Saliva as a diagnostic fluid. Literature review

Association between serum biomarkers and oral health status in children with chronic kidney disease: A cross-sectional study

OBJECTIVES

The aim of this study was to investigate the association between serum biomarkers and oral health parameters in children with chronic kidney disease (CKD).

MATERIALS AND METHODS

Serum hemoglobin, blood urea nitrogen, serum creatinine, calcium, parathormone, magnesium, and phosphorus levels were measured in 62 children with CKD aged between 4 and 17 years. Intraoral examinations of the patients were performed by two different pediatric dentists. Dental caries was assessed using the decayed-missing-filled-teeth (DMFT/dmft) indexes, and oral hygiene was assessed using the debris (DI), calculus (CI), and simplified oral hygiene (OHI-S) indexes. Spearman's rho coefficient and generalized linear modeling were used to examine the association between serum biomarkers and oral health parameters.

RESULTS

The results of the study showed that there were negative and statistically significant correlations between serum hemoglobin and creatinine levels and dmft scores in pediatric patients with CKD (p = 0.021 and p = 0.019, respectively). Furthermore, blood urea nitrogen levels and DI and OHI-S scores (p = 0.047 and p = 0.050, respectively); serum creatinine levels and DI, CI, and OHI-S scores (p = 0.005, p = 0.047, p = 0.043, respectively); and parathormone levels and CI and OHI-S scores (p = 0.001 and p = 0.017, respectively) were found to be positively and statistically significantly related.

CONCLUSIONS

There are associations between various serum biomarker levels and dental caries and oral hygiene parameters in pediatric patients with CKD.

CLINICAL RELEVANCE

The impact of changes in serum biomarkers on oral and dental health is important for dentists' and medical professionals' approaches to patients' oral and systemic health.

Impact of Thermal Pretreatment of Saliva on the RT-PCR Detection of SARS-CoV-2

The use of saliva directly as a specimen to detect viral RNA by RT-PCR has been tested for a long time as its advantages are relevant in terms of convenience and costs. However, as other body fluids, its proven inhibition effect on the amplification reaction can be troublesome and compromise its use in the detection of viral particles. The aim of the present work is to demonstrate that saliva pretreatment may influence the RT-PCR amplification of three gene targets of SARS-CoV-2 significantly. A pool of RNA from confirmed COVID-19 patients was used to test the influence of heat pretreatment of saliva samples at 95°C for 5, 10, 15 and 20 min on the amplification performance of ORF1ab, E, and N SARS-CoV-2 genes. Prolonged heating at 95°C significantly improves the Ct value shift, usually observed in the presence of saliva, increasing the limit of detection of viral genes ORF1ab, E, and N. When tested using a cohort of COVID-19 patients' saliva, the increased time of heat pretreatment resulted in a significant increase in the detection sensitivity.

Novel impacts of saliva with regard to oral health

The maintenance of balanced oral homeostasis depends on saliva. A readily available and molecularly rich source of biological fluid, saliva fulfills many functions in the oral cavity, including lubrication, pH buffering, and tooth mineralization. Saliva composition and flow can be modulated by different factors, including circadian rhythm, diet, age, drugs, and disease. Recent events have revealed that saliva plays a central role in the dissemination and detection of the SARS-CoV-2 coronavirus. A working knowledge of saliva function and physiology is essential for dental health professionals.

Chemical and physical features of biological fluids in treatment of hydatid disease

The aim of this paper is to better understand the dynamics of crystallogenic and starting activity in biological fluids of patients throughout surgery and the late postoperative phase in alveococcosis. Samples of saliva from 22 individuals with alveococcosis were included in the research. Biological fluid samples were taken at the time of admission and before the patient was discharged. Following that, slides were made utilizing the teziocrystalloscopy method, which incorporates the investigation of the crystal forming activity of mixed saliva with its starting characteristics using a 0.9 percent sodium chloride solution as the foundation ingredient. Using our own set of criteria, we evaluated the outcomes of crystalloscopic and tezigraphic experiments. Specrophotometric examination of tezigraphic and crystalloscopic facies was done using a PowerWave XS microplate spectrophotometer at wavelengths of 400, 350, and 300 nm to augment the results from ocular morphometry of dried saliva micro slides. Surgical therapy results in a partial normalization of physical and chemical parameters, as well as the composition of the patient's biological fluids after the patient is discharged from the hospital.

