Saliva-based creatine kinase MB measurement as a potential point-of-care testing for detection of myocardial infarction

Biomarkers of Cardiovascular Diseases in Saliva and Gingival Crevicular Fluid: A Review

Due to the fact that cardiovascular diseases (CVDs) have become the most serious problem in public health, there is a need for new and efficient methods for screening and early detection. In the recent literature, saliva and gingival crevicular fluid (GCF) have been gaining recognition as sources of many potential biomarkers of various systemic diseases, mainly because of correlation between the level of some compounds in the blood and saliva and association between the composition of saliva and health status. In this review, we summarize published findings of patients with atherosclerosis, arterial hypertension, coronary artery disease (CAD), acute coronary syndrome (ACS), and stroke in the context of clinical utility of saliva and GCF in diagnosing and assessing CVD severity. We hypothesize that substances in saliva including inflammatory markers, enzymes, or hormones might become novel contributors to the diagnosis and screening of CVDs. In particular, C-reactive protein (CRP), tumor necrosis alpha (TNFα), and cortisol seem to be the most promising. However, further investigation is warranted to determine the most effective markers and methods for their analysis.

Biodegradable and Flexible Thermoplastic Composite Graphite Electrodes: A Promising Platform for Inexpensive and Sensitive Electrochemical Detection of Creatine Kinase at the Point-of-Care

Acute myocardial infarction (AMI) is the main cause of death worldwide, and the time of diagnosis is decisive for the effectiveness of the treatment of patients with AMI. Creatine kinase-myocardial band (CK-MB) has a predominance and high affinity with myocardial tissue, making it considered one of the main biomarkers for the diagnosis of AMI. In this work, we report a novel biodegradable composite material based on a polymer blend of Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) and Poly(butylene adipate-co-terephthalate) (PHBV:Ecoflex) and graphite microparticles for sensitive and selective electrochemical detection of CK-MB. The morphological and physicochemical characterizations of the thermoplastic composite material revealed a homogeneous and synergistic distribution of the graphite microparticles through the blend structure, providing low defects and high electrical conductivity with high electron transfer kinetics (k⁰ = 3.54 × 10^-3 cm s^-1) features with adequate flexibility for point-of-care applications. The portable and disposable devices were applied to detect CK-MB using the electrochemical impedance spectroscopy (EIS) technique in a relevant clinical concentration ranging from 5.0 ng mL^-1 to 100.0 ng mL^-1 and presented a limit of detection of 0.26 ng mL^-1 CK-MB. The selectivity of the sensor was confirmed by testing the potential interference of major biomolecules found in biofluids and other relevant macromolecules. The accuracy and robustness were assessed by addition and recovery protocol in urine and saliva samples without sample pretreatment and demonstrated the potential of our method for rapid and decentralized tests of AMI. In addition, the study of the thermal, biological, and photodegradation of the devices after being used was also carried out, aiming at the disposal of the material more sustainably.

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.

Gender Specificities of Cardiac Troponin Serum Levels: From Formation Mechanisms to the Diagnostic Role in Case of Acute Coronary Syndrome

Cardiac troponins T and I are the main (most sensitive and specific) laboratory indicators of myocardial cell damage. A combination of laboratory signs of myocardial cell damage (elevated levels of cardiac troponins T and I) with clinical (severe chest pain spreading to the left side of the human body) and functional (rise or depression of the ST segment, negative T wave or emergence of the Q wave according to electrocardiography and/or decrease in the contractility of myocardial areas exposed to ischemia according to echocardiography) signs of myocardial ischemia is indicative of the ischemic damage to cardiomyocytes, which is characteristic of the development of acute coronary syndrome (ACS). Today, with early diagnostic algorithms for ACS, doctors rely on the threshold levels of cardiac troponins (99th percentile) and on the dynamic changes in the serum levels over several hours (one, two, or three) from the moment of admission to the emergency department. That said, some recently approved highly sensitive methods for determining troponins T and I show variations in 99th percentile reference levels, depending on gender. To date, there are conflicting data on the role of gender specificities in the serum levels of cardiac troponins T and I in the diagnostics of ACS, and the specific mechanisms for the formation of gender differences in the serum levels of cardiac troponins T and I are unknown. The purpose of this article is to analyze the role of gender specificities in cardiac troponins T and I in the diagnostics of ACS, and to suggest the most likely mechanisms for the formation of differences in the serum levels of cardiac troponins in men and women.

