's disease). The assessment of salivary hypofunction includes sialometry, salivary gland imaging, salivary gland biopsy, and an assessment for relevant systemic diseases. Optimal management of dry mouth requires accurate definition of its cause, followed by general measures that serve to alleviate its symptoms and prevent its complications.

AREAS COVERED

Through a literature search on xerostomia and salivary hypofunction, we provide an overview of the causes of dry mouth, highlight the potential impact of salivary hypofunction on oral and systemic health, detail routine evaluation methods and treatment strategies, and emphasize the importance of collaboration with oral health care providers.

EXPERT OPINION

Our Expert Opinion is provided on unmet needs in the management of dry mouth and relevant research progress in the field.

Unstimulated whole saliva flow for diagnosis of primary Sjögren's syndrome: time to revisit the threshold?

Background

Unstimulated whole saliva (UWS) flow rate is one of the ACR/EULAR 2016 criteria for primary Sjögren’s syndrome (pSS). With a single threshold of ≤ 0.1 mL/min, UWS flow does not take into account the age- and sex-related physiological variations. Furthermore, it has a low sensitivity for the diagnosis of pSS (about 50%), contrary to the screening test for xerophthalmia, Schirmer’s test (sensitivity of about 70%). We aimed to identify UWS thresholds allowing better performances for a screening test for pSS comparable to Schirmer’s test, and considering age- and sex-related variations.

Methods

A prospective cohort of 185 patients with oral and/or ocular dryness was classified into 3 groups: men, women < 50 (< 50 years old), and women ≥ 50 (≥ 50 years old). The diagnostic performances of UWS flow rate in these groups were compared in terms of sensitivity, specificity, positive and negative predictive values, and ROC curves. The identification of thresholds that optimize diagnostic performances was carried out using Youden’s index.

Results

The diagnostic performances of UWS flow rate varied according to age and sex. UWS had poor diagnostic performances whatever the threshold in the women ≥ 50 group. The threshold of 0.2 mL/min had a sensitivity of ≥ 70% and a specificity of ≥ 50% in both men and women < 50 groups. In the whole population and compared to the current cutoff, a threshold of 0.2 mL/min increased sensitivity (+ 19.8%) and positive (+ 2.3%) and negative (+ 7.0%) predictive values, with a better specificity (65.2%) than Schirmer’s test.

Conclusion

For objective assessment of xerostomia, raising the threshold of the UWS flow rate to 0.2 mL/min would optimize its screening performances for pSS.

Tear Metabolomics in Dry Eye Disease: A Review

Dry eye disease (DED) is a multifactorial syndrome that can be caused by alteration in the quality or quantity of the precorneal tear film. It is considered one of the most common ocular conditions leading patients to seek eye care. The current method for diagnostic evaluations and follow-up examinations of DED is a combination of clinical signs and symptoms determined by clinical tests and questionnaires, respectively. The application of powerful omics technologies has opened new avenues toward analysis of subjects in health and disease. Metabolomics is a new emerging and complementary research discipline to all modern omics in the comprehensive analysis of biological systems. The identification of distinct metabolites and integrated metabolic profiles in patients can potentially inform clinicians at an early stage or during monitoring of disease progression, enhancing diagnosis, prognosis, and the choice of therapy. In ophthalmology, metabolomics has gained considerable attention over the past decade but very limited such studies have been reported on DED. This paper aims to review the application of tear metabolomics in DED.

Clinical Characteristics and Outcome of Primary Sjogren's Syndrome: A Large Asian Indian Cohort

Objective :

To characterise the clinical features, immunological profile and outcome in a cohort of Asian Indian patients with primary Sjögren's syndrome (SS).

Methods :

Electronic medical records from a tertiary care teaching hospital in south India were screened for SS between 2004 and 2011. Patients fulfilling American European Consensus group (AECG) 2002 or American College of Rheumatology (ACR) 2012 classification criteria were included. Agglomerative hierarchical cluster analysis to identify patterns of associations between clinical and immunological features was done. Multivariate logistic regression to identify predictors of major systemic involvement was performed. Data on treatment and outcome were retrieved from electronic records.

Results :

Of 423 patients suspected to have SS, 332 fulfilled inclusion criteria. Only 8.3% of patients complained of sicca symptoms on their own at initial presentation. Younger age of onset, higher female to male ratio, paucity of cryoglobulinemia, Raynaud’s phenomenon and hyperglobulinemia were unique to this cohort. Cluster analysis revealed two subsets: The first cluster comprised of patients having a major systemic illness with high antibody titers and the second comprised of seronegative patients with mild disease. Over a third of SS cases had severe systemic manifestations necessitating treatment with immunosuppressants. In multivariate logistic regression analysis, anti-Ro and anti-La antibody positivity was associated with higher odds for systemic disease features (OR=2.67, P=0.03 and OR=3.25, P=0.003, respectively) whereas chronic pain was associated with lower odds (OR=0.4, p=0.032). Clinical improvement including symptomatic benefit in sicca and musculoskeletal features was noted with immunomodulators in the majority.

Conclusion :

Our cohort of patients with SS has characteristic clinical features; some of them are in contrast with previous observations reported in European patients. This cohort consisted of two distinct patient clusters. The first cluster was associated with major systemic illness and high antibody titers, where as the second cluster comprised of seronegative patients with mild disease. Association of antibody positivity with systemic features was further confirmed on logistic regression analysis.

Oral manifestations of hepatitis C virus infection

Extrahepatic manifestations (EHMs) of hepatitis C virus (HCV) infection can affect a variety of organ systems with significant morbidity and mortality. Some of the most frequently reported EHM of HCV infection, involve the oral region predominantly or exclusively. Oral lichen planus (OLP) is a chronic inflammatory condition that is potentially malignant and represents cell-mediated reaction to a variety of extrinsic antigens, altered self-antigens, or super antigens. Robust epidemiological evidence support the link between OLP and HCV. As the virus may replicate in the oral mucosa and attract HCV-specific T lymphocytes, HCV may be implicated in OLP pathogenesis. Sjögren syndrome (SjS) is an autoimmune exocrinopathy, characterized by dryness of the mouth and eyes and a multitude of other systemic signs and symptoms. SjS patients have also an increased risk of non-Hodgkin lymphoma. Patients with chronic hepatitis C do frequently have histological signs of Sjögren-like sialadenitis with mild or even absent clinical symptoms. However, it is still unclear if HCV may cause a disease mimicking SjS or it is directly responsible for the development of SjS in a specific subset of patients. Oral squamous cell carcinoma is the most common oral malignant tumour and at least in some part of the world could be linked to HCV.