Saliva as a diagnostic fluid

Enhancing antibody detection sensitivity in lateral flow immunoassays using endospores of Bacillus subtilis as signal amplifiers

Antibody detection is the critical first step for tracking the spread of many diseases including COVID-19. Lateral flow immunoassay (LFIA) is the most commonly used method for rapid antibody detection because it is easy-to-use and inexpensive. However, LFIA has limited sensitivity when gold nanoparticles (AuNPs) are used as the signals. In this study, the endospores of Bacillus subtilis were used in combination with AuNP in a LFIA to detect antibodies. The endospores serve as a signal amplifier. The detection limit was about 10-8 M for anti-beta galactosidase antibody detection whereas the detection limit of conventional LFIA is about 10-6 M. Furthermore, the proposed methods have no additional user steps compared with the traditional LFIA. This method, therefore, improved the sensitivity 100-fold without compromising any advantages of LFIA. We believe that the proposed method will be useful for detection of antibodies against HIV, Zika virus, SARS-CoV-2, and so on.

Effect of non-surgical periodontal therapy on salivary histone deacetylases expression: A prospective clinical study

AIM

To evaluate the effect of non-surgical periodontal therapy (NSPT) on salivary histone deacetylases (HDACs) gene expression in patients with Stage III-IV periodontitis at baseline and at 3 and 6 months post NSPT treatment.

MATERIALS AND METHODS

Twenty patients completed the study. Periodontitis (as well as the corresponding staging and grading) was diagnosed according to the 2017 World Workshop Classification. Clinical measures were recorded and whole unstimulated saliva was collected at baseline and at 3 and 6 months after NSPT. The expression of 11 HDACs was determined using reverse-transcription PCR, and the respective changes over time were evaluated.

RESULTS

Six months after NSPT, significant improvements in all clinical periodontal parameters were observed, concomitant with significant up-regulation of HDAC2, 4, 6, 8, 9 and 11 expressions. Subgroup analyses of non-responders and responders revealed no significant differences in HDACs mRNA expression between groups at any time point.

CONCLUSIONS

This prospective clinical study identified longitudinal changes in salivary HDACs expression in response to NSPT, which provides new insights into the epigenetic mechanisms underlying the pathobiology of periodontitis and creates avenues for the discovery of novel biomarkers.

Relationship between human oral microbiome dysbiosis and neuropsychiatric diseases: An updated overview

The role of the gut-brain axis in mental health disorders has been extensively studied. As the oral cavity is the starting point of the digestive tract, the role that the oral microbiota plays in mental health disorders has gained recent attention. Oral microbiota can enter the bloodstream and trigger inflammatory responses or translocate to the brain through the trigeminal nerve or olfactory system. Hence, the concept of the oral microbiota-brain axis has emerged. Several hypotheses have been suggested that the oral microbiota can enter the gastrointestinal tract and affect the gut-brain axis; however, literature describing oral-brain communication remains limited. This review summarizes the characteristics of oral microbiota and its mechanisms associated with mental health disorders. Through a comprehensive examination of the relationship between oral microbiota and various neuropsychiatric diseases, such as anxiety, depression, schizophrenia, autism spectrum disorder, epilepsy, Parkinson's disease, and dementia, this review seeks to identify promising avenues of future research.

Comparison of smoking traditional, heat not burn and electronic cigarettes on salivary cytokine, chemokine and growth factor profile in healthy young adults-pilot study

Objective: Smoking is the cause of numerous oral pathologies. The aim of the study was to evaluate the effect of smoking traditional cigarettes, e-cigarettes, and heat-not-burn products on the content of salivary cytokines, chemokines, and growth factors in healthy young adults. Design: Three groups of twenty-five smokers each as well as a control group matched in terms of age, gender, and oral status were enrolled in the study. In unstimulated saliva collected from study groups and participants from the control group, the concentrations of cytokines, chemokines, and growth factors were assessed by Bio-Plex® Multiplex System. Results: We demonstrated that smoking traditional cigarettes is responsible for increasing the level of IFN-γ compared to non-smokers and new smoking devices users in unstimulated saliva in the initial period of addiction. Furthermore, e-cigarettes and heat-not-burn products appear to have a similar mechanism of affecting the immune response system of unstimulated saliva, leading to inhibition of the local inflammatory response in the oral cavity. Conclusion: Smoking traditional cigarettes as well as e-cigarettes and heat-not-burn products is responsible for changes of the local immune response in saliva. Further research is necessary to fill the gap in knowledge on the effect of new smoking devices on the oral cavity immune system.

Salivary spectral signature using ATR-FTIR spectroscopy in different exercise protocols

The Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR) has been applied to determine salivary biomarkers with high sensitivity and cost-effectiveness. Our study aimed to test the hypothesis that the spectral profile of saliva demonstrates distinct vibrational modes corresponding to different exercise protocols, thereby facilitating exercise monitoring. Saliva samples were collected from trained male subjects at three intervals: pre-exercise, post-exercise, and 3 h post-exercise. The protocols included acute sessions of continuous exercise (CE), high-intensity interval exercise (HIIE), and resistance exercise (RE). ATR-FTIR analysis revealed that salivary biochemical components changed uniquely with each exercise protocol. Specific spectral vibrational modes were identified as potential biomarkers for each exercise type. Notably, the salivary spectrum pattern of CE closely resembled that of HIIE, whereas RE showed minor alterations. Furthermore, we attempted to apply an algorithm capable of distinguishing the spectral range that differentiates the exercise modalities. This pioneering study is the first to compare changes in saliva spectra following different exercise protocols and to suggest spectrum peaks of vibrational modes as markers for specific types of exercises. We emphasize that the spectral wavenumbers identified by FTIR could serve as practical markers in distinguishing between different exercise modalities, with sensitivity, specificity, and accuracy correlating with the metabolic changes induced by exercise. Therefore, this study contributes a panel of ATR-FTIR spectral wavenumbers that can be referenced as a spectral signature capable of distinguishing between resistance and endurance exercises.

Use of saliva-based qPCR diagnostics for the accurate, rapid, and inexpensive detection of strep throat

OBJECTIVES

Outpatient health care facilities are essential for quickly diagnosing common infectious diseases such as bacterial and viral pharyngitis. The only form of pharyngitis requiring antibiotics is strep throat (ST); however, antibiotic prescription rates are much higher than ST prevalence, suggesting antibiotics are being inappropriately prescribed. Current rapid ST diagnostics may be contributing to this problem due to the low sensitivity and variable specificity of these tests. It is best practice to verify a negative ST diagnosis with a group A Streptococcus (GAS) culture, but many clinics do not perform this test due to the additional cost and 24-72 h required to obtain results. This indicates there is great need for more accurate rapid diagnostic tools in outpatient facilities. We hypothesized that next generation qPCR technology could be adapted to detect GAS DNA from saliva samples (instead of the traditional throat swab) by creating a simple, fast, and inexpensive protocol.

METHODS

Saliva specimens collected from patients at James Madison University Health Center were used to test the effectiveness of our Chelex 100-based rapid DNA extraction method, followed by a fast protocol developed for the Open qPCR machine to accurately detect ST.

RESULTS

Our final saliva processing and qPCR protocol required no specialized training to perform and was able to detect ST with 100 % sensitivity and 100 % specificity (n=102) in 22-26 min, costing only $1.12 per sample.

CONCLUSIONS

Saliva can be rapidly analyzed via qPCR for the accurate and inexpensive detection of ST.

Non-invasive biomarkers for sperm retrieval in non-obstructive patients: a comprehensive review

Recent advancements in reproductive medicine have guided novel strategies for addressing male infertility, particularly in cases of non-obstructive azoospermia (NOA). Two prominent invasive interventions, namely testicular sperm extraction (TESE) and microdissection TESE (micro-TESE), have emerged as key techniques to retrieve gametes for assisted reproduction technologies (ART). Both heterogeneity and complexity of NOA pose a multifaceted challenge to clinicians, as the invasiveness of these procedures and their unpredictable success underscore the need for more precise guidance. Seminal plasma can be aptly regarded as a liquid biopsy of the male reproductive tract, encompassing secretions from the testes, epididymides, seminal vesicles, bulbourethral glands, and prostate. This fluid harbors a variety of cell-free nucleic acids, microvesicles, proteins, and metabolites intricately linked to gonadal activity. However, despite numerous investigations exploring potential biomarkers from seminal fluid, their widespread inclusion into the clinical practice remains limited. This could be partially due to the complex interplay of diverse clinical and genetic factors inherent to NOA that likely contributes to the absence of definitive biomarkers for residual spermatogenesis. It is conceivable that the integration of clinical data with biomarkers could increase the potential in predicting surgical procedure outcomes and their choice in NOA cases. This comprehensive review addresses the challenge of sperm retrieval in NOA through non-invasive biomarkers. Moreover, we delve into promising perspectives, elucidating innovative approaches grounded in multi-omics methodologies, including genomics, transcriptomics and proteomics. These cutting-edge techniques, combined with the clinical and genetics features of patients, could improve the use of biomarkers in personalized medical approaches, patient counseling, and the decision-making continuum. Finally, Artificial intelligence (AI) holds significant potential in the realm of combining biomarkers and clinical data, also in the context of identifying non-invasive biomarkers for sperm retrieval.

