Performance of multiplex cytokine assays in serum and saliva among community-dwelling postmenopausal women

Changes of Cytokines in Saliva of Pigs with Streptococcus suis Infection Measured with a Multiplex Assay

Experimental Objective: This study evaluated potential changes in cytokines in the saliva of pigs with meningitis and Streptococcus suis (S. suis) infection, using a multiplex assay. Methods: For this purpose, levels of 13 cytokines, namely GM-CSF, IFNγ, IL-1α, IL-1β, IL-1ra, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12, IL-18, and TNF-α, were measured in porcine saliva from 29 male weaning piglets (6 to 9 weeks old) with meningitis and S. suis infection (S. suis group, n = 15) and healthy controls (healthy group, n = 14). Samples were measured using Luminex xMAP® technology with a multiplex assay that was analytically evaluated in this study. Results: The measurement of these cytokines provided adequate values during the analytical validation conducted in this study, except for GM-CSF, TNF-α, IFNγ, and IL-8. Particularly for GM-CSF and TNF-α, many values, especially in healthy pigs, fell below the limit of quantification of the assay. In pigs with S. suis infection, 11 out of the 13 cytokines, namely GM-CSF, IFNγ, IL-1α, IL-1β, IL-2, IL-4, IL-6, IL-10, IL-12, IL-18, and TNF-α, showed statistically (p < 0.05) higher levels compared to the healthy controls. Conclusions: These findings underscore an association between S. suis infection and alterations in selected cytokine levels in the saliva of pigs afflicted with this disease, thus highlighting the potential role of these cytokines in the immune response to infection.

Arginine-specific gingipains (RgpA/RgpB) knockdown modulates neutrophil machinery

Background

Gingipains are important virulence factors present in Porphyromonas gingivalis. Arginine-specific gingipains (RgpA and RgpB) are critically associated with increased proteolytic activity and immune system dysfunction, including neutrophilic activity. In this study, we assessed the impact of gingipains (RgpA and RgpB) on neutrophil function.

Methods

Peripheral blood samples were obtained; neutrophils were isolated and incubated with P. gingivalis A7436, W50, and the double RgpA/RgpB double knockout mutant E8 at MOI 20 for 2 hours. Neutrophil viability was assessed by Sytox staining. Phagocytic capacity and apoptosis were measured by flow cytometry. Superoxide release was measured by superoxide dismutase and cytochrome c reduction assay. Gene expression of TLR2, p47-phox, p67-phox, and P2 × 7was measured by qPCR. Inflammatory cytokine and chemokine production was measured by IL-1β, IL-8, RANTES, and TNF-α in cell supernatants.

Results

Neutrophil TLR2 gene expression was reduced in the absence of RgpA/RgpB (p < 0.05), while superoxide production was not significantly impacted. RgpA/RgpB-/- significantly impaired neutrophil phagocytic function (p < 0.05) and increased TNF-α production when compared with the wild-type control (p < 0.05). Neutrophil apoptosis was not altered when exposed to RgpA/RgpB-/- E8 (p > 0.05).

Conclusion

These data suggest that arginine-specific gingipains (RgpA/RgpB) can modulate neutrophil responses against P. gingivalis infection.

Salivary CRP predicts treatment response to virtual reality exposure therapy for social anxiety disorder

BACKGROUND

Social anxiety disorder (SAD) places a profound burden on public health and individual wellbeing. Systemic inflammation may be important to the onset and maintenance of SAD, and anti-inflammatory treatments have shown promise in relieving symptoms of SAD. In the present study, we conducted secondary analyses on data from a randomized clinical trial to determine whether C-reactive protein (CRP) concentrations and social anxiety symptoms decreased over the course of virtual reality exposure therapy, and whether changes in social anxiety symptoms as a function of treatment varied as a function of CRP.

METHOD

Adult participants (N = 78) with a diagnosis of SAD (59 % female) were randomized to receive exposure therapy alone, or exposure therapy supplemented with scopolamine. Social anxiety symptoms, salivary CRP, and subjective units of distress were measured across three exposure therapy sessions, at a post-treatment extinction retest, and at a 1-month follow-up.

RESULTS

CRP decreased over the course of treatment, b = -0.03 (SE = 0.01), p =.02 95 %CI [-0.06, -0.004], as did all social anxiety symptom domains and subjective distress. Higher CRP was associated with greater decreases from pre-treatment to 1-month follow-up in fear, b = -0.45 (SE = 0.15), p =.004 95 %CI [-0.74, -0.15], and avoidance, b = -0.62 (SE = 0.19), p =.002 95 %CI [-1.01, -0.23], and in-session subjective distress from pre-treatment to post-treatment, b = -0.42 (SE = 0.21), p =.05 95 %CI [-0.83, -0.001]. However, declines in CRP were not correlated with declines in fear, r = -0.07, p =.61, or avoidance, r = -0.10, p =.49, within-persons.

CONCLUSIONS

Virtual reality exposure therapy may be associated with an improvement in systemic inflammation in patients with severe SAD. Pre-treatment CRP may also be of value in predicting which patients stand to benefit the most from this treatment.

Salivary inflammatory burden in pre- and postmenopausal women: Associations with body mass index, patient-reported health, serum cytokines, and periodontal parameters

BACKGROUND

The decline of estrogen levels during menopause impacts weight, mood, and overall health, both orally and systemically. This study assessed salivary levels of tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), IL-10, and IL-7 in postmenopausal (PMW) and regularly menstruating premenopausal (RMPW) women, while considering serum cytokine levels, body mass index (BMI), periodontal health, and self-reported physical and emotional well-being.

METHODS

In this study, 75 PMW and 71 RMPW were included. Clinical and periodontal parameters were evaluated, and perceived health was assessed with the Women's Health Questionnaire (WHQ). Cytokine levels in both saliva and serum were quantified by enzyme-linked immunosorbent assay (ELISA). Covariate evaluations of salivary cytokines were conducted using hierarchical linear regression modeling.

RESULTS

Cytokines were detectable in saliva from 71 PMW and 67 RMPW. In the initial unadjusted model, IL-7, IL-10, and TNF-α exibited significant differences between RMPW and PMW. However, these differences became non-significant (p > 0.05) in the final model after adjusting for age, which implies a negligible effect of the investigated covariates on salivary cytokine levels when age was considered. Lower levels of IL-6 in PMW, which initially showed no significant difference, became borderline (p = 0.054) in the final model after adjusting for age.

CONCLUSIONS

After adjusting for multiple factors, no significant difference was found in the salivary levels of the investigated cytokines between RMPW and PMW. Factors such as BMI, perceived health, serum cytokine levels, and periodontal parameters seem to minimally influence these levels in PMW. However, age may be a stronger confounding factor.

Salivary levels of inflammatory and anti-inflammatory biomarkers in periodontitis patients with and without acute myocardial infarction: implications for cardiovascular risk assessment

Background

Periodontitis is initiated by a dysbiotic activity and furthermore leads to a chronic inflammatory response. The presence of pro-inflammatory markers plays an important role in the inflammatory load. Macrophage inflammatory protein-1 alpha (MIP-1α) and C-reactive protein (CRP) are pro- inflammatory biomarkers that quantify clinical and subclinical inflammation in cardiac ischemia in cardiac inflammation and disease. Adiponectin is an anti-inflammatory marker associated with good health. The susceptibility of periodontitis patients to cardiovascular events needs to be evaluated.

Objective

This study aims to assess the levels of biomarkers in periodontitis patients with and without acute myocardial infarction (AMI) compared to controls.

Material and methods

Pro-inflammatory and anti-inflammatory analytes were examined by collecting unstimulated saliva from three groups (n = 20/each): healthy individuals, individuals with stage III periodontitis, and post-myocardial infarction patients with stage III periodontitis. The samples were collected within 48 h of AMI.

Results

Adiponectin levels were significantly lower in patients with periodontitis with and without AMI compared to controls, while CRP and MIP-1α were significantly higher in patients with periodontitis with and without AMI compared to controls. The highest titers for MIP-1α and CRP were detected among patients with periodontitis with and AMI.

Conclusion

Our study provides possible evidence of the association between periodontitis and salivary analytes that occur in tandem with cardiovascular disease. The lower levels of Adiponectin and higher levels of CRP and MIP-1α in patients with periodontitis indicate that this condition is a potential risk factor for cardiovascular disease. The findings emphasize the importance of early detection and intervention for periodontitis patients to prevent cardiovascular events.

