Reduction of CD4+CD25+ regulatory T-cells in migraine: Is migraine an autoimmune disorder?

Headaches in SLE patients: a cross-sectional analysis of clinical, immunological, and Radiological Correlations

BACKGROUND

Systemic Lupus Erythematosus (SLE) is a multifaceted autoimmune disorder characterized by diverse clinical manifestations, including a significant prevalence of headaches. This cross-sectional study aimed to thoroughly explore the relationship between SLE and headaches by analysing their prevalence, types, and associated clinical, immunological, and radiological factors.

METHOD

A comparative analysis was conducted on 179 SLE patients, who were categorized into two groups: those with headaches and those without. Data collection encompassed demographic details, disease activity levels, neurological assessments, immunological profiles, and brain imaging results. Headaches were diagnosed and classified following the International Classification of Headache Disorders (ICHD-3). Disease activity was measured using the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI). Statistical analyses were performed to identify significant associations and correlations.

RESULTS

Headaches were observed in 55% of the SLE patients, predominantly presenting as tension-type headaches (65%) and migraines (27%). Notably, no patients met the criteria for a lupus-specific headache. The Headache Group exhibited significantly higher disease activity (SLEDAI scores). Tension-type and migraine headaches were particularly associated with increased muco-cutaneous manifestations. The presence of antiphospholipid (aPL) antibodies was significantly linked to migraines and cluster headaches. While neurological disorders such as ischemic stroke and venous sinus thrombosis were more prevalent in the Headache Group, these findings were not statistically significant. Brain MRI abnormalities were detected in 9.4% of patients with headaches, including venous sinus thrombosis (2.3%), ischemic stroke (5.8%), and white matter hyperintensities (1.1%).

CONCLUSION

This study underscore es the complex relationship between SLE and headaches, suggesting that headaches may serve as an indicator of heightened SLE disease activity. Immunological factors, particularly aPL antibodies, show a strong association with specific headache types. MRI abnormalities further emphasize the intricate neurobiological aspects in SLE patients experiencing headaches. Continued research is essential to better understand biomarkers, genetic factors, and effective treatment strategies for managing headaches in SLE patients.

Neuroimmune interactions in the development and chronification of migraine headache

Migraine is highly prevalent and debilitating. The persistent headaches in this condition are thought to arise from the activation and sensitization of the trigeminovascular pathway. Both clinical and animal model studies have suggested that neuroimmune interactions contribute to the pathophysiology of migraine headache. In this review, we first summarize the findings from human studies implicating the dysregulation of the immune system in migraine, including genetic analyses, measurement of circulatory factors, and neuroimaging data. We next discuss recent advances from rodent studies aimed at elucidating the neuroimmune interactions that manifest at various levels of the trigeminovascular pathway and lead to the recruitment of innate and adaptive immune cells as well as immunocompetent glial cells. These cells reciprocally modulate neuronal activity via multiple pro- and anti-inflammatory mediators, thereby regulating peripheral and central sensitization. Throughout the discussions, we highlight the potential clinical and translational implications of the findings.

Heightened migraine risk in patients with rheumatoid arthritis: A national retrospective cohort study

OBJECTIVE

This study aimed to evaluate the association between rheumatoid arthritis (RA) and subsequent migraine risk using the Korean National Health Insurance Service database.

BACKGROUND

Migraine may be related to immune dysfunction and previous studies have suggested an association with chronic inflammatory rheumatic diseases; however, the relationship between RA and migraine remains unclear.

METHODS

This was a population-based, nationwide, retrospective, longitudinal cohort study. Participants were enrolled from 2010 to 2017 and followed up until 2019. A total of 42,674 patients who had undergone a health checkup within 2 years prior to the initial diagnosis of RA were included in the study, after applying the exclusion criteria (previous migraine, other rheumatic disease, missing variables of interest). A non-RA control was obtained by age and sex-matching (1:5). Finally, 42,644 patients with RA were enrolled, with 213,370 individuals without RA included as controls. Among the patients with RA, 29,744 had seropositive RA (SPRA), and 12,900 had seronegative RA (SNRA). SPRA was defined by the International Classification of Diseases 10th revision (ICD-10) code M05, prescription of disease-modifying anti-rheumatic drugs (DMARDs), and enrollment in a special copayment reduction program. SNRA was defined by the ICD-10 code M06 and prescription of any DMARD. The primary endpoint was the occurrence of migraine incidents, defined using the ICD-10 code of migraine (G43).

RESULTS

A total of 22,294 migraine cases (17,912/213,370 [8.3%] in controls and 4382/42,674 [10.2%] in RA) were reported during a mean follow-up of 4.4 years after a 1-year lag period. Patients with RA had a 1.2-fold higher risk of migraine compared with controls (adjusted hazard ratio [aHR] 1.21, 95% confidence interval [CI] 1.17-1.26). Increased risk of migraine was found in both patients with SNRA and SPRA compared with controls (aHR 1.20, CI 1.15-1.24 in SPRA; aHR 1.26, CI 1.19-1.34 in SNRA). Compared to patients with SNRA, those with SPRA did not demonstrate a heightened risk (aHR 0.94, CI 0.88-1.01). A significant interaction was confirmed between covariates (male, current smoker, those with diabetes mellitus, and dyslipidemia) and the risk of migraine (p for interaction of <0.05).

CONCLUSION

RA was linked to a higher migraine risk, regardless of seropositivity.

Differentiation of hemispheric white matter lesions in migraine and multiple sclerosis with similar radiological features using advanced MRI

Background and aim

White matter hyperintensities (WMHs), presented on T2-weighted or fluid-attenuated inversion recovery magnetic resonance imaging (MRI) sequences, are lesions in the human brain that can be observed in both migraine and multiple sclerosis (MS).