Salivary biomarkers for diagnosis of acute myocardial infarction: A systematic review

BACKGROUND

Acute myocardial infarction (AMI) accounts for about 7 million deaths per year worldwide. The early identification of signs and symptoms and the detection of specific serological markers of this disease are mandatory to reach a prompt diagnosis and begin potentially life-saving treatment. Point-of-care technologies applied to salivary diagnostics can provide rapid, simple, low-cost, and accurate measurements of specific markers and can also be used in emergency settings. The present systematic review was developed to answer the following question: "Are salivary biomarkers useful in identifying patients with acute myocardial infarction?"

METHODS

Following the "Preferred Reporting Item for Systematic Reviews and Meta-analysis" (PRISMA) guidelines, we selected 17 papers. The critical appraisal and quality assessment were performed following the National Institute of Health and the classification of the Oxford Center for Evidence-Based Medicine.

RESULTS

Twenty-six salivary biomarkers were explored in association with AMI. Troponins, C-reactive protein, and adiponectin were the most frequently investigated molecules. We found that the evaluated biomarkers had different levels of diagnostic accuracy in discriminating patients with AMI from healthy controls. We also observed a lack of good-quality studies on the association between the occurrence of AMI and the presence of related salivary biomarkers.

CONCLUSIONS

There is evidence that salivary isoforms of cardiac troponin, C-reactive protein, and creatine phosphokinase (CPK) could be useful markers for the prompt diagnosis of AMI. However, the effective use of these markers as possible substitutes for serological markers should be confirmed by further studies that avoid the bias highlighted in the present review.

Aptamers Targeting Cardiac Biomarkers as an Analytical Tool for the Diagnostics of Cardiovascular Diseases: A Review

The detection of cardiac biomarkers is used for diagnostics, prognostics, and the risk assessment of cardiovascular diseases. The analysis of cardiac biomarkers is routinely performed with high-sensitivity immunological assays. Aptamers offer an attractive alternative to antibodies for analytical applications but, to date, are not widely practically implemented in diagnostics and medicinal research. This review summarizes the information on the most common cardiac biomarkers and the current state of aptamer research regarding these biomarkers. Aptamers as an analytical tool are well established for troponin I, troponin T, myoglobin, and C-reactive protein. For the rest of the considered cardiac biomarkers, the isolation of novel aptamers or more detailed characterization of the known aptamers are required. More attention should be addressed to the development of dual-aptamer sandwich detection assays and to the studies of aptamer sensing in alternative biological fluids. The universalization of aptamer-based biomarker detection platforms and the integration of aptamer-based sensing to clinical studies are demanded for the practical implementation of aptamers to routine diagnostics. Nevertheless, the wide usage of aptamers for the diagnostics of cardiovascular diseases is promising for the future, with respect to both point-of-care and laboratory testing.

Salivary biomarkers in cardiovascular disease: An insight into the current evidence

Cardiovascular diseases (CVDs) are the most common cause of mortality worldwide. In acute cardiovascular conditions, time is a crucial player in the outcomes of disease management. Given the ease and noninvasiveness of obtaining saliva, salivary biomarkers may provide a rapid and efficient diagnosis of CVD. Here, we reviewed the published data on the value of salivary molecules for diagnosis of CVD, especially in acute care settings. In this review, we show that some biomarkers such as salivary creatinine kinase myocardial band, C-reactive protein, troponin-1, and myoglobin exhibited promising diagnostic values that were comparable to their serum counterparts. Other molecules were also investigated and showed controversial results, including myeloperoxidase, brain natriuretic peptide, and some oxidative stress markers. Based on our review, we concluded that the clinical use of salivary biomarkers to diagnose CVD is promising; however, it is still in the early stage of development. Further studies are needed to validate these findings, determine cutoff values for diagnosis, and compare them to other established biomarkers currently in clinical use.

Acute Myocardial Infarction Biosensor: A Review From Bottom Up

Acute myocardial infarction (AMI) is a cardiovascular disease that is produced due to a deficiency of oxygen generating irreversible damage in the heart muscle. In diagnosis, electrocardiogram (ECG) investigation has been the main method but is insufficient, so approaches like the measurement of biomarkers levels in plasma or saliva have become one of the most commonly applied strategies for prognosis of AMI, as some of them are specifically related to a heart attack. Many tests are carrying on to determine biological markers changes, but usually, they present disadvantages related to time consumption and laborious work. To overcome the issues, researchers around the world have been developing different ways to enhance detection through the use of biosensors. These diagnostic devices have a biological sensing element associated to a physicochemical transducer that can be made from different materials and configurations giving place to different kinds of detection: Electrical/Electrochemical, Optical and Mechanical. In this review, the authors presents relevant investigations related to the most important biomarkers and biosensors used for their detection having in mind the nanotechnology participation in the process through the application of nanostructures as a good choice for device configuration.