Correlation of serum biochemical parameters and saliva pH in healthy individuals

Saliva has the potential to work alongside needles in standard medical diagnosis. Yet the number of studies aimed at deciphering the biochemical communication between saliva and the rest of the body's systems is still very limited. The aim of this study is to investigate the interfluid interaction between saliva and serum by determining the correlation between saliva pH and serum biochemical parameters under mild conditions. Ultimately, using saliva may provide a stress-free diagnostic tool, but more ambitiously, the pH of saliva could present a genuine cost-effective screening tool that may immensely benefit areas with limited access to health care and diagnostic labs. Saliva and blood samples were collected from 43 randomly selected children (7-12 years), living in Jeddah, free from obesity and chronic or systemic body and mouth diseases. A complete serum biochemical analysis was performed, and the salivary pH of all samples was measured immediately at the time of collection. The correlations between saliva pH and serum biochemical parameters were investigated using Univariate and multiple linear regression models. Our results showed that pH has a weak significant positive correlation with total protein and a negative weak significant correlation with urea. Weak correlations suggest the existence of more serum factors to be investigated for their effect on the pH using a stepwise multiple linear regression. The multiple linear models' calculated saliva pH values were close to the measured values, demonstrating its possible capacity to predict saliva pH using serum parameters. The regression model's successful prediction of saliva pH using serum biochemicals reflects the significant correlations between the body fluids' parameters and invites more research to elucidate these relationships.

Associations between saliva and plasma cytokines in cognitively normal, older adults

BACKGROUND

Inflammatory responses play key roles in the development and progression of many pathological conditions, including neurodegenerative diseases. Accurate quantification of inflammatory factors in saliva would be highly advantageous, given its convenience and non-invasive nature, especially in elderly populations.

METHODS

In this study, we measured levels of 10 cytokines, and the pro-inflammatory factor, YKL-40, in plasma and saliva samples from a cohort of nondemented older adults (n = 71; 62% female; 70.3 ± 6.4 years) using sensitive electrochemiluminescence-based immunoassays.

RESULTS

We found that the mean levels of all cytokines were higher in saliva compared to plasma and that strong sex differences were observed for both saliva and plasma cytokines in this population. Comparing each cytokine between the two biofluids, we found that levels of interferon-gamma (IFNγ), interleukin (IL)-6 and tumor necrosis factor-alpha (TNFα) in blood were significantly correlated with their respective levels in saliva. We further observed that levels of these cytokines in blood were significantly correlated with additional cytokines in saliva, including IL-1β, IL-10, IL-8, IL12p70 and IL-13.

CONCLUSIONS

These findings show that inflammatory markers in saliva are associated with those found in circulation, suggesting shared inflammatory mechanisms between these two fluids. The higher levels of cytokines measured in saliva suggest that it might represent a better peripheral fluid to gauge inflammatory processes. Finally, our findings of robust sex differences in several salivary cytokines could have important implications for their potential use as disease biomarkers in the elderly and might be related to sex differences in the prevalence of age-related conditions.

Longitudinal associations between salivary cortisol to C-reactive protein ratios and psychological well-being in Chinese adults

BACKGROUND

Salivary C-reactive protein (CRP) could be a viable biomarker of inflammation and has been associated with stress outcomes. The hypothalamic-pituitary-adrenal axis can modulate stress-related inflammation. This study aimed to evaluate the interaction effects of immune-endocrine markers on psychological outcomes.

METHODS

The study participants were 52 healthy Chinese adults who collected 10 saliva samples over 2 consecutive days at baseline. The participants completed validated measures on anxiety, depression, positive affect, and sleep disturbance at baseline and 1 month later. The stability and diurnal patterns of salivary cortisol and CRP were investigated via paired t-tests and repeated-measures analyses of variance. Regression analysis was used to examine the longitudinal associations between immune-endocrine markers and their interactions (cortisol [Cort]: morning CRP [CRP_morn] and Cort:CRP_even) and psychological measures.

RESULTS

Salivary cortisol and CRP displayed satisfactory stability over 2 consecutive days and diurnal patterns of abrupt and gradual decline during the day, respectively. Controlling for baseline psychological measures and confounding variables, Cort_morn and diurnal cortisol slope was significantly and negatively associated with anxiety symptoms and positive affect 1 month later, respectively. Cort:CRP_even and Cort:CRP_morn was significantly and positively associated with depressive symptoms and sleep disturbance 1 month later, respectively.

CONCLUSION

These findings offer initial support for the prognostic utility of salivary cortisol and CRP and their balance as determinants of psychological health in healthy adults.

Molecular biomarker research in periodontology: A roadmap for translation of science to clinical assay validation

The number of studies that aims to apply host‐ or microbe‐derived biochemical biomarkers to periodontal disease diagnosis has increased significantly during the last three decades. The biochemical markers can reflect the presence, severity, and activity of periodontal diseases; however, heterogeneities in applied laboratory methods, data presentation, statistical analysis, and data interpretation prevent the translation of candidate host‐ or microbe‐derived biochemical biomarkers to clinical assay validation. Here, we propose a roadmap for making the research outcomes comparable and re‐analysable with the ultimate goal of translating research to clinical practice. This roadmap presents reporting recommendations for host‐ or microbe‐derived biochemical biomarker studies in periodontology. We aim to make essential elements of the research work (including diagnostic criteria, clinical endpoint definitions, participant recruitment criteria, sample collection and storage techniques, biochemical and microbiological detection methods, and applied statistical analysis) visible and comparable.

Rapid, Multianalyte Detection of Opioid Metabolites in Wastewater

By monitoring opioid metabolites, wastewater-based epidemiology (WBE) could be an excellent tool for real-time information on the consumption of illicit drugs. A key limitation of WBE is the reliance on costly laboratory-based techniques that require substantial infrastructure and trained personnel, resulting in long turnaround times. Here, we present an aptamer-based graphene field effect transistor (AptG-FET) platform for simultaneous detection of three different opioid metabolites. This platform provides a reliable, rapid, and inexpensive method for quantitative analysis of opioid metabolites in wastewater. The platform delivers a limit of detection 2-3 orders of magnitude lower than previous reports, but in line with the concentration range (pg/mL to ng/mL) of these opioid metabolites present in real samples. To enable multianalyte detection, we developed a facile, reproducible, and high-yield fabrication process producing 20 G-FETs with integrated side gate platinum (Pt) electrodes on a single chip. Our devices achieved the selective multianalyte detection of three different metabolites: noroxycodone (NX), 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP), and norfentanyl (NF) in wastewater diluted 20× in buffer.

Association of Dental and Prosthetic Status with Oral Health-Related Quality of Life in Centenarians

To date, there is little evidence on centenarians’ dental and prosthetic status or their oral-health-related quality of life (OHRQoL). Therefore, the aim of this study was to assess possible associations between sociodemographic and oral health factors, including prosthetic needs in this special age group and their potential influence on OHRQoL. Persons born before 1920 were recruited from population registries in south-western Germany. Fifty-five centenarians participated and underwent a comprehensive oral examination. Cognitive capacity was evaluated using the short Mini-Mental State Examination (S-MMSE, max. 21 points). At an S-MMSE > 10, an analysis of OHRQoL by means of the Geriatric Oral Health Assessment Index (max. ADD-GOHAI score 60 points) was performed (n = 43). Bivariate statistics and a linear regression model were used after variable selection to analyze data. Centenarians presented with a mean (SD) of 22 (7.2) missing teeth. Complete (65.5%) or partial dentures (21.8%) in at least one jaw were most common. One-third of the dentures needed repair/replacement; 16% of the centenarians presented with denture sores. In 60% of cases, OHRQoL was rated unsatisfactory (ADD-GOHAI < 57). Trouble biting or chewing resulted in the lowest levels of OHRQoL. Fewer remaining teeth, reduced functional capacity and removable prostheses correlated with an impaired OHRQoL (r_s = −0.36, p = 0.01; r_s = −0.34, p = 0.01; r_s = −0.29, p = 0.03, respectively). After variable selection, the final linear regression model included only the number of missing teeth, the associated ADD-GOHAI score decreasing by 0.3 points per missing tooth. In conclusion, tooth loss and removable prostheses in need of repair or replacement are highly prevalent in centenarians. These factors seem to modulate OHRQoL negatively, assumedly due to impaired chewing function. Larger confirmatory studies are needed to validate these first results.

Cytokine Patterns in Maternal Serum From First Trimester to Term and Beyond

Pregnancy implies delicate immunological balance between two individuals, with constant changes and adaptions in response to maternal capacity and fetal demands. We performed cytokine profiling of 1149 longitudinal serum samples from 707 pregnant women to map immunological changes from first trimester to term and beyond. The serum levels of 22 cytokines and C-reactive protein (CRP) followed diverse but characteristic trajectories throughout pregnancy, consistent with staged immunological adaptions. Eotaxin showed a particularly robust decrease throughout pregnancy. A strong surge in cytokine levels developed when pregnancies progressed beyond term and the increase was amplified as labor approached. Maternal obesity, smoking and pregnancies with large fetuses showed sustained increase in distinct cytokines throughout pregnancy. Multiparous women had increased cytokine levels in the first trimester compared to nulliparous women with higher cytokine levels in the third trimester. Fetal sex affected first trimester cytokine levels with increased levels in pregnancies with a female fetus. These findings unravel important immunological dynamics of pregnancy, demonstrate how both maternal and fetal factors influence maternal systemic cytokines, and serve as a comprehensive reference for cytokine profiles in normal pregnancies.