Methods

Seventeen migraine patients and 15 patients with relapsing-remitting multiple sclerosis with WMHs, and 17 healthy subjects age-and sex-matched to the migraine group were prospectively enrolled and underwent conventional and advanced MRI studies with diffusion-and perfusion-weighted imaging and single voxel proton magnetic resonance spectroscopy.

Results

In both disease groups, elevated T2 relaxation time, apparent diffusion coefficient (ADC) values, and decreased N-acetyl-aspartate levels were found in the intralesional white matter compared to the contralateral normal-appearing white matter (NAWM), while there was no difference between the hemispheres of the control subjects. Migraine patients had the lowest intralesional creatine + phosphocreatine and myo-inositol (mI) values among the three groups, while patients with MS showed the highest intralesional T1 and T2 relaxation times, ADC, and mI values. In the contralateral NAWM, the same trend with mI changes was observed in migraineurs and MS patients. No differences in perfusion variables were observed in any groups.

Conclusion

Our multimodal study showed that tissue damage is detectable in both diseases. Despite the differences in various advanced MRI measures, with more severe injury detected in MS lesions, we could not clearly differentiate the two white matter lesion types.

The relationship between migraine and Hashimoto's thyroiditis: a single center experience

Introduction

Hashimoto's thyroiditis (HT) is nowadays the leading cause of hypothyroidism with high and still growing prevalence in general population, but there are lack of data regarding migraine and HT connection.

Methods

The aim of this study was to analyze the prevalence of HT in migraine and to check if the presence of HT influence migraine severity. This retrospective observational cohort study involved consecutive migraine patients consulted at our Headache Center with diagnosis of migraine. Electronic charts of patients were collected, including data on migraine type, presence of cranial autonomic symptoms (CAS), monthly migraine days (MMD), medication overuse headache (MOH), and the presence of comorbidities including HT.

Results

We found 928 eligible migraine patients, 88.7% were women. The mean age was 36.09 years. 592 (63.8%) were diagnosed with episodic migraine (EM), the rest with chronic migraine (CM). MOH was additionally diagnosed in 258 (27.8%) patients. The duration of migraine was 15.99 years. 106 (11.4%) was diagnosed with HT, 148 (15.9%) with hypothyroidisms, while 84 (9.05%) had both diagnosis. Migraine patients with HT were significantly older (p < 0.001), were more frequently women (p = 0.0017), had longer duration of migraine (p < 0.001), had CAS more frequently (<0.001), developed CM (p = 0.0169) and depression more frequently (p = 0.0047) and had more MMD (p = 0.0195) as compared with individuals without HT. According to our multivariate logistic model, the presence CM was positively associated with HT (OR 1.76, p = 0.045), MOH and duration of migraine, while negatively associated with aura.

Conclusion

HT is very prevalent in migraine patients. This is the first study considering migraine and HT to be comorbid and suggesting that HT may influence the course of migraine causing its chronification.

Understanding the Biological Relationship between Migraine and Depression

Migraine is a highly prevalent neurological disorder. Among the risk factors identified, psychiatric comorbidities, such as depression, seem to play an important role in its onset and clinical course. Patients with migraine are 2.5 times more likely to develop a depressive disorder; this risk becomes even higher in patients suffering from chronic migraine or migraine with aura. This relationship is bidirectional, since depression also predicts an earlier/worse onset of migraine, increasing the risk of migraine chronicity and, consequently, requiring a higher healthcare expenditure compared to migraine alone. All these data suggest that migraine and depression may share overlapping biological mechanisms. Herein, this review explores this topic in further detail: firstly, by introducing the common epidemiological and risk factors for this comorbidity; secondly, by focusing on providing the cumulative evidence of common biological aspects, with a particular emphasis on the serotoninergic system, neuropeptides such as calcitonin-gene-related peptide (CGRP), pituitary adenylate cyclase-activating polypeptide (PACAP), substance P, neuropeptide Y and orexins, sexual hormones, and the immune system; lastly, by remarking on the future challenges required to elucidate the etiopathological mechanisms of migraine and depression and providing updated information regarding new key targets for the pharmacological treatment of these clinical entities.

The effect of omega-3 fatty acids supplementation on inflammatory biomarkers in subjects with migraine: a randomized, double-blind, placebo-controlled trial

OBJECTIVE

Imbalances in immune regulation are important features of migraine pathophysiology. In line with this, the current study investigated the efficacy of omega-3 fatty acids supplementation on inflammatory and anti-inflammatory markers in patients with migraines.

MATERIALS AND METHODS

This randomized, double-blind, placebo-controlled trial consisted of 40 patients that were prone to experiencing episodic migraines. For two months, participants were randomized into one group that received omega-3 supplementation (n= 20), 600 mg of EPA and 300 mg of DHA, twice daily) or another group that received a placebo (n= 20). Transforming growth factor β (TGF-β), interleukin (IL)-4, interferon-gamma (IFN-γ), and interleukin (IL)-17 serum levels were assessed using enzyme-linked immunosorbent assay methods at baseline and following the intervention. The current study was registered on ClinicalTrials.gov with the registration number NCT02532023.

RESULTS

After two months of intervention, the administration of omega-3 fatty acids resulted in a significant rise in the concentrations of anti-inflammatory cytokine IL-4 (p=0.010) as well as a significant reduction in concentrations of pro-inflammatory cytokine IFN-γ (p=0.001) compared with the placebo. However, no significant changes were observed in serum TGF-β and IL-17 levels.

DISCUSSION

Our findings indicated consumption of omega-3 fatty acids may have a potentially beneficial response on the inflammatory immune response in patients with migraines. Larger trials are needed to corroborate these findings.