Salivary High-Sensitivity C-Reactive Protein and Its Clinical Relevance in Modern Medicine: A Comprehensive Review

High-sensitivity C-reactive protein (hsCRP) has emerged as a critical biomarker in inflammation, offering insights into various chronic diseases. However, traditional blood-based assays for hsCRP measurement pose limitations regarding invasiveness and cost. In recent years, saliva has garnered attention as an alternative diagnostic medium, presenting a noninvasive and easily accessible option for biomarker analysis. Salivary hsCRP has thus emerged as a promising avenue for research and clinical application, offering potential advantages over blood-based assays. This comprehensive review aims to elucidate the biological basis of salivary hsCRP, its clinical applications, and methodologies for measurement. By exploring its diagnostic potential, prognostic value, and implications for treatment monitoring, this review highlights the potential impact of salivary hsCRP in modern medicine. Moreover, it emphasizes the need for continued exploration, validation, and integration of salivary hsCRP into routine clinical practice to realize its full potential for enhancing patient care and advancing personalized medicine approaches.

Salivary Proteinase 3 as a Biomarker for Caries Severity in Children: A Cross-sectional Study

AIM

This study aims to evaluate the relation between salivary proteinase 3 (PR3) concentration and caries severity in children.

MATERIALS AND METHODS

Six-to-eight-year age group children, from the Outpatient Department of Pediatric and Preventive dentistry at PMS Dental College were selected for the study. From these children, three groups each consisting of 28 children were selected according to the dental caries severity. Three groups were: (1) No Dental Caries group, (2) Low Dental Caries group with DMFT/DEFT score of 1-4, and (3) High Dental Caries group with DMFT/DEFT score of 5-15. Thus, a total of 84 children who satisfied the inclusion criteria were selected. The concentration of PR3 in saliva of the donors were analyzed using an ELISA kit. One way ANOVA was used for finding the relation of salivary PR3 concentration with caries severity. Pairwise comparison of PR3 concentration and caries severity were analyzed using post hoc Tukey test.

RESULTS

Severity of caries and concentration of salivary PR3 showed an inverse relation. As the caries severity increases there was a decrease in PR3 concentration and vice versa.

CONCLUSION

The children with high caries severity showed lower concentration of PR3 in their saliva compared with those with lower caries severity which indicates that PR3 can be used as a biomarker for assessing caries severity and also paves way to use PR3 as a caries vaccine in future. Nowadays, interest toward noninvasive and personalized dentistry has been increased. Molecular assays using salivary biomarkers can be an effective tool in detecting the caries in earlier stages and assessing a patient's caries risk.

CLINICAL SIGNIFICANCE

Salivary PR3 can be used as prognostic biomarker for assessing caries severity and after treatment the value of PR3 can be used as a assessment tool to confirm its relation with caries. How to cite this article: Karthika S, George S, Soman A, et al. Salivary Proteinase 3 as a Biomarker for Caries Severity in Children: A Cross-sectional Study. J Contemp Dent Pract 2024;25(3):236-240.

Ultrasensitive colorimetric detection of creatinine via its dual binding affinity for silver nanoparticles and silver ions

Creatinine is an important biomarker for the diagnosis of chronic kidney disease (CKD). Recently, it has been reported that the concentration of salivary creatinine correlates well with the concentration of serum creatinine, which makes the former useful for the development of non-invasive and point-of-care (POC) detection for CKD diagnosis. However, there exists a technical challenge in the rapid detection of salivary creatinine at low concentrations of 3-18 μM when using the current kidney function test strips as well as the traditional methods employed in hospitals. Herein, we demonstrate a simple, sensitive colorimetric assay for the detection of creatinine with a limit-of-detection (LOD) down to the nanomolar level. Our approach utilises the dual binding affinity of creatinine for citrate-capped silver nanoparticles (Ag NPs) and Ag(i) ions, which can trigger the aggregation of Ag NPs and thus lead to the colour change of a sample. The quantitative detection of creatinine was achieved using UV-Vis spectroscopy with a LOD of 6.9 nM in artificial saliva and a linear dynamic range of 0.01-0.06 μM. This method holds promise to be further developed into a POC platform for the CKD diagnosis.

Non-invasive stress estimation in simulative endoscopy setting: literature review

One of the most common stressors is so-called "occupational stress." It is defined as the sum of physical, mental and physiological responses to work in situations where the workload or stress associated with it intensifies for an extended period of time. It is a gradual process in which individual cognitive assessments of occupational stressors generate adverse health events and may lead to burnout. Since it has become a major problem in the medical field, studying, measuring and limiting it have been set as goals for the future.

Influence of controlled environmental conditions in potential salivary ocular pain biomarkers for enhancing the assessment of ocular pain

PURPOSE

We endeavored to identify objective salivary biomarkers for pain, a subjective sensation with a biological basis, using molecules already described related to pain. The study aimed to analyze inter-individual differences and intersession variability in salivary potential ocular pain biomarkers on healthy subjects, in samples obtained under the influence of controlled environmental conditions.

METHODS

Thirty-four healthy subjects, 20 male, 14 female, median age 35.44 years (range 30-40) were exposed for 30 minutes under standard environmental conditions (T: 22°C, 50% relative humidity) in the Controlled Environmental Research Laboratory (CE-Lab, Vision R&D, Valladolid Spain) in two separate visits (V1, V2) at least 24 hours apart. Saliva was collected after the exposure in each of the visits, and cortisol, α-amylase (sAA), secretory IgA (sIgA), testosterone, and soluble fraction of TNFα receptor II (sTNFαRII) were analyzed by ELISA. Repeatability of inter-subject inter-session measurements was assayed by intraclass correlation coefficient (ICC).

RESULTS

There were no significant inter-session differences in testosterone (p = 0.2497), sTNFαRII (p = 0.6451) and sIgA (p = 0.9689) salivary levels. The reproducibility for salivary cortisol, sAA, testosterone, sTNFαRII and sIgA were 0.98 ng/ml, 20.58 U/ml, 21.07 μg/ml, 24.68 pg/ml and 0.19 pg/ml, respectively. Salivary cortisol, sAA, testosterone, sTNFαRII and sIgA yielded the following ICCs: 0.506, 0.569, 0.824, 0.870 and 0.4295, respectively; all these ICCs (except that for cortisol and sIgA) were found to be improved compared to those found previously by our group in a previous study in salivary samples obtained from healthy subjects under non-controlled environmental conditions; Cortisol´s ICC didn´t improve and was in both cases at the limit of acceptability.

CONCLUSION

Environmental factors such as temperature and relative humidity affect the reproducibility of measurement of some salivary molecules which have been proposed as potential pain biomarkers. The exposure of subjects to standard controlled environmental conditions before salivary sample obtention would improve the reproducibility of these molecule measures' as potential biomarkers of chronic ocular pain.

Uncovering transcriptomic biomarkers for enhanced diagnosis of methamphetamine use disorder: a comprehensive review

Introduction

Methamphetamine use disorder (MUD) is a chronic relapsing disorder characterized by compulsive Methamphetamine (MA) use despite its detrimental effects on physical, psychological, and social well-being. The development of MUD is a complex process that involves the interplay of genetic, epigenetic, and environmental factors. The treatment of MUD remains a significant challenge, with no FDA-approved pharmacotherapies currently available. Current diagnostic criteria for MUD rely primarily on self-reporting and behavioral assessments, which have inherent limitations owing to their subjective nature. This lack of objective biomarkers and unidimensional approaches may not fully capture the unique features and consequences of MA addiction.

Methods

We performed a literature search for this review using the Boolean search in the PubMed database.

Results

This review explores existing technologies for identifying transcriptomic biomarkers for MUD diagnosis. We examined non-invasive tissues and scrutinized transcriptomic biomarkers relevant to MUD. Additionally, we investigated transcriptomic biomarkers identified for diagnosing, predicting, and monitoring MUD in non-invasive tissues.

Discussion

Developing and validating non-invasive MUD biomarkers could address these limitations, foster more precise and reliable diagnostic approaches, and ultimately enhance the quality of care for individuals with MA addiction.

