Variability of flow rate when collecting stimulated human parotid saliva

Saliva sampling strategies affecting the salivary glucose measurement

Characterized by sustained elevated blood glucose levels, diabetes mellitus has become one of the largest global public health concerns by imposing a heavy global burden on socio-economic development. To date, regular blood glucose level check by performing a finger-prick test has been a routine strategy to monitor diabetes. However, the intrusive nature of finger blood prick tests makes it challenging for individuals to maintain consistent testing routines. Recently, salivary glucose measurement (SGM) has increasingly become a non-invasive alternative to traditional blood glucose testing for diabetes. Despite that, further research is needed to standardize the collection methods and address the issues of variability to ensure accurate and reliable SGM. To resolve possible remaining issues in SGM, we here thoroughly explored saliva sampling strategies that could impact the measurement results. Additionally, the effects of supplements taken, mouth washing, gum chewing, and smoking were collectively analyzed, followed by a continuous SGM over a long period, forming the stepping stone for the practical transitional development of SGM in non-invasive diabetes monitoring.

Advances in the Diagnosis, Monitoring, and Progression of Oral Cancer through Saliva: An Update

The early detection of cancer, and in particular oral cancer, has been a priority objective of study in recent years. Saliva has been proposed as an easy-to-obtain means of providing the necessary information to diagnose malignant lesions in the oral cavity, since it can be obtained very easily and completely noninvasively. There are a number of molecules, known as biomarkers, which may be involved in the malignant transformation of oral lesions, and which have different natures. The involvement of proteins (“proteomics”), metabolites (“metabolomics”), and even certain genes in the structural changes of altered tissue has been investigated in order to establish validated parameters for the early diagnosis of oral cancer. In addition, the development of new analytical assay methods that can reduce costs and obtain better results in terms of sensitivity and specificity has been a key point in recent research in this field. Even though there are numerous biomarkers with results showing high sensitivity and specificity, there is still a need for more studies, with a larger sample and with analytical methods that can constitute a real advance in time and cost. Although salivary biomarkers are a promising new diagnostic tool for oral cancer, for the moment they do not replace biopsy as the “gold standard”.

Parotid Gland Stem Cell Sparing Radiation Therapy for Patients With Head and Neck Cancer: A Double-Blind Randomized Controlled Trial

PURPOSE

Radiation therapy for head and neck cancer frequently leads to salivary gland damage and subsequent xerostomia. The radiation response of the parotid glands of rats, mice, and patients critically depends on dose to parotid gland stem cells, mainly located in the gland's main ducts (stem cell rich [SCR] region). Therefore, this double-blind randomized controlled trial aimed to test the hypothesis that parotid gland stem cell sparing radiation therapy preserves parotid gland function better than currently used whole parotid gland sparing radiation therapy.

METHODS AND MATERIALS

Patients with head and neck cancer (n = 102) treated with definitive radiation therapy were randomized between standard parotid-sparing and stem cell sparing (SCS) techniques. The primary endpoint was >75% reduction in parotid gland saliva production compared with pretreatment production (FLOW12M). Secondary endpoints were several aspects of xerostomia 12 months after treatment.

RESULTS

Fifty-four patients were assigned to the standard arm and 48 to the SCS arm. Only dose to the SCR regions (contralateral 16 and 11 Gy [P = .004] and ipsilateral 26 and 16 Gy [P = .001] in the standard and SCS arm, respectively) and pretreatment patient-rated daytime xerostomia (35% and 13% [P = .01] in the standard and SCS arm, respectively) differed significantly between the arms. In the SCS arm, 1 patient (2.8%) experienced FLOW12M compared with 2 (4.9%) in the standard arm (P = 1.00). However, a trend toward better relative parotid gland salivary function in favor of SCS radiation therapy was shown. Moreover, multivariable analysis showed that mean contralateral SCR region dose was the strongest dosimetric predictor for moderate-to-severe patient-rated daytime xerostomia and grade ≥2 physician-rated xerostomia, the latter including reported alteration in diet.

CONCLUSIONS

No significantly better parotid function was observed in SCS radiation therapy. However, additional multivariable analysis showed that dose to the SCR region was more predictive of the development of parotid gland function-related xerostomia endpoints than dose to the entire parotid gland.

Histopathology, salivary flow and ultrasonography of the parotid gland: three complementary measurements in primary Sjögren's syndrome

OBJECTIVE

The involvement of salivary glands in primary Sjögren's syndrome (pSS) can be assessed in different ways: histopathology, salivary flow and ultrasonography. To understand the relative value of these different approaches, it is crucial to understand the relationship between them. As we routinely perform these three modalities in the parotid gland for disease evaluation, our aim was to investigate the construct validity between these modalities in one and the same gland.

METHODS

Consecutive sicca patients underwent a multidisciplinary diagnostic work-up including parotid gland biopsy, collection of parotid gland-specific saliva and parotid gland ultrasonography. Patients who were classified as pSS according to the ACR-EULAR criteria were included. Construct validity was assessed using Spearman's correlation coefficients.

RESULTS

The 41 included pSS patients completed a full work-up within mean time interval of 2.6 months. Correlations between histopathological features and stimulated parotid salivary flow were fair (ρ=-0.123 for focus score, and ρ=-0.259 for percentage of CD45+ infiltrate). Likewise, poor correlations were observed between stimulated parotid salivary flow and parotid ultrasonography (ρ=-0.196). Moderate to good associations were found between the histopathological items focus score and percentage of CD45+ infiltrate, with parotid ultrasound scores (total ultrasound score: ρ = 0.510 and ρ = 0.560; highest for homogeneity: ρ = 0.574 and ρ = 0.633).

CONCLUSION

Although pSS associated ultrasonographic findings did correlate with histopathological features, the three modalities that evaluate salivary gland involvement assess different (or at best partly related) constructs. Therefore, histopathology, salivary flow and ultrasonography are complementary measurements and cannot directly replace each other in the work-up of pSS.