Stabilization of Salivary Biomarkers

The use of saliva as a diagnostic biofluid has been increasing in recent years, thanks to the identification and validation of new biomarkers and improvements in test accuracy, sensitivity, and precision that enable the development of new noninvasive and cost-effective devices. However, the lack of standardized methods for sample collection, treatment, and storage contribute to the overall variability and lack of reproducibility across analytical evaluations. Furthermore, the instability of salivary biomarkers after sample collection hinders their translation into commercially available technologies for noninvasive monitoring of saliva in home settings. The present review aims to highlight the status of research on the challenges of collecting and using diagnostic salivary samples, emphasizing the methodologies used to preserve relevant proteins, hormones, genomic, and transcriptomic biomarkers during sample handling and analysis.

Salivary parameters alterations after early exposure to environmental methylmercury: A preclinical study in offspring rats

BACKGROUND

Methylmercury (MeHg) is still considered a global pollutant of major concern; thus, it becomes relevant to investigate and validate alternative diagnostic methods to track early-life human exposure. This study aimed to evaluate the salivary parameters and to characterize potential mechanisms of oxidative damage on the salivary glands (SG) of offspring rats after pre- and postnatal environmental-experimental MeHg exposure.

METHODS

Pregnant Wistar rats were daily exposed to 40 μg/kg MeHg during both gestational and lactation periods. Then, the saliva of offspring rats was analyzed in terms of flow rate, amylase activity, and total protein concentration. The SG of the offspring rats were dissected to perform the oxidative biochemistry analyses of antioxidant capacity against peroxyl radicals (ACAP), lipid peroxidation (LPO), and nitrite levels.

RESULTS

Exposure to MeHg significantly decreased the ACAP, increased LPO and nitrite levels, decreased salivary flow rate, amylase activity, and total protein concentration.

CONCLUSION

Saliva analyses can predict damages induced by early-life MeHg exposure and may be used as an auxiliary diagnostic method.

R. Buzalaf M, Crespo-Lopez ME, Lima RR. Maternal methylmercury exposure changes the proteomic profile of the offspring's salivary glands: Prospects on translational toxicology

Background

Methylmercury (MeHg) remains a public health issue since developing organisms are particularly vulnerable to this environmental contaminant. This study investigated the effect of maternal MeHg exposure on the modulation of proteomic profile of parotid (PA), submandibular (SM), and sublingual (SL) glands of offspring rats.

Materials and methods

Pregnant Wistar rats were daily exposed to 40 μg/kg MeHg during both gestational and lactation periods. The proteomic profiles of the major salivary glands of the offspring rats were analyzed through mass spectrometry.

Results

The offspring rats exposed to MeHg showed significant alterations in the proteomic profiles of the PA, SM, and SL glands. Altered proteins were associated with cytoskeleton components, tissue morphogenesis, and response to stimulus and stress.

Conclusion

This original study showed that maternal MeHg exposure significantly modulates the expression of proteins and induces alterations in the proteomic profiles of developing salivary glands.

Differential Glycosylation Levels in Saliva from Patients with Lung or Breast Cancer: A Preliminary Assessment for Early Diagnostic Purposes