Aryl hydrocarbon receptors improve migraine-like pain behaviors in rats through the regulation of regulatory T cell/T-helper 17 cell-related homeostasis

OBJECTIVE

To investigate the effect of the aryl hydrocarbon receptor (AHR)/regulatory T cell (Treg)/T-helper 17 (Th17) cell pathway on the pathogenesis of migraine.

BACKGROUND

Migraine is a disabling neurovascular disease that imposes an enormous burden on both individuals and society. The pathophysiological mechanisms of migraine remain controversial. Recent studies have suggested that immune dysfunction may be involved in the pathogenesis of migraine. The AHR, a receptor expressed on most immune cells, has been implicated in the occurrence of many autoimmune diseases; however, whether it is involved in the pathogenesis of migraine is unclear.

METHODS

A chronic migraine rat model was established through repeated intraperitoneal injection of nitroglycerin (NTG). The mechanical and thermal pain thresholds were assessed using von Frey filaments and radiant heat. Next, the protein expression levels of AHR in the trigeminal nucleus caudalis (TNC) region of chronic migraine (CM)-like rats were quantified and the changes in Treg/Th17-related transcription factors and inflammatory factors in the TNC were explored. To determine the role of AHR in CM, we examined the effects of the AHR agonist 2-(1'-indole-3'-carbonyl)-thiazole-4-carboxylic acid methyl ester (ITE), and AHR antagonist CH-223191 on pain behavior, c-Fos, calcitonin gene-related peptide (CGRP), AHR, and Treg/Th17-related factor expression in CM-like rats.

RESULTS

Repeated administration of NTG significantly enhanced nociceptive hypersensitivity and increased expression of c-Fos and CGRP in rats, while AHR was significantly decreased in the TNC. In addition, the expression of the transcription factor forkhead box protein P3 and the signal transducer and activator of transcription 5 decreased significantly. In contrast, the expression of the transcription factor retinoic acid receptor-related orphan receptor γ t and signal transducer and activator of transcription 3 were significantly increased. Moreover, the mRNA level of transforming growth factor beta-1 was decreased, while that of interleukin (IL)-10 and IL-22 was increased in the TNC. The AHR agonist ITE alleviated migraine-like pain behaviors in rats, activated the AHR signaling pathway, and improved the imbalance of Treg/Th17-related transcription factors and inflammatory factors. Conversely, the AHR antagonist CH-223191 did not alleviate migraine-like pain behaviors in rats; and even exacerbated them.

CONCLUSIONS

The AHR participates in the development of CM by regulating Treg/Th17-related homeostasis. Therefore, treatments targeting the AHR/Treg/Th17 signaling pathway could be new effective interventions for CM treatment.

Migraine and risk of rheumatoid arthritis: A systematic review and meta-analysis of observational studies

Background

Exposure to Migraine may be one of the risk factors for the onset of rheumatoid arthritis (RA), while the relationship between the two is debatable. In this study, the connection between migraine and the risk of RA was investigated using a systematic review and meta-analysis of the pertinent literature.

Methods

Up to July 2022, the PubMed, EMBASE, Web of Science (WOS), and scopus databases were employed to search for observational studies on the risk of RA in migraineurs. The effect sizes were pooled using a random-effects model or a fixed-effects model.

Results

Out of 2345 records, 5 studies (3 case and control studies and 2 cohort studies) were identified and included in the meta-analysis. According to a pooled analysis, migraine sufferers had a higher chance of developing RA (pooled adjusted effect estimate: 1.94, 95% confidence interval: 1.74-2.17; p < 0.01).

Conclusions

Migraine can be legitimately regarded as a risk factor for RA since this study demonstrated a relationship between migraine and RA. This conclusion should be treated with caution due to low power and precision. Rigorous design and larger sample sizes of studies are needed to verify the findings.

Common Clinical and Molecular Pathways between Migraine and Sarcoidosis

Migraine and sarcoidosis are two distinct medical conditions that may have some common biological and clinical pathways. Sarcoidosis is a chronic granulomatous disease characterized by the formation of granulomas in various organs, including the lungs, skin, cardiovascular system, lymph nodes, and brain. Migraine is a common comorbidity in sarcoidosis patients and a common neurological disorder characterized by recurrent headaches that can be accompanied by other symptoms, such as nausea, vomiting, and sensitivity to light and sound. There have been several reports of individuals with neurosarcoidosis experiencing migraines, though the exact relationship between the two disorders is not well understood. Both conditions have been associated with inflammation and the activation of the immune system. In sarcoidosis, the formation of granulomas is thought to be an immune response to the presence of an unknown antigen. Similarly, the pain and other symptoms associated with migraines are thought to be caused by inflammation in the brain and the surrounding blood vessels. There is also evidence to suggest an interplay of environmental and genetic factors playing a role in both conditions, but evidence is inconsistent with the hypothesis of shared genetic susceptibility. This review aims to illustrate common clinical and biological pathways between migraine and sarcoidosis, including inflammation and dysregulation of the immune system, with a focus on the cumulative burden of concurrent disorders and therapeutic implications.

rs3761548 (C/A) and rs5902434 (del/ATT) polymorphisms of Foxp3 gene in Iranian patients with migraine

Background

Migraine is a neurovascular disorder; several studies have demonstrated the immune system plays a key role in migraine pathogenesis. The aim of this study was to investigate the association between FOXP3 gene polymorphism and susceptibility to migraine.

Methods

In a case–control study, 55 whole blood samples of patients with migraine and 80 healthy samples were collected. After DNA extraction, genotyping of the rs5902434 (del/ATT) and rs3761548 (C/A) FOXP3 was performed using sequence-specific primers method (PCR-SSP).