Salivary biomarkers for diagnosis of systemic diseases and malignant tumors. A systematic review

Background

Saliva evaluation could be a possible alternative to blood and/or tissue analyses, for researching specific molecules associated to the presence of systemic diseases and malignancies. The present systematic review has been designed in order to answer to the question “are there significant associations between specific salivary biomarkers and diagnosis of systemic diseases or malignancies?”.

Material and Methods

The Preferred Reporting Item for Systematic Reviews and Meta-analysis (PRISMA) statement was used to guide the review. The combinations of “saliva” and “systemic diseases” or “diagnosis” or “biomarkers” or “cancers” or “carcinoma” or “tumors”, were used to search Medline, Scopus and Web of Science databases. Endpoint of research has been set at May 2019. Studies were classified into 3 groups according to the type of disease investigated for diagnosis: 1) malignant tumors; 2) neurologic diseases and 3) inflammatory/metabolic/cardiovascular diseases. Assessment of quality has been assigned according to a series of questions proposed by the National Institute of Health. Level of evidence was assessed using the categories proposed in the Oxford Center for Evidence-Based medicine (CEMB) levels for diagnosis (2011).

Results

Seventy-nine studies met the inclusion and exclusion criteria. Fifty-one (64%) investigated malignant tumors, 14 (17.5%) neurologic and 14 (18.5%) inflammatory/cardiovascular/metabolic diseases. Among studies investigating malignant tumors, 12 (23.5%) were scored as “good” and 11 of these reported statistically significant associations between salivary molecules and pathology. Two and 5 studies were found to have a good quality, among those evaluating the association between salivary biomarkers and neurologic and inflammatory/metabolic/cardiovascular diseases, respectively.

Conclusions

The present systematic review confirms the existence of some “good” quality evidence to support the role of peculiar salivary biomarkers for diagnosis of systemic diseases (e.g. lung cancer and EGFR).

Key words:Salivary diagnostics, biomarkers, systemic diseases, malignant tumors, early diagnosis.

Impact of Saliva Collection and Processing Methods on Aspartate Aminotransferase, Creatin Kinase and Lactate Dehydrogenase Activities

We aimed to investigate the impact of saliva collection and processing methods on AST, CK and LDH. Saliva was collected from 17 healthy participants by a passive drool. Each saliva sample was distributed into 3 aliquots: not treated, centrifuged, and passed through cotton. Centrifugation improved the precision of assays and produced lower values of AST and CK. The use of cotton resulted in decreased levels of LDH. This data stress the importance of the standardization of sample processing to measure enzymes in saliva.

Realising the Potential of Urine and Saliva as Diagnostic Tools in Sport and Exercise Medicine

Accurate monitoring of homeostatic perturbations following various psychophysiological stressors is essential in sports and exercise medicine. Various biomarkers are routinely used as monitoring tools in both clinical and elite sport settings. Blood collection and muscle biopsies, both invasive in nature, are considered the gold standard for the analysis of these biomarkers in exercise science. Exploring non-invasive methods of collecting and analysing biomarkers that are capable of providing accurate information regarding exercise-induced physiological and psychological stress is of obvious practical importance. This review describes the potential benefits, and the limitations, of using saliva and urine to ascertain biomarkers capable of identifying important stressors that are routinely encountered before, during, or after intense or unaccustomed exercise, competition, over-training, and inappropriate recovery. In particular, we focus on urinary and saliva biomarkers that have previously been used to monitor muscle damage, inflammation, cardiovascular stress, oxidative stress, hydration status, and brain distress. Evidence is provided from a range of empirical studies suggesting that urine and saliva are both capable of identifying various stressors. Although additional research regarding the efficacy of using urine and/or saliva to indicate the severity of exercise-induced psychophysiological stress is required, it is likely that these non-invasive biomarkers will represent "the future" in sports and exercise medicine.

Salivary biomarkers and cardiovascular disease: a systematic review

Background:

The purpose of this systematic review is to summarize the literature examining associations between salivary biomarkers and cardiovascular disease (CVD) status.