Composite of Relevant Endpoints for Sjögren's Syndrome (CRESS): development and validation of a novel outcome measure

BACKGROUND

Recent randomised controlled trials (RCTs) in primary Sjögren's syndrome used the European League Against Rheumatism (EULAR) Sjögren's Syndrome Disease Activity Index (ESSDAI) as their primary endpoint. Given the heterogeneous and complex nature of primary Sjögren's syndrome, it might be more appropriate to also assess other clinically relevant disease features. We aimed to develop a novel composite endpoint for assessing treatment efficacy in patients with primary Sjögren's syndrome: the Composite of Relevant Endpoints for Sjögren's Syndrome (CRESS).

METHODS

A multidisciplinary expert team selected clinically relevant items and candidate measurements for inclusion in the composite score. For each measurement, cutoff points for response to treatment were chosen based on expert opinion, previously published data on minimal clinically important improvements, and trial data, primarily the week-24 data of the single-centre ASAP-III trial of abatacept versus placebo. CRESS was validated using data from three independent RCTs: one trial of rituximab (TRACTISS), one of abatacept (multinational trial), and one of tocilizumab (ETAP). We calculated the number and percentage of patients who were responders in the separate CRESS items, and the percentage of responders based on the total CRESS at the primary endpoint visits (week 48 for TRACTISS, week 24 for the other two trials). Patients with fewer than three items available for evaluating CRESS response were imputed as non-responders.

FINDINGS

Based on expert opinion, five complementary items were selected to assess response: (1) systemic disease activity by Clinical ESSDAI (less than 5 points); (2) patient-reported symptoms by EULAR Sjögren's Syndrome Patient Reported Index, assessed by a decrease of at least 1 point or at least 15% from baseline; (3) tear gland item by Schirmer's test and ocular staining score, assessed by an increase of at least 5 mm or decrease of at least 2 points, respectively, in patients with abnormal Schirmer's test or ocular staining score findings at baseline, or, in patients with normal baseline values, assessed by no change to abnormal for both; (4) salivary gland item, assessed by unstimulated whole saliva secretion (increase of at least 25%) and salivary gland ultrasonography (decrease of at least 25%); and (5) serology, assessed by rheumatoid factor (decrease of at least 25%) and IgG (decrease of at least 10%). Total CRESS response is defined as response on at least three of five items. Post-hoc assessment of phase 3 trial data showed that CRESS response rates at the primary endpoint visits were 60% (24 of 40) for abatacept versus 18% (seven of 39) for placebo (p<0·0001) in ASAP-III, 49% (33 of 67) for rituximab versus 30% (20 of 66) for placebo (p=0·026) in the TRACTISS trial, 45% (41 of 92) for abatacept versus 32% (30 of 95) for placebo (p=0·067) in the multinational abatacept trial, and 18% (10 of 55) for tocilizumab versus 24% (13 of 55) for placebo (p=0·48) in the ETAP trial.

INTERPRETATION

The CRESS is a feasible, well-balanced, composite endpoint for use in trials of primary Sjögren's syndrome. As a next step, the CRESS will require validation in a prospective RCT.

FUNDING

None.

TRANSLATION

For the Dutch translation of the abstract see Supplementary Materials section.

Mastication, swallowing, and salivary flow in patients with head and neck cancer: objective tests versus patient-reported outcomes

Purpose

Before and after treatment for head and neck cancer (HNC), many patients have problems with mastication, swallowing, and salivary flow. The aim of this study was to investigate the association between objective test outcomes of mastication, swallowing, and salivary flow versus patient-reported outcomes (PROs) measuring mastication-, swallowing-, and salivary flow–related quality of life.

Methods

Data of the prospective cohort “Netherlands Quality of Life and Biomedical Cohort Study” was used as collected before treatment, and 3 and 6 months after treatment. Spearman’s rho was used to test the association between objective test outcomes of the mixing ability test (MAT) for masticatory performance, the water-swallowing test (WST) for swallowing performance, and the salivary flow test versus PROs (subscales of the EORTC QLQ-H&N35, Swallow Quality of Life questionnaire (SWAL-QoL-NL) and Groningen Radiation-Induced Xerostomia (GRIX)).

Results

Data of 142 patients were used, and in total, 285 measurements were performed. No significant correlations were found between the MAT or WST and subscales of the EORTC QLQ-H&N35. Significant but weak correlations were found between the MAT or WST and 4 subscales of the SWAL-QoL-NL. Weak to moderate correlations were found between the salivary flow test and GRIX at 3 and 6 months after treatment, with the highest correlation between salivary flow and xerostomia during the day (Spearman’s rho =  − 0.441, p = 0.001).

Conclusion

The association between objective test outcomes and PROs is weak, indicating that these outcome measures provide different information about masticatory performance, swallowing, and salivary flow in patients with HNC.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00520-021-06368-6.

Abatacept treatment for patients with early active primary Sjögren's syndrome: a single-centre, randomised, double-blind, placebo-controlled, phase 3 trial (ASAP-III study)

BACKGROUND

Several small open-label studies have suggested efficacy of abatacept-a co-stimulation inhibitor-in patients with primary Sjögren's syndrome. These promising results warranted further evaluation. We therefore aimed to further assess the safety and efficacy of abatacept compared with placebo in patients with primary Sjögren's syndrome.

METHODS

We did a single-centre, randomised, double-blind, placebo-controlled, phase 3 trial at the University Medical Center Groningen (Groningen, Netherlands). We included patients with primary Sjögren's syndrome fulfilling the American-European Consensus Group criteria, aged 18 years or older, with positive salivary gland biopsies, time from diagnosis of 7 years or less, and a European League Against Rheumatism Sjögren's Syndrome Disease Activity Index (ESSDAI) score of 5 or more. Independent pharmacists randomly allocated patients (1:1) to either the abatacept group or placebo group using a computer-generated sequence stratified by previous use of disease-modifying anti-rheumatic drugs. Patients received at-home subcutaneous injections of abatacept (125 mg) or placebo once a week for 24 weeks. The primary outcome was the between-group difference in ESSDAI score at week 24. Efficacy was analysed in patients who received at least one drug dose and for whom post-baseline data were collected. Safety was analysed in all patients who received at least one drug dose.

