Periodontal inflammation is related to increased serum calcitonin gene‐related peptide levels in patients with chronic migraine

Association of periodontitis and periodontal parameters with migraine and mortality in people with migraine disease: A nationally representative observational study

OBJECTIVE

To investigate the association of periodontitis and clinical periodontal parameters with migraine as well as mortality among people with migraine disease.

BACKGROUND

Periodontitis has been shown to increase the systemic inflammatory burden thereby promoting various systemic health outcomes; however, the evidence regarding the relationship between periodontitis and migraine is scarce.

METHODS

A cross-sectional study was performed, and it included 13,108 participants from the National Health and Nutrition Examination Survey (1999-2004). Weighted logistic regression analysis was used to evaluate the association between periodontitis/clinical periodontal parameters and migraine. Mediation analysis was performed to explore the potential mediating role of inflammatory response. A cohort study including 1909 participants with migraine disease was further conducted to assess the associations between periodontitis/clinical periodontal parameters and mortality from all causes, cardiovascular disease (CVD), and cancer in participants with migraine disease using Cox proportional hazards models. Death outcomes were ascertained by linkage to National Death Index records through December 31, 2018.

RESULTS

Periodontitis was positively associated with migraine (odds ratio [OR] 1.29, 95% confidence interval [CI] 1.01-1.65). Each 1-unit rise in attachment loss and pocket depth was linked to a 17.5% (OR 1.18, 95% CI 1.08-1.29) and 28.1% (OR 1.28, 95% CI 1.08-1.51) increase in migraine risk, respectively. Mediation analyses revealed that leukocyte, monocyte, and lymphocyte counts mediated 17.9%, 7.3%, and 20.1%, respectively, of the association between periodontitis and migraine. During a median follow-up of 17.7 years among 1909 participants with migraine disease, periodontitis was associated with greater all-cause mortality (hazard ratio 1.82, 95% CI 1.25-2.66), but was not significantly associated with mortality from CVD or cancer among participants with migraine disease. Similar association patterns were also observed for attachment loss and pocket depth.

CONCLUSIONS

This study provides evidence that periodontitis and clinical periodontal parameters were significantly associated with migraine as well as all-cause mortality in people with migraine disease. These findings underscore the importance of considering periodontal health in the prevention and management strategies for migraine disease.

5-HT/CGRP pathway and Sumatriptan role in Covid-19

Coronavirus disease 2019 (Covid-19) is a pandemic caused by severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2). In Covid-19, there is uncontrolled activation of immune cells with a massive release of pro-inflammatory cytokines and the development of cytokine storm. These inflammatory changes induce impairment of different organ functions, including the central nervous system (CNS), leading to acute brain injury and substantial changes in the neurotransmitters, including serotonin (5-HT) and calcitonin gene-related peptide (CGRP), which have immunomodulatory properties through modulation of central and peripheral immune responses. In Covid-19, 5-HT neurotransmitters and CGRP could contribute to abnormal and atypical vascular reactivity. Sumatriptan is a pre-synaptic 5-HT (5-HT1D and 5-HT1B) agonist and inhibits the release of CGRP. Both 5-HT and CGRP seem to be augmented in Covid-19 due to underlying activation of inflammatory signaling pathways and hyperinflammation. In virtue of its anti-inflammatory and antioxidant properties with inhibition release of 5-HT and CGRP, Sumatriptan may reduce Covid-19 hyperinflammation. Therefore, Sumatriptan might be a novel potential therapeutic strategy in managing Covid-19. In conclusion, Sumatriptan could be an effective therapeutic strategy in managing Covid-19 through modulation of 5-HT neurotransmitters and inhibiting CGRP.

Periodontal disease: A systemic condition

For decades, periodontitis has been considered to be a local inflammatory disease of the periodontal tissues in the oral cavity. Initially, associations of periodontitis with a multitude of noncommunicable diseases were each studied separately, and relationships were shown. The associations of periodontitis with morbidities, such as cardiovascular diseases, rheumatoid arthritis, diabetes mellitus, respiratory diseases, have been demonstrated. As most such studies were cross-sectional in nature, questions about causality cannot be univocally answered. And periodontitis as an independent risk factor for one systemic disease, becomes even more difficult to assess since recently periodontitis has also been associated with multimorbidity. Periodontitis and many systemic diseases share environmental, lifestyle and genetic risk factors, and share immunopathology. Moreover, suffering from one common noncommunicable disease may increase the susceptibility for another such chronic disease; the systemic effects of one condition may be one of various risk factors for another such disease. The overarching effect of any systemic disease is it causing a pro-inflammatory state in the individual; this has also been shown for periodontitis. Moreover, in periodontitis a prothrombotic state and elevated immunological activity have been shown. As such, when we consider periodontal disease as another systemic disease, it can affect the susceptibility and progression of other systemic diseases, and importantly, vice versa. And with this, it is not surprising that periodontitis is associated with a variety of other noncommunicable diseases. The medical definition of a systemic disease includes diseases that affect different organs and systems. Thus, the aim of this opinion paper is to propose that periodontitis should be considered a systemic disease in its own right and that it affects the individual's systemic condition and wellbeing. The dental and medical profession and researchers alike, should adapt this paradigm shift, advancing periodontal disease out of its isolated anatomical location into the total of chronic noncommunicable diseases, being for some conditions a comorbid disease and, vice versa, comorbidities can affect initiation and progression of periodontal disease.