Contents:

An advanced search was conducted using MeSH terms related to salivary biomarkers and CVD, and entered into the PubMed, Web of Science, and Google Scholar search databases. Four hundred and thirty-three records were narrowed to 22 accepted articles. Included titles were assessed for quality using the Newcastle-Ottawa scale, and ranked into categories of low, moderate, or high.

Summary:

A total of 40 salivary biomarkers were analyzed among accepted articles. The most studied markers were salivary creatine kinase isoform MB, C-reactive protein (CRP), matrix metalloproteinase-9, troponin I, myeloperoxidase, myoglobin, and brain natriuretic peptide. Salivary CRP provided the most consistent trends. Statistically significant increases of salivary CRP were present with CVD in every study that analyzed it. The remaining six markers demonstrated varying patterns.

Outlook:

Existing studies provide insufficient data to draw definitive conclusions. Current research shows that there is an association between some salivary biomarkers and CVD, but the details of existing studies are conflicting. Despite inconclusive results, the diagnostic potential of saliva shows promise as a non-invasive means of cardiovascular risk assessment.

Stimulated and Unstimulated Saliva Levels of Calcium and Magnesium in Giardiasis

Giardia lamblia causes malabsorption. The aim of this study was to evaluate serum and saliva calcium and magnesium levels in patients with giardiasis. Thirty patients with giardiasis as a case and 30 person without giardiasis as a control group were enrolled. The stimulated and unstimulated whole saliva and serum calcium and magnesium levels were assayed by Arsenazo reaction and xylidyl blue complex methods, respectively. Mean calcium and magnesium level was low in serum and stimulated saliva of case group than that of controls. However, they were higher in the unstimulated saliva of the case group. It is suggested that patients suffering from giardiasis have low calcium and magnesium levels, and they lose the most of calcium and magnesium by saliva during unstimulated condition.

Saliva and plasma levels of cardiac-related biomarkers in post-myocardial infarction patients

AIM

To relate cardiac biomarkers, such as cystatin C and growth differentiation factor-15 (GDF-15) in saliva to myocardial infarction (MI) and to periodontal status, and to investigate the relation between salivary and plasma cardiac biomarkers.

MATERIALS AND METHODS

Two hundred patients with MI admitted to coronary care units and 200 matched controls without MI were included. Dental examination and collection of blood and saliva samples was performed 6-10 weeks after the MI for patients and in close proximity thereafter for controls. Analysing methods: ARCHITECT i4000SR, Immulite 2000 XPi or ELISA.

RESULTS

The mean age was 62 ± 8 years and 84% were male. Total probing pocket depth, fibrinogen, white blood cell counts and HbA1c were higher in patients than controls. GDF-15 levels correlated with most of the included clinical variables in both study groups. No correlation was found between plasma and saliva levels of cystatin C or GDF-15.

CONCLUSION

Salivary cystatin C and GDF-15 could not differentiate between MI patients and controls.

Measurement of Creatine kinase and Aspartate aminotransferase in saliva of dogs: a pilot study

Background

Muscle enzymes in saliva have been reported to be possible markers of heart and muscle damage in humans. The aim of this study was to assess if Creatine kinase (CK) and Aspartate aminotransferase (AST) activities could be measured in canine saliva, and to evaluate their possible changes in situations of muscle damage.

Results

The spectrophotometric assays for CK and AST measurement in saliva of dogs showed intra- and inter-assay imprecision lower than 1 and 16% and coefficients of correlation close to 1 in linearity under dilution tests. Healthy dogs showed activities in saliva of CK between 27 and 121 U/L and AST between 46 and 144 U/L, whereas in saliva of dogs with muscle damage CK ranged between 132 and 3862 U/L and AST between 154 and 4340 U/L. Positive moderate correlations were found between saliva and serum activities of the two enzymes (CK, r = 0.579; P = 0.001; AST, r = 0.674; P = 0.001).

Conclusions

CK and AST activities can be measured in canine saliva with commercially available spectrophotometric assays. In addition these enzymes show higher values in saliva of dogs with muscle damage and their values are moderately correlated with those of serum.