Glycans play a fundamental role in several biological processes, such as cell-cell adhesion, signaling, and recognition. Similarly, abnormal glycosylation is involved in many pathological processes, among which include tumor growth and progression. Several highly glycosylated proteins found in blood are currently used in clinical practice as cancer biomarkers (e.g., CA125, PSA, and CA19-9). The development of novel non-invasive diagnostic procedures would greatly simplify the screening and discovery of pathologies at an early stage, thus also allowing for simpler treatment and a higher success rate. In this observational study carried out on 68 subjects diagnosed with either breast or lung cancer and 34 healthy volunteers, we hydrolyzed the glycoproteins in saliva and quantified the obtained free sugars (fucose, mannose, galactose, glucosamine, and galactosamine) by using high-performance anion-exchange chromatography with pulsed-amperometric detection (HPAEC-PAD). The glycosidic profiles were compared by using multivariate statistical analysis, showing differential glycosylation patterns among the three categories. Furthermore, Receiver Operating Characteristics (ROC) analysis allowed obtaining a reliable and minimally invasive protocol able to discriminate between healthy and pathological subjects.

Alternative matrices in forensic toxicology: a critical review

Purpose

The use of alternative matrices in toxicological analyses has been on the rise in clinical and forensic settings. Specimens alternative to blood and urine are useful in providing additional information regarding drug exposure and analytical benefits. The goal of this paper is to present a critical review on the most recent literature regarding the application of six common alternative matrices, i.e., oral fluid, hair, sweat, meconium, breast milk and vitreous humor in forensic toxicology.

Methods

The recent literature have been searched and reviewed for the characteristics, advantages and limitations of oral fluid, hair, sweat, meconium, breast milk and vitreous humor and its applications in the analysis of traditional drugs of abuse and novel psychoactive substances (NPS).

Results

This paper outlines the properties of six biological matrices that have been used in forensic analyses, as alternatives to whole blood and urine specimens. Each of this matrix has benefits in regards to sampling, extraction, detection window, typical drug levels and other aspects. However, theses matrices have also limitations such as limited incorporation of drugs (according to physical–chemical properties), impossibility to correlate the concentrations for effects, low levels of xenobiotics and ultimately the need for more sensitive analysis. For more traditional drugs of abuse (e.g., cocaine and amphetamines), there are already data available on the detection in alternative matrices. However, data on the determination of emerging drugs such as the NPS in alternative biological matrices are more limited.

Conclusions

Alternative biological fluids are important specimens in forensic toxicology. These matrices have been increasingly reported over the years, and this dynamic will probably continue in the future, especially considering their inherent advantages and the possibility to be used when blood or urine are unavailable. However, one should be aware that these matrices have limitations and particular properties, and the findings obtained from the analysis of these specimens may vary according to the type of matrix. As a potential perspective in forensic toxicology, the topic of alternative matrices will be continuously explored, especially emphasizing NPS.

Functionalized Mouth-Conformable Interfaces for pH Evaluation of the Oral Cavity

Oral health monitoring is highly desired, especially for in home use, however, current methods are not sensitive enough and technically convoluted for this purpose. This paper presents incorporation of bioactive materials and colorimetric chemical sensors into routinely used oral appliances transforming them into bioresponsive, conformable interfaces. Specifically, endodontic paper points and dental floss can be functionalized to locally sense and monitor pH variations within the oral cavity via color changes. Moreover, edible colorimetric indicators are developed and used to make sensing, edible devices in the form factor of candies that can dynamically and visually respond to acidity changes in saliva. These interfaces would enable early detection of caries (e.g., using dental floss and paper points) providing low-cost point of care devices that respond in real-time by detecting pH variations in biological fluids thus bringing monitoring to home settings .

Application of microextraction techniques in alternative biological matrices with focus on forensic toxicology: a review

The interest in alternative biological matrices (e.g., hair and saliva) for forensic toxicology analysis has increased, and recent developments in sample preparation have targeted rapid, cheap, efficient and eco-friendly methods, including microextraction techniques. For this review, we have gathered information about these two hot topics. We discuss the composition, incorporation of analytes and advantages and disadvantages of different biological matrices, and also present the operation principles of the most reported microextraction procedures and their application in forensic toxicology. The outcome of this review may encourage future forensic researches into alternative samples and microextraction techniques.