Untangling the mess of CGRP levels as a migraine biomarker: an in-depth literature review and analysis of our experimental experience

BACKGROUND

Calcitonin gene-related peptide (CGRP) is the most promising candidate to become the first migraine biomarker. However, literature shows clashing results and suggests a methodological source for such discrepancies. We aimed to investigate some of these methodological factors to evaluate the actual role of CGRP as biomarker.

METHODS

Previous to the experimental part, we performed a literature review of articles measuring CGRP in migraine patients. Using our 399 bio-bank sera samples, we performed a series of experiments to test the validity of different ELISA kits employed, time of sample processing, long-term storage, sampling in rest or after moderate exercise. Analysis of in-house data was performed to analyse average levels of the peptide and the effect of sex and age.

RESULTS

Literature review shows the high variability in terms of study design, determination methods, results and conclusions obtained by studies including CGRP determinations in migraine patients. CGRP measurements depends on the method and specific kit employed, also on the isoform detected, showing completely different ranges of concentrations. Alpha-CGRP and beta-CGRP had median with IQR levels of 37.5 (28.2-54.4) and 4.6 (2.4-6.4)pg/mL, respectively. CGRP content is preserved in serum within the 24 first hours when samples are stored at 4°C after clotting and immediate centrifugation. Storages at -80°C of more than 6 months result in a decrease in CGRP levels. Moderate exercise prior to blood extraction does not modulate the concentration of the peptide. Age positively correlates with beta-CGRP content and men have higher alpha-CGRP levels than women.

CONCLUSIONS

We present valuable information for CGRP measurements in serum. ELISA kit suitability should be tested prior to the experiments. Alpha and beta-CGRP levels should be analysed separately as they can show different behaviours even within the same condition. Samples can be processed in a 24-h window if they have been kept in 4°C and should not be stored for more than 6 months at -80°C before assayed. Patients do not need to rest before the blood extraction unless they have performed a high-endurance exercise. For comparative studies, sex and age should be accounted for as these parameters can impact CGRP concentrations.

Exploring the Potential Consortium of Migraine and Periodontitis

Objectives

Various researches have shown periodontitis to share common pathophysiological pathways with systemic diseases such as diabetes, cardiovascular diseases, and osteoporosis and recently neurological disorders. This article provides a narrative review summarizing the various linking mechanisms and the nature of association between two multifactorial diseases-periodontitis and migraine.

Materials and Methods

A literature search was performed for articles related to periodontitis and migraine up till the year 2023 which yielded totally 14 articles. There were only three randomized controlled clinical trials; therefore, we were unable to conduct a systematic review and focused on a narrative review. The keywords searched were "migraine", "periodontitis" and "biomarkers" in PubMed/Medline, Web of Science, and Embase databases. Any article related to the association of periodontitis and migraine and the dental management of subjects with headache disorders were included and studies with migraine and other dental diseases were excluded.

Results

It is found that the occurrence of periodontitis and migraine are associated with each other. There is reasonable evidence to believe that periodontitis and migraine are linked by direct and indirect mechanisms which can eventually lead to chronic inflammatory conditions like periodontitis worsening neurovascular conditions such as migraine. However, upon detailed analysis it was found that the strength of association is weak owing to the presences of various common confounding and risk factors.

Conclusions

The association between periodontitis and migraine cannot be denied, however, not all the criteria are fulfilled while examining the nature of association and future long-term studies are required to prove the same. Clinical Relevance. Various studies have reported poor periodontal health in patients with migraine. The risk of exacerbation of migraine also increases in subject undergoing dental therapy if the triggering factors are manipulated. Hence, knowing the precise pathophysiologic mechanisms linking both the diseases would be favorable in planning treatment protocols for subjects with migraine.

Differential network connectivity analysis for microbiome data adjusted for clinical covariates using jackknife pseudo-values

BACKGROUND

A recent breakthrough in differential network (DN) analysis of microbiome data has been realized with the advent of next-generation sequencing technologies. The DN analysis disentangles the microbial co-abundance among taxa by comparing the network properties between two or more graphs under different biological conditions. However, the existing methods to the DN analysis for microbiome data do not adjust for other clinical differences between subjects.