Results

The results of this study showed that there were statistically significant differences between patient and control group in genotype frequencies of rs3761548. In addition, the frequency of heterozygous genotype AC at rs3761548 in patients was found to be significantly higher than controls. We also found no significant differences between cases and controls were found in the allelic and genotype distribution of the rs5902434 (del/ATT) polymorphism. None of the rs5902434 (del/ATT) genotypes showed any significant association with the migraine.

Conclusions

According to finding of our study, polymorphism rs3761548 in FOXP3 gene were associated with susceptibility to migraine. Further studies with larger sample sizes and different populations in other parts of the world are needed to investigate relationship between this polymorphism on migraine susceptibility.

Potential Association between Subclinical Hypothyroidism and Childhood Migraine

Background and Objectives: Migraine is caused by genetic susceptibility that is triggered by environmental as well as biological factors, and it is also linked to many somatic comorbidities, including clinical and subclinical hypothyroidism. We aimed to estimate the potential association between subclinical hypothyroidism (ScH) and migraine in children at our tertiary hospital. Materials and Methods: Using a case−control strategy, 200 children and adolescents were assigned to two equal groups: a case group (patients with migraine) of 100 patients and a control group of 100 patients without migraine. Clinical and biochemical parameters (TSH, FT4) were compared between the groups using statistical analysis. Results: Thyroid function comparison between the groups showed higher TSH but normal FT4 among children with migraine headache compared to the control group, which means more frequent ScH cases among the migraine group relative to the control (17% vs. 2%, p < 0.001). Obesity and overweight were more frequent among patients with migraine than the control group (8 and 5% vs. 2 and 1%, respectively). The (overweight/obese) patients with migraine had about 77% ScH and 15.4% overt hypothyroidism compared to 8% ScH and no overt hypothyroidism among normal body weight migraine patients (p < 0.001). No significant difference in the prevalence of nodular goiter between patients with migraine and controls was found. Conclusions: Based on our results, subclinical hypothyroidism is significantly linked to childhood migraine. Obesity and being overweight are more frequent among patients with migraine. Therefore, it may be logical to test the thyroid function in migraineur children, especially those with high BMI. Further studies are recommended to discover the mechanism of this association in children.

Leukocyte inflammatory phenotype and function in migraine patients compared with matched non-migraine volunteers: a pilot study

Background

Migraine is a neurological condition characterized by chronic inflammation. However, not much is known about the potential role of peripheral blood immune cells in the pathophysiology of migraine.

Methods

We investigated the status of peripheral blood immune cells of 15 adults with frequent episodic or chronic migraine recruited chronologically from a randomized clinical trial (RCT) on Nutrition for Migraine (NCCIH 5R01AT007813-05) and 15 non-migraine, healthy volunteers (control) matched by age, gender, and Body Mass Index (BMI).

Continuous variables were presented as means ± standard deviationas well as medians, and comparisons between patients and healthy volunteers were performed with non-parametric Wilcoxon signed rank tests. Statistical analysis was performed using Stata (StataCorp. 2019. Stata Statistical Software). Fluorescence-Activated Cell Sorting (FACS) data were processed using FlowJo software (Ashland, OR: Becton, Dickenson and Company; 2019).

Results

We observed that migraineurs had a significantly lower percentage of non-classical monocytes (CD14⁺CD16⁺⁺) in blood circulation, compared to the control group. In addition, Migraineurs also showed a significantly lower percentage of blood CD3⁺CD4⁺ helper T cells and CD4⁺CD25⁺ regulatory T cells, compared to controls. Differences in leukocyte surface markers between chronic migraine patients and their matched controls were more prominent than those between episodic migraine patients and their matched controls.

Conclusions

Our results suggest that migraine is associated with dysregulated peripheral immune homeostasis and that inflammation and autoimmunity may play a role in its pathophysiology.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-022-02781-4.

Evaluation of simple antioxidant blood parameters in patients with migraine

Background

The study aims to investigate the role of serum albumin (ALB) and creatinine (CRE), bilirubin (BIL), and uric acid (UA) as major intravascular antioxidants in migraine.

Methods

We enrolled 148 patients with migraine and 150 age- and sex-matched healthy controls. The serum levels of ALB, TBIL, CRE, and UA were measured in patients with migraine of different subtypes. The risk of migraine was assessed by multiple stepwise logistic regression analysis.

Results

The serum levels of ALB, total BIL (TBIL), CRE, and UA were significantly lower in the migraine group than in the HC group (p < 0.05). The ALB and UA levels were lower during migraine attack periods (p < 0.05). There were no statistically significant differences observed in serum ALB, TBIL, CRE, and UA levels between aura/without aura and episodic/chronic migraine subtypes (p > 0.05). The multiple stepwise logistic regression revealed that ALB [odds ratio (OR) 0.79, 95% confidence interval (CI) 0.69–0.89, p < 0.001], TBIL (OR 0.61, 95% CI 0.5–0.75, p < 0.001), and UA (OR 0.97, 95% CI 0.96–0.99, p = 0.014) were independently associated with migraine. In addition, the serum levels of ALB, TBIL, and UA were significantly lower in the migraine group when compared by sex.

Conclusion

The serum levels of UA, TBIL, ALB, and CRE were lower in the patients with migraine, indicating a lower antioxidant status. In addition, ALB, TBIL, and UA were independently related to migraine. These results could provide insights into the possible role of oxidative stress in the pathogenesis of migraine.

Migraine, interferon β1a and siponimod immunomodulator therapies

Background

Autoimmunity seems to play a great role in the pathogenesis of migraine headache pain. There is far more evidence that interferon can exacerbate migraines. We report a case where remission of severe comorbid migraine attacks happened with the start of interferon β1a (Merck, Netherlands) immunomodulation therapy. Therapy for multiple sclerosis was decided according to the severity of the debilitating comorbid migraine headache pain rather than the evolution of multiple sclerosis the far more serious disease.