Salivary Heme Oxygenase-1: A Potential Biomarker for Central Neurodegeneration

BACKGROUND

Parkinson disease (PD) is the second most common neurodegenerative disease, affecting 2% of the population over 65 years of age. PD diagnosis is based on clinical examination and can only be confirmed during autopsy. In 2018, we reported that heme oxygenase-1 (HO-1), an inducible stress response protein important for heme catabolism and implicated in PD pathology, was higher in PD saliva relative to healthy controls, suggesting that salivary HO-1 may serve as a potential biomarker of PD.

OBJECTIVES

To ascertain whether HO-1 protein levels are elevated in PD saliva relative to degenerative neurological, non-degenerative neurological and healthy controls.

METHODOLOGY

The study included 307 participants comprising 75 participants with idiopathic PD and 3 control groups: 162 non-neurological, 37 non-PD degenerative neurological, and 33 non-degenerative neurological participants. Salivary HO-1 and total protein concentrations were measured using ELISA and BCA assay, respectively. Receiver operating characteristic (ROC) curves were used to estimate model discrimination. Analyses were adjusted by age, sex, total protein, and relevant comorbidities.

RESULTS

Elevated HO-1 concentrations were observed in the PD group and other neurodegenerative conditions compared to subjects with no neurological or non-degenerative neurological conditions. ROC curves using HO-1 levels and covariates yielded areas under the curve above 85% in models for PD or neurodegenerative conditions versus controls.

CONCLUSIONS

Salivary HO-1 concentrations in combination with covariates may provide a biomarker signature that distinguishes patients with neurodegenerative conditions from persons without.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that salivary HO-1 multivariable models can distinguish neurodegenerative conditions.

Nonsurgical periodontal therapy decreases the severity of rheumatoid arthritis and the plasmatic and salivary levels of RANKL and Survivin: a short-term clinical study

AIM

To investigate the influence of nonsurgical periodontal treatment (NSPT) on clinical periodontal status, rheumatoid arthritis (RA) activity, and plasmatic and salivary levels of biomarkers through a controlled clinical trial on individuals with RA and periodontitis (PE).

METHODS

Sixty-six individuals from a convenience sample were considered eligible and consecutively allocated in 3 groups: (1) individuals without PE and RA (-PE-RA, n = 19); (2) individuals without PE and with RA (-PE+RA, n = 23), and (3) individuals with PE and RA (+PE+RA, n = 24). Full-mouth periodontal clinical examinations, Disease Activity Score (DAS-28) evaluations, and analysis in plasma and saliva of RANKL, OPG, RANKL/OPG, and Survivin were performed at baseline (T1) and 45 days after NSPT (T2).

RESULTS

NSPT in the +PE+RA group was very effective to improve periodontal condition. At T2, significant reductions in DAS-28 were observed in +PE+RA (p = 0.011). Significantly higher levels of Survivin and RANKL were observed in saliva and plasma from RA individuals (with and without PE) compared to controls. Additionally, Survivin e RANKL demonstrated positive correlations with DAS-28 and an expressively significant reduction in +PE+RA at T2 (p < 0.001).

CONCLUSIONS

NSPT was effective on improving both the periodontal and the RA clinical status and reducing the concentration of Survivin and RANKL in saliva and plasma.

PRACTICAL IMPLICATIONS

Nonsurgical periodontal treatment was effective on reducing the concentration of Survivin and RANKL and on improving both the periodontal and the RA clinical status of affected individuals.

TRIAL REGISTRATION

Brazilian Registry of Clinical Trials (ReBEC) protocol #RBR-8g2bc8 ( http://www.ensaiosclinicos.gov.br/rg/RBR-8g2bc8/ ).

Plasma 25-Hydroxyvitamin D Concentrations and Serum and Salivary C-Reactive Protein in the Osteoporosis and Periodontal Disease Study

Vitamin D has been hypothesized to play an important role in preventing the development and progression of periodontal disease, but the underlying immune modulatory mechanisms remain understudied. We examined the cross-sectional association between biomarkers of vitamin D status and C-reactive protein (CRP) among postmenopausal women aged 53–81 years. Linear regression was used to examine the association between plasma 25-hydroxyvitamin D (25[OH]D) concentrations, a biomarker of vitamin D status, and both salivary and serum CRP concentrations in 567 women from the Buffalo Osteoporosis and Periodontal Disease (OsteoPerio) Study (1997–2000). CRP concentrations were measured with multiplex arrays and transformed for normality using the natural log. Concentrations above and below the limit of detection were included in analysis as right- and left-censored observations. An inverse association was observed between 25(OH)D and salivary CRP in a model adjusted for age, smoking status, frequency of tooth brushing and flossing, and hormone therapy use (−7.56% difference in salivary CRP concentrations per 10 nmol/L increase in 25(OH)D, 95% CI: −12.78 to −2.03). Further adjustment for percent body fat attenuated this association (−2.48%, 95% CI: −7.88 to 3.24). No significant associations were found between 25(OH)D and serum CRP. Plasma vitamin D concentrations were not associated with salivary or serum CRP concentrations in this cohort of postmenopausal women.

Use of amnion-derived cellular cytokine solution for the treatment of gingivitis: A 2-week safety, dose-ranging, proof-of-principle randomized trial

Background

A 6‐week Phase I clinical trial was performed to primarily evaluate the safety and secondarily determine the preliminary efficacy of a novel biological solution, ST266, comprised of a mixture of cytokines, growth factors, nucleic acids, and lipids secreted by cultured amnion‐derived multipotent progenitor cells on gingival inflammation.

Methods

Fifty‐four adults with gingivitis/periodontitis were randomly assigned to 1X ST266 or diluted 0.3X ST266 or saline topically applied on facial/lingual gingiva (20 µL/tooth). Safety was assessed through oral soft/hard tissue exam, adverse events, and routine laboratory tests. Efficacy was assessed by modified gingival index (MGI), bleeding on probing, plaque index, probing depth (PD), and clinical attachment level (CAL). Assessments were performed on day 0, 8, 12, and 42. ST266 and saline applied daily starting at day 0 through day 12 except weekend days. Plasma was analyzed for safety and proinflammatory cytokines, interleukin (IL)‐1β, IL‐6, tumor necrosis factor‐alpha, and interferon gamma. Gingival crevicular fluid (GCF) was analyzed for the same cytokines. Subgingival plaque was primarily analyzed by checkerboard DNA‐DNA hybridization. Comparisons with saline were modeled through a generalized estimating equations method adjusting for baseline.

Results

No safety concern was found related to ST266. Statistically significant reduction in MGI was noted at day 42 by 1X ST266 compared with saline (P = 0.044). PD and CAL were reduced by both doses of ST266 at day 42 (P <0.01) and by 1X ST266 at day 12 (P <0.05). GCF IL‐1β and IL‐6 levels were reduced by both doses of ST266 at day 12 (P <0.05, P <0.01, respectively). IL‐6 was also significantly reduced in plasma of both ST266 groups (P <0.05). Significant reductions in red complex bacteria were detected in both ST266 doses.

Conclusions

In this “first in human oral cavity” study, topical ST266 was safe and effective in reducing gingival inflammation in 6 weeks. Longitudinal studies with large sample sizes are warranted to assess the therapeutic value of this novel host modulatory compound in the treatment of periodontal diseases.

Oral health and functional capacity of centenarians

The number of very old individuals, namely centenarians, is growing fast. In dentistry, the increasing number of older adults retaining natural teeth present new challenges for preventive and restorative dental care. However, there is a considerable lack of knowledge on the oral health status and needs in this exceptional age group. The aim of this population-based study was to identify the prevalence of oral diseases, therapeutic needs and functional capacity (evaluating centenarians' autonomy and their capabilities regarding treatment and oral hygiene) in centenarians. Subjects born before 1920 were recruited from population registries in South-Western Germany, providing information on dental health experiences, oral health behaviors and undergoing dental examination. 55 centenarians participated in the study (mean age ± SD = 101.2 ± 1.6, 83.6% females). Results were compared to epidemiological data on adults aged 75-100 years examined in the Fifth German Oral Health Study. Adherence to recommended dental behaviors and dental check-ups was lower in the centenarian population. Moreover, with the exception of a lower Root Caries Index, centenarians showed a higher caries experience, and presented with a mean DMFT of 25.2 ± 3.9, a DMFS of 111.0 ± 21.8, a root caries prevalence of 34.5% and a Restorative Index of 54.0%. Centenarians' functional capacity was also considerably lower. Non-existent or greatly reduced treatment capabilities and oral hygiene capabilities were registered in 63.7% and 43.6% of cases, respectively. Centenarians with a lower educational level (p = 0.018), in a care facility (p = 0.045) or in need of nursing care (p = 0.001) were more likely to have a low functional capacity. 98.2% of centenarians received help in their daily activities but only 12.7% in their oral hygiene. In conclusion, although most still have natural teeth, a decline of oral health can be perceived. As compliance with recommended behaviors is limited and most centenarians can no longer undergo dental treatment, the lack of assistance in daily oral health care is problematic.