RESULTS

We propose a Statistical Approach via Pseudo-value Information and Estimation for Differential Network Analysis (SOHPIE-DNA) that incorporates additional covariates such as continuous age and categorical BMI. SOHPIE-DNA is a regression technique adopting jackknife pseudo-values that can be implemented readily for the analysis. We demonstrate through simulations that SOHPIE-DNA consistently reaches higher recall and F1-score, while maintaining similar precision and accuracy to existing methods (NetCoMi and MDiNE). Lastly, we apply SOHPIE-DNA on two real datasets from the American Gut Project and the Diet Exchange Study to showcase the utility. The analysis of the Diet Exchange Study is to showcase that SOHPIE-DNA can also be used to incorporate the temporal change of connectivity of taxa with the inclusion of additional covariates. As a result, our method has found taxa that are related to the prevention of intestinal inflammation and severity of fatigue in advanced metastatic cancer patients.

CONCLUSION

SOHPIE-DNA is the first attempt of introducing the regression framework for the DN analysis in microbiome data. This enables the prediction of characteristics of a connectivity of a network with the presence of additional covariate information in the regression. The R package with a vignette of our methodology is available through the CRAN repository ( https://CRAN.R-project.org/package=SOHPIE ), named SOHPIE (pronounced as Sofie). The source code and user manual can be found at https://github.com/sjahnn/SOHPIE-DNA .

Oral biosciences: The annual review 2023

BACKGROUND

The Journal of Oral Biosciences is dedicated to advancing and disseminating fundamental knowledge with regard to every aspect of oral biosciences. This review features review articles in the fields of "bone regeneration," "periodontitis," "periodontal diseases," "salivary glands," "sleep bruxism," and "Sjögren's syndrome."

HIGHLIGHT

This review focuses on human demineralized dentin and cementum matrices for bone regeneration, oxidized low-density lipoprotein in periodontal disease and systemic conditions, the relationship between inflammatory mediators in migraine and periodontitis, phosphoinositide signaling molecules in the salivary glands, and the pathophysiologies of sleep bruxism and Sjögren's syndrome.

CONCLUSION

The review articles featured in the Journal of Oral Biosciences have broadened the knowledge of readers regarding various aspects of oral biosciences. The current editorial review discusses the findings and significance of these review articles.

Genetic Predisposition to Periodontitis and Risk of Migraine: A Two-Sample Mendelian Randomization Study

INTRODUCTION

Previous observational studies have associated periodontitis (PD) with migraine; however, the results are inconclusive and the causality of the association between PD and migraine remains unclear. This two-sample Mendelian randomization (MR) study was performed to explore the bi-directional causal relationship between PD and migraine.

METHODS

To investigate the relationship between PD (17,353 cases; 28,210 controls) and migraine (1072 cases; 360,122 controls), we used genetic tools from the largest available genome-wide association study of European descent. Inverse variance-weighted (IVW) and a series of sensitivity analyses were used to explore the association between migraine and PD. We performed an MR study using seven SNPs (single nucleotide polymorphisms) as instrumental variables for PD to investigate the causal relationship between migraine and PD.

RESULTS

We found no significant causal relationship between PD and migraine (odds ratio, OR = 1.000; 95% confidence interval, CI = 0.99-1.00; p = 0.65). Similarly, no evidence supported a causal relationship between migraine and PD (OR = 0.07; CI = 2.04 × 10-9-2.65 × 106; p = 0.77). A sensitivity analysis revealed that no potential polymorphic effect (p = 0.356) and heterogeneity (p = 0.652) exists for the variants used in constructing the genetic instrument.

CONCLUSIONS

Based on the results of our MR study, there is no causal relationship between PD and migraines or migraines and PD.

The Association Between Periodontal Disease and Chronic Migraine: A Systematic Review

Migraine is a neurologic illness that produces intense throbbing pain on one side of the head and affects roughly 1 billion people worldwide. Recent research indicates a relationship between periodontitis and chronic migraines. This study aimed to review the association between chronic migraines and periodontitis through a systematic literature review. Four research databases (Google Scholar, PubMed, ProQuest, and SpringerLink) were searched according to PRISMA guidelines to retrieve the studies included in this review. A search strategy was developed to answer the study question with appropriate inclusion and exclusion criteria. Out of 34 published studies, 8 studies were included in this review. Three of the studies were cross-sectional, 3 were case-control, and 2 were clinical report and medical hypothesis papers. Seven of the 8 included studies showed that there is an association between periodontal disease and chronic migraine. The elevated blood levels of some biomarkers such as leptins, ProCalcitonin (proCT), calcitonin gene-related peptides (CGRPs), Pentraxin 3 (PTX3), and Soluble Tumor Necrosis Factor-like Weak Inducer Of Apoptosis (sTWEAK) play a significant role in this association. The limitations include a small sample size, the influence of anti-inflammatory drugs, and a self-reported headache measure that is subject to misclassification bias. This systematic review reveals a supposed correlation between periodontal disease and chronic migraine, as evidenced by various biomarkers and inflammatory mediators. This suggests that periodontal disease could potentially contribute to the development of chronic migraine. However, to further assess the potential benefits of periodontal treatment in patients with chronic migraine, additional longitudinal studies with larger sample sizes and interventional studies are needed.