Saliva Preparation Method Exploration for ATR-FTIR Spectroscopy: Towards Bio-fluid Based Disease Diagnosis

Saliva has garnered a lot of interest as a non-invasive, easy to collect, and biochemical rich sample for attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) based disease diagnosis. Although a large number of studies have explored its potential, the preparation methods used differ greatly. For large scale clinical studies to aid translation into clinics, the collection/processing methodology needs to be standardized. Therefore, in this study, we explored different saliva collection (spitting, method A/cotton soaking, method B) and processing protocols (unprepared, TS; supernatant from the centrifugation, CS; and drying, C) to find which gives the best ATR-FTIR signals. Analysis showed highest proteins, carbohydrates, amino acids, and nucleic acid + proteins/lipids in BTS, BCS, ACS, and BC, respectively. Notably, only BC shows a 1377 cm-1 nucleic acid band that is also uniquely identified in multivariate analysis. We conclude that the collection-processing protocol should be based on a biochemical component that best gives a differential diagnosis.

An In Vitro Barrier Model of the Human Submandibular Salivary Gland Epithelium Based on a Single Cell Clone of Cell Line HTB-41: Establishment and Application for Biomarker Transport Studies

The blood–saliva barrier (BSB) consists of the sum of the epithelial cell layers of the oral mucosa and salivary glands. In vitro models of the BSB are inevitable to investigate and understand the transport of salivary biomarkers from blood to saliva. Up to now, standardized, cell line-based models of the epithelium of the submandibular salivary gland are still missing for this purpose. Therefore, we established epithelial barrier models of the submandibular gland derived from human cell line HTB-41 (A-253). Single clone isolation resulted in five different clones (B2, B4, B9, D3, and F11). Clones were compared to the parental cell line HTB-41 using measurements of the transepithelial electrical resistance (TEER), paracellular marker permeability assays and analysis of marker expression for acinar, ductal, and myoepithelial cells. Two clones (B9, D3) were characterized to be of acinar origin, one clone (F11) to be of myoepithelial origin and one isolation (B4) derived from two cells, to be presumably a mixture of acinar and ductal origin. Clone B2, presumably of ductal origin, showed a significantly higher paracellular barrier compared to other clones and parental HTB-41. The distinct molecular identity of clone B2 was confirmed by immunofluorescent staining, qPCR, and flow cytometry. Experiments with ferritin, a biomarker for iron storage, demonstrated the applicability of the selected model based on clone B2 for transport studies. In conclusion, five different clones originating from the submandibular gland cell line HTB-41 were successfully characterized and established as epithelial barrier models. Studies with the model based on the tightest clone B2 confirmed its suitability for transport studies in biomarker research.

Comparative evaluation of salivary malondialdehyde levels as a marker of lipid peroxidation in early childhood caries

Objective

The aim of this study was to evaluate the association between lipid peroxidation and dental caries in children with ECC by estimating the levels of MDA in saliva of children.

Materials and Methods

A total of 150 children were selected; 75 children with ECC and 75 children without caries (non-ECC). Saliva samples were collected and centrifuged at 12,000 rpm for 24 min at 4°C to obtain a supernatant. MDA levels were estimated by Buege and Aust method by using thiobarbituric acid. The data obtained were analyzed by Student's t-test to compare MDA levels between the groups.

Results

MDA levels were higher in children with ECC. There was no statistically significant difference between children with ECC and without ECC (non-ECC).

Conclusion

MDA levels were slightly higher in children with ECC, indicating the role of lipid peroxidation in the carious process.

Gelatinolytic activity in gingival crevicular fluid and saliva of growing patients with Marfan syndrome: a case-control study

Background

Aim of the study was to evaluate the gelatinolytic activity in the saliva and gingival crevicular fluid from a sample group of subjects with Marfan syndrome.

Methods

Two groups were analyzed in this case-control study. A group of 28 subjects with Marfan syndrome (MG) was recruited from the Centre for Rare Disease, Marfan Clinic of Tor Vergata University Hospital. The second sample, 23 subjects, with the same characteristics and without any syndrome, was the control group (CG). Saliva and gingival crevicular fluid were collected and transferred to a sterile test tube and stored frozen at − 20 °C until analysis at the Medical Chemistry Laboratory. Gelatin substrate zymography was used for the evaluation and characterization of saliva and crevicular fluid proteinases. Correlation test and Student’s t-test have been used to analyze data.