Salivary IL-8 and IL-1RA changes induced by exercise in cold-dry and normal conditions

The purpose of this study was to compare the effects of exercise in cold-dry (CC, -20 °C, RH 40%) and normal conditions (NC, 20 °C, RH 60%) on salivary levels of pro-inflammatory and regulatory cytokines (IL-1RA, IL-8, and IL-5) and the airway response (FEV₁ and FVC) in young healthy males. Participants (n = 11, age: 23.6 ± 3.1 years) completed an incremental to maximal exercise test and two exercise sessions in an environmental chamber in random order. Saliva samples were collected, and spirometry was performed prior to the maximal exercise test as well as pre and post-exercise for the CC and NC sessions. IL-8 levels increased from pre to post-exercise during NC but not during CC; the opposite trend was observed for IL-1RA. These data may provide insight into pathways associated with the development of airway hyperresponsiveness in healthy athletes.

The association between serum inflammatory biomarkers and incident hypertension among postmenopausal women in the Buffalo OsteoPerio Study

Several serum inflammatory biomarkers have been associated with blood pressure and hypertension prevalence in cross-sectional studies. Few of these associations have been evaluated prospectively. We examined associations for 10 serum inflammatory biomarkers with incident hypertension among 471 postmenopausal women (mean age = 65) in the Buffalo OsteoPerio Study. Concentrations of C-reactive protein, interleukin (IL)-2, IL-4, IL-6, IL-8, IL-10, tumor necrosis factor (TNF)-α, monocyte chemoattractant protein (MCP)-1, adiponectin, and leptin were measured using multiplexed sandwich immunoassays on fasting serum samples collected at baseline (1997–2001). Incident hypertension (195 cases) was defined as physician-diagnosed hypertension and treatment with medication identified on annual mailed health surveys during follow-up (mean 10 years). Cox regression was used to estimate hazard ratios (HR) and 95% confidence intervals (CI) between log-transformed biomarkers (per 1-SD) and hypertension. When adjusted for age, leptin was significantly associated with hypertension risk (HR=1.55, 95% CI: 1.04, 2.29), however, the association was attenuated and not significant after adjustment for demographic and lifestyle factors, including BMI. Significant (P<0.10) interactions were observed for smoking (never, ever) with CRP (HR: Never, 1.31; Ever, 0.91; P=0.06) and MCP-1 (HR: Never, 0.59; Ever, 5.11; P=0.004); for BMI (<25, ≥25) with MCP-1(HR: <25, 3.45; ≥25, 0.95; P=0.07); for systolic BP with IL-10 (HR: <120, 0.85; 120–139, 1.11; P=0.07); and for diastolic BP with MCP-1 (HR: <80, 1.29; 80–89, 0.84; P=0.03) and with adiponectin (HR: <80, 0.86; 80–89, 1.50; P=0.03). This study adds needed understanding on prospective associations between several serum inflammatory biomarkers and hypertension risk in older postmenopausal women, among whom hypertension burden is substantial.

Comparison of serum cytokine concentrations between healthy dogs and canine osteosarcoma patients at the time of diagnosis

Systemic immune responses in cancer patients are of tremendous importance, both to advance understanding of disease mechanisms and for development of new diagnostic testing. Minimal published information is available on the systemic cytokine response in canine osteosarcoma (OS) patients. The goal of this study was to investigate serum cytokine alterations present in OS patients at the time of diagnosis. Serum samples from 22 canine OS patients at the time of diagnosis and 18 healthy control dogs were evaluated via multiplex immunoassay for 14 analytes. Significant increases in serum interleukin-8 (IL-8) and interleukin-12p40 (IL-12p40) concentrations were found in OS patients when compared to healthy controls. The results correlate with several published studies on serum cytokine alterations in human OS patients. These data add to the growing body of knowledge on immunologic alterations in OS, including potential immunomodulatory therapy of canine patients, and support future studies on serum cytokine testing to investigate diagnostic and prognostic utility.

Efficacy of a novel post-foaming dental gel on gingival inflammation: A randomized controlled clinical trial

BACKGROUND

A pilot randomized controlled clinical trial was performed to evaluate the efficacy of a post-foaming dental gel containing cetylpridinium chloride (CPC), hydrogen peroxide (H₂ O₂ ), sodium bicarbonate, and antioxidants on periodontal/oral health.

METHODS

Individuals with gingivitis or mild-moderate periodontitis (n=36) were included and randomly assigned to Group 1 and 2 with foaming gel loaded on a mouthpiece with a light source and controlled warming heat built-in unit or on a toothbrush, respectively, in addition to regular twice-daily brushing. Group 3 served as control with twice daily brushing and further assigned split-mouth to Group 3a-un-flossed and Group 3b-flossed. Gingival index (GI) and bleeding on probing (BOP) were evaluated in addition to plaque index (PI), pocket depth, and clinical attachment level at days 14, 28, 42 (treatment), and 60 (maintenance). Subgingival plaque microbial profiles and gingival crevicular fluid (GCF) cytokine levels were determined by DNA-DNA hybridization and multiplexing assays, respectively. Exploratory analyses included esthetic outcomes: changes in tooth color and levels of volatile sulfur compounds in breath. Statistical analyses were conducted using ANOVA with a post hoc analysis of Fisher's LSD.

RESULTS

Use of post-foaming gel in both test groups resulted in significant changes in GI and BOP at Day 42 compared to control and un-flossed control (P<0.05). Device-enhanced foaming gel significantly reduced the PI in Group 1 at Day 42 compared to control and un-flossed control (P=0.02; P=0.007, respectively). GCF IL-6 and TNF-α levels were significantly reduced in Group 2 compared to control (P_IL-6 =0.01, P_TNF-α =0.02). Post-foaming gel resulted in greater reductions in periodontopathogens, whereas health-associated species remained stable. Despite cessation of adjunct treatments, Group 1 and 2 continued having reduced levels of GI, BOP, and PI at Day 60 (P<0.05).

CONCLUSIONS

The novel post-foaming dental gel improves oral health by reducing gingival inflammation at the local site in addition to better esthetic outcomes.

The Buffalo OsteoPerio Studies: Summary of our findings and the unique contributions of Robert J. Genco, DDS, PhD

Purpose

Robert ("Bob") Genco was a member of the research team that established the Buffalo Osteoporosis and Periodontal Disease (OsteoPerio) study. Here we detail the scientific discoveries emanating from this enduring collaboration.

Study cohorts

OsteoPerio is ancillary to the Women's Health Initiative Observational Study (WHI-OS). WHI-OS is a longitudinal study of 93,000 postmenopausal women aged 50-79 enrolled at 40 U.S. centers (enrolled 1993-1998). OsteoPerio enrolled 1342 women 3 years later (1997-2001) from the Buffalo WHI-OS participants to study the association of osteoporosis and periodontal disease. OsteoPerio has 5-year (N=1026) and 17-year (N=518) follow-up examinations.

Participants

In addition to information on health status from the WHI-OS, OsteoPerio further included comprehensive oral examinations assessing probing pocket depth, clinical attachment loss, gingival bleeding, alveolar crestal height, and DMFT. Systemic bone density (measured by DXA), blood, saliva and plaque also were collected at all three visits.

Summary

Findings from these studies are summarized here.

Saliva Samples as A Tool to Study the Effect of Meal Timing on Metabolic And Inflammatory Biomarkers

Meal timing affects metabolic regulation in humans. Most studies use blood samples for their investigations. Saliva, although easily available and non-invasive, seems to be rarely used for chrononutritional studies. In this pilot study, we tested if saliva samples could be used to study the effect of timing of carbohydrate and fat intake on metabolic rhythms. In this cross-over trial, 29 nonobese men were randomized to two isocaloric 4-week diets: (1) carbohydrate-rich meals until 13:30 and high-fat meals between 16:30 and 22:00 or (2) the inverse order of meals. Stimulated saliva samples were collected every 4 h for 24 h at the end of each intervention, and levels of hormones and inflammatory biomarkers were assessed in saliva and blood. Cortisol, melatonin, resistin, adiponectin, interleukin-6 and MCP-1 demonstrated distinct diurnal variations, mirroring daytime reports in blood and showing significant correlations with blood levels. The rhythm patterns were similar for both diets, indicating that timing of carbohydrate and fat intake has a minimal effect on metabolic and inflammatory biomarkers in saliva. Our study revealed that saliva is a promising tool for the non-invasive assessment of metabolic rhythms in chrononutritional studies, but standardisation of sample collection is needed in out-of-lab studies.