Case presentation

A 63-years old patient suffered for 30-years from migraine headache of severe disability assessment scale (MIDAS) Grade-IV = 27. He also suffered for 25-years from optic-sensory relapsing remitting multiple sclerosis (RRMS). Subcutaneous interferon β1a 44-µg immunomodulation therapy for 4-years resulted in multiple sclerosis complete remission. The start of interferon β1a therapy for multiple sclerosis seemed to help resolving the comorbid migraine attacks. The visual aura premonitory symptom preceding migraine headache would end up with a feeling of post visual aura clearer field of vision and a feeling of wellbeing. As the patient developed secondary progressive multiple sclerosis (SPMS), oral siponimod 2 mg (Novartis, Ireland), currently the only available therapy for SPMS, replaced his interferon therapy. This was associated with a relapse of migraine severe attacks. Reverting back to interferon therapy was again associated with migraine headache remission.

Conclusions

Interferon β1a might be an efficic therapy for “autoimmune migraine”. With numerous immunomodulators currently available for other systemic autoimmune diseases associated with comorbid migraine; examining the effect of these immunomodulatory therapies on comorbid migraine headache could be beneficial in finding a specific immunomodulator therapy for “autoimmune migraine”.

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.

Headache and immunological/autoimmune disorders: a comprehensive review of available epidemiological evidence with insights on potential underlying mechanisms

Several lines of evidence support a role of the immune system in headache pathogenesis, with particular regard to migraine. Firstly, alterations in cytokine profile and in lymphocyte subsets have been reported in headache patients. Secondly, several genetic and environmental pathogenic factors seem to be frequently shared by headache and immunological/autoimmune diseases. Accordingly, immunological alterations in primary headaches, in particular in migraine, have been suggested to predispose some patients to the development of immunological and autoimmune diseases. On the other hand, pathogenic mechanisms underlying autoimmune disorders, in some cases, seem to favour the onset of headache. Therefore, an association between headache and immunological/autoimmune disorders has been thoroughly investigated in the last years. The knowledge of this possible association may have relevant implications in the clinical practice when deciding diagnostic and therapeutic approaches. The present review summarizes findings to date regarding the plausible relationship between headache and immunological/autoimmune disorders, starting from a description of immunological alteration of primary headaches, and moving onward to the evidence supporting a potential link between headache and each specific autoimmune/immunological disease.

Recent preclinical study offers a promising clue: Role of regulatory T cells as biomarkers in migraine

The exact etiology of migraine has not yet been fully understood. There is no specific diagnostic test for migraine and is often misdiagnosed like all other types of headaches. The lack of a diagnostic test is also a significant impediment to migraine management. In previous clinical studies, the author and his team found decreased levels of CD4⁺CD25⁺ Regulatory T cells (Treg) in migraine patients. These reductions were significant in the ictal phase of migraine, regardless of the subtype of migraines. Interestingly, the recent preclinical study demonstrated a significant improvement in nitroglycerine induced headache by activating Treg cells. Therefore, the author argued that peripheral Treg cell levels can be a therapeutically relevant biomarker for migraine.

Migraine and gastrointestinal disorders in middle and old age: A UK Biobank study

INTRODUCTION

Migraine is a prevalent condition causing a substantial level of disability worldwide. Despite this, the pathophysiological mechanisms are not fully understood. Migraine often co-occurs with gastrointestinal disorders, but the direction of a potential causal link is unclear. The aim of this project was to investigate the associations between migraine and several gastrointestinal disorders in the same cohort in order to determine the relative strengths of these associations.

METHODS

This cross-sectional study examined whether migraine is associated with irritable bowel syndrome (IBS), peptic ulcers, Helicobacter pylori (HP) infections, celiac disease, Crohn's disease and ulcerative colitis. Baseline data covering 489,753 UK Biobank participants (migraine group: n = 14,180) were analyzed using Pearson's chi-square tests and adjusted binary logistic regression models.

RESULTS

Migraine was significantly associated with IBS (odds ratio [OR] 2.24, 95% confidence interval [CI] 2.08-2.40, p <.001) and peptic ulcers (OR 1.55, 95% CI 1.35-1.77, p <.001). Migraine was not associated with HP infection (OR 1.34, 95% CI 1.04-1.73, p = .024), celiac disease (OR 1.29, 95% CI 1.04-1.60, p = .023), Crohn's disease (OR 1.08, 95% CI 0.80-1.45, p = .617) or ulcerative colitis (OR 1.00, 95% CI 0.79-1.27, p = .979) after adjusting for multiple testing.

CONCLUSIONS

Migraine was associated with IBS and peptic ulcers in this large population-based cohort. The associations with HP infection, celiac disease, Crohn's disease, and ulcerative colitis did not reach significance, suggesting a weaker link between migraine and autoimmune gastrointestinal conditions or HP infection.

Pathophysiological Bases of Comorbidity in Migraine

Despite that it is commonly accepted that migraine is a disorder of the nervous system with a prominent genetic basis, it is comorbid with a plethora of medical conditions. Several studies have found bidirectional comorbidity between migraine and different disorders including neurological, psychiatric, cardio- and cerebrovascular, gastrointestinal, metaboloendocrine, and immunological conditions. Each of these has its own genetic load and shares some common characteristics with migraine. The bidirectional mechanisms that are likely to underlie this extensive comorbidity between migraine and other diseases are manifold. Comorbid pathologies can induce and promote thalamocortical network dysexcitability, multi-organ transient or persistent pro-inflammatory state, and disproportionate energetic needs in a variable combination, which in turn may be causative mechanisms of the activation of an ample defensive system with includes the trigeminovascular system in conjunction with the neuroendocrine hypothalamic system. This strategy is designed to maintain brain homeostasis by regulating homeostatic needs, such as normal subcortico-cortical excitability, energy balance, osmoregulation, and emotional response. In this light, the treatment of migraine should always involves a multidisciplinary approach, aimed at identifying and, if necessary, eliminating possible risk and comorbidity factors.