FINDINGS

Between Aug 14, 2014, and Aug 23, 2018, 580 patients were reviewed for eligibility, of which 80 patients were randomly assigned to receive study treatment. Efficacy was analysed in 40 patients receiving abatacept and 39 patients receiving placebo (one patient in this group was lost to follow-up). The primary outcome did not significantly differ between the treatment groups. The adjusted mean difference in ESSDAI score at week 24 between the abatacept group and placebo group was -1·3 (95% CI -4·1 to 1·6). No deaths or treatment-related serious adverse events occurred. In 38 (95%) of 40 patients in the abatacept group, 103 adverse events occurred, including one serious adverse event and 46 infections. In 38 (95%) of 40 patients in the placebo group, 87 adverse events occurred, including four serious adverse events and 49 infections.

INTERPRETATION

On the basis of this trial, we cannot recommend abatacept treatment as standard of care to reduce systemic disease activity in patients with primary Sjögren's syndrome. Further studies should evaluate whether patients with specific clinical manifestations and biological characteristics might benefit from abatacept treatment.

FUNDING

Bristol-Myers Squibb.

Role of Salivary Duct Morphology in the Etiology of Chronic Obstructive Parotitis: Statistical Analysis of Sialographic Features and Computational Fluid Dynamics Analysis of Salivary Flow

PURPOSE

The causes of some cases of chronic obstructive parotitis (COP) without obstructive factors are still unclear. The authors hypothesized that some morphologic features of salivary ducts might contribute to the development of COP. This study investigated the role of salivary duct morphology in the etiology of COP.

MATERIALS AND METHODS

The authors designed and implemented a case-and-control study. Cases were defined as patients with COP, diagnosed from September 2014 to May 2017 at the Affiliated Hospital of Stomatology of the Sun Yat-sen University (Guangzhou, China), and controls were healthy participants. The primary predictor variables were the occurrence of an accessory duct (AD), the number of branches uniting to form the Stensen duct (SD), the angle between the AD and the SD, and the angle between branches identified on sialographic computed tomograms. Data from the 2 groups were compared to investigate the association between these variables and COP. The χ² test, Student t test, and logistic regression were computed, with significance set at a P value less than .05. Fluid dynamics analysis was used to analyze salivary flow field in models of salivary ducts with different morphologic features reconstructed from sialographic computed tomograms.

RESULTS

The sample was composed of 39 patients with COP and 18 controls without COP. The 2 groups were not similar for incidences of an AD (71.8 vs 38.9%) and the angle between branches (96.5 ± 26.0° vs 71.5 ± 21.2°). There was no relevant difference between groups in the number of branches and the angle between the AD and the SD. The area of low velocity was larger in the model with the wider angle between branches.

CONCLUSIONS

The results suggest that the presence of an AD and a wider angle between duct branches are associated with COP.

Evaluation of Parotid Gland Function Before and After Endoscopy-Assisted Stone Removal

PURPOSE

To quantify gland function before and after endoscopy-assisted lithectomy for patients with parotid stones and to analyze correlations among different evaluation modalities.

MATERIALS AND METHODS

This study investigated 58 patients (27 men and 31 women) with a stone larger than 5 mm or multiple parotid stones who underwent successful endoscopy-assisted surgery at the authors' center from August 2007 through September 2017. Meticulous postoperative manipulations were administered routinely for 3 to 6 months to promote functional recovery of the affected gland. Gland function was evaluated preoperatively and 6 to 36 months (mean, 12 months) postoperatively by sialography, scintigraphy, and sialometry. Statistical analyses were conducted to quantify gland function recovery and to distinguish correlations among the 3 objective tests.

RESULTS

Preoperative sialograms exhibited ductal ectasia at the stone site with ductal stenosis anterior to the stone (n = 53) or duct interruption at the stone site (n = 5). Postoperative sialograms of 45 patients without stones were categorized as approximately normal (type I; n = 17); showing ectasia or stenosis of the main duct without persistent contrast on the functional film (type II; n = 16); showing ectasia or stenosis of the main duct with mild contrast retention (type III; n = 6); or showing poor ductal shape with evident contrast retention (type IV; n = 6). Scintigraphy of 23 preoperative and 12 postoperative patients and sialometry of 24 preoperative and 12 postoperative patients indicated severe preoperative impairment and postoperative improvement of gland function. Postoperatively, although no relevant differences in saliva flow rate were found between the 2 sides, scintigraphy showed lower function of the affected gland compared with the control side. Statistical data showed positive correlations among the 3 methods. Sialography intuitively reflected the ductal shape, whereas sialometry and scintigraphy were more sensitive for evaluating gland function.

CONCLUSION

For patients with parotid stones, minimally invasive endoscopic surgery and meticulous postoperative manipulations help preserve the glands and facilitate recovery of gland function. The 3 evaluating modalities have certain positive correlations.

A Review of Selected Studies That Determine the Physical and Chemical Properties of Saliva in the Field of Dental Treatment

Physiological whole saliva is a unique body fluid constantly washing the mucous membranes of the mouth, throat, and larynx. Saliva is a clear, slightly acidic mucinous-serous secretion, composed of various electrolytes, small organic substances, proteins, peptides, and polynucleotides. There are many ways to use saliva as a biological fluid (biofluid). The significant advantages of saliva as a unique diagnostic material are its availability and the noninvasive method of collection. The aim of this review is to emphasize the diagnostic value of saliva as a research material in the configuration of its structure and secretion disorders. The data were obtained using the MEDLINE (PubMed) search engine, as well as an additional manual search. The analysis covered 77 articles selected from a group of 1986 publications and initially qualified for devising. The results were evaluated and checked for the correctness of qualifying in accordance with inclusion and exclusion criteria. The diagnostic use of saliva has attracted the attention of many researchers due to its noninvasive nature and relative simplicity of collection. In addition, it should be noted that the determination of chemical and physical saliva parameters can be effectively performed in the patient's presence in the dental office.