The impact of saliva collection methods on measured salivary biomarker levels

Saliva diagnostics have become increasingly popular due to their non-invasive nature and patient-friendly collection process. Various collection methods are available, yet these are not always well standardized for either quantitative or qualitative analysis. In line, the objective of this study was to evaluate if measured levels of various biomarkers in the saliva of healthy individuals were affected by three distinct saliva collection methods: 1) unstimulated saliva, 2) chew stimulated saliva, and 3) oral rinse. Saliva samples from 30 healthy individuals were obtained by the three collection methods. Then, the levels of various salivary biomarkers such as proteins and ions were determined. It was found that levels of various biomarkers obtained from unstimulated saliva were comparable to those in chew stimulated saliva. The levels of potassium, sodium, and amylase activity differed significantly among the three collection methods. Levels of all biomarkers measured using the oral rinse method significantly differed from those obtained from unstimulated and chew-stimulated saliva. In conclusion, both unstimulated and chew-stimulated saliva provided comparable levels for a diverse group of biomarkers. However, the results obtained from the oral rinse method significantly differed from those of unstimulated and chew-stimulated saliva, due to the diluted nature of the saliva extract.

Evaluation of salivary endothelin-1 as a biomarker for oral cancer and precancer

CONTEXT

Oral cancer is highly prevalent in India. Lack of awareness and delay in diagnosis and treatment of patients with oral cancer leads to high mortality and poor survival of patients. Salivary endothelin-1 is proposed as a prospective biomarker for oral squamous cell carcinoma.

AIMS

Aim of the study was to evaluate salivary level of endothelin-1 in oral cancer and precancer as a biomarker.

SETTINGS AND DESIGN

We planned a case control study to evaluate salivary level of Endothelin-1 in oral cancer and precancer as a biomarker.

MATERIALS AND METHODS

A total of 72 subjects were taken in study out of which 24 cases were of histopathologically confirmed premalignat oral lesion (oral leukoplakia and oral submucous fibrosis), 24 cases were of histopathologically confirmed oral squamous cell carcinoma, and 24 cases of healthy age and gender matched controls without any addiction to tobacco in any form from a tertiary care hospital were taken. Saliva was collected from all following standard guidelines and estimation of salivary endothelin-1 was done by ELISA.

STATISTICAL ANALYSIS USED

SPSS software version 15.

RESULTS

Salivary endothelin-1 values of controls ranged between 0.09 and 1.88 pg/ml while that of premalignant cases ranged between 1.16 and 16.135 pg/ml and of SCC cases ranged between 2.567 and 22.98 pg/ml.

CONCLUSIONS

Salivary endothelin-1 is raised in oral squamous cell carcinoma compared to premalignant and controls therefore, shows capability to differentiate between premalignant lesion and oral cancer. So, it could be used as a biomarker for early diagnosis.

A Narrative Review on Strategies for the Reversion of Prediabetes to Normoglycemia: Food Pyramid, Physical Activity, and Self-Monitoring Innovative Glucose Devices

In 2019, "Nutrition Therapy for Adults with Diabetes or Prediabetes: A Consensus Report" was published. This consensus report, however, did not provide an easy way to illustrate to subjects with prediabetes (SwPs) how to follow a correct dietary approach. The purpose of this review is to evaluate current evidence on optimum dietary treatment of SwPs and to provide a food pyramid for this population. The pyramid built shows that everyday consumption should consist of: whole-grain bread or potatoes eaten with their skins (for fiber and magnesium) and low glycemic index carbohydrates (GI < 55%) (three portions); fruit and vegetables (5 portions), in particular, green leafy vegetables (for fiber, magnesium, and polyphenols); EVO oil (almost 8 g); nuts (30 g, in particular, pistachios and almonds); three portions of dairy products (milk/yogurt: 300-400 g/day); mineral water (almost 1, 5 L/day for calcium intake); one glass of wine (125 mL); and three cups of coffee. Weekly portions should include fish (four portions), white meat (two portions), protein plant-based food (four portions), eggs (egg portions), and red/processed meats (once/week). At the top of the pyramid, there are two pennants: a green one means that SwPs need some personalized supplementation (if daily requirements cannot be satisfied through diet, vitamin D, omega-3, and vitamin B supplements), and a red one means there are some foods and factors that are banned (simple sugar, refined carbohydrates, and a sedentary lifestyle). Three to four times a week of aerobic and resistance exercises must be performed for 30-40 min. Finally, self-monitoring innovative salivary glucose devices could contribute to the reversion of prediabetes to normoglycemia.

Identification of salivary metabolic biomarker signatures for oral tongue squamous cell carcinoma

OBJECTIVE

To identify the salivary metabolites associated with squamous cell carcinoma of the tongue to develop easy and non-invasive potential biomarkers for disease diagnosis.

DESIGN

Initially, the study utilized untargeted metabolomics to analyze 20 samples of tongue squamous cell carcinoma and 10 control samples. The objective was to determine the salivary metabolites that exhibited differential expression in tongue squamous cell carcinoma. Then the selected metabolites were validated using targeted metabolomics in saliva samples of 100 patients diagnosed with squamous cell carcinoma of the tongue, as well as 30 healthy control individuals.

RESULTS

From the analysis of untargeted metabolomics, 10 metabolites were selected as potential biomarkers. In the subsequent targeted metabolomics study on these selected metabolites, it was observed that N-Acetyl-D-glucosamine, L-Pipecolic acid, L-Carnitine, Phosphorylcholine, and Deoxyguanosine exhibited significant differences. The receiver operating characteristic curve analysis indicates a combination of three important metabolites such as N-Acetyl-D-glucosamine, L-Pipecolic acid and L-Carnitine provided the best prediction with an area under the curve of 0.901.

CONCLUSIONS

The present result reveals that the N-Acetyl-D-glucosamine, L-Pipecolic acid and L-Carnitine are the signature diagnostic biomarkers for oral tongue squamous cell carcinoma. These findings can be used to develop a rapid and non-invasive method for disease monitoring and prognosis in oral tongue cancer.

Does smoking influence tryptophan metabolism in periodontal inflammation? A cross-sectional study

OBJECTIVES

The aim of this study was to identify the effects of smoking and periodontal inflammation on tryptophan-kynurenine metabolism as well as the correlation between these findings and clinical periodontal parameters.

BACKGROUND

It has been shown that the tryptophan amino acid's primary catabolic pathway, the kynurenine pathway (KP), may serve as a key biomarker for periodontal disease. Although there are studies investigating the effect of smoking on KYN-TRP metabolism, the effect of smoking on periodontal disease through KP has not been revealed so far.

METHODS

The salivary and serum samples were gathered from 24 nonsmoker (NS-P) stage III, grade B generalized periodontitis and 22 smoker (S-P) stage III, grade C generalized periodontitis patients, in addition to 24 nonsmoker (NS-C) and 24 smoker (S-C) periodontally healthy control individuals. Saliva and serum IL-6, kynurenine (KYN), and tryptophan (TRP) values, and KYN/TRP ratio were analyzed by liquid chromatography-mass spectrometry. Clinical periodontal measurements were recorded.

RESULTS

Salivary TRP values were significantly higher in both periodontitis groups than control groups (p < .05). Salivary KYN values were highest in NS-P group (p < .05). Salivary KYN values did not differ significantly between periodontitis groups (p = .84). Salivary KYN/TRP ratio was significantly lower in NS-P group compared to other groups (p < .001). Serum TRP value is higher in S-P group than other groups; however, significant difference was found in S-C group (p < .05). Serum KYN values were significantly lower in smokers than nonsmokers. Serum KYN/TRP ratio is higher in NS-P group. NS-P group has the highest salivary IL-6 levels, NS-C group has the lowest values (p < .05).

CONCLUSIONS

Our results point out that smoking exacerbates inflammation in the periodontium and increases TRP destruction and decreases IDO activity by suppressing KP in serum. As a result, kynurenine and its metabolites may be significant biomarkers in the link between smoking and periodontal disease.

Proteome profiling of salivary small extracellular vesicles in glioblastoma patients

BACKGROUND

Extracellular vesicles (EVs) play a critical role in intercellular communication under physiological and pathological conditions, including cancer. EVs cargo reflects their cell of origin, suggesting their utility as biomarkers. EVs are detected in several biofluids, and their ability to cross the blood-brain barrier has highlighted their potential as prognostic and diagnostic biomarkers in gliomas, including glioblastoma (GBM). Studies have demonstrated the potential clinical utility of plasma-derived EVs in glioma. However, little is known about the clinical utility of saliva-derived EVs in GBM.

METHODS

Small EVs were isolated from whole mouth saliva of GBM patients pre- and postoperatively. Isolation was performed using differential centrifugation and/or ultracentrifugation. EVs were characterized by concentration, size, morphology, and EVs cell-surface protein markers. Protein cargo in EVs was profiled using mass spectrometry.