Reduced regulatory T lymphocytes in migraine patients

Objectives: Migraine is a primary headache disorder with unknown pathophysiology. Recently, many studies have suggested the role of immune dysfunction in the pathophysiology of this disorder. In this study, we investigated the percentage of regulatory T cells (Treg cells) in different migraine categories.Methods: Peripheral blood samples of 40 newly diagnosed cases of migraine and 33 healthy individuals were collected for Treg cell analysis by flow cytometry.Results: The percentage of Treg cells in migraine patients with all subgroups including patients with or without auras and patients with chronic or episodic migraine was significantly lower than that of the control group. Also, a significant increase in the CD25 means fluorescence intensity (MFI) was observed in migraine without aura and chronic migraine groups, compared to the normal group.Conclusions: In this study, the number of Treg cells significantly decreased in new cases of migraine, which suggests that migraine is a result of an impairment in the immunological system or an autoimmune disease. Also, the insignificant difference in the number of Treg cells between the two categories of migraine suggests that there is no link between the reduced number of Treg cells and the emergence of aura symptoms or duration of the disease.

Caesarean section and the association with migraine: a retrospective register-linked HUNT population cohort study

OBJECTIVES

To evaluate the association between caesarean section and migraine in a population-based register-linked cohort study.

SETTING

Data from the population-based Nord-Trøndelag Health Studies (HUNT2 and HUNT3) were linked to information from the Norwegian Medical Birth Registry.

PARTICIPANTS

65 343 participants responded to the headache questions in any of the two HUNT studies. Only those answering the headache questions in HUNT2 or 3 and had information about mode of delivery in the Norwegian Medical Birth Registry (born after 1967) were included. Our final sample consisted of 6592 women and 4602 men, aged 19-41 years.

OUTCOMES

ORs for migraine given caesarean section. Analyses were performed in multivariate logistic regression models.

RESULTS

After adjusting for sex, age and fetal growth restriction, delivery by caesarean section was not associated with migraine later in life (OR 0.86, 95% CI 0.64 to 1.15). Delivery by caesarean section was associated with a reduced OR of non-migrainous headache (OR 0.77, 95% CI 0.60 to 0.99).

CONCLUSION

No association was found between caesarean section and migraine in this population-based register-linked study.

RAR-related orphan receptor A: One gene with multiple functions related to migraine

Aims

RAR‐related orphan receptor (RORA) involves in regulation of several biological processes including inflammation and circadian rhythm that probably are involved in migraine pathophysiology. In the current study, the association between RORA rs11639084 and rs4774388 variants and susceptibility to migraine were investigated in a sample of Iranian migraine patients for the first time.

Methods

In a case‐control study including 400 participants, 200 migraineurs and 200 healthy controls, genotyping of RORA rs4774388 and rs11639084 polymorphisms was performed using tetra‐primer amplification refractory mutation system–polymerase chain reaction (TP‐ARMS‐PCR).

Results

The distribution of rs4774388 C/T and T/T genotypes differed significantly between the studied groups. Moreover, an association was observed between rs4774388 and migraine under the recessive mode of inheritance (P = 0.002; OR = 1.89.; CI = 1.25‐2.87). The distribution of rs11639084 alleles and genotypes was not significantly different between migraineurs and healthy controls.

Conclusion

Current results suggest RORA, as a molecular link, may explain inflammation and circadian rhythm dysfunction in migraine. Further studies in different ethnicities are required to confirm the function of RORA in migraine development.

The role of the immune system and the biomarker CD3 + CD4 + CD45RA-CD62L- in the pathophysiology of migraine

The role of the immune system as an integral component of the inflammatory response in the pathophysiology of migraine remains unclear. The aim of this study was to evaluate the differences in immune system parameters (acquired immunity parameters) in patients with episodic migraine (EM) and in healthy controls. In EM patients, we aimed to determine whether the changes found in peripheral blood parameters were related to migraine severity according to the standardised MIDAS and HIT-6 tests. Forty-nine patients with EM and 50 healthy controls were included in this study. The authors compared different lymphocyte parameters obtained by multicolor flow cytometry in the EM and control groups by performing statistical tests. The relationship between the changes in peripheral blood parameters and migraine severity in EM patients was investigated using correlation and regression analysis. EM patients showed higher values than healthy controls, especially in nine parameters: relative count of lymphocytes, relative and absolute counts of CD3 T cells, relative and absolute counts of CD8 suppressor cytotoxic T cells, relative and absolute counts of CD4 + TEMRA (terminally differentiated helper T lymphocytes), absolute count of CD8 naïve T cells, and absolute count of CD19 switched memory B cells. Among the lymphocyte parameters, CD4 + TEM (effector memory helper T lymphocytes) and CD8 + TEMRA (terminally differentiated cytotoxic T lymphocytes) were statistically significantly associated with HIT-6. Patients with a CD4 + TEM value below 15 had a high probability (90%) that the HIT-6 value would be higher than 60. The results of this study show that EM patients have changes in immune system parameters measured in the peripheral blood. Changes in the abundance of CD4 + TEM could be used as a biomarker for disease severity.