Effectiveness of Traditional Chinese Medicine Compound JieDuTongLuoShengJin Granules Treatment in Primary Sjögren's Syndrome: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial

Objective

To evaluate the clinical therapeutic efficacy and safety of JieDuTongLuoShengJin granules + HCQ in patients with pSS.

Methods

40 patients with low-activity-level pSS and without visceral involvement participated in this study and were randomized to receive either JieDuTongLuoShengJin granules with HCQ or placebo with HCQ. Patients and investigators were blinded to treatment allocation. The primary endpoint was week 12 ESSPRI score, while secondary endpoints included ESSDAI, salivary and lacrimal gland function, and some laboratory variables. Safety-related data were also assessed.

Results

Comparing with the placebo group, the treatment group experienced statistically significant improvement in the mean change from baseline for the primary endpoint of ESSPRI score and also in PGA. Moreover, in comparison with baseline values, the treatment group had significantly improved ESSDAI score, unstimulated saliva flow rate, and several laboratory variables. However, upon comparison of the two groups, there were no significant differences for them. The incidence of AEs was 10.0%, one in treatment group and three in placebo group.

Conclusion

Treatment with a combination of JieDuTongLuoShengJin granules with HCQ is effective in improving patients' subjective symptoms and some objective indicators of pSS. These results indicate that JieDuTongLuoShengJin is promising as a safe and effective treatment of pSS.

The value of rituximab treatment in primary Sjögren's syndrome

The rationale for B cell depletion therapy with rituximab in primary Sjögren's syndrome relies upon the well-established role of B cell hyperactivity in immunopathogenesis. In line with this notion, several biomarkers of B cell activity are significantly affected by treatment, both in the target organs and periphery. In contrast to most biological outcomes, clinical outcomes are not consistent between studies. Although two large RCTs did not meet their primary endpoint, several beneficial clinical effects of treatment have been shown. As discussed in this review, differences in study design and patient characteristics could explain the variation in results. Interestingly, a newly developed composite endpoint of subjective and objective outcomes did show a significant effect of rituximab in one of the large RCTs. Response predictors need to be identified to define more targeted inclusion criteria and achieve precision medicine. The positive effects seen on biological and clinical parameters warrant future studies to investigate this promising treatment modality.

The effect of clinical setting on the unstimulated salivary flow rate

OBJECTIVE

Unstimulated whole saliva (UWS) sialometry uses the spitting method to assess occurrence of hyposalivation. This study compares the UWS flow rates in volunteers sitting in a laboratory or in a clinical setting, in order to evaluate the influence of environment on salivary secretion.

DESIGN

25 healthy volunteers were recruited and divided into two groups to perform UWS sialometry under the two different settings (T1). Eleven weeks later, the participants repeated the same test (T2). At a unique time point and under the clinical setting, 18 patients complaining of xerostomia also performed the UWS sialometry; these values were used as control to corroborate findings.

RESULTS

Different scenarios - laboratory one vs. clinical one - did not affect measurements of mean UWS flow rates. Both intra- and inter-individual variabilities, reported as standard error of the mean (SEM) and within-subject variance (WSV), resulted below the threshold of 0.1g/min. A significant difference was found between UWS flow rates from healthy volunteers and those from patients with xerostomia (p<0.05). Test/retest reliability showed a moderate correlation of datasets collected at the two time points from healthy volunteers (T1 vs. T2, 11 weeks later): under laboratory and clinical settings, Pearson's coefficients of correlation were r=0.62 and r=0.32, respectively.

CONCLUSIONS

Type of environment did not influence UWS sialometry via spitting method, which appeared reliable for intra-day analysis of the salivary flow rate, although prone to physiological variations over time.

A randomized, double-blind, placebo-controlled trial of a traditional herbal formula, Yukmijihwang-tang in elderly subjects with xerostomia

ETHNOPHARMACOLOGICAL RELEVANCE

Yukmijihwang-tang (YMJ) is a typical herbal formula to treat Yin-deficiency (YD) syndrome by enriching the fluid-humor of the body. YMJ has been used to treat dry mouth symptoms for hundreds of years in traditional East Asian medicine. Xerostomia, a subjective oral dryness, is common in the elderly and results in impaired quality of life. Many conventional treatments for xerostomia provide only temporary symptom relief, and have side effects. The aim of this study is to investigate the efficacy and safety of YMJ for the treatment of xerostomia in the elderly.

METHODS

This study was designed as a randomized, placebo-controlled, double-blinded, two center trial. Ninety-six subjects aged 60-80 years who had experienced xerostomia for at least 3 months and presented with score>40 on the visual analog scale (VAS) for subjective oral dryness were recruited and randomly allocated to YMJ and placebo groups. YMJ or placebo was administered to each group for 8 weeks (3g of YMJ or placebo, three times per day). The primary outcome was change of VAS for xerostomia from 0 to 8 weeks.

RESULTS

VAS for xerostomia was decreased by 22.04±22.76 in the YMJ group and 23.58±23.04 in the placebo group. YMJ had no effect on xerostomia. However, participants with BMIs lower than 29.37kg/m(2) showed improvement of xerostomia after 8 weeks of treatment with YMJ compared to placebo. In addition, YMJ improved oral moisture, which is associated with subjective oral dryness in the YMJ group, and the relationship between VAS for xerostomia and YD was significant.

CONCLUSION

A trend was observed in which YMJ improved oral moisture status and subjective oral dryness in elderly subjects with lower BMI and greater tendency toward YD.

