Unstimulated whole salivary flow in Sjögren’s Syndrome: systematic literature review and meta-analysis

Abstract

Background Sjögren’s Syndrome compromises the exocrine function, producing xerostomia and xerophthalmia. It can appear as an isolated condition or associated with other autoimmune diseases (polyautoimmunity). The Unstimulated Salivary Flow rate (UWSF) is used to quantify saliva production. There is no objective evidence to differentiate the values in patients with Sjögren’s versus healthy people or patients with non-Sjögren’s sicca. The objective of the present review was to evaluate the UWSF in patients with Sjögren’s syndrome in comparison to controls (healthy and non-Sjögren’s sicca patients). Methods A systematic literature review was carried out (PRISMA guidelines). Analytical observational studies of cases and controls, cross-sectional studies, cohort studies and randomized clinical trials (including healthy controls) were considered. The Medline/OVID, Lilacs, Embase, and Cochrane/OVID databases were consulted. MeSH, DeCS, keywords, and Boolean operators were used. The meta-analysis (RevMan 5.2) was done through the random-effects model [mean difference (MD)]. Level and quality of evidence were evaluated by the Oxford Center Levels of Evidence and Joanna Brigs list respectively. Results Thirty-two articles were included (20 were case-control studies, 6 were cross-sectional, 2 prospective cohort, 2 retrospective cohort, and 2 studies were abstracts) and 28 were meta-analyzed. The unstimulated whole salivary flow rate in the Sjögren’s group was lower than in controls (healthy and patients with non-Sjögren Sicca syndrome) (MD-0.18 ml/min; 95% CI, − 0.24 to − 0.13; chi2-P-value < 0.00001). Heterogeneity was 97% and there was publication bias (funnel plot). The level of evidence was mostly 3 or 4. The quality of evidence was met (97% of items valued). Conclusion For the first time, the unstimulated whole salivary flow rate is found to be lower in patients with Sjögren’s syndrome compared to controls (healthy and non-SS sicca) through a meta-analysis. Trial registration PROSPERO CRD42020211325.

Salivary Flow Rate and Oral Status in Patients with Primary Sjögren’s Syndrome and Diffuse Cutaneous Systemic Sclerosis: A Cross-Sectional Study

“…This can be explained by the etiopathogenetic mechanism of SS, i.e., focal lymphocytic infiltration of the salivary glands. The UWSFR in pSS patients in our study is consistent with the systematic review of the literature and meta-analysis by Martínez-Ceballos et al (0.18 mL/min) [ 22 ].…”

High-Throughput Sequencing of Oral Microbiota in Candida Carriage Sjögren’s Syndrome Patients: A Pilot Cross-Sectional Study

“…However, species level classification is not reliable with 200–400 bp reads of the 16S rRNA gene, and analyses have been confined to genus and higher taxonomies [ 62 ]. Finally, as one of the clinical characteristics, the UWSF in primary SS patients was −0.43 mL/min compared to controls [ 63 ]. It is difficult to conclude whether the microbial dysbiosis was caused by SS or hyposalivation.…”

Metabolic Profile of Whole Unstimulated Saliva in Patients with Sjögren’s Syndrome

“…A possible explanation for this finding may reside in the test interpretation itself. Even if ACR/EULAR guidelines set the test limit to <0.1 mL/min and this value is considered for disease management and therapy administration [ 33 ], recently published reviews have suggested an adjustment of the threshold for hyposalivation, modifying the cutoff to <0.2 mL/min to better fit the population over 60 years of age, thus increasing the sensitivity and specificity of the pSS diagnosis [ 34 , 35 ].…”