The association between migraines and periodontal disease: A systematic review of clinical studies

BACKGROUND

Recent studies have postulated several hypotheses explaining the association between migraines and periodontitis. We aimed to systematically review and assess if there is an association between inflammatory mediators in migraines and periodontal disease. Indexed database search was performed from inception up to and including April 2022. Data such as study design, study grouping, participants, age, sex, migraine characteristics, assessment criteria for periodontitis and outcomes were collected. Methodological index for non-randomized studies was used to assess the risk of bias. The systematic analysis format was personalized to review the appropriate information.

HIGHLIGHTS

Levels of pro-inflammatory mediators such as serum procalcitonin, leptin, calcitonin gene related peptide and interleukin-6 were elevated in patients with chronic periodontitis and migraines.

CONCLUSION

Chronic periodontitis may be a contributing factor for migraines. However, future standardized studies are required to understand the true relationship at a clinical and molecular level. This may better help in managing patients with comorbid conditions in the future.

Biomarkers of Migraine: An Integrated Evaluation of Preclinical and Clinical Findings

In recent years, numerous efforts have been made to identify reliable biomarkers useful in migraine diagnosis and progression or associated with the response to a specific treatment. The purpose of this review is to summarize the alleged diagnostic and therapeutic migraine biomarkers found in biofluids and to discuss their role in the pathogenesis of the disease. We included the most informative data from clinical or preclinical studies, with a particular emphasis on calcitonin gene-related peptide (CGRP), cytokines, endocannabinoids, and other biomolecules, the majority of which are related to the inflammatory aspects and mechanisms of migraine, as well as other actors that play a role in the disease. The potential issues affecting biomarker analysis are also discussed, such as how to deal with bias and confounding data. CGRP and other biological factors associated with the trigeminovascular system may offer intriguing and novel precision medicine opportunities, although the biological stability of the samples used, as well as the effects of the confounding role of age, gender, diet, and metabolic factors should be considered.

Association between periodontitis and peripheral markers of innate immunity activation and inflammation

BACKGROUND

Immune response leading to increased systemic inflammation is one of the mechanisms linking periodontitis to chronic inflammatory diseases. The aim of this study was to compare the expression of toll-like receptors 2 and 4 in monocytes and neutrophils (TLR2M, TLR2N, TLR4M, and TLR4N) and its endogenous ligands (cellular fibronectin [cFN] and heat shock protein 60 [HSP60]) in patients with and without periodontitis. Additionally, the relationship between cFN and HSP60 expression with innate immunity activation and systemic inflammatory response (interleukin 6 [IL-6]) was also evaluated.

METHODS

A case-controlled study was designed in which 30 patients with periodontitis (cases) and 30 age- and sex-matched participants without periodontitis (controls) were included. Fasting blood samples were collected to determine: (1) expression of TLR2N, TLR2M, TLR4N, and TLR4M by flow cytometry; and (2) serum concentrations of cFN, HSP60, and IL-6 by ELISA technique.

RESULTS

Expression of TLR2M (411.5 [314.2, 460.0] vs. 236.5 [204.0, 333.0] AFU), TLR2N (387.0 [332.0, 545.5] vs 230.0 [166.2, 277.7] AFU), TLR4M (2478.5 [1762.2, 2828.0] vs 1705.0 [1274.5, 1951.2] AFU), and TLR4N (2791.0 [2306.7, 3226.2] vs. 1866.0 [1547.5, 2687.2] AFU) as well as serum levels of cFN (301.1 [222.2, 410.9] vs. 156.4 [115.3, 194.0] ng/ml) and IL-6 (10.4 [6.5, 11.5] vs. 3.5 [2.6, 4.9] pg/ml) were significantly higher in periodontitis patients than those without periodontitis. A positive association was found between periodontitis and cFN (odds ratio [OR] = 1.028, p < 0.001), TLR2N (OR = 1.026, p < 0.001), TLR4M (OR = 1.001, p = 0.002), and IL-6 (OR = 1.774, p < 0.001).