Results

In all samples different gelatin-degrading activities were observed. Two bands, which are related to the molecular weights of pro-MMP-9 and active MMP-9, respectively, were detectable in 100% of Marfan and control samples. MMP-2 activity was higher in Marfan group. Additional bands (55/48 kDa), corresponding to the activated forms of collagenase (MMP-13), were observed in saliva samples of both groups.

Conclusions

The association of an enhanced activity by MMP-13 with an increased amount of active MMP-9 might be an important biomarker for the diagnosis of Marfan syndrome.

Diagnostic Value of Salivary Markers in Neuropsychiatric Disorders

A growing interest in the usability of saliva has been observed recently. Using saliva as a diagnostic material is possible because it contains a varied range of composites, organic and inorganic like proteins, carbohydrates, and lipids, which are secreted into saliva. Moreover, this applies to drugs and their metabolites. Saliva collection is noninvasive, and self-collection is possible. There is a lack of risk of injuries related to injection with needle, and it is generally safe. Human saliva has been successfully used, for example, in the diagnosis of many systemic diseases like cancers, autoimmunological diseases, infectious diseases (HIV, hepatitis, and malaria), and endocrinological diseases, as well as diseases of the gastrointestinal tract. Also, it is used in toxicological diagnostics, drug monitoring, and forensic medicine. The usefulness of saliva as a biological marker has also been extended to psychiatry. The specificity of mental illness and patients limits or prevents cooperation and diagnosis. In many cases, the use of saliva as a marker seems to be the most sensible choice.

Applicability of Oral Fluid and Dried Blood Spot for Hepatitis B Virus Diagnosis

Hepatitis B virus (HBV) is one of the major causes of chronic liver disease worldwide; however most of individuals are not aware about the infection. Oral fluid and dried blood spot (DBS) samples may be an alternative to serum to HBV diagnosis to increase the access to diagnosis in remote areas or high-risk groups. The main objective of this review is to give an insight about the usefulness of oral fluid and DBS for detecting HBV markers. Several groups have evaluated the detection of HBsAg, anti-HBc, and anti-HBs markers in oral fluid and DBS samples demonstrating 13 to 100% of sensitivity and specificity according different groups, sample collectors, and diagnosis assays. In the same way, HBV DNA detection using oral fluid and DBS samples demonstrate different values of sensitivity according type of collection, studied group, extraction, and detection methods. Thus, serological and molecular diagnostic tests demonstrated good performance for detecting HBV using oral fluid and DBS according some characteristics and could be useful to increase the access to the diagnosis of HBV.

Electrochemical testing of a novel alloy in natural and artificial body fluids

There is a recent trend in tissue engineering and regenerative medicine to use nanotechnology and bionanomaterials to obtain materials that mimic the surface properties of a natural tissue. From this perspective, nanolevel tissue engineering can be viewed as a novel anatomy of the future. In this paper, a novel titanium-based alloy is studied following this strategy. The alloy nanostructuration is proposed as an improved alternative for restorative prosthodontics or an implantable biomaterial. Tests in (i) standard solution of simulated body fluid (SBF) and (ii) natural saliva were performed to investigate the alloy's electrochemical stability. The results show that nanochannel growth on the alloy surface confers a higher stability than that of the untreated one in both natural and simulated environments.

Human saliva as a diagnostic material

Today blood biochemical laboratory tests are essential elements to the diagnosis and monitoring of the treatment of diseases. However, many researchers have suggested saliva as an preferable diagnostic material. The collection of saliva is simple, painless, cheap and safe, both for patients and medical staff. An additional advantage of saliva is the fact that it may be retrieved several times a day, which makes repeat analysis much easier. Furthermore, saliva has very high durability. Although 94-99% of salivary content is water, saliva also contains numerous cellular elements and many organic and inorganic substances, including most biological markers present in the blood and urine that may be used in the early detection and monitoring of many dental and general diseases.