Saliva Liquid Biopsy for Point-of-Care Applications

Saliva is a non-invasive biofluid, which is easy to collect, transport, and store. Because of its accessibility and connection to systemic diseases, saliva is one of the best candidates for the advancement of point-of-care medicine, where individuals are able to easily monitor their health status by using portable convenient tools such as smartphones. There are a variety of scenarios with which saliva can be used: studies have been conducted on using saliva to measure stress hormones, enzyme levels, developmental disease biomarkers, and even cancer mutations. If validated biomarkers were combined with high-quality detection tools, saliva would open up a new frontier in high-quality healthcare, allowing physicians and patients to work together for real-time health monitoring and high-impact personalized preventative medicine. One of the most exciting emerging frontiers of saliva is liquid biopsy, which is a non-invasive means to assess the presence and characteristics of cancer in a patient. This article will review current basic knowledge of biomarkers, review their relation to different diseases and conditions, and explore liquid biopsy for point-of-care applications.

Total esterase activity in human saliva: Validation of an automated assay, characterization and behaviour after physical stress

Although saliva has esterase activity, this activity has not been characterized or studied in individuals subjected to physical stress. The aim of this report was to develop and validate an automated spectrophotometric assay for total esterase activity measurement in human saliva, as well as to study the contribution of different enzymes on this activity and its behaviour under physical stress in healthy subjects. The assay used 4-nitrophenyl acetate as substrate and was precise, accurate and provided low limits of detection and quantification. Inhibition with diisopropylfluorophosphate showed that cholinesterase, carboxylesterase and cholesterol esterase contributions not represented more than 20% of total esterase. Addition of standards of lipase and albumin to saliva samples showed that both proteins significantly contributed to esterase activity only when equal or higher than 11.6 IU/L and 250 μg/mL, respectively. Western blot analyses showed absence of paraoxonase-1 and high amount of carbonic anhydrase-VI. The high affinity of purified carbonic anhydrase-VI for the substrate supported a major contribution of this enzyme. Total esterase activity and alpha-amylase was measured in saliva samples from 12 healthy male students before and after participation in an indoor football match. The activity significantly increased after match and positively correlated with salivary alpha-amylase. This method could be used as a biomarker of physical stress in humans, with carbonic anhydrase-VI being the esterase that contributed more to the activity of the assay.

Detection of inflammatory biomarkers in saliva and urine: Potential in diagnosis, prevention, and treatment for chronic diseases

Inflammation is a part of the complex biological response of inflammatory cells to harmful stimuli, such as pathogens, irritants, or damaged cells. This inflammation has been linked to several chronic diseases including cancer, atherosclerosis, rheumatoid arthritis, and multiple sclerosis. Major biomarkers of inflammation include tumor necrosis factor, interleukins (IL)-1, IL-6, IL-8, chemokines, cyclooxygenase, 5-lipooxygenase, and C-reactive protein, all of which are regulated by the transcription factor nuclear factor-kappaB. Although examining inflammatory biomarkers in blood is a standard practice, its identification in saliva and/or urine is more convenient and non-invasive. In this review, we aim to (1) discuss the detection of these inflammatory biomarkers in urine and saliva; (2) advantages of using salivary and urinary inflammatory biomarkers over blood, while also weighing on the challenges and/or limitations of their use; (3) examine their role(s) in connection with diagnosis, prevention, treatment, and drug development for several chronic diseases with inflammatory consequences, including cancer; and (4) explore the use of innovative salivary and urine based biosensor strategies that may permit the testing of biomarkers quickly, reliably, and cost-effectively, in a decentralized setting.

Salivary creatinine and urea analysis in patients with chronic kidney disease: a case control study

Background

Many metabolic changes develop in patients with chronic kidney disease which often necessitate frequent biochemical analysis of blood. Saliva analysis as an alternative to blood has many advantages. The aims of this study were to evaluate levels of salivary creatinine and urea in patients with chronic kidney disease in comparison to healthy individuals; to determine correlation between salivary creatinine/urea and blood creatinine/urea and to evaluate the diagnostic potential of saliva.

Methods

A case control study, involving 50 patients with late stage chronic kidney disease and 49 healthy individuals as control. Blood and saliva samples were analyzed for urea and creatinine levels. Data are presented as median with interquartile range and compared using Independent Samples Mann Whitney U test. Correlation between plasma and salivary creatinine as well as urea was determined using Spearman’s correlation test. Receiver operating characteristics (ROC) analysis was done to determine the diagnostic ability of salivary creatinine and urea and cut-off values were established.