Characterization of burning mouth syndrome profiles based on response to a local anaesthetic lozenge

OBJECTIVE

Burning mouth syndrome (BMS) is a chronic oral pain condition with unknown aetiology but assumed to involve peripheral/central neuropathological and immune-mediated inflammatory factors. We aimed at characterizing inflammatory and neurogenic profiles and oral symptomatology of patients with BMS based on response to a local anaesthetic lozenge.

METHODS

Patients with BMS were divided into an Effect (n = 13), No effect (n = 8) or Unspecified (n = 2) group according to their response to a local anaesthetic lozenge on oral pain. Inflammation was assessed in blood plasma and saliva by analyses of IL-6, IL-8, IL-17A, IL-23 and TNF-α levels. The degree of inflammation and distribution of oestrogen receptor, NGF, NGF-receptor, TRPV-1 and IL-17F in buccal mucosal tissue were investigated by immunohistochemistry.

RESULTS

Immunoreactivity to the oestrogen receptor was most intense in the Effect group, whereas the No effect group tended to have higher plasma levels of the pro-inflammatory cytokines.

CONCLUSIONS

Our findings indicate that the response to treatment with local anaesthesia enables subgrouping of patients with BMS according to the potential pathogenic mechanisms. Effect of local anaesthesia indicates a peripheral neuropathology involving lack of oestrogen and upregulation of oestrogen receptors, and no effect indicates a systemic inflammation-induced mechanism leading to increased levels of plasma cytokines.

Novel Bead-Based Epitope Assay is a sensitive and reliable tool for profiling epitope-specific antibody repertoire in food allergy

Identification of allergenic IgE epitopes is instrumental for the development of novel diagnostic and prognostic methods in food allergy. In this work, we present the quantification and validation of a Bead-Based Epitope Assay (BBEA) that through multiplexing of epitopes and multiple sample processing enables completion of large experiments in a short period of time, using minimal quantities of patients’ blood. Peptides that are uniquely coupled to beads are incubated with serum or plasma samples, and after a secondary fluorophore-labeled antibody is added, the level of fluorescence is quantified with a Luminex reader. The signal is then normalized and converted to epitope-specific antibody binding values. We show that the effect of technical artifacts, i.e. well position or reading order, is minimal; and batch effects - different individual microplate runs - can be easily estimated and eliminated from the data. Epitope-specific antibody binding quantified with BBEA is highly reliable, reproducible and has greater sensitivity of epitope detection compared to peptide microarrays. IgE directed at allergenic epitopes is a sensitive biomarker of food allergy and can be used to predict allergy severity and phenotypes; and quantification of the relationship between epitope-specific IgE and IgG4 can further improve our understanding of the immune mechanisms behind allergic sensitization.

PlateDesigner: a web-based application for the design of microplate experiments

SUMMARY

In biological assays, systematic variability, known as a batch effect, can often confound the effects of true biological conditions and has been well documented for a variety of high-throughput technologies. In microplate-based multiplex experiments, such as Luminex or OLINK assays, researchers need to consider both position and plate effects. Those effects can be easily accounted for if the experiments are properly designed, which includes randomization of the samples across multiple experimental runs. However, doing the ad hoc randomization becomes challenging when handling multiple samples. PlateDesigner is the first web-based application that provides randomization for microplate experiments, ensuring that the main principles of the experimental design, such as grouping samples from the same biological units and balancing the distribution of experimental conditions, are applied. Creating randomizations with PlateDesigner is simple and the results can be exported in a variety of formats, and easily integrated with microplate readers and statistical analysis software.

AVAILABILITY AND IMPLEMENTATION

PlateDesigner is written in R/Shiny and is hosted online by the Center of Biostatistics at the Icahn School of Medicine at Mount Sinai. This application is freely available at platedesigner.net.

Serum cytokine patterns in first half of pregnancy

INTRODUCTION

Human pregnancy is a state of elevated maternal systemic inflammation, and pregnancy complications are often associated with a dysfunctional immune response. The network of cytokines reflects this complex immune activity, and broad serum cytokine profiling provides a new tool to understand the changes in immune status during pregnancy.

OBJECTIVE

This study aimed to determine how maternal serum cytokine patterns change during the first half of pregnancy.

METHODS

Maternal peripheral serum samples collected at a mean gestation of 10, 13, 18 and 24 weeks were included from a prospective clinical study of healthy women (n = 110) in first half of normal pregnancy. The serum samples were analysed for 27 different cytokines using multiplex magnetic bead-based immunoassays, and high sensitivity C-reactive protein (CRP) was analysed by ELISA. Serum cytokine and CRP patterns were explored with linear mixed effects models (LMM) and multilevel partial least squares discriminant analysis (PLS-DA).

RESULTS

Serum cytokine profiling provided partial overview of the maternal immune status and corresponding reference values for serum cytokine levels during the first half of pregnancy. Several cytokines decreased in concentration from first to second trimester. Cytokine pattern analysis revealed that chemokines provided the most sensitive measurement of variation with gestational age in normal pregnancies. The nine inflammatory cytokines showed the highest intra-group correlation during pregnancy, while CRP levels did not correlate with changes in the inflammatory cytokines.

CONCLUSION

Chemokines showed the greatest gestational variation and inflammatory cytokines showed a strong intra-group correlation during the first half of pregnancy.

Dietary phosphorus enhances inflammatory response: A study of human gingivitis

Phosphates are associated with numerous disorders, ranging from vascular calcification to premature aging, possibly because of an increased inflammatory response. We therefore investigated the association of dietary phosphorus with gingivitis. We analyzed consumption of both phosphorus and sugar and related it to the concentrations of inflammatory biomarkers in saliva samples collected from 8314 children (mean age, 9.99 ± 0.68 years). About 64% of the children consumed more than 1250 mg phosphorus daily, and 34% consumed more than 82 g of sugar daily. Gingivitis was prevalent, with an average of 74% of possible gingival sites considered red. Quantile regression analysis revealed a statistically significant correlation between the occurrence of gingivitis and calorie-adjusted phosphorus intake and between gingivitis and calorie-adjusted sugar intake (both significant either as a linear trend or a categorical variable). In a subset (n = 744) investigation of nutrient consumption related to salivary biomarkers, we found that elevated calorie-adjusted phosphorus intake was directly associated with salivary IL-1β concentration (OR1.40, 95% CI 1.04-1.89), and inversely associated with salivary IL-4 concentration (OR0.62, 95% CI 0.46-0.84). Sugar intake was not significantly associated with either biomarker. Thus, elevated dietary phosphorus consumption may influence inflammatory disease by altering cytokine levels.

Cohort profile: the Buffalo OsteoPerio microbiome prospective cohort study

PURPOSE

The Buffalo Osteoporosis and Periodontal Disease (OsteoPerio) study is a prospective cohort study focused on the relationship between the microbiome and oral and systemic health outcomes in postmenopausal women. The cohort was established to examine how the oral microbiome is affected by (and how it affects) periodontal disease presence, severity and progression and to characterise the relationship between the microbiome, lifestyle habits and systemic disease outcomes.

PARTICIPANTS

Participants (n=1342) were postmenopausal women who were participating in the Women's Health Initiative observational study at the Buffalo, New York clinical centre. There were 1026 participants at the 5-year follow-up visit and 518 at the 15-year visit.

FINDINGS TO DATE

Data collected include questionnaires, anthropometric measures, serum blood and saliva samples. At each clinic visit, participants completed a comprehensive oral examination to measure oral health and the oral microbiome. Preliminary findings have contributed to our understanding of risk factors for periodontal disease and the relationship between the oral microbiome and periodontal disease.

FUTURE PLANS

The novel microbiome data collected on a large sample of participants at three time points will be used to answer a variety of research questions focused on temporal changes in the microbiome and the relationship between the oral microbiome and oral and systemic disease outcomes. Little is currently known about the relationship between the oral microbiome and health outcomes in older adults; data from the OsteoPerio cohort will fill this gap. Microbiome samples are currently being analysed using next-generation sequencing technology with an anticipated completion date of late 2018.