Low-dose interleukin-2 reverses behavioral sensitization in multiple mouse models of headache disorders

Headache disorders are highly prevalent and debilitating, with limited treatment options. Previous studies indicate that many proinflammatory immune cells contribute to headache pathophysiology. Given the well-recognized role of regulatory T (Treg) cells in maintaining immune homeostasis, we hypothesized that enhancing Treg function may be effective to treat multiple headache disorders. In a mouse model of chronic migraine, we observed that repeated nitroglycerin (NTG, a reliable trigger of migraine in patients) administration doubled the number of CD3 T cells in the trigeminal ganglia without altering the number of Treg cells, suggesting a deficiency in Treg-mediated immune homeostasis. We treated mice with low-dose interleukin-2 (ld-IL2) to preferentially expand and activate endogenous Treg cells. This not only prevented the development of NTG-induced persistent sensitization but also completely reversed the established facial skin hypersensitivity resulting from repeated NTG administration. The effect of ld-IL2 was independent of mouse sex and/or strain. Importantly, ld-IL2 treatment did not alter basal nociceptive responses, and repeated usage did not induce tolerance. The therapeutic effect of ld-IL2 was abolished by Treg depletion and was recapitulated by Treg adoptive transfer. Furthermore, treating mice with ld-IL2 1 to 7 days after mild traumatic brain injury effectively prevented as well as reversed the development of behaviors related to acute and chronic post-traumatic headache. In a model of medication overuse headache, Ld-IL2 completely reversed the cutaneous hypersensitivity induced by repeated administration of sumatriptan. Collectively, this study identifies ld-IL2 as a promising prophylactic for multiple headache disorders with a mechanism distinct from the existing treatment options.

Purinergic Profiling of Regulatory T-cells in Patients With Episodic Migraine

Objectives: Immune responses in migraine are poorly characterized, yet implicated in the disease pathogenesis. This study was carried out to characterize purinergic profiles of T-cells in patients with episodic migraine without aura (MWoA) to provide mechanistic evidence for ATP and adenosine involvement in modulation of immune regulation in migraine. Methods: Peripheral blood samples were obtained from patients with migraine (n = 16) and age-matched control subjects (n = 21). Subsets of T-cells were identified by flow cytometry based on specific membrane markers. Results: Migraine patients showed reduced total T-cell counts in the peripheral blood. Whereas the total number of CD3+CD4+, CD3+CD8+, or regulatory T lymphocytes (Treg) was not changed, the proportion of Treg CD45R0+CD62L- and CD45R0-CD62L- cells was increased. Interestingly, in migraine, less Treg cells expressed CD39 and CD73 suggesting disrupted ATP breakdown to adenosine. The negative correlations were observed between the duration of migraine and the relative number of CD73+CD39- Tregs and total number of CD73-positive CD45R0+CD62L+ Tregs. Conclusion: Obtained data indicate that T-cell populations are altered in episodic migraine and suggest the involvement of Tregs in the pathophysiology of this disorder. Reduced expression of CD39 and CD73 suggests promotion of ATP-dependent pro-inflammatory and reduction of adenosine-mediated anti-inflammatory mechanisms in migraine.

Subclinical hypothyroidism is associated with migraine: A case-control study

BACKGROUND

Recent studies suggested a potential association between both overt and subclinical hypothyroidism and migraine. Aims of this study were to estimate the comorbidity of migraine in patients with subclinical hypothyroidism and to evaluate associated clinical characteristics.

METHODS

Using a case-control strategy, 151 consecutive subclinical hypothyroidism patients (mean age 48.36 ± 15.86 years) and 150 controls (mean age 50.86 ± 9.19 years) were recruited. In all subjects, migraine characteristics were collected through a direct interview. Clinical and biochemical parameters (thyroid-stimulating hormone, free triiodothyronine, free thyroxine, and anti-thyroid antibodies) were compared between subclinical hypothyroidism patients in comorbidity with migraine and subclinical hypothyroidism patients without migraine.

RESULTS

The prevalence of lifetime migraine was significantly higher in subclinical hypothyroidism patients in comparison with controls (46% vs. 13%, p < 0.001; OR 5.80; 95% CI = 3.35-10.34). Both migraine without and with aura were significantly higher in subclinical hypothyroidism patients than controls ( p < 0.001 and p = 0.010, respectively). Thyroid hormones and concentrations of antibodies did not differ between subclinical hypothyroidism patients with and without migraine. Interestingly, a comorbidity for autoimmune diseases was observed in subclinical hypothyroidism patients with migraine in respect to those without migraine ( p = 0.005).

CONCLUSIONS

Our data suggest that migraine is more frequent in patients with subclinical hypothyroidism in respect to controls. Further studies are needed in order to confirm this association.

PACAP and migraine headache: immunomodulation of neural circuits in autonomic ganglia and brain parenchyma

The discovery that intravenous (IV) infusions of the neuropeptide PACAP-38 (pituitary adenylyl cyclase activating peptide-38) induced delayed migraine-like headaches in a large majority of migraine patients has resulted in considerable excitement in headache research. In addition to suggesting potential therapeutic targets for migraine, the finding provides an opportunity to better understand the pathological events from early events (aura) to the headache itself. Although PACAP-38 and the closely related peptide VIP (vasoactive intestinal peptide) are well-known as vasoactive molecules, the dilation of cranial blood vessels per se is no longer felt to underlie migraine headaches. Thus, more recent research has focused on other possible PACAP-mediated mechanisms, and has raised some important questions. For example, (1) are endogenous sources of PACAP (or VIP) involved in the triggering and/or propagation of migraine headaches?; (2) which receptor subtypes are involved in migraine pathophysiology?; (3) can we identify specific anatomical circuit(s) where PACAP signaling is involved in the features of migraine? The purpose of this review is to discuss the possibility, and supportive evidence, that PACAP acts to induce migraine-like symptoms not only by directly modulating nociceptive neural circuits, but also by indirectly regulating the production of inflammatory mediators. We focus here primarily on postulated extra-dural sites because potential mechanisms of PACAP action in the dura are discussed in detail elsewhere (see X, this edition).