CONCLUSIONS

Periodontitis patients exhibited high expression of TLRs, cFN, and IL-6.

Establishing the Role of Neurogenic Inflammation in the Pathogenesis of Periodontitis: A Systematic Review

The role of neurogenic inflammation in various systemic diseases has been well established, but there is a dearth of studies and evidence regarding its role in periodontitis. This study aimed to systematically review the evidence in establishing the role of neurogenic inflammation in chronic periodontitis. Databases such as PubMed, Scopus, and Google Scholar were reviewed. We analyzed studies of any design that compared and evaluated the presence of neuropeptides such as substance P, calcitonin gene-related peptide, neurokinin A, neuropeptide Y, and vasoactive intestinal polypeptide in systemically healthy patients with and without periodontitis. We screened 2,495 articles and abstracts electronically and manually, which yielded 191 articles relevant to our study. Full-text examination of these 191 articles led to the final inclusion of 14 publications. Most studies here confirmed an association between various neuropeptides and periodontitis, but there is a high heterogeneity between the studies, making it necessary to clarify the mechanism between these two. Although most studies included in this review found a positive association between neurogenic inflammation and periodontitis, the evidence is of moderate to low quality.

Surrogate biomarkers of outcome for wake-up ischemic stroke

Background

Wake-up ischemic stroke (IS) has been usually excluded from acute stroke therapy options for being outside of the safe treatment window. We identified risk factors, and clinical or molecular biomarkers that could be therapeutic targets for wake-up stroke prevention, thus hopefully leading to a decrease in its mortality and disability in medium to long-term outcome.

Methods

4251 ischemic stroke (IS) patients from a prospectively registered database were recruited; 3838 (90.3%) had known onset-symptom time, and 413 (9.7%) were wake-up strokes. The main endpoint was to analyze the association between different serum biomarkers with wake-up IS episodes and their progression. Leukocytes count, serum levels of C-reactive protein, fibrinogen, interleukin 6 (IL-6), and vitamin D were analyzed as inflammation biomarkers; N-terminal pro-B-type Natriuretic-Peptide and microalbuminuria, used as atrial/endothelial dysfunction biomarkers; finally, glutamate levels as excitotoxicity biomarker. In addition, demographic, clinical and neuroimaging variables associated with the time-evolution of wake-up IS patients and functional outcome at 3 months were evaluated. Good and poor functional outcome were defined as mRS ≤2 and mRS > 2 at 3 months, respectively.

Results

Wake-up IS showed a poorer outcome at 3-months than in patients with known on-set-symptom time (59.1% vs. 48.1%; p < 0.0001). Patients with wake-up IS had higher levels of inflammation biomarkers; IL-6 levels at admission (51.5 ± 15.1 vs. 27.8 ± 18.6 pg/ml; p < 0.0001), and low vitamin D levels at 24 h (5.6 ± 5.8 vs. 19.2 ± 9.4 ng/ml; p < 0.0001) are worthy of attention. In a logistic regression model adjusted for vitamin D, OR was 15.1; CI 95%: 8.6–26.3, p < 0.0001. However, we found no difference in vitamin D levels between patients with or without clinical-DWI mismatch (no: 18.95 ± 9.66; yes: 17.84 ± 11.77 ng/mL, p = 0.394). No difference in DWI volume at admission was found (49.3 ± 96.9 ml in wake-up IS patients vs. 51.7 ± 98.2 ml in awake IS patients; p = 0.895).

Conclusions

Inflammatory biomarkers are the main factors that are strongly associated with wake-up IS episodes. Wake-up IS is associated with lower vitamin D levels. These data indicate that vitamin D deficiency could become a therapeutic target to reduce wake-up IS events.

Interplay of Oral, Mandibular, and Facial Disorders and Migraine

PURPOSE OF THE REVIEW

Migraine and other primary headache disorders can be localized in the face resembling facial or dental pain, indicating the influence of the trigeminovascular system in the structures innervated by the maxillary (V2) and mandibulary (V3) branches of the trigeminal nerve. Disorders of oral and craniofacial structures may influence primary headache disorders. In the current article, we review the potential links of this interplay.

RECENT FINDINGS

This interplay may be related to anatomy, with the trigeminal pathway and the involvement of both peripheral and central mechanisms, and the presence of calcitonin gene-related peptide (CGRP), a key mediator in migraine pathophysiology. CGRP is also involved in the pathophysiology of temporomandibular disorders (TMD) and their comorbidity with migraine and is also implicated in dental and periodontal pathology. Inflammatory and pathological processes of these structures and their trigeminal nociceptive pathways may influence the trigeminovascular system and consequently may exacerbate or even potentially trigger migraine.