RESULTS

There were no statistically significant differences in size and concentration of EVs derived from pre- and post GBM patients' saliva samples. A higher number of proteins were detected in preoperative samples compared to postoperative samples. The authors found four highly abundant proteins (aldolase A, 14-3-3 protein ε, enoyl CoA hydratase 1, and transmembrane protease serine 11B) in preoperative saliva samples from GBM patients with poor outcomes. Functional enrichment analysis of pre- and postoperative saliva samples showed significant enrichment of several pathways, including those related to the immune system, cell cycle and programmed cell death.

CONCLUSIONS

This study, for the first time, demonstrates the feasibility of isolating and characterizing small EVs from pre- and postoperative saliva samples from GBM patients. Preliminary findings encourage further large cohort validation studies on salivary small EVs to evaluate prognosis in GBM.

Oral Microbiota: The Influences and Interactions of Saliva, IgA, and Dietary Factors in Health and Disease

Recent advances in metagenomic analyses have made it easier to analyze microbiota. The microbiota, a symbiotic community of microorganisms including bacteria, archaea, fungi, and viruses within a specific environment in tissues such as the digestive tract and skin, has a complex relationship with the host. Recent studies have revealed that microbiota composition and balance particularly affect the health of the host and the onset of disease. Influences such as diet, food preferences, and sanitation play crucial roles in microbiota composition. The oral cavity is where the digestive tract directly communicates with the outside. Stable temperature and humidity provide optimal growth environments for many bacteria. However, the oral cavity is a unique environment that is susceptible to pH changes, salinity, food nutrients, and external pathogens. Recent studies have emphasized the importance of the oral microbiota, as changes in bacterial composition and balance could contribute to the development of systemic diseases. This review focuses on saliva, IgA, and fermented foods because they play critical roles in maintaining the oral bacterial environment by regulating its composition and balance. More attention should be paid to the oral microbiota and its regulatory factors in oral and systemic health.

Association, diagnostic accuracy and optimal threshold of salivary IGF-1 and vitamin DBP levels for estimation of pubertal growth spurt: A cross sectional study

AIM

To determine the association of salivary IGF-1 and vitamin D Binding Protein with cervical vertebral maturation index (CVMI) across the pubertal stages and to determine the diagnostic accuracy and optimal threshold of these biomarkers for estimation of pubertal growth.

DESIGN

Cross-sectional observational study.

SETTING

Material and methods. All patients in the age group of 8-23 years from the Outpatient Department of Orthodontics and Dentofacial orthopaedics, between the period of July 2020 to December 2020 meeting the eligibility criteria were included. Lateral cephalograms obtained from the patients were divided into pre pubertal, pubertal & post pubertal groups based on CVMI by Baccetti et al. Unstimulated whole saliva was collected by a swab-based method & analyzed with ELISA.

RESULTS

Ninety-four participants were divided in three stages: prebubertal (30), pubertal (33), post pubertal (31). A significant difference was observed in the salivary IGF-1 & DBP across the three stages. Post-hoc test revealed significantly higher mean salivary IGF-1 & DBP in pubertal group than in pre & post-pubertal group. Receiver operator characteristic curve revealed excellent diagnostic accuracy for salivary IGF-1with areas under the curve (AUC) of 0.962, satisfactory for vitamin DBP with AUC of 0.831 and poor diagnostic accuracy for age with AUC of 0.536. Youden index revealed the optimal threshold to be 3.96ng/ml and 124.13pg/ml for salivary IGF-1 and vitamin DBP respectively.

CONCLUSION

The levels of Salivary IGF-1 and Vitamin DBP increased during C3 and C4 stages. Compared to vitamin DBP diagnostic accuracy of salivary IGF-1 was excellent and an optimal threshold of 3.96ng/ml can be utilized to distinguish pubertal & non-pubertal participants.

Mass Spectrometric Interrogation of Earwax: Toward the Detection of Ménière's Disease

Many diseases remain difficult to identify because the occurrence of characteristic biomarkers within traditional matrices such as blood and urine remain unknown. Disease diagnosis could, therefore, benefit from the analysis of readily accessible, non-traditional matrices that have a high chemical content and contain distinguishing biomarkers. One such matrix is cerumen (i.e., earwax), whose chemical complexity can pose challenges when analyzed by conventional methods. A combination of cerumen chemical profiles analyzed by gas chromatography-mass spectrometry (GC-MS) and direct analysis in real time-high-resolution mass spectrometry (DART-HRMS) were investigated to ascertain the possible presence of the rare otolaryngological disorder Ménière's disease. This illness is currently identified via "diagnosis by exclusion" in which the disease is distinguished from others with overlapping symptoms by the process of elimination. GC-MS revealed a chemical profile difference between those with and without a Ménière's disease diagnosis by a visually apparent diminution of the compounds present in the Ménière's disease samples. DART-HRMS revealed that the two classes could be differentiated using three fatty acids: cis-9-hexadecenoic acid, cis-10-heptadecenoic acid, and cis-9-octadecenoic acid. These compounds were subsequently quantified by GC-MS and overall, the amounts of these fatty acids were decreased in Ménière's disease patients. The average levels for non-Ménière's disease samples were 7.89 μg/mg for cis-9-hexadecenoic acid, 0.87 μg/mg for cis-10-heptadecenoic acid, and 4.94 μg/mg for cis-9-octadecenoic acid. The average levels for Ménière's disease samples were 1.70 μg/mg for cis-9-hexadecenoic acid, 0.13 μg/mg for cis-10-heptadecenoic acid, and 2.07 μg/mg for cis-9-octadecenoic acid. The confidence levels for cis-9-hexadecenoic acid, cis-10-heptadecenoic acid, and cis-9-octadecenoic acid were 98.7%, 99.9%, and 95.4%, respectively. The results suggest that assessment of the concentrations of these fatty acids could be a useful clinical tool for the more rapid and accurate detection of Ménière's disease.

Saliva as Biomarker for Oral and Chronic Degenerative Non-Communicable Diseases

Saliva is a very complex fluid and it is essential to maintain several physiological processes and functions, including oral health, taste, digestion and immunological defenses. Saliva composition and the oral microbiome can be influenced by several factors, like diet and smoking habits, and their alteration can represent an important access point for pathogens and, thus, for systemic illness onset. In this review, we explore the potentiality of saliva as a new tool for the early detection of some pathological conditions, such as oral diseases, chronic degenerative non-communicable diseases, among these chronic kidney disease (CKD). We also examined the possible correlation between oral and systemic diseases and oral and gut microbiota dysbiosis. In particular, we deeply analyzed the relationship between oral diseases and CKD. In this context, some salivary parameters can represent a new device to detect either oral or systemic pathologies. Moreover, the positive modulation of oral and gut microbiota induced by prebiotics, postbiotics, or symbiotics could represent a new possible adjuvant therapy in the clinical management of oral diseases and CKD.

Evaluation of Salivary Opiorphin, pH and Flow Rate in Oral Submucous Fibrosis - A Case - Control Observational Study

Aim and Objectives

The aim of the study was to evaluate the salivary pH, flow rate and opiorphin in Oral submucous fibrosis patients and to compare them with healthy individuals.

Materials and Methods

A comparative study was conducted to evaluate the salivary opiorphin levels, pH and flow rate among 78 patients (39 Oral submucous fibrosis + 39 control). Burning sensation was assessed using VAS score. Opiorphin levels were assessed using Cusabio Human Salivary Opiorphin ELISA kit. Salivary flow rate was assessed using graduated syringes and salivary pH was assessed using Hydrion salivary pH strips. Kolmogorov-Smirnov and Shapiro Wilk test were assessed for normality testing and distribution. Inferential statistics was done by using Unpaired t test/Independent sample t test to compare the mean values of variables included in the study among the OSMF and healthy patients.

Results

There was statistically significant difference in pH and flow rate with a reduction in the mean pH (p=0.024) and flow rate (p<0.01) among the oral submucous fibrosis patients compared to the control group. A statistically significant increase (p<0.01) in salivary opiorphin levels was noted in the oral submucous fibrosis patients. Majority of the study participants had mild to moderate burning sensation.

Conclusion

This study was a pilot evaluation of salivary opiorphin in OSMF. Salivary opiorphin could be used as an objective marker for chronic subjective conditions The pre-treatment and post treatment evaluation of salivary opiorphin could provide more insight on its role.