Regional radiation dose susceptibility within the parotid gland: effects on salivary loss and recovery

PURPOSE

Xerostomia is one of the most likely late toxic effects of radiotherapy treatment in patients with head-and-neck cancers. Modern treatment techniques can incorporate knowledge of complication risk into treatment plans. To this end, the authors attempt to quantify the regional radiotherapy dose-dependence of salivary output loss and recovery in a prospective study.

METHODS

Salivary output was collected from patients undergoing radiotherapy treatment for head-and-neck cancers at the BC Cancer Agency between February 2008 and May 2013. Regional dose-dependence (i.e., dose susceptibility) of loss and recovery is quantified using nonparametric (Spearman's rank correlation coefficients, local linear regression) and parametric (least-sum of squares, least-median of squares) techniques.

RESULTS

Salivary flow recovery was seen in 79 of 102 patients considered (p < 0.0001, Wilcoxon sign rank test). Output loss was strongly correlated with left- and right parotid combined dose φ = min (DL,  45 Gy) + min (DR,  45 Gy), and can be accurately predicted. Median early loss (three months) was 72% of baseline, while median overall loss (1 yr) was 56% of baseline. Fitting an exponential model to whole parotid yields dose sensitivities A3m = 0.0604 Gy(-1) and A1y = 0.0379 Gy(-1). Recovery was not significantly associated with dose. Hints of lateral organ sub-segment dose-response dimorphism were observed.

CONCLUSIONS

Sub-segmentation appears to predict neither loss nor recovery with any greater precision than whole parotid mean dose, though it is not any worse. Sparing the parotid to a combined dose φ of <50 Gy is recommended for a patient to keep ≈40% of baseline function and thus avoid severe xerostomia at 12 months post-treatment. It seems unlikely that a population's mean recovery will exceed 20%-30% of baseline output at 1 yr after radiotherapy treatment using current (whole-organ based) clinical guidelines.

Characteristics of the saliva flow rates of minor salivary glands in healthy people

OBJECTIVES

To investigate the normal range and characteristics of saliva secretion in the minor salivary glands (MSGs).

DESIGN

The flow rates of MSGs were measured in 4 anatomical locations of oral mucosa, and the relationship between MSG flow rates and whole saliva flow rates were assessed in 300 healthy subjects stratified by age and sex. An additional 30 young females were further evaluated for flow symmetry, effects of stimulation, circadian effects in MSGs, and the relationship with the flow rates of major salivary glands.

RESULTS

(1) The mean saliva flow rates were 2.10 ± 0.66 (lower labial glands), 2.14 ± 0.62 (upper labial glands), 2.88 ± 0.72 (buccal glands) and 2.15 ± 0.51 (palatal glands) μl/min/cm(2), respectively. The flow rate of buccal glands was significantly higher than the rates of SMGs in other locations (P < 0.01). (2) 5-year-old children had the lowest MSG flow rates (P < 0.0001) while the 10-14-year-old group had the highest (P < 0.001). (3) MSG flow rates were independent of sex (P > 0.05), right vs. left (P > 0.05), and citric acid (2.5%) stimulation (P > 0.05). (4) Only labial MSG displayed a significant secretory circadian rhythm with the highest rate in the evening (P < 0.05). (5) A weak correlation was found between the flow rate of palatal glands and that of unstimulated whole saliva (r = 0.195, P = 0.007).

CONCLUSIONS

Our findings provide a reference for functional evaluation of MSGs and for donor site selection of MSG transplantation for treatment of severe dry eye syndrome.

Salivary gland dysfunction and xerostomia in Sjögren's syndrome

In this article, salivary gland dysfunction and xerostomia in Sjögren's syndrome (SS) are discussed, with a focus on the pathophysiology of salivary dysfunction in SS, the clinical presentation of dry mouth in SS, how to assess salivary gland hypofunction and xerostomia in SS, and the impact of salivary gland dysfunction on quality of life in patients with SS.

Effect of mobile phone use on salivary concentrations of protein, amylase, lipase, immunoglobulin A, lysozyme, lactoferrin, peroxidase and C-reactive protein of the parotid gland

BACKGROUND

The possibility of side effects associated with the electromagnetic waves emitted from mobile phones is a controversial issue. The present study aimed to evaluate the effect of mobile phone use on parotid gland salivary concentrations of protein, amylase, lipase, immunoglobulin A, lysozyme, lactoferrin, peroxidase and C-reactive protein.

METHODS

Stimulated salivary samples were collected simultaneously from both parotid glands of 86 healthy volunteers. Salivary flow rate and salivary concentrations of proteins, amylase, lipase, lysozyme, lactoferrin, peroxidase, C-reactive protein and immunoglobulin A, were measured. Data were analysed using t-tests and one-way analyses of variance.

RESULTS

Salivary flow rate and parotid gland salivary concentrations of protein were significantly higher on the right side compared to the left in those that predominantly held mobile phones on the right side. In addition, there was a decrease in concentrations of amylase, lipase, lysozyme, lactoferrin and peroxidase.

CONCLUSION

The side of dominant mobile phone use was associated with differences in salivary flow rate and parotid gland salivary concentrations, in right-dominant users. Although mobile phone use influenced salivary composition, the relationship was not significant.

Urban legends series: Sjögren's syndrome

Sjögren's syndrome (SjS) is one of the most common autoimmune rheumatic diseases, clinically characterized by xerostomia and keratoconjunctivitis sicca. We investigated the following controversial topics: (i) Do we have reliable ways of assessing saliva production? (ii) How important are the quantity and quality of saliva? (iii) Are only anti-SSA/Ro and anti-SSB/La relevant for the diagnosis of SjS? (iv) Are the American-European Consensus criteria (AECC) the best way to diagnose SjS? Results from literature searches suggested the following: (i) Despite the fact that numerous tests are available to assess salivation rates, direct comparisons among them are scarce with little evidence to suggest one best test. (ii) Recent developments highlight the importance of investigating the composition of saliva. However, more research is needed to standardize the methods of analysis and collection and refine the quality of the accumulating data. (iii) In addition to anti-Ro/La autoantibodies, anti α-fodrin IgA and anti-MR3 autoantibodies seem to be promising diagnostic markers of SjS, but more studies are warranted to test their sensitivity and specificity. (iv) AECC are classification, not diagnostic criteria. Moreover, recent innovations have not been incorporated into these criteria. Consequently, treatment directed to patients diagnosed using the AECC might exclude a significant proportion of patients with SjS.