Biomarkers common for inflammatory periodontal disease and depression: A systematic review

Background

Dysregulated immune response arising in the periphery can induce depressive symptoms through neuroimmune interactions. Inflammatory oral pathology can be a potent inducer of chronic neuroimmune response relevant to depression. We aimed to synthesize available evidence for the association between inflammatory periodontal diseases (IPD) and major depression (MD) in relation to a broad range of biomarkers.

Methods

Medline, Embase, PsycInfo, Cochrane Library, Web of Science and Scopus databases were searched from inception until January 27, 2022. Search terms included subject headings and synonyms for inflammatory periodontal disease and depression. Studies that reported data on both depression and inflammatory periodontal disease as categories along with measurement of a biomarker were considered. Two reviewers independently selected the articles for inclusion, extracted data and assessed the quality of each study. The protocol for this study was registered with PROSPERO, CRD42021215524.

Results

Twenty-eight studies were included in the final review-eleven cross-sectional studies, seven case-control studies, and six prospective cohort studies conducted in humans; the remaining four were experimental animal studies. Eighteen studies including all animal studies reported a positive association between depression and periodontal disease; one study reported a negative association and another nine studies found no such associations. Twenty studies reported mixed associations between IPD and biomarkers (i.e, salivary, serum, urine or gingival crevicular fluid cortisol, C reactive protein, cytokines, etc.). Biomarkers related to depression were gingival crevicular fluid cortisol, interleukin 6 (IL-6), Il-1β, immunoglobulin G against Bacterioides forsythus; root canal lipopolysaccharides; blood IL-6, IL-1β, cortisol, advanced oxidation protein products, nitric oxide metabolites, lipid hydroperoxides and trapping antioxidant parameter; whereas five studies found no associations between depression and a biomarker. Although animal studies showed interaction of immune, inflammatory and neurotrophic biomarkers in the relationship between depression and periodontal disease, human studies showed mixed findings. In most studies, there were risks of bias due to the sample selection and assessment protocol. Study heterogeneity and limited number of comparable studies reporting on shared biomarkers precluded a meta-analysis.

Conclusion

Immune-inflammatory contribution to depression was evident in the context of inflammatory periodontal diseases, but whether biomarkers mediate the associations between IPD and MD needs to be tested through methodologically rigorous studies aiming specifically at this hypothesis.

Immunological findings in patients with migraine and other primary headaches: a narrative review

Experimental findings suggest an involvement of neuroinflammatory mechanisms in the pathophysiology of migraine. Specifically, preclinical models of migraine have emphasized the role of neuroinflammation following the activation of the trigeminal pathway at several peripheral and central sites including dural vessels, the trigeminal ganglion, and the trigeminal nucleus caudalis. The evidence of an induction of inflammatory events in migraine pathophysiological mechanisms has prompted researchers to investigate the human leukocyte antigen (HLA) phenotypes as well as cytokine genetic polymorphisms in order to verify their potential relationship with migraine risk and severity. Furthermore, the role of neuroinflammation in migraine seems to be supported by evidence of an increase in pro-inflammatory cytokines, both ictally and interictally, together with the prevalence of Th1 lymphocytes and a reduction in regulatory lymphocyte subsets in peripheral blood of migraineurs. Cytokine profiles of cluster headache (CH) patients and those of tension-type headache patients further suggest an immunological dysregulation in the pathophysiology of these primary headaches, although evidence is weaker than for migraine. The present review summarizes available findings to date from genetic and biomarker studies that have explored the role of inflammation in primary headaches.

Periodontal Inflammation and Systemic Diseases: An Overview

Periodontitis is a common inflammatory disease of infectious origins that often evolves into a chronic condition. Aside from its importance as a stomatologic ailment, chronic periodontitis has gained relevance since it has been shown that it can develop into a systemic condition characterized by unresolved hyper-inflammation, disruption of the innate and adaptive immune system, dysbiosis of the oral, gut and other location's microbiota and other system-wide alterations that may cause, coexist or aggravate other health issues associated to elevated morbi-mortality. The relationships between the infectious, immune, inflammatory, and systemic features of periodontitis and its many related diseases are far from being fully understood and are indeed still debated. However, to date, a large body of evidence on the different biological, clinical, and policy-enabling sources of information, is available. The aim of the present work is to summarize many of these sources of information and contextualize them under a systemic inflammation framework that may set the basis to an integral vision, useful for basic, clinical, and therapeutic goals.

CGRP outflow into jugular blood and cerebrospinal fluid and permeance for CGRP of rat dura mater

Background

Calcitonin gene-related peptide (CGRP) is released from activated meningeal afferent fibres in the cranial dura mater, which likely accompanies severe headache attacks. Increased CGRP levels have been observed in different extracellular fluid compartments during primary headaches such as migraine but it is not entirely clear how CGRP is drained from the meninges.