Salivary Glycopatterns as Potential Biomarkers for Screening of Early-Stage Breast Cancer

OBJECTIVE

We systematically investigated and assessed the alterations of salivary glycopatterns and possibility as biomarkers for diagnosis of early-stage breast cancer.

DESIGN

Alterations of salivary glycopatterns were probed using lectin microarrays and blotting analysis from 337 patients with breast benign cyst or tumor (BB) or breast cancer (I/II stage) and 110 healthy humans. Their diagnostic models were constructed by a logistic stepwise regression in the retrospective cohort. Then, the performance of the diagnostic models were assessed by ROC analysis in the validation cohort. Finally, a double-blind cohort was tested to confirm the application potential of the diagnostic models.

RESULTS

The diagnostic models were constructed based on 9 candidate lectins (e.g., PHA-E+L, BS-I, and NPA) that exhibited significant alterations of salivary glycopatterns, which achieved better diagnostic powers with an AUC value >0.750 (p<0.001) for the diagnosis of BB (AUC: 0.752, sensitivity: 0.600, and specificity: 0.835) and I stage breast cancer (AUC: 0.755, sensitivity: 0.733, and specificity: 0.742) in the validation cohort. The diagnostic model of I stage breast cancer exhibited a high accuracy of 0.902 in double-blind cohort.

CONCLUSIONS

This study could contribute to the screening for patients with early-stage breast cancer based on precise alterations of salivary glycopatterns.

Correlation between salivary cortisol levels and dental anxiety in children of smokers and nonsmokers

Objectives:

The present study was undertaken to evaluate salivary cortisol levels in children of smokers and nonsmokers and thereby establishing the relationship between cortisol levels in response to anxiety in children based on their father's habit of smoking.

Materials and Methods:

The study population aged between 8 and 10 years includes two groups. Group 1 is comprised 20 children of cigarette smokers and Group 2 is comprised 20 children of nonsmokers. The passive drooling technique was used to collect unstimulated saliva from the children using a sterile container. Salivary cortisol levels were evaluated using Enzyme-linked Immunosorbent Assay method. The obtained data were subjected to statistical analysis using SPSS software and paired t-test.

Results:

Higher mean salivary cortisol levels were found in children of smokers compared to children of nonsmokers and the difference between them was significant statistically (P < 0.05). Higher salivary cortisol levels were found in females compared to males and the result was significant statistically (P < 0.05).

Conclusion:

This study has proved that the smoking habit of the father has a negative influence on the anxiety levels of their children.

Salivary Amylase as a Marker of Salivary Gland Function in Patients Undergoing Radiotherapy for Oral Cancer

BACKGROUND

The aim of this study was to evaluate salivary amylase in patients with primary oral cancer undergoing radiotherapy as the main modality of treatment.

MATERIALS/METHODS

The study was conducted on ten histologically proven cases of oral cancer undergoing radiotherapy. Stimulated whole saliva was collected at three stages of radiotherapy-0, 3, and 6 weeks. Salivary amylase was estimated using Henry-Chiamori method and comparison was made with appropriate age- and gender-matched controls.

RESULTS

Salivary amylase levels showed significant decrease in healthy subjects when compared to oral cancer patients (P < 0.001). The latter group also showed changing trend with initial decrease from 0 to 3 weeks followed by increase from 3 to 6 weeks following radiotherapy (P < 0.0528).

CONCLUSIONS

The trend in changes in the levels of salivary amylase could be used as a surrogate marker of salivary gland function in patients with oral cancer undergoing radiotherapy as primary treatment.

Simultaneous determination of cocaine/crack and its metabolites in oral fluid, urine and plasma by liquid chromatography-mass spectrometry and its application in drug users

INTRODUCTION

A single LC-MS equipment was used to validate three methods for simultaneously analyzing cocaine (COC), benzoylecgonine (BZE), cocaethylene (CE), anhydroecgonine methyl ester (AEME) and anhydroecgonine (AEC) in oral fluid (OF), urine and plasma.