A Review on Saliva-Based Health Diagnostics: Biomarker Selection and Future Directions

The human body has a unique way of saying when something is wrong with it. The molecules in the body fluids can be helpful in the early detection of diseases by enabling health and preventing disease progression. These biomarkers enabling better healthcare are becoming an extensive area of research interest. Biosensors that detect these biomarkers are becoming the future, especially Point Of Care (POC) biosensors that remove the need to be physically present in the hospital. Detection of complex and systemic diseases using biosensors has a long way to go. Saliva-based biosensors are gaining attention among body fluids due to their non-invasive collection and ability to detect periodontal disease and identify systemic diseases. The possibility of saliva-based diagnostic biosensors has gained much publicity, with companies sending home kits for ancestry prediction. Saliva-based testing for covid 19 has revealed effective clinical use and relevance of the economic collection. Based on universal biomarkers, the detection of systemic diseases is a booming research arena. Lots of research on saliva-based biosensors is available, but it still poses challenges and limitations as POC devices. This review paper talks about the relevance of saliva and its usefulness as a biosensor. Also, it has recommendations that need to be considered to enable it as a possible diagnostic tool.

Graphical Abstract

The Concentration of Pro- and Antiangiogenic Factors in Saliva and Gingival Crevicular Fluid Compared to Plasma in Patients with Peripheral Artery Disease and Type 2 Diabetes

Several studies have investigated various biomarkers in relation to peripheral artery disease (PAD) for disease stratification and early-onset detection. In PAD, angiogenesis is required for tissue restoration and tissue perfusion. Considering changes in angiogenesis in patients with PAD, angiogenic factors could be explored as one of the new prognostic molecules. In recent studies, saliva and gingival crevicular fluid (GCF) have gained recognition as new, easily obtained diagnostic materials. This study aimed to compare the levels of selected circulating angiogenic factors (VEGF-A, PDGF-BB, and ANG-1) in unstimulated whole saliva (WS) and GCF versus plasma at three points in time to find possible correlations between their concentrations among patients with PAD and diabetes type 2 in 32 patients with Rutherford stages 5 and 6. A significant positive correlation has been demonstrated between circulating PDGF-BB levels in GCF and plasma. In most cases, comorbidities do not have an impact on the change in general correlation for the whole group. Our results clearly showed that GCF could be a good source for PDGF assessment. However, future studies with a larger number of subjects are warranted to confirm this finding and identify the most accurate angiogenic biomarkers in saliva or GCF that could be applied in clinical practice.

Unlocking the Diagnostic Potential of Saliva: A Comprehensive Review of Infrared Spectroscopy and Its Applications in Salivary Analysis

Infrared (IR) spectroscopy is a noninvasive and rapid analytical technique that provides information on the chemical composition, structure, and conformation of biomolecules in saliva. This technique has been widely used to analyze salivary biomolecules, owing to its label-free advantages. Saliva contains a complex mixture of biomolecules including water, electrolytes, lipids, carbohydrates, proteins, and nucleic acids which are potential biomarkers for several diseases. IR spectroscopy has shown great promise for the diagnosis and monitoring of diseases such as dental caries, periodontitis, infectious diseases, cancer, diabetes mellitus, and chronic kidney disease, as well as for drug monitoring. Recent advancements in IR spectroscopy, such as Fourier-transform infrared (FTIR) spectroscopy and attenuated total reflectance (ATR) spectroscopy, have further enhanced its utility in salivary analysis. FTIR spectroscopy enables the collection of a complete IR spectrum of the sample, whereas ATR spectroscopy enables the analysis of samples in their native form, without the need for sample preparation. With the development of standardized protocols for sample collection and analysis and further advancements in IR spectroscopy, the potential for salivary diagnostics using IR spectroscopy is vast.

Abnormal expression of CXCL13, MIF and IL-35 in patients with primary Sjögren's syndrome and its relationship with disease severity

Introduction

The aim of the study was to detect the saliva chemokine (C-X-C motif) ligand 13 (CXCL13), macrophage migration inhibitory factor (MIF), and interleukin 35 (IL-35) levels in patients with primary Sjögren's syndrome (pSS) and pSS-associated interstitial lung disease (pSS-ILD), and to explore the relationship between CXCL13, MIF, IL-35 levels, and disease severity.

Material and methods

ESSDAI score was used to evaluate the disease activity of pSS patients, and the levels of CXCL13, MIF and IL-35 in saliva of subjects were detected and analyzed, and the relationship between CXCL13, MIF, IL-35 and the occurrence of pSS was evaluated. Pearson's correlation coefficient was used to analyze the correlation between CXCL13, MIF, IL-35 and ESSDAI score. ROC curve analysis was conducted to assess the diagnostic value of CXCL13, MIF, IL-35 and their combined application in pSS.

Results

The levels of CXCL13, MIF, and IL-35 in saliva were positively correlated with ESSDAI score. Saliva CXCL13 and IL-35 are risk factors for the development of pSS into pSS-ILD. The ROC curve shows that the combination of saliva CXCL13, MIF and IL-35 has the highest diagnostic efficiency for pSS-ILD.

Conclusions

CXCL13, MIF and IL-35 are related to the activity of pSS, and the combined diagnosis of these three indexes is expected to be an important method to predict the occurrence and development of pSS.

New Frontiers in Autoimmune Diagnostics: A Systematic Review on Saliva Testing

(1) Background: Immunological laboratory testing is known to be complex, and it is usually performed in tertiary referral centers. Many criticalities affect diagnostic immunological testing, such as limited availability, the need for specifically trained laboratory staff, and potential difficulties in collecting blood samples, especially in the most vulnerable patients, i.e., the elderly and children. For this reason, the identification of a new feasible and reliable methodology for autoantibody detection is urgently needed. (2) Methods: We designed a systematic review to investigate the available literature on the utilization of saliva samples for immunological testing. (3) Results: A total of 170 articles were identified. Eighteen studies met the inclusion criteria, accounting for 1059 patients and 671 controls. The saliva collection method was mostly represented by passive drooling (11/18, 61%), and the most frequently described methodology for antibody detection was ELISA (12/18, 67%). The analysis included 392 patients with rheumatoid arthritis, 161 with systemic lupus erythematosus, 131 with type 1 diabetes mellitus, 116 with primary biliary cholangitis, 100 with pemphigus vulgaris, 50 with bullous pemphigoids, 49 with Sjogren syndrome, 39 with celiac disease, 10 with primary antiphospholipid syndromes, 8 with undifferentiated connective tissue disease, 2 with systemic sclerosis, and 1 with autoimmune thyroiditis. The majority of the reviewed studies involved adequate controls, and saliva testing allowed for a clear distinction of patients (10/12 studies, 83%). More than half of the papers showed a correlation between saliva and serum results (10/18, 55%) for autoantibody detection, with varying rates of correlation, sensitivity, and specificity. Interestingly, many papers showed a correlation between saliva antibody results and clinical manifestations. (4) Conclusions: Saliva testing might represent an appealing alternative to serum-based testing for autoantibody detection, considering the correspondence with serum testing results and the correlation with clinical manifestations. Nonetheless, standardization of sample collection processing, maintenance, and detection methodology has yet to be fully addressed.

A pilot study: Metabolic profiling of plasma and saliva samples from newly diagnosed glioblastoma patients

BACKGROUND

Despite aggressive treatment, more than 90% of glioblastoma (GBM) patients experience recurrences. GBM response to therapy is currently assessed by imaging techniques and tissue biopsy. However, difficulties with these methods may cause misinterpretation of treatment outcomes. Currently, no validated therapy response biomarkers are available for monitoring GBM progression. Metabolomics holds potential as a complementary tool to improve the interpretation of therapy responses to help in clinical interventions for GBM patients.

METHODS

Saliva and blood from GBM patients were collected pre and postoperatively. Patients were stratified conforming their progression-free survival (PFS) into favourable or unfavourable clinical outcomes (>9 months or PFS ≤ 9 months, respectively). Analysis of saliva (whole-mouth and oral rinse) and plasma samples was conducted utilising LC-QqQ-MS and LC-QTOF-MS to determine the metabolomic and lipidomic profiles. The data were investigated using univariate and multivariate statistical analyses and graphical LASSO-based graphic network analyses.

RESULTS

Altogether, 151 metabolites and 197 lipids were detected within all saliva and plasma samples. Among the patients with unfavourable outcomes, metabolites such as cyclic-AMP, 3-hydroxy-kynurenine, dihydroorotate, UDP and cis-aconitate were elevated, compared to patients with favourable outcomes during pre-and post-surgery. These metabolites showed to impact the pentose phosphate and Warburg effect pathways. The lipid profile of patients who experienced unfavourable outcomes revealed a higher heterogeneity in the abundance of lipids and fewer associations between markers in contrast to the favourable outcome group.

CONCLUSION

Our findings indicate that changes in salivary and plasma metabolites in GBM patients can potentially be employed as less invasive prognostic biomarkers/biomarker panel but validation with larger cohorts is required.