Salivary biomarkers of inflammation and oxidative stress in healthy adults

OBJECTIVES

Diagnostic value of saliva depends on the reproducibility of data in repeatedly collected samples and predictable correlations between saliva and blood. We aimed to investigate the reliability, blood reflectance, and influence of blood contamination in the analysis of inflammatory and oxidative stress biomarkers in saliva samples.

DESIGN

In total, 37 healthy young male participants (26.7 ± 2.2 years) were included. Unstimulated whole saliva and blood samples were collected on the first visit, and saliva samples were collected again after 2-3 days. The concentrations of total protein and inflammatory [C-reactive protein (CRP), IL-1β, IL-6, and TNF-α] and oxidative stress [8-hydroxy-2'-deoxyguanosine (8-OHdG), malondialdehyde (MDA), and total antioxidant capacity (TAC)] biomarkers in saliva and blood, and as well as blood contamination biomarkers (transferrin and hemoglobin) in saliva were analyzed.

RESULTS

The intra-class correlations of all examined biomarkers except TNF-α were fair to excellent. Significant positive correlations between CRP and IL-6 and between total protein and TAC were stable in the saliva samples collected on different days. Notably, IL-6 was the only biomarker that showed a significant correlation between saliva and blood. As the concentration of salivary transferrin increased, the saliva/blood ratios of total protein and TAC also increased. The concentration of salivary hemoglobin did not affect the saliva/blood ratios of biomarkers.

CONCLUSIONS

The findings of this study are limited to healthy young males. For clinical applications, studies on salivary diagnostics should be performed for individual disease and health conditions, demographic characteristics, and biomarkers.

The relationship between interleukin-6 and functional connectivity in methamphetamine users

Methamphetamine (MA) causes an increase in pro-inflammatory cytokines in animal models and in humans. Resulting activation of microglia and neuro-inflammation could, via effects on reward networks, mediate behavioral characteristics of addiction. We examined the relationship between interleukin-6 (IL-6) and corticolimbic and striatolimbic resting-state functional connectivity (RSFC). Thirty adults diagnosed with MA dependence and 20 control subjects underwent a resting-state functional magnetic resonance imaging (fMRI) scan and gave a blood sample for determination of plasma IL-6 levels. Seed-based RSFC analyses were performed to examine the interactive effect of group and IL-6 on ventral striatal and prefrontal connectivity. Within the MA group, IL-6 levels were positively related to striatolimbic RSFC but negatively related to corticostriatal RSFC. Our findings with IL-6 support the idea that inflammation may at least partly mediate the link among MA use disorder, RSFC, and behavior, possibly via effects on mesolimbic and mesocortical dopaminergic systems.

Circulating monocyte chemoattractant protein-1 (MCP-1) is associated with cachexia in treatment-naïve pancreatic cancer patients

BACKGROUND

Cancer-associated wasting, termed cancer cachexia, has a profound effect on the morbidity and mortality of cancer patients but remains difficult to recognize and diagnose. While increases in circulating levels of a number of inflammatory cytokines have been associated with cancer cachexia, these associations were generally made in patients with advanced disease and thus may be associated with disease progression rather than directly with the cachexia syndrome. Thus, we sought to assess potential biomarkers of cancer-induced cachexia in patients with earlier stages of disease.

METHODS

A custom multiplex array was used to measure circulating levels of 25 soluble factors from 70 pancreatic cancer patients undergoing attempted tumour resections. A high-sensitivity multiplex was used for increased sensitivity for nine cytokines.

RESULTS

Resectable pancreatic cancer patients with cachexia had low levels of canonical pro-inflammatory cytokines including interleukin-6 (IL-6), interleukin-1β (IL-1β), interferon-γ (IFN-γ), and tumour necrosis factor (TNF). Even in our more sensitive analysis, these cytokines were not associated with cancer cachexia. Of the 25 circulating factors tested, only monocyte chemoattractant protein-1 (MCP-1) was increased in treatment-naïve cachectic patients compared with weight stable patients and identified as a potential biomarker for cancer cachexia. Although circulating levels of leptin and granulocyte-macrophage colony-stimulating factor (GM-CSF) were found to be decreased in the same cohort of treatment-naïve cachectic patients, these factors were closely associated with body mass index, limiting their utility as cancer cachexia biomarkers.

CONCLUSIONS

Unlike in advanced disease, it is possible that cachexia in patients with resectable pancreatic cancer is not associated with high levels of classical markers of systemic inflammation. However, cachectic, treatment-naïve patients have higher levels of MCP-1, suggesting that MCP-1 may be useful as a biomarker of cancer cachexia.

Salivary sCD14 as a potential biomarker of dental caries activity in adults

CD14 is a co-receptor involved in the recognition of Gram-negative and Gram-positive bacteria, the latter known to cause dental caries. The aim of this study was to determine whether soluble CD14 (sCD14) in saliva was associated with caries activity and the collection method from the saliva. The study included 55 participants aged 20 to 40 years, 30 with dental caries and 25 caries-free controls. We collected 110 saliva samples in total, 55 of resting saliva and 55 of mechanically stimulated saliva. Median levels of sCD14, measured with a matrix-matched enzyme-linked immunosorbent assay (ELISA), were higher in the caries-active than in the caries-free group in either resting (203.3 vs.167.9 ng mL-1; P<0.01) or stimulated saliva (201 vs.105.7 ng mL-1; P<0.01). The resting salivary flow rate was lower in the caries-active than caries-free group (0.61±0.42 vs. 0.98±0.52 mL min-1; P<0.01). Hyposalivation was observed only in the caries-active group (10 and 13 % in stimulated and resting saliva, respectively). Higher salivary sCD14 levels and secretion rates were clearly associated with dental caries and resting saliva. Future studies should focus on the clinical utility of salivary sCD14 as a potential biomarker and predictor of future caries events.

An analytical approach to reduce between-plate variation in multiplex assays that measure antibodies to Plasmodium falciparum antigens

Background

Antibodies play an important role in immunity to malaria. Recent studies show that antibodies to multiple antigens, as well as, the overall breadth of the response are associated with protection from malaria. Yet, the variability and reliability of antibody measurements against a combination of malarial antigens using multiplex assays have not been well characterized.

Methods

A normalization procedure for reducing between-plate variation using replicates of pooled positive and negative controls was investigated. Sixty test samples (30 from malaria-positive and 30 malaria-negative individuals), together with five pooled positive-controls and two pooled negative-controls, were screened for antibody levels to 9 malarial antigens, including merozoite antigens (AMA1, EBA175, MSP1, MSP2, MSP3, MSP11, Pf41), sporozoite CSP, and pregnancy-associated VAR2CSA. The antibody levels were measured in triplicate on each of 3 plates, and the experiments were replicated on two different days by the same technician. The performance of the proposed normalization procedure was evaluated with the pooled controls for the test samples on both the linear and natural-log scales.

Results

Compared with data on the linear scale, the natural-log transformed data were less skewed and reduced the mean–variance relationship. The proposed normalization procedure using pooled controls on the natural-log scale significantly reduced between-plate variation.

Conclusions

For malaria-related research that measure antibodies to multiple antigens with multiplex assays, the natural-log transformation is recommended for data analysis and use of the normalization procedure with multiple pooled controls can improve the precision of antibody measurements.

Electronic supplementary material

The online version of this article (doi:10.1186/s12936-017-1933-6) contains supplementary material, which is available to authorized users.

Shortened sleep fuels inflammatory responses to marital conflict: Emotion regulation matters

Sleep problems can boost inflammation and may jeopardize interpersonal functioning, risks that may be magnified in couples. This observational study examined the effects of self-reported recent sleep duration on couples' inflammation, inflammatory responses to a problem discussion, interpersonal behavior, and use of emotion regulation strategies (emotion expression, cognitive reappraisal) during conflict. People who slept less had higher stimulated interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) production after the marital problem discussion than those who slept more. However, using emotion expression and cognitive reappraisal strategies during conflict protected couples who slept less from inflammatory reactivity. Specifically, people's short sleep did not relate to inflammatory increases when they expressed their own feelings more or when their partner reappraised or expressed their emotions more. When both partners slept less, couples interacted in a more hostile way than when at least one partner slept more. These data point to the combination of short sleep and marital conflict as a novel path to heightened inflammation, a risk that partners' emotion regulation strategies may counteract. The study also highlights the role of short sleep in more negative or punishing marital behavior.