Results

Median salivary creatinine levels were 2.60 mg/dl and 0.20 mg/dl while median salivary urea levels were 92.00 mg/dl and 20.50 mg/dl in patients with chronic kidney disease and controls respectively. Salivary levels of creatinine and urea were significantly elevated in chronic kidney disease patients (p < 0.001). In addition, there was positive correlation between blood and salivary creatinine as well as urea levels. Total areas under the curve for salivary creatinine and urea were 0.97 and 0.89 respectively. Cut-off values for salivary creatinine and urea were 0.55 mg/dl and 27.50 mg/dl respectively which gave sensitivity and specificity of 94 % and 85 % for creatinine; as well as 86 % and 93 % for urea.

Conclusions

Findings of this study suggest that analysis of salivary creatinine and urea in patients with chronic kidney disease reflects their levels in blood. Hence, salivary creatinine and urea could be used as diagnostic biomarkers of chronic kidney disease.

Salivary Biomarkers of Chronic Psychosocial Stress and CVD Risks

Background:

The use of salivary biomarkers in stress research is increasing, and the precision and accuracy with which researchers are able to measure these biomarkers have dramatically improved. Chronic psychosocial stress is often linked to the pathogenesis of cardiovascular disease (CVD). Salivary biomarkers represent a noninvasive biological method of characterizing the stress phenomenon that may help to more fully describe the mechanism by which stress contributes to the pathogenesis and outcomes of CVD.

Objectives:

We conducted a systematic review of 40 research articles to identify the salivary biomarkers researchers have most commonly used to help describe the biological impact of chronic psychosocial stress and explore its associations with CVD risk. We address strengths and weaknesses of specimen collection and measurement.

Methods:

We used PubMed, CINAHL, EBSCO host, Web of Science, BIOSIS Previews, Biological Sciences (ProQuest), and Dissertations/Theses (ProQuest) to retrieve 387 initial articles. Once we applied our inclusion/exclusion criteria to specifically target adult human studies dealing with chronic stress rather than acute/laboratory-induced stress, 40 studies remained, which we synthesized using Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria.

Results:

Cortisol was the biomarker used most frequently. Sources of psychosocial stress included job strain, low socioeconomic status, and environmental factors. Overall, psychosocial stress was associated with CVD risks such as vascular pathology (hypertension, blood pressure fluctuation, and carotid artery plaque) as well as metabolic factors such as abnormal blood glucose, dyslipidemia, and elevated cardiac enzymes.

Conclusion:

Diverse salivary biomarkers have been useful in stress research, particularly when linked to CVD risks.

Can Saliva Proteins Be Used to Predict the Onset of Acute Myocardial Infarction among High-Risk Patients?

Human saliva plays a pivotal role in digesting food and maintaining oral hygiene. The presence of electrolytes, mucus, glycoproteins, enzymes, antibacterial compounds, and gingival crevicular fluid in saliva ensures the optimum condition of oral cavity and general health condition. Saliva collection has been proven non-invasive, convenient, and inexpensive compared to conventional venipuncture procedure. These distinctive advantages provide a promising potential of saliva as a diagnostic fluid. Through comprehensive analysis, an array of salivary proteins and peptides may be beneficial as biomarkers in oral and systemic diseases. In this review, we discuss the utility of human salivary proteomes and tabulate the recent salivary biomarkers found in subjects with acute myocardial infarction as well as respective methods employed. In a clinical setting, since acute myocardial infarction contributes to large cases of mortality worldwide, an early intervention using these biomarkers will provide an effective solution to reduce global heart attack incidence particularly among its high-risk group of type-2 diabetes mellitus patients. The utility of salivary biomarkers will make the prediction of this cardiac event possible due to its reliability hence improve the quality of life of the patients. Current challenges in saliva collection are also addressed to improve the quality of saliva samples and produce robust biomarkers for future use in clinical applications.

Stimulated saliva aminotransaminase alteration after experiencing acute hypoxia training

OBJECTIVE

Acute cypobarih hypoxia is generally recognized to be the most serious single physiological hazard during flight at altitude. Simulation of acute hypoxia in an altitude chamber is used for the training of military aircrew. Acute hypobaric hypoxia affects critical organ systems in different manners. The purpose of this study was to investigate stimulated saliva glutamic pyruvic transaminase (GPT) and glutamic oxaloacetic transaminase (GOT) alteration after the hypobaric hypoxia process.

METHODS

A cross-sectional study was performed in 44 normal healthy military aircrew conducted at the hypobaric chamber of physiology at the University of Medical Sciences, Tehran, Iran. The GPT and GOT activities were assayed in stimulated whole saliva before and after the experience of hypobaric hypoxia by the International Federation of Clinical Chemistry method. Statistical analysis of the Student t-test was performed.