The Effect of Biological Treatment on Stress Parameters Determined in Saliva in Patients with Severe Psoriasis

Background and objectives: In psoriatic patients, stress is the most common aggravating factor. Despite the use of quality-of-life assessment questionnaires, diagnosing stress in psoriatic patients is not a flawless procedure. This study aimed to assess the usefulness of potential stress biomarkers in saliva for monitoring the treatment of psoriasis. Materials and methods: A total of 104 adult patients with severe psoriasis were included and randomly treated via biological treatment or symptomatic therapy: 84 received biological treatment, with 20 formed a control group receiving symptomatic therapy. The administered biological treatment was adalimumab, whilst in controls calcipotriol/betamethasone dipropionate topical gel and emollients were used. Patients were monitored monthly with a dermatological examination and the dispensing of a biological drug. During each of the four visits, the severity of the disease was assessed (PASI, BSA, and DLQI), and a sample of the patient’s saliva was taken. In all the participants, the saliva concentrations of immunoglobulin A (sIgA), α-amylase (sAA), and chromogranin A (CgA) were measured. Results: The majority of patients in both the study and control groups achieved clinical improvement, though favoring the group receiving biological treatment. The concentration of sIgA in the saliva was constantly increasing in the study group during subsequent visits (Fr = 27.26; p < 0.001). Meanwhile, there were no statistically significant changes in the control group during the same follow-up period (Fr = 6.66; p = 0.084). Levels of sAA underwent statistically significant changes in both groups (Fr = 58.02; p < 0.001—study group and Fr = 13.74; p = 0.003—control group). In the study group, a steady, statistically significant increase in sAA was observed from the first to the third visit. In the study group, a downward trend in CgA concentration was observed. In the control group, no significant differences in the level of CgA were obtained. Conclusions: sIgA, sAA, and CgA are potential markers of the severity of psoriasis and the associated stress reaction. Based on the presented observations, only sIgA and CgA seem to be valuable biomarkers for monitoring the effectiveness of the systemic treatment of psoriasis.

Epidermolysis bullosa in oral health: clinical manifestations and salivary alterations

Epidermolysis bullosa (EB) is an inherited disease characterized by the fragility of the skin and mucous membranes. All types/subtypes of EB can lead to alterations in the mouth and glands.

OBJECTIVE

To evaluate clinical manifestations of EB on the oral mucosa and alterations in salivary flow.

MATERIALS AND METHODS

Sociodemographic and clinical data were obtained from EB individuals. The salivary flow analysis was performed in EB and in non-EB patients. Fischer's exact test was applied to the qualitative variables, and the Mann-Whitney test was applied to the quantitative data.

RESULTS

A total of 11 cases of EB were evaluated, and 3 types of EB were diagnosed (recessive dystrophic-RDEB; junctional-JEB; and simplex-EBS). Only individuals with RDEB or JEB showed the oral manifestation of the disease. The most affected sites were the lips (54%), hard palate (36%), and oral mucosa (27%). Ulcer and ankyloglossia were diagnosed in all RDEB cases. Regarding salivary flow, an intragroup comparison revealed an increase in stimulated versus unstimulated collection in the control sample (p = 0.0064). The EB group showed no difference (p = 0.6086). We also observed no differences in salivary volume between the control and EB groups (p = 0.7117 and p = 0.5557, unstimulated and stimulated flows, respectively).

CONCLUSIONS

No oral manifestations were observed in EBS subjects. It is unclear whether individuals with EB are predisposed to manifest hyposalivation.

CLINICAL RELEVANCE

Severe cases of EB show broad alterations in the oral mucosa, whereas the saliva needs to be better evaluated.

SalivaDB-a comprehensive database for salivary biomarkers in humans

Saliva as a non-invasive diagnostic fluid has immense potential as a tool for early diagnosis and prognosis of patients. The information about salivary biomarkers is broadly scattered across various resources and research papers. It is important to bring together all the information on salivary biomarkers to a single platform. This will accelerate research and development in non-invasive diagnosis and prognosis of complex diseases. We collected widespread information on five types of salivary biomarkers-proteins, metabolites, microbes, micro-ribonucleic acid (miRNA) and genes found in humans. This information was collected from different resources that include PubMed, the Human Metabolome Database and SalivaTecDB. Our database SalivaDB contains a total of 15 821 entries for 201 different diseases and 48 disease categories. These entries can be classified into five categories based on the type of biomolecules; 6067, 3987, 2909, 2272 and 586 entries belong to proteins, metabolites, microbes, miRNAs and genes, respectively. The information maintained in this database includes analysis methods, associated diseases, biomarker type, regulation status, exosomal origin, fold change and sequence. The entries are linked to relevant biological databases to provide users with comprehensive information. We developed a web-based interface that provides a wide range of options like browse, keyword search and advanced search. In addition, a similarity search module has been integrated which allows users to perform a similarity search using Basic Local Alignment Search Tool and Smith-Waterman algorithm against biomarker sequences in SalivaDB. We created a web-based database-SalivaDB, which provides information about salivary biomarkers found in humans. A wide range of web-based facilities have been integrated to provide services to the scientific community. https://webs.iiitd.edu.in/raghava/salivadb/.

Diagnostic potential of salivary interleukin-17, RANKL, and OPG to differentiate between periodontal health and disease and discriminate stable and unstable periodontitis: A case-control study

Background and Aims

Limitations of the conventional diagnostic techniques urged researchers to seek novel methods to predict, diagnose, and monitor periodontal disease. Use of the biomarkers available in oral fluids could be a revolutionary surrogate for the manual probing/diagnostic radiograph. Several salivary biomarkers have the potential to accurately discriminate periodontal health and disease. This study aimed to determine the diagnostic sensitivity and specificity of salivary interleukin (IL)-17, receptor activator of nuclear factor-κB ligand (RANKL), osteoprotegerin (OPG), RANKL/OPG for differentiating (1) periodontal health from disease and (2) stable and unstable periodontitis.

Methods

Participants with periodontitis (n = 50) and gingivitis (n = 25), both diseases represented the cases, and subjects with healthy periodontium (n = 15) as a control were recruited for this study. Periodontitis cases were further equally subdivided into stable and unstable. Whole unstimulated salivary sample were collected from all participants. Periodontal parameters including bleeding on probing, probing pocket depth, clinical attachment loss, and number of missing teeth were recorded. The protein levels of salivary IL-17, RANKL, and OPG were determined by using enzyme-linked immunosorbent assays technique.

Results

Salivary IL-17, OPG, RANKL, and RANKL/OPG showed high sensitivity and specificity to differentiate periodontal health from gingivitis and periodontitis. Similar pattern was observed in discriminating stable and unstable periodontitis. Salivary IL-17 and RANKL showed a good accuracy to differentiate gingivitis from periodontitis. However, OPG and RANKL/OPG did not exhibit enough sensitivity and specificity to differentiate the latter conditions.

Conclusion

Salivary IL-17, RANKL, OPG, and RANKL/OPG system are potential candidates for differentiating periodontal health and disease and discriminate stable and unstable periodontitis.

Salivary IgA as a Surrogate Biomarker for Microbial Infections in Postoperative Patients Receiving Chemo-Radio-Therapy for Head and Neck Cancer

Objective Radiotherapy (RT) and chemotherapy (CT) are important treatment options in patients with head and neck cancers. A common complication of this is microbial colonization or infection of mucosal surfaces. These infections may commonly be due to bacteria or yeasts. Salivary proteins with their buffering activity and immunoglobulin, especially immunoglobulin A (IgA), protect oral tissue, mucosal surfaces, and teeth from various microorganisms. This study characterizes the common microorganisms encountered and evaluates the role of salivary IgA in predicting microbial infections in this group of patients with mucositis.

Methods A total of 150 adult head and neck cancer patients on CTRT were evaluated at baseline and at the end of 3 and 6 weeks, respectively. Oral swabs collected from buccal mucosa were processed in the microbiology laboratory for the presence of microorganisms. Saliva was processed for IgA level estimation on Siemens Dimension Automated biochemistry analyzer.

Results Pseudomonas aeruginosa and Klebsiella pneumoniae were the most common organisms found in our patients, followed by Escherichia coli and group A beta-hemolytic Streptococci. A significant increase (p = 0.0203) in the incidence of bacterial infection was observed in post-CTRT patients (61%) compared to pre-CTRT patients (49.33%). There was significant increase in levels of salivary IgA (p = 0.003) in patients with bacterial and fungal infection (n = 135/267) when compared to those in samples showing no growth (n = 66/183).

Conclusion A significant increase in the incidence of bacterial infection in post-CTRT patients was observed in this study. This study also indicated that postoperative head and neck cancer patients with oral mucositis that developed an infection were associated with high salivary IgA levels, and it may serve as a surrogate biomarker of infection in these patients.