Methods

We have used an in vivo preparation of the rat to examine after which time and at which concentration CGRP applied onto the exposed parietal dura mater appears in the jugular venous blood and the cerebrospinal fluid (CSF) collected from the cisterna magna. Recordings of meningeal (dural) and cortical (pial) blood flow were used to monitor the vasodilatory effect of CGRP. In a new ex vivo preparation we examined how much of a defined CGRP concentration applied to the arachnoidal side penetrates the dura. CGRP concentrations were determined with an approved enzyme immunoassay.

Results

CGRP levels in the jugular plasma in vivo were slightly elevated compared to baseline values 5-20 min after dural application of CGRP (10 μM), in the CSF a significant three-fold increase was seen after 35 min. Meningeal but not cortical blood flow showed significant increases. The spontaneous CGRP release from the dura mater ex vivo was above the applied low concentration of 1 pM. CGRP at 1 nM did only partly penetrate the dura.

Conclusions

We conclude that only a small fraction of CGRP applied onto the dura mater reaches the jugular blood and, in a delayed manner, also the CSF. The dura mater may constitute a barrier for CGRP and limits diffusion into the CSF of the subarachnoidal space, where the CGRP concentration is too low to cause vasodilatation.

Periodontal inflamed surface area is associated with hs-CRP in septuagenarian Japanese adults in cross-sectional findings from the SONIC study

Periodontal disease is a chronic inflammatory condition that affects various peripheral organs. The periodontal inflamed surface area (PISA) quantifies periodontitis severity and the spread of inflammatory wounds. This study aimed to investigate the association between PISA and high-sensitivity C-reactive protein (hs-CRP), a systemic inflammation marker. This study included 250 community-dwelling septuagenarians (69-71 years). We collected information on their medical (e.g., diabetes and dyslipidemia) and dental examinations (e.g., measurement of the probing pocket depth). Generalized linear model analysis was used to explore the association between PISA and hs-CRP levels. There was a significant difference in hs-CRP levels between groups with PISA ≥ 500 and < 500 (p = 0.017). Moreover, the generalized linear model analysis revealed a significant association between PISA and hs-CRP levels (risk ratio = 1.77; p = 0.033) even after adjusting other factors. Further, we found a correlation between PISA and hs-CRP (Spearman's rank correlation coefficient, rs = 0.181; p = 0.023). Our findings suggest that PISA is an effective index for estimating the effect of periodontitis on the whole body, enabling medical-dental cooperation.

Increased Risk of Migraine in Patients with Chronic Periodontitis: A Population-Based Cohort Study

Migraine is considered to be a neurovascular disease that manifests as a throbbing headache, possibly caused by the activation of the trigeminovascular system. Several studies have supported the role of inflammation in the pathogenesis of migraine. Chronic periodontitis (CP) is an infectious inflammatory disease triggered by bacterial products evoking an immune response which could result in the destruction of the periodontium. However, little is known about the longitudinal association between CP and migraine. In this study, we designed a nationwide population-based cohort study to investigate the risk of migraine and CP exposure in Taiwan. In total, 68,282 patients with CP were identified from the National Health Insurance Research Database (NHIRD), and 68,282 comparisons were randomly captured and matched by age, sex, monthly income, urbanization and comorbidities. The association between CP exposure and migraine risk was evaluated by Cox proportional hazards regression models. In this study, 785 migraine patients were identified in the CP cohort, and 641 migraine cases were found in the non-CP cohort. The incidence rate of migraine was significantly higher in the CP cohort than the non-CP cohort (adjusted HR: 1.21, 95% CI: 1.09–1.34, p < 0.001) during the 13-year follow-up period. Females had a 2.69-fold higher risk for migraine than males (95% CI: 2.38–3.04, p < 0.001). In summary, CP is associated with an increased risk of subsequent migraine in Taiwan.

Estimation of the Periodontal Inflamed Surface Area by Simple Oral Examination

The periodontal inflamed surface area (PISA) is a useful index for clinical and epidemiological assessments, since it can represent the inflammation status of patients in one contentious variable. However, calculation of the PISA is difficult, requiring six point probing depth measurements with or without bleeding on probing on 28 teeth, followed by data input in a calculation program. More simple methods are essential for screening periodontal disease or in epidemiological studies. In this study, we tried to establish a convenient partial examination method to estimate PISA. Cross-sectional data of 254 subjects who completed active periodontal therapy were analyzed. Teeth that represent the PISA value were selected by an item response theory approach. The maxillary second molar, first premolar, and lateral incisor and the mandibular second molar and lateral incisor were selected. The sum of the PISAs of these teeth was significantly correlated with the patient’s PISA (R² = 0.938). More simply, the sum of the maximum values of probing pocket depth with bleeding for these teeth were also significantly correlated with the patient’s PISA (R² = 0.6457). The simple model presented in this study may be useful to estimate PISA.