RESULTS

The mean stimulated saliva GPT activity was significantly higher after the experience of the hypobaric hypoxia process (2.83 ± 0.34 vs. 0.42 ± 0.029 U/L, respectively; P = .001). Saliva GOT activity was also increased after this process (3.32 ± 0.43 vs. 1.22 ± 0.18 U/L, respectively; P = .001).

CONCLUSION

Results suggest that subsequent to the experience of the hypobaric hypoxia process, there is a rise in the salivary activities of aminotransferases.

Utility of salivary biomarkers for demonstrating acute myocardial infarction

The comparative utility of serum and saliva as diagnostic fluids for identifying biomarkers of acute myocardial infarction (AMI) was investigated. The goal was to determine if salivary biomarkers could facilitate a screening diagnosis of AMI, especially in cases of non-ST elevation MI (NSTEMI), since these cases are not readily identified by electrocardiogram (ECG). Serum and unstimulated whole saliva (UWS) collected from 92 AMI patients within 48 hours of chest pain onset and 105 asymptomatic healthy control individuals were assayed for 13 proteins relevant to cardiovascular disease, by Beadlyte technology (Luminex(®)) and enzyme immunoassays. Data were analyzed with concentration cut-points, ECG findings, logistic regression (LR) (adjusted for matching for age, gender, race, smoking, number of teeth, and oral health status), and classification and regression tree (CART) analysis. A sensitivity analysis was conducted by repetition of the CART analysis in 58 cases and 58 controls, each matched by age and gender. Serum biomarkers demonstrated AMI sensitivity and specificity superior to that of saliva, as determined by LR and CART. The predominant discriminators in serum by LR were troponin I (TnI), B-type natriuretic peptide (BNP), and creatine kinase-MB (CK-MB), and TnI and BNP by CART. In saliva, LR identified C-reactive protein (CRP) as the biomarker most predictive of AMI. A combination of smoking tobacco, UWS CRP, CK-MB, sCD40 ligand, gender, and number of teeth identified AMI in the CART decision trees. When ECG findings, salivary biomarkers, and confounders were included, AMI was predicted with 80.0% sensitivity and 100% specificity. These analyses support the potential utility of salivary biomarker measurements used with ECG for the identification of AMI. Thus, saliva-based tests may provide additional diagnostic screening information in the clinical course for patients suspected of having an AMI.

Oral fluids that detect cardiovascular disease biomarkers

OBJECTIVE

The aim of this study was to determine the utility of oral fluids for assessment of coronary and cardiovascular (CV) health.

STUDY DESIGN

Twenty-nine patients with preexisting CV disease underwent an invasive cardiac procedure (alcohol septal ablation or percutaneous coronary intervention) and provided unstimulated whole saliva (UWS), sublingual swabs (LS), gingival swabs (GS) and serum at 0, 8, 16, 24, and 48 hours. Concentrations of 13 relevant biomarkers were determined and correlated with levels in serum and the oral fluids.

RESULTS

Concentrations of the majority of biomarkers were higher in UWS than in LS and GS. Coronary and CV disease biomarkers in UWS correlated better with serum than with LS and GS based on group status and measures of time effect. Seven biomarkers demonstrated time effect changes consistent with serum biomarkers, including C-reactive protein and troponin I.

CONCLUSIONS

Changes in serum biomarker profiles are reflected in oral fluids suggesting that oral fluid biomarkers could aid in the assessment of cardiac ischemia/necrosis.

Serum and saliva levels of ischemia-modified albumin in patients with acute myocardial infarction

OBJECTIVE

Ischemia-modified albumin (IMA) is a novel marker for diagnosis of myocardial ischemia and it is considered as a serum marker. The aim of the study was to evaluate salivary IMA levels in patients with acute myocardial infarction (AMI) and to determine the relation between serum and salivary IMA levels.

METHODS

A total of 60 patients with AMI and 40 control subjects who are age and sex matched with AMI group were included in our study. The diagnosis of AMI was based on the WHO classification criteria. All patients underwent the clinical assessment, consisting of electrocardiography, and serum cardiac markers. Serum and salivary IMA levels were measured at the first and second days of AMI by using a colorimetric method.

RESULTS

Serum IMA levels were significantly higher in the first and second day of AMI patients, however, salivary IMA levels were significantly higher in the first day of AMI patients compared to the control (P < 0.05). There was a positive correlation between salivary IMA levels and serum IMA levels both in the first and second day of AMI patients (r = 0.298, P < 0.05; r = 0.319, P < 0.05, respectively).