Saliva - a new opportunity for fluid biopsy

Saliva is a complex biological fluid with a variety of biomolecules, such as DNA, RNA, proteins, metabolites and microbiota, which can be used for the screening and diagnosis of many diseases. In addition, saliva has the characteristics of simple collection, non-invasive and convenient storage, which gives it the potential to replace blood as a new main body of fluid biopsy, and it is an excellent biological diagnostic fluid. This review integrates recent studies and summarizes the research contents of salivaomics and the research progress of saliva in early diagnosis of oral and systemic diseases. This review aims to explore the value and prospect of saliva diagnosis in clinical application.

Assessment of Urinary Biomarkers for Infectious Diseases Using Lateral Flow Assays: A Comprehensive Overview

Screening of biomarkers is a powerful approach for providing a holistic view of the disease spectrum and facilitating the diagnosis and prognosis of the state of infectious diseases. Unaffected by the homeostasis mechanism in the human body, urine accommodates systemic changes and reflects the pathophysiological condition of an individual. Easy availability in large volumes and non-invasive sample collection have rendered urine an ideal source of biomarkers for various diseases. Infectious diseases may be communicable, and therefore early diagnosis and treatment are of immense importance. Current diagnostic approaches preclude the timely identification of clinical conditions and also lack portability. Point-of-care (POC) testing solutions have gained attention as alternative diagnostic measures due to their ability to provide rapid and on-site results. Lateral flow assays (LFAs) are the mainstay in POC device development and have attracted interest owing to their potential to provide instantaneous results in resource-limited settings. The discovery and optimization of a definitive biomarker can render POC testing an excellent platform, thus impacting unwarranted antibiotic administration and preventing the spread of infectious diseases. This Review summarizes the importance of urine as an emerging biological fluid in infectious disease research and diagnosis in clinical settings. We review the academic research related to LFAs. Further, we also describe commercial POC devices based on the identification of urinary biomarkers as diagnostic targets for infectious diseases. We also discuss the future use of LFAs in developing more effective POC tests for urinary biomarkers of various infections.

Analysis of the Saliva Proteome Using 2D-DIGE

Saliva is now an established biofluid with a number of important applications in use across research and clinical settings. Saliva contains an assortment of biomolecules, including proteins, metabolites, RNA, DNA, and microorganisms. Numerous biomolecules enter saliva from the blood by passing through the intercellular spaces, reflecting the physiological state of the body. Saliva can be collected directly or using one of the numerous devices/systems that are available, each of which has its own specific applications. The identification and classification of salivary biomolecules, using increasing advanced omics approaches, have contributed to the reality that saliva is a creditable diagnostic fluid for oral and systemic diseases.

Prospective biomarkers of Alzheimer's disease: A systematic review and meta-analysis

OBJECTIVE

Alzheimer's disease (AD) involves a series of pathological changes and some biomarkers were reported to assist in monitoring and predicting disease progression before the emergence of clinical symptoms. We aimed to identify prospective biomarkers and quantify their effect on AD progression.

METHODS

PubMed, EMBASE and Web of Science databases were searched for prospective cohort studies published up to October 2021. Eligible studies were included, and the available data were extracted. Meta-analyses were conducted based on random-effect models. Relative risk (RR) with 95% confidence interval (CI) was adopted as the final effect size.

RESULTS

Totally 48,769 articles were identified, of which 84 studies with 20 prospective biomarkers were included in meta-analyses. In the present study, 15 biomarkers were associated with AD progression, comprising CSF Aβ42 (RR=2.49, 95%CI=1.68-3.69), t-tau (RR=1.88, 95%CI=1.49-2.37), p-tau (RR=1.74, 95%CI=1.37-2.21), tau/Aβ42 ratio (RR=5.11, 95%CI=2.01-13.00); peripheral blood Aβ42/Aβ40 (RR=1.26, 95%CI=1.05-1.51), t-tau (RR=1.33, 95%CI=1.08-1.64), NFL (RR=1.75, 95%CI=1.07-2.87); whole, left and right hippocampal volume (HV) (whole: RR=1.65, 95%CI=1.39-1.95; left: RR=2.60, 95%CI=1.02-6.64; right: RR=1.43, 95%CI=1.23-1.66), entorhinal cortex (EC) volume (RR=1.69, 95%CI=1.24-2.30), medial temporal lobe atrophy (MTA) (RR=1.52, 95%CI=1.33-1.74), 18 F-FDG PET (RR=2.24, 95%CI=1.29-3.89), 11 C-labeled Pittsburgh Compound B PET (11 C-PIB PET) (RR=3.91, 95%CI=1.06-14.41); APOE ε4 (RR=2.16, 1.83-2.55). A total of 70 articles were included in the qualitative review, in which 61 biomarkers were additionally associated with AD progression.

CONCLUSION

CSF Aβ42, t-tau, p-tau, tau/Aβ42; peripheral blood t-tau, Aβ42/Aβ40, NFL; whole, left and right HV, EC volume, MTA, 18 F-FDG PET, 11 C-PIB PET; APOE ε4 may be promising prospective biomarkers for AD progression.

Automated assays for trace elements and ferritin measurement in saliva of pigs: Analytical validation and a pilot application to evaluate different iron status

The aim of this study was to validate automated methods to measure iron (Fe), zinc (Zn), copper (Cu) and ferritin in pig saliva samples. A complete analytical validation was performed of all assays. In addition, these methods were applied to saliva of Fe supplemented (n = 22) and non-supplemented (n = 20) piglets. All assays were able to measure these biomarkers in pig saliva with adequate precision, accuracy and high sensitivity and, in case of trace elements without needing a deproteinization pre-process. The group of piglets supplemented with Fe presented significantly higher levels of ferritin and Zn in saliva. In conclusion, the automated assays evaluated were able to measure Fe, Zn, Cu and ferritin in saliva of pigs, and in case of trace elements, they have the advantage of not needing a deproteinization pre-treatment and thus these analytes can be measured in a simple and fast manner.

Effect of Recombinant Antibodies and MIP Nanoparticles on the Electrical Behavior of Impedimetric Biorecognition Surfaces for SARS-CoV-2 Spike Glycoprotein: A Short Report

Electrochemical immunosensors are often described as innovative strategies to tackle urgent epidemiological needs, such as the detection of SARS-CoV-2 main biomarker, the spike glycoprotein. Nevertheless, there is a great variety of receptors, especially recombinant antibodies, that can be used to develop these biosensing platforms, and very few reports compare their suitability in analytical device design and their sensing performances. Therefore, this short report targeted a brief and straightforward investigation of the performance of different impedimetric biorecognition surfaces (BioS) for SARS-CoV-2, which were crafted from three commonly reported recombinant antibodies and molecularly-imprinted polymer (MIP) nanoparticles (nanoMIP). The selected NanoMIP were chosen due to their reported selectivity to the receptor binding domain (RBD) of SARS-CoV-2 spike glycoprotein. Results showed that the surface modification protocol based on MUDA and crosslinking with EDC/NHS was successful for the anchoring of each tested receptor, as the semicircle diameter of the Nyquist plots of EIS increased upon each modification, which suggests the increase of Rct due to the binding of dielectric materials on the conductive surface. Furthermore, the type of monoclonal antibody used to craft the BioS and the artificial receptors led to very distinct responses, being the RBD5305 and the NanoMIP-based BioS the ones that showcased the highest increment of signal in the conditions herein reported, which suggests their adequacy in the development of impedimetric immunosensors for SARS-CoV-2 spike glycoprotein.

Milk as a Non-Invasive and Alternative Sample for Serum in the Diagnosis of Animal Toxoplasmosis: A Systematic Review

Background

Toxoplasmosis is one of the most important zoonotic parasitic diseases worldwide with a high impact on human and animal health. Body fluids such as milk are used to diagnose many parasitic diseases, including toxoplasmosis. Therefore, this study aimed to investigate the role of milk as a non-invasive and alternative sample for serum in the diagnosis of animal toxoplasmosis.

Methods

Five English-language databases (ScienceDirect, PubMed, ProQuest, Scopus, and Web of Science) were explored for published articles before Dec 2020.

Results

In total, 42 out of 2256 published articles were included in this systematic review. In 21 articles, serum and milk samples were evaluated simultaneously with serological or molecular tests, and the results were compared. The results of descriptive studies and a review of nine experimental studies showed that milk could be used as a non-invasive and alternative sample for the serum in the diagnosis of toxoplasmosis.

Conclusion

Due to the relatively high prevalence of Toxoplasma gondii (T. gondii) infection in milk, consumption of raw milk from infected animals can be a potential source of human infection and a significant threat to public health. On the other hand, due to the ease and cheapness of collecting milk samples, the use of milk is recommended for the diagnosis of toxoplasmosis.