A systematic review of methods to diagnose oral dryness and salivary gland function

Background

The most advocated clinical method for diagnosing salivary dysfunction is to quantitate unstimulated and stimulated whole saliva (sialometry). Since there is an expected and wide variation in salivary flow rates among individuals, the assessment of dysfunction can be difficult. The aim of this systematic review is to evaluate the quality of the evidence for the efficacy of diagnostic methods used to identify oral dryness.

Methods

A literature search, with specific indexing terms and a hand search, was conducted for publications that described a method to diagnose oral dryness. The electronic databases of PubMed, Cochrane Library, and Web of Science were used as data sources. Four reviewers selected publications on the basis of predetermined inclusion and exclusion criteria. Data were extracted from the selected publications using a protocol. Original studies were interpreted with the aid of Quality Assessment of Diagnostic Accuracy Studies (QUADAS) tool.

Results

The database searches resulted in 224 titles and abstracts. Of these abstracts, 80 publications were judged to meet the inclusion criteria and read in full. A total of 18 original studies were judged relevant and interpreted for this review. In all studies, the results of the test method were compared to those of a reference method.

Based on the interpretation (with the aid of the QUADAS tool) it can be reported that the patient selection criteria were not clearly described and the test or reference methods were not described in sufficient detail for it to be reproduced. None of the included studies reported information on uninterpretable/intermediate results nor data on observer or instrument variation. Seven of the studies presented their results as a percentage of correct diagnoses.

Conclusions

The evidence for the efficacy of clinical methods to assess oral dryness is sparse and it can be stated that improved standards for the reporting of diagnostic accuracy are needed in order to assure the methodological quality of studies. There is need for effective diagnostic criteria and functional tests in order to detect those individuals with oral dryness who may require oral treatment, such as alleviation of discomfort and/or prevention of diseases.

Salivary gland sparing in the treatment of head and neck cancer

Radiotherapy is an important component of the multimodality treatment of head and neck cancer. Although an effective treatment for many patients, it can have significant long-term sequelae. In particular, xerostomia - or dry mouth - caused by salivary gland injury is a serious problem suffered by most patients and leads to problems with oral comfort, dental health, speech and swallowing. This article explores the mechanisms behind radiation injury to the major salivary glands, as well as different strategies to minimize and alleviate xerostomia. This includes technical approaches to minimize radiation dose to salivary tissue, such as intensity-modulated radiotherapy and surgical transfer of salivary glands, as well as pharmacologic approaches to stimulate or protect the salivary tissue. The scientific literature will be critically examined to see what works and what strategies have been less effective in attempting to minimize xerostomia in head and neck cancer patients.

Salivary anti-Ro60 and anti-Ro52 antibody profiles to diagnose Sjogren's Syndrome

Simple and non-invasive saliva-based diagnostics may be useful for the identification, understanding, and monitoring of autoimmune and infectious diseases. Previously, Luciferase Immunoprecipitation Systems (LIPS) were used for sensitive detection of patient serum autoantibodies in Sjögren's Syndrome (SjS), a chronic autoimmune disease affecting the salivary and lacrimal glands. Here we explored the ability of LIPS to diagnose SjS based on IgG autoantibodies in patient saliva. From LIPS testing, anti-Ro60 autoantibodies were detected in the saliva of 70% (19/27) of SjS patients with 96% specificity. Positive anti-Ro60 autoantibodies were also found in 70% of the matched serum samples (96% specificity). LIPS detected Ro52 autoantibodies in the saliva and serum of 67% of SjS patients with 100% specificity. Overall, the autoantibody titers in saliva were approximately 4000-fold lower by volume than serum, but still distinguished seropositive patients from controls. These results suggest that LIPS salivary-based testing for SjS autoantibodies is a practical alternative to serum and compatible with point-of-care testing.

Salivary neutrophils level as an indicator of bone marrow engraftment

AIM

The aim of this study was to investigate the neutrophils level in saliva as an adequate alternative to other methods for evaluating the neutrophil engraftment after autologous stem cell transplantation (ASCT) in hemato-oncology.

METHOD

A total of 35 patients treated for non-Hodgkin's lymphoma or multiple myeloma were stomatologically examined before planned high-dose chemotherapy with ASCT. After removal of potential foci of odontogenic infection all the patients underwent transplantation and during the treatment they were monitored for the level of neutrophils in saliva as a possible early indicator of the neutrophil engraftment. Neutrophil levels in saliva were compared to the neutrophil level in blood and to the degree of oral mucositis (the nurses study).

RESULTS

An increase of salivary neutrophils in the mouth rinse of > 25 x 10/\6/l was identified as an early sign of successful neutrophil engraftment that occurred 1 to 2 days before the rise of neutrophils in peripheral blood (> 0.5- x 10/\9/l).

CONCLUSIONS

Follow-up of neutrophil levels in saliva might be an adequate alternative to other methods for evaluating the neutrophil engraftment after ASCT in hemato-oncology.

Effectiveness of rituximab treatment in primary Sjögren's syndrome: a randomized, double-blind, placebo-controlled trial

OBJECTIVE

To study the efficacy and safety of B cell depletion with rituximab, a chimeric murine/human anti-CD20 monoclonal antibody, in patients with primary Sjögren's syndrome (SS) in a double-blind, randomized, placebo-controlled trial.