METHODS

The methods were carried out using a Kinetex HILIC column for polar compounds at 30°C. Mobile phase with isocratic condition of acetonitrile: 13mM ammonium acetate pH 6.0: methanol (55:35:10 v/v/v) at 0.8mL/min flow rate was used.

RESULTS

After buffer dilution (OF) and protein precipitation (urine and plasma), calibration curve ranges were 4.25-544ng/mL for oral fluid and 5-320ng/mL for urine and plasma with correlation coefficients (r) between 0.9947 and 0.9992. The lowest concentration of the calibration curves were the lower limit of quantification. No major matrix effect could be noted, demonstrating the efficiency of the cleaning procedure.

DISCUSSION

The methods were fully validated and proved to be suitable for analysis of 124 cocaine and/or crack cocaine users. Among the subjects, 56.5% reported daily use of cocaine in the previous three months. Results show a high prevalence of the analytes, with BZE as the most prevalent (94 cases), followed by COC (93 cases), AEC (70 cases), CE (33 cases) and AEME (13 cases). In addition, the concentration of BZE in urine was higher compared to OF and plasma found in the real samples, showing the facility of accumulation in chronic users in matrices with a large detection window.

Comparative study of saliva peptide signatures between gastric carcinoma and chronic gastritis

AIM: To screen differential protein expression profiles in saliva between gastric carcinoma and chronic gastritis, and to establish a model for differentiating these groups.

METHODS: Saliva samples from 57 patients with gastric carcinoma and 28 patients with gastritis were purified with weak cationic-exchange magnetic beads (MB-WCX) and then analyzed by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Subsequently, we compared the saliva peptide signatures of the two groups and obtained differently expressed peptides by using Biomarker Wizard. Then, we established two diagnostic models to distinguish the gastric carcinoma group from the gastritis group and normal control group by using Biomarker Patterns 5.0.2.

RESULTS: A diagnostic pattern for discriminating between the gastric carcinoma group and gastritis group using three peptides (m/z 4267.09, 6564.85, 2138.14) was established with a 96% (55/57) sensitivity and an 86% (24/28) specificity. A sensitivity of 89%(51/57) and a specificity of 75% (21/28) were obtained in cross validation.

CONCLUSION: The novel molecular diagnostic model obtained by saliva protein fingerprinting for distinguishing gastric carcinoma from chronic gastritis is sensitive and noninvasive.

Absolute quantification of 35 plasma biomarkers in human saliva using targeted MS

BACKGROUND

Although the use of human saliva for diagnosing disease has been known to be of great clinical potential, few attempts have been made so far to develop its use. In this work, we developed an MRM-MS approach for 35 plasma biomarkers using human saliva in a clinical environment.

METHODS & RESULTS

A 30-min micro LC-MS/MS run in MRM mode was conducted in order to quantify the 35 plasma proteins in human saliva. Sample preparation procedures were performed in quadruplicate and analyzed in duplicate. Results show that 32 of the 35 plasma proteins were quantified in human saliva using calibration curves in the 2- log10 dynamic ranges with excellent linearity.

DISCUSSION/CONCLUSION

Our MRM method is compatible with routine measurements in daily clinical practice.

Salivary markers of kidney function - Potentials and limitations

Saliva can be collected non-invasively, repeatedly and without trained personnel. It is a promising diagnostic body fluid with clinical use in endocrinology and dentistry. For decades, it is known that saliva contains also urea, creatinine and other markers of renal function. Clinical studies have shown that the salivary concentrations of these markers could be useful for the assessment of kidney function without the need of blood collection. This article summarizes the clinical and experimental data on the use of saliva as a diagnostic fluid in nephrology and points out the advantages, pitfalls, technical requirements and future perspective for the use of saliva as a novel potential diagnostic biofluid.