Energy Balance Modulation Impacts Epigenetic Reprogramming, ERα and ERβ Expression, and Mammary Tumor Development in MMTV-neu Transgenic Mice

The association between obesity and breast cancer risk and prognosis is well established in estrogen receptor (ER)-positive disease but less clear in HER2-positive disease. Here, we report preclinical evidence suggesting weight maintenance through calorie restriction (CR) may limit risk of HER2-positive breast cancer. In female MMTV-HER2/neu transgenic mice, we found that ERα and ERβ expression, mammary tumorigenesis, and survival are energy balance dependent in association with epigenetic reprogramming. Mice were randomized to receive a CR, overweight-inducing, or diet-induced obesity regimen (n = 27/group). Subsets of mice (n = 4/group/time point) were euthanized after 1, 3, and 5 months to characterize diet-dependent metabolic, transcriptional, and epigenetic perturbations. Remaining mice were followed up to 22 months. Relative to the overweight and diet-induced obesity regimens, CR decreased body weight, adiposity, and serum metabolic hormones as expected and also elicited an increase in mammary ERα and ERβ expression. Increased DNA methylation accompanied this pattern, particularly at CpG dinucleotides located within binding or flanking regions for the transcriptional regulator CCCTC-binding factor of ESR1 and ESR2, consistent with sustained transcriptional activation of ERα and ERβ. Mammary expression of the DNA methylation enzyme DNMT1 was stable in CR mice but increased over time in overweight and diet-induced obesity mice, suggesting CR obviates epigenetic alterations concurrent with chronic excess energy intake. In the survival study, CR elicited a significant suppression in spontaneous mammary tumorigenesis. Overall, our findings suggest a mechanistic rationale to prevent or reverse excess body weight as a strategy to reduce HER2-positive breast cancer risk. Cancer Res; 77(9); 2500-11. ©2017 AACR.

Opportunities and Challenges of Multiplex Assays: A Machine Learning Perspective

Multiplex assays that allow the simultaneous measurement of multiple analytes in small sample quantities have developed into a widely used technology. Their implementation spans across multiple assay systems and can provide readouts of similar quality as the respective single-plex measures, albeit at far higher throughput. Multiplex assay systems are therefore an important element for biomarker discovery and development strategies but analysis of the derived data can face substantial challenges that may limit the possibility of identifying meaningful biological markers. This chapter gives an overview of opportunities and challenges of multiplexed biomarker analysis, in particular from the perspective of machine learning aimed at identification of predictive biological signatures.

Strain-Specific Impact of Fusobacterium nucleatum on Neutrophil Function

BACKGROUND

Neutrophil function is critical for initiation and progression of infecto-inflammatory diseases. Key quorum-sensing plaque bacteria, such as Fusobacterium nucleatum, act as bridging species between early and late colonizer pathogens, such as Porphyromonas gingivalis, as the biofilm ages and periodontal inflammation increases. This study is designed to determine impact of different F. nucleatum strains on neutrophil function.

METHODS

Cells of human promyelocytic leukemia cell line-60 were differentiated into neutrophil-like cells and cultured with F. nucleatum strains of subspecies (ssp.) nucleatum ATCC 25586, ssp. polymorphum ATCC 10953, and ssp. vincentii ATCC 49256. Neutrophil phagocytosis of F. nucleatum strains and neutrophil apoptosis were analyzed by flow cytometry. Superoxide generation was measured by cytochrome C reduction in the presence and absence of N-formyl-L-methionyl-L-leucyl-L-phenylalanine (fMLP) (1 μM) stimulation. Proinflammatory cytokine release was determined after 2, 6, and 24 hours of culture in the presence/absence of different F. nucleatum strains. Expression of Toll-like receptor (TLR)2, TLR4, and nuclear factor (NF)-kappa B mRNA levels were analyzed using real-time quantitative polymerase chain reaction. Each experiment was repeated at least three times in triplicate. Data were analyzed using analysis of variance followed by post hoc Bonferroni correction.

RESULTS

All strains of F. nucleatum significantly increased phagocytic capacity of neutrophils. Neutrophil phagocytosis of F. nucleatum ssp. polymorphum was significantly greater than that of F. nucleatum ssp. vincentii and ssp. nucleatum (P <0.001). F. nucleatum ssp. nucleatum and ssp. polymorphum significantly blocked fMLP-induced superoxide generation (P <0.001). Although F. nucleatum vincentii also reduced superoxide generation (25%), the impact was not as strong as that of ssp. nucleatum (83%) and ssp. polymorphum (100%). All F. nucleatum strains stimulated significant increase in neutrophil apoptosis compared with control (P <0.001) and significantly increased expression of NF-κB mRNA in neutrophils (P <0.05). Levels of interleukin-8 and tumor necrosis factor-α produced by neutrophils were significantly increased in all F. nucleatum groups compared with control (P <0.001).

CONCLUSIONS

These findings suggest that different strains of F. nucleatum impact neutrophil function in different ways. Two of three subspecies blocked neutrophil superoxide generation in response to a secondary stimulus, preventing oxidative killing by neutrophils. The direct role of bridging species in pathogenesis of periodontitis may be greater than previously suspected in which they create a favorable environment for pathogenic transition of the dental ecosystem.

Salivary and serum adiponectin and C-reactive protein levels in acute myocardial infarction related to body mass index and oral health

BACKGROUND AND OBJECTIVE

Adiponectin is produced by adipose cells and is considered an anti-inflammatory molecule. In contrast, C-reactive protein (CRP) has been identified as a hallmark of systemic inflammation and used as a risk marker of cardiovascular disease (CVD). Of interest was the relationship of these two biomarkers to oral health and CVD risk.

MATERIAL AND METHODS

This investigation examined these two molecules in serum and unstimulated whole saliva of patients within 48 h of an acute myocardial infarction (AMI) compared to control subjects. We hypothesized a differential response in these biomolecules resulting from the heart attack that would be affected by both the body mass index and oral health characteristics of the individuals.

RESULTS

Significantly lower adiponectin levels were observed in the serum of patients with AMI. Serum adiponectin in both groups and salivary adiponectin in patients with AMI decreased with increasing body mass index. Oral health was significantly worse in patients with AMI, and both serum and salivary adiponectin were elevated with better oral health in control subjects. Serum CRP levels were increased in patients with AMI regardless of their oral health, and both serum and salivary CRP were significantly elevated in S-T wave elevated patients with MI.

CONCLUSIONS

These initial data provide evidence relating obesity and oral health to salivary and serum analyte levels that occur in association with cardiac events. Relationships have been described between CVD risk and periodontal disease. Additionally, various systemic inflammatory biomarkers appear to reflect both the CVD risk and the extent/severity of periodontitis. Our findings indicated that oral health and obesity contribute to altering levels of these salivary and serum analytes in association with cardiac events. The potential that serum and/or salivary biomarkers could aid in evaluating CVD risk requires knowledge regarding how the oral health of the individual would impact the effectiveness of these biological measures.

Potential Use of Salivary Markers for Longitudinal Monitoring of Inflammatory Immune Responses to Vaccination

Vaccination, designed to trigger a protective immune response against infection, is a trigger for mild inflammatory responses. Vaccination studies can address the question of inflammation initiation, levels, and resolution as well as its regulation for respective studied pathogens. Such studies largely based on analyzing the blood components including specific antibodies and cytokines were usually constrained by number of participants and volume of collected blood sample. Hence, blood-based studies may not be able to cover the full dynamic range of inflammation responses induced by vaccination. In this review, the potential of using saliva in addition to blood for studying the kinetics of inflammatory response studies was assessed. Saliva sampling is noninvasive and has a great potential to be used for studies aimed at analysing the magnitude, time course, and variance in immune responses, including inflammation after vaccination. Based on a literature survey of inflammatory biomarkers that can be determined in saliva and an analysis of how these biomarkers could help to understand the mechanisms and dynamics of immune reactivity and inflammation, we propose that the saliva-based approach might have potential to add substantial value to clinical studies, particularly in vulnerable populations such as infants, toddlers, and ill individuals.

Associations among Inflammatory Biomarkers in the Circulating, Plasmatic, Salivary and Intraluminal Anatomical Compartments in Apparently Healthy Preschool Children from the Western Highlands of Guatemala

Background

Undernutrition and inflammation are related in many ways; for instance, non-hygienic environments are associated with both poor growth and immunostimulation in children.

Objective

To describe any existing interaction among different inflammation biomarkers measured in the distinct anatomical compartments of whole blood, feces, plasma and saliva.

Methods

In this descriptive, cross-sectional study, samples of whole blood, feces, plasma and saliva were collected on the 8^th and last week of observation among 87 attendees (42 girls and 45 boys) of 3 daycare centers offering a common 40-day rotating menu in Guatemala’s Western Highlands. Analyses included white blood cell count (WBC), fecal calprotectin, and plasmatic and salivary cytokines including IL-1B, IL-6, IL-8, IL-10 and TNF-α. Associations were assessed using Spearman rank-order and goodness-of-fit correlations, as indicated, followed by backwards-elimination multiple regression analyses to determine predictor variables for IL-10 in both anatomical compartments.