Elevated Salivary Inflammatory Biomarkers are Associated with SARS-CoV-2 Infection Severity

High levels of inflammatory cytokines in serum have been reported in patients with severe SARS-CoV-2 infection. There is growing interest in recognizing the role of inflammatory biomarkers in saliva in diagnosing systemic diseases. This study assumed that estimating biomarkers in saliva samples from patients infected with SARS-CoV-2 would distinguish between mild and severe cases. Saliva was collected from 142 controls and 158 SARS-CoV-2 patients (mild 72 and severe 86) to measure interleukin-6 (IL-6), C-reactive protein (CRP), and C-X-C motif chemokine ligand-10 (CXCL-10). IL-6 and CXCL-10 were significantly increased in patients with mild and severe SARS-CoV-2 infections. CRP was significantly increased only in severe SARS-CoV-2 cases. All biomarkers were significantly higher in severe cases than in mild cases (p < 0.001). Among patients with SARS-CoV-2 infection, men showed significantly higher CRP and CXCL-10 levels than females (p < 0.01 and 0.05, respectively). In addition, elderly patients (40–80 years) had significantly higher IL-6, CRP, and CXCL-10 (p < 0.001). Patients with diabetes and hypertension showed elevated IL-6, CRP, and CXCL-10 (p < 0.001). There was a significant positive correlation between IL-6, CRP, CXCL-10, and between age, IL-6, CRP, and CXCL-10. Saliva may have a future value in measuring the inflammatory biomarkers associated with the severity of SARS-CoV2 infection and therapeutic monitoring.

Electrochemical detection of uric acid in undiluted human saliva using uricase paper integrated electrodes

In this study, we introduce a uricase-immobilized paper (UOx­-paper) integrated electrochemical sensor for detection of uric acid (UA) in saliva. The UOx was immobilized on the detection zone in the wax-patterned paper substrate. This UOx-paper was integrated with a Prussian blue­-modified, screen-printed carbon electrode after electropolymerization of o-phenylenediamine to construct an electrochemical cell for small-volume (20 μL) of samples. First, we optimized the fabrication conditions of UOx-paper. Next, the amperometric response of the UOx-paper-based electrochemical UA sensor was analyzed using a known concentration of UA standard solution in artificial saliva at an applied potential of − 0.1 V (versus Ag pseudo-reference electrode). The UOx-­paper based electrochemical UA sensor showed a sensitivity of 4.9 μA·mM⁻¹ in a linear range of 50 to 1000 μM (R² = 0.998), high selectivity and good reproducibility, as well as a limit of detection of 18.7 μM (0.31 mg/dL) UA. Finally, we quantified the UA levels in undiluted saliva samples of healthy controls (n = 20) and gout patients (n = 8). The levels were correlated with those measured with conventional salivary UA enzymatic assays as well as serum UA levels. The UOx-paper-based electrochemical UA sensor is a user-friendly and convenient tool to assess salivary UA levels.

The New Era of Salivaomics in Dentistry: Frontiers and Facts in the Early Diagnosis and Prevention of Oral Diseases and Cancer

Nowadays, with the development of new and highly sensitive, blood is not the only medium of choice for the diagnosis of several diseases and pathological conditions. Saliva is now considered a safe and non-invasive sample to study oral and systemic diseases, showing great diagnostic potential. According to several recent studies, saliva has emerged as an emerging biofluid for the early diagnosis of several diseases, indicated as a mirror of oral and systemic health and a valuable source of clinically relevant information. Indeed, several studies have observed that saliva is useful for detecting and diagnosing malignant tumours, human immunodeficiency virus, heart disease, and autoimmune diseases. The growing realisation that saliva is an inexhaustible source of information has led to the coining of the term ‘Salivaomics’, which includes five “omics” in connection with the main constituents of saliva: genome and epigenome, transcriptomics, metabolomics, lipidomics, proteomics and microbiota. All those may be changed by disease state, so they offer significant advantages in the early diagnosis and prognosis of oral diseases. The aim of the present review isto update and highlight the new frontiers of salivaomics in diagnosing and managing oral disorders, such as periodontitis, premalignant disorders, and oral squamous cell carcinoma (OSCC).

Changes in salivary biomarkers associated with periodontitis and diabetic neuropathy in individuals with type 1 diabetes

The objective of this pilot clinical study was to identify salivary biomarkers that are associated with periodontal disease and measures of diabetic autonomic dysfunction. Saliva samples from 32 participants were obtained from 3 groups: healthy (H), type 1 diabetes mellitus (DM), and type 1 diabetes mellitus with neuropathy (DMN). Based on the periodontal examination, individuals’ mean Periodontal Screening and Recording scores were categorized into two groups (periodontally healthy and gingivitis), and correlated to specific salivary inflammatory biomarkers assessed by a customized protein array and enzyme assay. The mean salivary IgA level in DM was 9211.5 ± 4776.4 pg/ml, which was significantly lower than H (17,182.2 ± 8899.3 pg/ml). IgA in DMN with healthy periodontium was significantly lower (5905.5 ± 3124.8 pg/ml) compared to H, although IgA levels in DMN patients with gingivitis (16,894. 6 ± 7084.3) were not. According to the result of a logistic regression model, IgA and periodontal condition were the indicators of the binary response given by H versus DM, and H versus DMN, respectively. These data suggest that selected salivary biomarkers, such as IgA, combined with a periodontal examination prior to obtaining salivary samples can offer a non-invasive method to assess risk for developing diabetic neuropathy.

Improving the Molecular Diagnosis of Malaria: Droplet Digital PCR-Based Method Using Saliva as a DNA Source

Malaria is an acute febrile disease caused by a protozoan of the genus Plasmodium. Light microscopy (LM) is the gold standard for the diagnosis of malaria. Despite this method being rapid and inexpensive, it has a low limit of detection, which hampers the identification of low parasitemia infections. By using multicopy targets and highly sensitive molecular techniques, it is possible to change this scenario. In this study, we evaluated the performance of droplet digital PCR (ddPCR) to detect Plasmodium DNA obtained from saliva samples (whole saliva and buccal swab) of 157 individuals exposed to malaria transmission from the Brazilian Amazon region. We used the highly sensitive ddPCR method with non-ribosomal multicopy targets for Plasmodium vivax (Pvr47) and Plasmodium falciparum (Pfr364). There was good concordance between the quantitative real-time PCR (qPCR) results from the saliva and blood, except for mixed-species infections. The sensitivity of qPCR was 93% for blood, 77% for saliva, and 47% for swabs. Parasite DNA was not detected in saliva samples in low-density infections compared with the detection in blood samples. ddPCR showed increased sensitivity for detecting Plasmodium in the blood and swabs (99% in blood, 73% in saliva, and 59% in swabs). Notably, ddPCR detected more mixed infections in the blood (15%), saliva (9%), and swabs (18%) than qPCR. Our data showed that the differences between ddPCR and qPCR were the result of a higher number of P. falciparum infections detected by ddPCR. Overall, there was a moderate correlation between parasite densities estimated by the different methods in the blood. Our findings highlight the possibility of using non-invasive sample collection methods for malaria diagnosis by targeting multicopy sequences combined with highly sensitive molecular methods.

Saliva sampling methods. Cariogenic streptococci count using two different methods of saliva collection in children

The aim of this study is to compare the efficacy of two methods for collecting saliva samples from infants under 2 years of age for cariogenic streptococci (CS) count. Two collection methods were applied in 11 infants. In Method (A), saliva samples were collected by swabbing the inner cheek mucosa and floor of the mouth in figure of eight motions with a sterile cotton swab until it was soaked. In method (B), saliva samples were collected by aspiration of 1 ml of saliva with a sterile plastic syringe on the floor of the mouth, after stimulation with glove. The samples were cultured in modified Gold's broth (MSMG), and on trypticase, yeast extract, sucrose, cystine and bacitracin culture medium (TYSCB). In method (A), the swab with the sample was unloaded in situ on TYSCB and placed in PBS medium for transport. Then, 100 μl of the eluate was seeded in MSMG. In method (B) 100 μl were seeded in TYSCB and 100 μl in MSMG. Both culture media were incubatedundercapnophilicconditions for 48 hours at 37 °C. Colony forming units (CFU/ml) were counted by calibrated operators (kappa = 0.75). The presence of cariogenic streptococci (CS) (Streptococcus mutans-Streptococcus sobrinus) was determined by qPCR in the samples collected by both methods. The CFU/ml counts in MSMG differed significantly between methods (p = 0.021). In TYSCB, the recovery of CFU/ml was higher in method (A), without significant difference (p = 0.705). The molecular technique detected presence of CS, with no difference between collection methods. Collecting saliva samples by swabbing proved more effective in terms of recovery of microorganisms, and did not affect the detection of presence of CS by molecular techniques.