Cerebellar Atrophy and Changes in Cytokines Associated with the CACNA1A R583Q Mutation in a Russian Familial Hemiplegic Migraine Type 1 Family

Background: Immune mechanisms recently emerged as important contributors to migraine pathology with cytokines affecting neuronal excitation. Therefore, elucidating the profile of cytokines activated in various forms of migraine, including those with a known genetic cause, can help in diagnostic and therapeutic approaches.

Methods: Here we (i) performed exome sequencing to identify the causal gene mutation and (ii) measured, using Bio-Plex technology, 22 cytokines in serum of patients with familial migraine (two with hemiplegic migraine and two with migraine with aura) from a Russian family that ethnically belongs to the Tatar population. MRI scanning was used to assess cerebellar atrophy associated with migraine in mutation carriers.

Results: Whole-exome sequencing revealed the R583Q missense mutation in the CACNA1A gene in the two patients with hemiplegic migraine and cerebellar ataxia with atrophy, confirming a FHM1 disorder. Two further patients did not have the mutation and suffered from migraine with aura. Elevated serum levels of pro-inflammatory and pro-nociceptive IL-6 and IL-18 were found in all four patients (compared to a reference panel), whereas pro-apoptotic SCGF-β and TRAIL were higher only in the patients with the FHM1 mutation. Also, cytokines CXCL1, HGF, LIF, and MIF were found particularly high in the two mutation carriers, suggesting a possible role of vascular impairment and neuroinflammation in disease pathogenesis. Notably, some “algesic” cytokines, such as β-NGF and TNFβ, remained unchanged or even were down-regulated.

Conclusion: We present a detailed genetic, neurological, and biochemical characterization of a small Russian FHM1 family and revealed evidence for higher levels of specific cytokines in migraine patients that support migraine-associated neuroinflammation in the pathology of migraine.

[Headache immunology]

The overview is dedicated to the neuroimmunological mechanisms of headache development and chronification. Based on the analyzed data, the authors determined the relationship between immunological parameters and duration, intensity and other characteristics of this disease. These findings confirm that immunocompetent cells can be used as headache biomarkers and predictors of treatment efficacy. Questions about the role of separate parts of the immune system in the development and maintenance of a headache require further research. Studies of humoral immunity appeared to be very promising.

Association of migraine with asthma risk: A retrospective population-based cohort study

BACKGROUND

Both migraine and asthma are common health problems in the general population. However, the association between these two disorders is yet to be fully explored.

OBJECTIVE

We examined whether adult patients with migraine are at a higher risk of asthma development.

METHODS

We used data retrieved from the National Health Insurance Research Database in Taiwan to conduct this nationwide population-based cohort study. We identified 6647 patients aged 20-60 years who were newly diagnosed with migraine between 2000 and 2005 for the migraine group and identified 26 588 patients without migraine for the nonmigraine group. Both groups were followed up until the end of 2011 to examine the incidence of asthma. Cox proportional hazards regression analysis was used to measure the hazard ratio (HR) of asthma in the migraine group compared with the nonmigraine group.

RESULTS

The HR of asthma development was 1.37 (95% confidence interval = 1.21-1.56) for the migraine group compared with the nonmigraine group after adjustment for age, sex, occupational status, insurance premium, urbanization, comorbidities, and annual outpatient department visits. Further stratified analysis revealed that this risk was also significantly higher for both sexes and in the 40- to 60-year age group. The main limitation of this study was that some relevant data were unavailable, such as pain medication prescriptions and family history of migraine and asthma.

CONCLUSION

Adult patients with migraine are at a higher future risk of asthma development.

Comorbid association of antiphospholipid antibodies and migraine: A systematic review and meta-analysis

BACKGROUND

Antiphospholipid antibodies (aPLs) namely anticardiolipin (aCL) antibody, anti-β2-glycoprotein I (β2GPI) antibody and lupus anticoagulant (LA) are autoantibodies produced against anionic phospholipids and proteins on plasma membranes. Migraine is a primary headache disorder which has growing evidences of autoimmune-mediated pathogenesis and previous studies suggested the presence of aPLs in migraine patients.

AIMS

The aim of this study was to evaluate the comorbid association between aPLs (aCL, anti-β2GPI and LA) and migraine compared to healthy controls.

METHODS

Studies were searched through PubMed, ISI Web of Science and Google Scholar databases without restricting the languages and year (up to October 2016) and were selected based on the inclusion criteria. Two authors independently extracted data from the included studies. All analyses were conducted by using random effects model to calculate the odds ratio (OR) and 95% confidence interval (CI). Quality assessment was carried out by using the modified Newcastle-Ottawa Scale (NOS). Publication bias was evaluated via visualization of funnel plots, Begg's and Egger's tests.

RESULTS

The database searches produced 1995 articles, 13 of which were selected (912 migraineurs and 822 healthy controls). 8.59%, 15.21% and 4.11% of the migraineurs exhibited aCL, anti-β2GPI and LA which was 4.83, 1.63 and 3.03 times higher, respectively, than healthy controls. A significant presence of aCL (OR: 3.55, 95% CI: 1.59-7.95; p=0.002) or anti-β2GPI antibodies (OR: 2.02, 95% CI: 1.20-3.42; p=0.008) was observed in migraine patients, however, LA was not significantly associated (OR: 2.02, 95% CI: 0.50-8.37; p=0.320). Majority of the studies (n=10 of 13) demonstrated NOS score of 7 or above and no significant publication bias was observed.

CONCLUSION

Migraine might be an autoimmune-associated neurologic disorder. The presence of aCL or anti-β2GPI antibodies was significant in migraine patients compared to healthy controls, suggesting an involvement of these autoantibodies in migraine attack.