CONCLUSION

We concluded that salivary IMA levels at the first day of AMI could be used as an alternative marker to serum IMA levels for diagnosis of AMI.

Salivary biomarkers associated with myocardial necrosis: results from an alcohol septal ablation model

OBJECTIVE

To determine if salivary biomarkers demonstrate utility for identifying aspects of myocardial necrosis.

METHODS

Twenty-one patients undergoing alcohol septal ablation (ASA) for treatment of hypertrophic cardiomyopathy provided serum and unstimulated whole saliva at baseline and incremental time points post-ASA. Samples were analyzed for seven biomarkers related to myocardial damage, inflammation, and tissue remodeling using immunosorbent assays. Levels were compared with baseline and levels observed in 97 healthy controls.

RESULTS

Biomarkers of myocardial damage and inflammation (ie, troponin I, creatine kinase-MB, myoglobin, C-reactive protein) rose in serum 2- to 812-fold after ASA (P < .01). Significant elevations of 2.0- to 3.5-fold were observed with C-reactive protein and troponin I in saliva (P < .02). Significant correlations between levels in serum and saliva were observed for C-reactive protein, matrix metalloproteinase-9, and myeloperoxidase (P < .001).

CONCLUSIONS

Select salivary biomarkers reflect changes that occur during, and subsequent to, myocardial necrosis caused by ASA.

Salivary high-sensitivity cardiac troponin T levels in patients with acute myocardial infarction

OBJECTIVE

Accurate and rapid diagnosis of acute myocardial infarction (MI) is of major medical and economic importance. The objective of this study was to identify whole saliva high-sensitivity cardiac troponin T (hs-cTnT) in patients with acute MI.

SUBJECTS AND METHODS

A case-control study was carried out in 30 normal healthy individuals, and 30 patients with acute MI were hospitalized in CCU of Imam Hossein hospital, Tehran, Iran. The hs-cTnT levels were assayed in serum and whole saliva in the first and second morning following the MI by ELISA method. Statistical analysis of the Student's t-test and Pearson correlation coefficient was performed.

RESULTS

The mean stimulated and unstimulated saliva and serum levels of hs-cTnT at both the first and the second morning following the acute MI were significantly higher in patients with acute MI compared with healthy individuals. Furthermore, stimulated and unstimulated saliva hs-TnT levels correlated significantly with serum hs-TnT level (r = 0.415, P < 0.023; r = 0.466, P < 0.021, respectively).

CONCLUSION

Results suggest that salivary hs-cTnT can be used as an alternative to serum hs-cTnT for diagnosis and monitoring of myocardial infarction.

Serum and saliva levels of cathepsin L in patients with acute coronary syndrome

AIM

Coronary artery disease (CAD) is the major cause of death nearly all over the world, and accurate and rapid diagnosis of CAD is of major medical and economic importance. The aim of this study was to evaluate the serum and saliva levels of cathepsin L in patients with acute coronary syndrome (ACS).

MATERIALS AND METHODS

In a cross-sectional study, 39 patients with ACS and 28 with controls were recruited to the study, and cathepsin L levels were measured in serum, resting saliva, and stimulated saliva obtained 12 and 24 h after the onset of ACS by ELISA method. Statistical analyses of Fisher's exact test, the Student's t-test or Kruskal-Wallis test were performed.

RESULTS

Stimulated saliva cathepsin L levels in patients with ACS 12 hours but not 24 hours after admission showed significant decrease compared with that in control subjects. However, there were no significant differences in serum and unstimulated saliva cathepsin L levels between groups.

CONCLUSION

Serum and saliva levels of cathepsin L remain unchanged in patients with ACS and hence may not be a promising factor in CAD risk assessment.

CLINICAL SIGNIFICANCE

It seems that serum and saliva cathepsin L may not be a good biomarker for CHD.

ABBREVIATIONS

CAD: Coronary artery disease, ACS: Acute coronary syndrome, CHD: Coronary heart disease, EU: Emergency unit, MI: Myocardial infarction.

KEYWORDS

Cathepsin L, Acute coronary syndrome, Resting saliva, Stimulated saliva. How to cite this article: Mirzaii-Dizgah I, Riahi E. Serum and Saliva Levels of Cathepsin L in Patients with Acute Coronary Syndrome. J Contemp Dent Pract 2011;12(2):114-119.