METHODS

Patients with active primary SS, as determined by the revised American-European Consensus Group criteria, and a rate of stimulated whole saliva secretion of > or =0.15 ml/minute were treated with either rituximab (1,000 mg) or placebo infusions on days 1 and 15. Patients were assigned randomly to a treatment group in a ratio of 2:1 (rituximab:placebo). Followup was conducted at 5, 12, 24, 36, and 48 weeks. The primary end point was the stimulated whole saliva flow rate, while secondary end points included functional, laboratory, and subjective variables.

RESULTS

Thirty patients with primary SS (29 female) were randomly allocated to a treatment group. The mean +/- SD age of the patients receiving rituximab was 43 +/- 11 years and the disease duration was 63 +/- 50 months, while patients in the placebo group were age 43 +/- 17 years and had a disease duration of 67 +/- 63 months. In the rituximab group, significant improvements, in terms of the mean change from baseline compared with that in the placebo group, were found for the primary end point of the stimulated whole saliva flow rate (P = 0.038 versus placebo) and also for various laboratory parameters (B cell and rheumatoid factor [RF] levels), subjective parameters (Multidimensional Fatigue Inventory [MFI] scores and visual analog scale [VAS] scores for sicca symptoms), and extraglandular manifestations. Moreover, in comparison with baseline values, rituximab treatment significantly improved the stimulated whole saliva flow rate (P = 0.004) and several other variables (e.g., B cell and RF levels, unstimulated whole saliva flow rate, lacrimal gland function on the lissamine green test, MFI scores, Short Form 36 health survey scores, and VAS scores for sicca symptoms). One patient in the rituximab group developed mild serum sickness-like disease.

CONCLUSION

These results indicate that rituximab is an effective and safe treatment strategy for patients with primary SS.

Parotid gland function after radiotherapy: the combined michigan and utrecht experience

PURPOSE

To analyze the combined and updated results from the University of Michigan and University Medical Center Utrecht on normal tissue complication probability (NTCP) of the parotid gland 1 year after radiotherapy (RT) for head-and-neck (HN) cancer.

PATIENTS AND METHODS

A total of 222 prospectively analyzed patients with various HN malignancies were treated with conventional and intensity-modulated RT. Stimulated individual parotid gland flow rates were measured before RT and 1 year after RT using Lashley cups at both centers. A flow ratio <25% of pretreatment was defined as a complication. The data were fitted to the Lyman-Kutcher-Burman model.

RESULTS

A total of 384 parotid glands (Michigan: 157; Utrecht: 227 glands) was available for analysis 1 year after RT. Combined NTCP analysis based on mean dose resulted in a TD(50) (uniform dose leading to 50% complication probability) of 39.9 Gy and m (steepness of the curve) of 0.40. The resulting NTCP curve had good qualitative agreement with the combined clinical data. Mean doses of 25-30 Gy were associated with 17-26% NTCP.

CONCLUSIONS

A definite NTCP curve for parotid gland function 1 year after RT is presented, based on mean dose. No threshold dose was observed, and TD(50) was equal to 40 Gy.

A comparison of dose-response models for the parotid gland in a large group of head-and-neck cancer patients

PURPOSE

The dose-response relationship of the parotid gland has been described most frequently using the Lyman-Kutcher-Burman model. However, various other normal tissue complication probability (NTCP) models exist. We evaluated in a large group of patients the value of six NTCP models that describe the parotid gland dose response 1 year after radiotherapy.

METHODS AND MATERIALS

A total of 347 patients with head-and-neck tumors were included in this prospective parotid gland dose-response study. The patients were treated with either conventional radiotherapy or intensity-modulated radiotherapy. Dose-volume histograms for the parotid glands were derived from three-dimensional dose calculations using computed tomography scans. Stimulated salivary flow rates were measured before and 1 year after radiotherapy. A threshold of 25% of the pretreatment flow rate was used to define a complication. The evaluated models included the Lyman-Kutcher-Burman model, the mean dose model, the relative seriality model, the critical volume model, the parallel functional subunit model, and the dose-threshold model. The goodness of fit (GOF) was determined by the deviance and a Monte Carlo hypothesis test. Ranking of the models was based on Akaike's information criterion (AIC).

RESULTS

None of the models was rejected based on the evaluation of the GOF. The mean dose model was ranked as the best model based on the AIC. The TD(50) in these models was approximately 39 Gy.

CONCLUSIONS

The mean dose model was preferred for describing the dose-response relationship of the parotid gland.

Parotid-gland-sparing 3D conformal radiotherapy in patients with bilateral radiotherapy of the head and neck region--results in clinical practice

The aim was to improve the prediction rate of hyposalivation after using a modern 3D-conformal-radiotherapy-technique (3D-CRT) by sparing of the contralateral parotid gland. Between June 2002 and October 2006, 107 patients (90 male, 17 female, average age: 58 years) with squamous cell carcinoma of the head and neck were included in a prospective, non-randomized study. All patients were treated using 3D-CRT. Parotid function was assessed by measuring stimulated salivary flow before, during and at the end of radiotherapy, as well as 1, 6 and 12 months after radiotherapy. Measurements were converted to flow rates and normalized relative to that before treatment. Mean doses (D(mean)) were calculated from dose-volume histograms (DVHs) based on computed tomographies (CTs) for the left and right parotid gland separately. Patients were grouped according to the D(mean) of the lowest irradiated parotid gland. Group I included all patients who received a D(mean)<26Gy (n=23), group II D(mean) 26-40Gy (n=38) and group III D(mean)>40Gy (n=46). By the time of 6 months after irradiation, salivary flow rates decreased continuously during the therapy. In group I the flow rate decreased to 59%, in group II to 40% and in group III to 14%, p<0.05. One year after irradiation a recovery effect could be measured in all groups. A sufficient saliva flow rate can be proven if one parotid gland is spared with a D(mean) dose <26Gy. Approximately, one quarter of the participants showed a significant improvement.