Mild systemic inflammation enhances response to OnabotulinumtoxinA in chronic migraineurs

The anti-inflammatory effect of OnabotulinumtoxinA (OnabotA) has been a matter of discussion for many years. In chronic migraine, however, increased pro-inflammatory state is associated with good response to OnabotA. We aimed to investigate whether a mild systemic inflammatory state elicited by a common oral infection (periodontitis) could enhance treatment response to OnabotA. In this study, we included 61 chronic migraineurs otherwise healthy treated with OnabotA of which 7 were poor responders and 54 good responders. Before receiving OnabotA therapy, all participants underwent a full-mouth periodontal examination and blood samples were collected to determine serum levels of calcitonin gene-related peptide (CGRP), interleukin 6 (IL-6), IL-10 and high sensitivity C-reactive protein (hs-CRP). Periodontitis was present in 70.4% of responders and 28.6% of non-responders (P = 0.042). Responders showed greater levels of inflammation than non-responders (IL-6: 15.3 ± 8.7 vs. 9.2 ± 4.7 ng/mL, P = 0.016; CGRP: 18.8 ± 7.6 vs. 13.0 ± 3.1 pg/mL, P = 0.002; and hs-CRP: 3.9 ± 6.6 vs. 0.9 ± 0.8 mg/L, P = 0.003). A linear positive correlation was found between the amount of periodontal tissue inflamed in the oral cavity and markers of inflammation (IL-6: r = 0.270, P = 0.035; CGRP: r = 0.325, P = 0.011; and hs-CRP: r = 0.370, P = 0.003). This report shows that in presence of elevated systemic inflammatory markers related to periodontitis, OnabotA seems to reduce migraine attacks. The changes of scheduled inflammatory parameters after treatment and subsequent assessment during an adequate period still need to be done.

A review of T helper 17 cell-related cytokines in serum and saliva in periodontitis

Periodontitis is a chronic inflammatory disease with a complex underlying immunopathology. Cytokines, as molecular mediators of inflammation, play a role in all stages of disease progression. T helper 17 (Th17) cells are thought to play a role in periodontitis. Th17 cell development and maintenance requires a pro-inflammatory cytokine milieu, with many of the cytokines implicated in the pathogenesis of periodontitis. Serum and saliva are easily accessible biofluids which can represent the systemic and local environment to promote the development of Th17 cells. Here we review human clinical studies that investigate IL-1β, IL-4, IL-6, IL-10, IL-17A, IL-17F, IL-21, IL-22, IL-23, IL-25, IL-31, IL-33, IFN-γ, sCD40L and TNF-α in serum and saliva in periodontitis. We highlight their putative role in the pathogenesis of periodontitis and place them within a wider context of animal and other clinical studies.

The presence of leukoaraiosis enhances the association between sTWEAK and hemorrhagic transformation

Objective

To investigate whether elevated serum levels of sTWEAK (soluble tumor necrosis factor‐like inducer of apoptosis) might be involved in a higher frequency of symptomatic hemorrhagic transformation (HT) through the presence of leukoaraiosis (LA) in patients with acute ischemic stroke (IS) undergoing reperfusion therapies.

Methods

This is a retrospective observational study. The primary endpoint was to study the sTWEAK‐LA‐HT relationship by comparing results with biomarkers associated to HT and evaluating functional outcome at 3‐months. Clinical factors, neuroimaging variables and biomarkers associated to inflammation, endothelial/atrial dysfunction or blood‐brain barrier damage were also investigated.

Results

We enrolled 875 patients (mean age 72.3 ± 12.2 years; 46.0% women); 710 individuals underwent intravenous thrombolysis, 87 endovascular therapy and 78 both. HT incidence was 32%; LA presence was 75.4%. Patients with poor functional outcome at 3‐months showed higher sTWEAK levels at admission (9844.2 [7460.4–12,542.0] vs. 2717.3 [1489.7–5852.3] pg/mL, P < 0.0001). By means of logistic regression models, PDGF‐CC and sTWEAK were associated with mechanisms linked simultaneously to HT and LA. Serum sTWEAK levels at admission ≥6700 pg/mL were associated with an odds ratio of 13 for poor outcome at 3‐months (OR: 13.6; CI 95%: 8.2–22.6, P < 0.0001).

Conclusions

Higher sTWEAK levels are independently associated with HT and poor functional outcome in patients with IS undergoing reperfusion therapies through the presence of LA. sTWEAK could become a therapeutic target to reduce HT incidence in patients with IS.