Results

Of a total of 66 cross-tabulations in the Spearman hemi-matrix, 22 (33%) were significantly associated. All 10 paired associations among the salivary cytokines had a significant r value, whereas 7 of 10 possible associations among plasma cytokines were significant. Associations across anatomical compartments, however, were rarely significant. IL-10 in both biological fluids were higher than corresponding reference values. When a multiple regression model was run in order to determine independent predictors for IL-10 in each anatomical compartment separately, IL-6, IL-8 and TNF-α emerged as predictors in plasma (r² = 0.514) and IL-1B, IL-8 and TNF-α remained as independent predictors in saliva (r² = 0.762). Significant cross-interactions were seen with WBC, but not with fecal calprotectin.

Conclusion

Interactions ranged from robust within the same anatomical compartment to limited to nil across distinct anatomical compartments. The prominence of the anti-inflammatory cytokine, IL-10, in both plasma and saliva is consistent with its counter-regulatory role facing a broad front of elevated pro-inflammatory cytokines in the same compartment.

Antibody arrays in biomarker discovery

All of life is regulated by complex and organized chemical reactions that help dictate when to grow, to move, to reproduce, and to die. When these processes go awry, or are interrupted by pathological agents, diseases such as cancer, autoimmunity, or infections can result. Cytokines, chemokines, growth factors, adipokines, and other chemical moieties make up a vast subset of these chemical reactions that are altered in disease states, and monitoring changes in these molecules could provide for the identification of disease biomarkers. From the first identification of carcinoembryonic antigen, to the discovery of prostate-specific antigen, to numerous others described within, biomarkers of disease are detectable in a plethora of sample types. The growing number of biomarkers for infection, autoimmunity, and cancer allow for increasingly early detection, to identification of novel drug targets, to prognostic indicators of disease outcome. However, more and more studies are finding that a single cytokine or growth factor is insufficient as a true disease biomarker and that a more global perspective is needed to understand true disease biology. Such a broad view requires a multiplexed platform for chemical detection, and antibody arrays meet and exceed this need by performing this detection in a high-throughput fashion. Herein, we will discuss how antibody arrays have evolved, and how they have helped direct new drug target design, helped identify therapeutic disease markers, and helped in earlier disease detection. From asthma to renal disease, and neurological dysfunction to immunologic disorders, antibody arrays afford a bright future for new biomarkers discovery.

High sensitivity detection of salivary 8-hydroxy deoxyguanosine levels in patients with chronic periodontitis

BACKGROUND

Inflammation is associated with hydroxyl radical damage to DNA as a result of oxidative stress. 8-Hydroxy deoxyguanosine (8-OHdG) is a marker of this process and its levels in saliva could be linked to the severity of periodontal inflammation. The aim of this study was to test the sensitivity of liquid chromatography with tandem mass spectrometry (LC-MS/MS) in comparison to enzyme-linked immune sorbent assay (ELISA) for the detection of 8-OHdG in saliva in patients with chronic periodontitis before and after periodontal treatment.

METHODS

Saliva samples were collected from 23 patients (eight females and 15 males; 46.1 ± 5.1 years of age) with generalized chronic periodontitis and 25 (15 females and 10 males; 44.9 ± 6.8 years of age) periodontally healthy individuals. Patients received initial periodontal treatment consisting of scaling and root planing and were evaluated at baseline and after 6 wk of completion of non-surgical therapy. Salivary 8-OHdG levels were measured using ELISA and LC-MS/MS before and after the treatment. Clinically, plaque index, gingival index, clinical attachment level, bleeding on probing, gingival recession and probing pocket depth were measured at baseline and after 6 wk.

RESULTS

Salivary levels of 8-OHdG decreased significantly after the non-surgical periodontal treatment (p < 0.001). Statistically significant positive correlations were observed between plaque index, gingival index, probing pocket depth, clinical attachment level, bleeding on probing values and LC-MS/MS and ELISA levels of 8-OHdG (p < 0.001).

CONCLUSION

LC-MS/MS is a reliable and sensitive method for evaluating salivary 8-OHdG levels to monitor the treatment response of periodontitis.

Evaluation of salivary adiponectin profile in obese patients

Obesity is a chronic inflammatory disease significantly risen worldwide, especially among children. Adipokines, secreted from adipose tissue, are hormones involved in various cellular processes such as energy metabolism and inflammation. Among the others, adiponectin is gaining increasing interest for its insulin-sentitizing, anti-atherogenic and anti-inflammatory properties. This adipokine undergoes different post-translational modifications, after which it circulates as oligomers of high, medium and low molecular weight (HMW, MMW, LMW); HMW are the most biologically active oligomers. Serum adiponectin levels as well as the amount of its oligomers are inversely correlated to BMI and closely associated with obesity and related diseases. In this study, we analyzed total adiponectin expression and its oligomeric profile in saliva samples from 27 obese compared to 27 age- and sex-matched controls. Moreover, we compared adiponectin oligomerization between serum and saliva samples. The analysis of the different adiponectin oligomers reveals a slightly higher expression of total, HMW and LMW salivary adiponectin in obese patients compared to controls. Finally, FPLC analysis evidenced that HMW oligomers in saliva have a higher molecular weight than in serum confirming the presence of more complex oligomers in saliva, previously identified as super HMW (S-HMW). Saliva is considered a potential source of novel biomarkers for the diagnosis of metabolic disorders. The assessment of total adiponectin and its oligomeric profiles in saliva samples may represent a promising biological marker for the analysis of metabolic diseases.

Salivary glucose concentration exhibits threshold kinetics in normal-weight, overweight, and obese children

BACKGROUND

Metabolic syndrome in childhood predicts the development of cardiovascular disease and type 2 diabetes (T2D) in adulthood. Testing for features of metabolic syndrome, such as fasting plasma glucose concentration, requires blood sampling which can be difficult in children. Here we evaluated salivary glucose concentration as a surrogate measurement for plasma glucose concentration in 11-year-old US children.

METHODS

Children from Portland, Maine, and Cambridge, Massachusetts, with a mean age of 10.6±0.2 years provided 6-hour fasting samples of both blood and whole saliva. Salivary glucose levels were measured with a high-sensitivity assay (sensitivity =0.002 mg/dL). Plasma glucose levels were determined by a commercial clinical laboratory. Blood pressure, salivary flow rate, height, and weight were also measured.

RESULTS

Of the 65 children enrolled, there were two underweight children (3.1%), 30 normal-weight children (46.2%), 12 overweight children (18.4%), and 21 obese children (32.3%). The mean overall glucose concentrations were 0.11±0.02 mg/dL in saliva and 86.3±0.8 mg/dL in plasma, and these did not differ significantly by body-weight groups. By regression analysis, the plasma concentration equaled 13.5 times the saliva concentration, with a threshold level of 84.8 mg/dL. Salivary glucose values less than threshold plasma concentration were essentially zero. Diagnostic analysis indicated a positive predictive value of 50%, a negative predictive value of 90%, and a sensitivity and specificity both of approximately 75%. The salivary glucose concentration did not vary with saliva flow rate.

CONCLUSION

Taking into account the threshold response characteristics of the salivary glucose concentration response, these results suggest that testing salivary glucose levels may be useful as a screening assay for high fasting plasma glucose levels. The low false positive value is important to assure a low fraction of missed diagnoses.

A sustained hypothalamic-pituitary-adrenal axis response to acute psychosocial stress in irritable bowel syndrome

BACKGROUND

Despite stress being considered a key factor in the pathophysiology of the functional gastrointestinal (GI) disorder irritable bowel syndrome (IBS), there is a paucity of information regarding the ability of IBS patients to respond to acute experimental stress. Insights into the stress response in IBS could open the way to novel therapeutic interventions. To this end, we assessed the response of a range of physiological and psychological parameters to the Trier Social Stress Test (TSST) in IBS.

METHOD

Thirteen female patients with IBS and 15 healthy female age-matched control participants underwent a single exposure to the TSST. Salivary cortisol, salivary C-reactive protein (CRP), skin conductance level (SCL), GI symptoms, mood and self-reported stress were measured pre- and post-exposure to the TSST.

RESULTS

The hypothalamic-pituitary-adrenal (HPA) axis response to the TSST was sustained in IBS, as shown by a greater total cortisol output throughout (p = 0.035) and higher cortisol levels measured by an area under the curve with respect to ground (AUCG) analysis (p = 0.044). In IBS patients, GI symptoms increased significantly during the recovery period following exposure to the TSST (p = 0.045). Salivary CRP and SCL activity showed significant changes in relation to stress but with no differential effect between experimental groups.

CONCLUSIONS

Patients with IBS exhibit sustained HPA axis activity, and an increase in problematic GI symptoms in response to acute experimental psychosocial stress. These data pave the way for future interventional studies aimed at identifying novel therapeutic approaches to modulate the HPA axis and GI symptom response to acute psychosocial stress in IBS.