Measuring side effects after radiotherapy for pharynx cancer

Data on side effects after radiotherapy is needed to establish the benefits and drawbacks of new treatments, but side effects are not quantified as easily as survival or local control. Side effects may be quantified using physical measures. Unfortunately, only few endpoints exist where a physical measure is obtainable, and the case of a patient-relevant measure is even rarer. Radiotherapy is often followed by complex symptoms not easily quantifiable by the observer. Quantitative patient reported side effects can be retrieved using validated questionnaires, but this kind of data is often difficult to interpret and the correlation with clinically observable or measurable changes not straightforward. The exploitation of the possibilities of highly conformal radiotherapy and multimodality treatment depends on a better understanding of the correlation between dose, volume, modifying factors, and side effects. Using pharynx cancer as an example, the purpose of this article is to summarize the possibilities and limitations of different methods for measurement of radiotherapy-induced side effects.

Salivary proteomic and genomic biomarkers for primary Sjögren's syndrome

OBJECTIVE

To identify a panel of protein and messenger RNA (mRNA) biomarkers in human whole saliva (WS) that may be used in the detection of primary Sjögren's syndrome (SS).

METHODS

Mass spectrometry and expression microarray profiling were used to identify candidate protein and mRNA biomarkers of primary SS in WS samples. Validation of the discovered mRNA and protein biomarkers was also demonstrated using real-time quantitative polymerase chain reaction and immunoblotting techniques.

RESULTS

Sixteen WS proteins were found to be down-regulated and 25 WS proteins were found to be up-regulated in primary SS patients compared with matched healthy control subjects. These proteins reflected the damage of glandular cells and inflammation of the oral cavity system in patients with primary SS. In addition, 16 WS peptides (10 up-regulated and 6 down-regulated in primary SS) were found at significantly different levels (P < 0.05) in primary SS patients and controls. Using stringent criteria (3-fold change; P < 0.0005), 27 mRNA in saliva samples were found to be significantly up-regulated in the primary SS patients. Strikingly, 19 of 27 genes that were found to be overexpressed were interferon-inducible or were related to lymphocyte filtration and antigen presentation known to be involved in the pathogenesis of primary SS.

CONCLUSION

Our preliminary study has indicated that WS from patients with primary SS contains molecular signatures that reflect damaged glandular cells and an activated immune response in this autoimmune disease. These candidate proteomic and genomic biomarkers may improve the clinical detection of primary SS once they have been further validated. We also found that WS contains more informative proteins, peptides, and mRNA, as compared with gland-specific saliva, that can be used in generating candidate biomarkers for the detection of primary SS.

Protection of salivary function by concomitant pilocarpine during radiotherapy: a double-blind, randomized, placebo-controlled study

PURPOSE

To investigate the effect of concomitant administration of pilocarpine during radiotherapy for head-and-neck squamous cell carcinoma (HNSCC) on postradiotherapy xerostomia.

METHODS AND MATERIALS

A prospective, double blind, placebo-controlled randomized trial including 170 patients with HNSCC was executed to study the protective effect of pilocarpine on radiotherapy-induced parotid gland dysfunction. The primary objective endpoint was parotid flow rate complication probability (PFCP) scored 6 weeks, 6 months, and 12 months after radiotherapy. Secondary endpoints included Late Effects of Normal Tissue/Somatic Objective Management Analytic scale (LENT SOMA) and patient-rated xerostomia scores. For all parotid glands, dose-volume histograms were assessed because the dose distribution in the parotid glands is considered the most important prognostic factor with regard to radiation-induced salivary dysfunction.

RESULTS

Although no significant differences in PFCP were found for the two treatments arms, a significant (p = 0.03) reduced loss of parotid flow 1 year after radiotherapy was observed in those patients who received pilocarpine and a mean parotid dose above 40 Gy. The LENT SOMA and patient-rated xerostomia scores showed similar trends toward less dryness-related complaints for the pilocarpine group.

CONCLUSIONS

Concomitant administration of pilocarpine during radiotherapy did not improve the PFCP or LENT SOMA and patient-rated xerostomia scores. In a subgroup of patients with a mean dose above 40 Gy, pilocarpine administration resulted in sparing of parotid gland function. Therefore, pilocarpine could be provided to patients in whom sufficient sparing of the parotid is not achievable.

Progression of salivary gland dysfunction in patients with Sjogren's syndrome

BACKGROUND

Salivary gland dysfunction is one of the key manifestations of Sjögren's syndrome.

OBJECTIVES

(1) To assess prospectively loss of function of individual salivary glands in patients with primary and secondary Sjögren's syndrome in relation to disease duration and use of immunomodulatory drugs. (2) To study changes in sialochemical and laboratory values and subjective complaints over time.

METHODS

60 patients with Sjögren's syndrome were included in this study. Whole and gland-specific saliva (parotid and submandibular/sublingual (SM/SL)), samples were collected at baseline and after a mean of 3.6 (SD 2.3) years of follow-up. Disease duration was recorded for all patients.

RESULTS

Patients with Sjögren's syndrome with short disease duration had significantly higher stimulated flow rates at baseline than those with longer disease duration (p<0.05). When compared with healthy controls, the decrease in SM/SL flow rates at baseline was more prominent than that in parotid flow rates (p<0.05). Over time, there was a significant further decrease of stimulated flow rates, especially of the parotid gland, accompanied by increasing problems with swallowing dry food (p<0.05). The decrease was independent of the use of corticosteroids or disease-modifying antirheumatic drugs (DMARDs). Sialochemical variables remained stable.

CONCLUSIONS

Early Sjögren's syndrome is characterised by a decreased salivary gland function (parotis>SM/SL), which shows a further decrease over time, regardless of the use of DMARDs or steroids. Patients with Sjögren's syndrome with longer disease duration are characterised by severely reduced secretions of both the parotid and SM/SL glands. These observations are relevant for identifying patients who would most likely benefit from intervention treatment.