Association of HLA-DR and -DQ Genes with Familial Moyamoya Disease in Koreans

Research progress on moyamoya disease combined with thyroid diseases

Moyamoya disease (MMD), also known as abnormal cerebral vascular network disease, is characterized by progressive occlusion or stenosis of the internal carotid and cerebral arteries, as well as the formation of an abnormal cerebral vascular network. It can occur anywhere in the world but is most common in China, Japan, and the Republic of Korea. In recent years, there have been increasing reports on the coexistence of thyroid diseases and MMD, but the mechanism of their coexistence is still unclear. For this article, we used keywords such as "moyamoya disease", "thyroid", "Grave disease", "thyrotoxicosis", and "thyroid autoimmune antibodies" to search for 52 articles that met the requirements in medical databases such as PubMed and Web of Science. This article also reviews the research on the role of thyroid hormone, the mechanism of immune antibodies, the possible correlation between thyroid diseases and MMD disease genes, and the treatment methods, and discusses the possible relationship between MMD and thyroid diseases to provide a reference for the pathogenesis and treatment of MMD with thyroid diseases.

Association of moyamoya vasculopathy with autoimmune disease: a systematic review and pooled analysis

Despite more than six decades of extensive research, the etiology of moyamoya disease (MMD) remains unknown. Inflammatory or autoimmune (AI) processes have been suggested to instigate or exacerbate the condition, but the data remains mixed. The objective of the present systematic review was to summarize the available literature investigating the association of MMD and AI conditions as a means of highlighting potential treatment strategies for this subset of moyamoya patients. Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, the PubMed, Embase, Scopus, Web of Science, and Cochrane databases were queried to identify studies describing patients with concurrent diagnoses of MMD and AI disease. Data were extracted on patient demographics, clinical outcomes, and treatment. Stable or improved symptoms were considered favorable outcomes, while worsening symptoms and death were considered unfavorable. Quantitative pooled analysis was performed with individual patient-level data. Of 739 unique studies identified, 103 comprising 205 unique patients (80.2% female) were included in the pooled analysis. Most patients (75.8%) identified as Asian/Pacific Islanders, and the most commonly reported AI condition was Graves' disease (57.6%), with 55.9% of these patients presenting in a thyrotoxic state. Of the 148 patients who presented with stroke, 88.5% of cases (n = 131) were ischemic. Outcomes data was available in 152 cases. There were no significant baseline differences between patients treated with supportive therapy alone and those receiving targeted immunosuppressant therapy. Univariable logistic regression showed that surgery plus medical therapy was more likely than medical therapy alone to result in a favorable outcome. On subanalysis of operated patients, 94.1% of patients who underwent combined direct and indirect bypass reported favorable outcomes, relative to 76.2% of patients who underwent indirect bypass and 82% who underwent direct bypass (p < 0.05). On univariable analysis, the presence of multiple AI disorders was associated with worse outcomes relative to having a single AI disorder. Autoimmune diseases have been uncommonly reported in patients with MMD, but the presence of multiple AI comorbidities portends poorer prognosis. The addition of surgical intervention appears to improve outcomes and for patients deemed surgical candidates, combined direct and indirect bypass appears to offer better outcomes that direct or indirect bypass alone.

Comprehensive molecular analyses of an autoimmune-related gene predictive model and immune infiltrations using machine learning methods in moyamoya disease

Background: Growing evidence suggests the links between moyamoya disease (MMD) and autoimmune diseases. However, the molecular mechanism from genetic perspective remains unclear. This study aims to clarify the potential roles of autoimmune-related genes (ARGs) in the pathogenesis of MMD. Methods: Two transcription profiles (GSE157628 and GSE141025) of MMD were downloaded from GEO databases. ARGs were obtained from the Gene and Autoimmune Disease Association Database (GAAD) and DisGeNET databases. Differentially expressed ARGs (DEARGs) were identified using "limma" R packages. GO, KEGG, GSVA, and GSEA analyses were conducted to elucidate the underlying molecular function. There machine learning methods (LASSO logistic regression, random forest (RF), support vector machine-recursive feature elimination (SVM-RFE)) were used to screen out important genes. An artificial neural network was applied to construct an autoimmune-related signature predictive model of MMD. The immune characteristics, including immune cell infiltration, immune responses, and HLA gene expression in MMD, were explored using ssGSEA. The miRNA-gene regulatory network and the potential therapeutic drugs for hub genes were predicted. Results: A total of 260 DEARGs were identified in GSE157628 dataset. These genes were involved in immune-related pathways, infectious diseases, and autoimmune diseases. We identified six diagnostic genes by overlapping the three machine learning algorithms: CD38, PTPN11, NOTCH1, TLR7, KAT2B, and ISG15. A predictive neural network model was constructed based on the six genes and presented with great diagnostic ability with area under the curve (AUC) = 1 in the GSE157628 dataset and further validated by GSE141025 dataset. Immune infiltration analysis showed that the abundance of eosinophils, natural killer T (NKT) cells, Th2 cells were significant different between MMD and controls. The expression levels of HLA-A, HLA-B, HLA-C, HLA-DMA, HLA-DRB6, HLA-F, and HLA-G were significantly upregulated in MMD. Four miRNAs (mir-26a-5p, mir-1343-3p, mir-129-2-3p, and mir-124-3p) were identified because of their interaction at least with four hub DEARGs. Conclusion: Machine learning was used to develop a reliable predictive model for the diagnosis of MMD based on ARGs. The uncovered immune infiltration and gene-miRNA and gene-drugs regulatory network may provide new insight into the pathogenesis and treatment of MMD.

Analysis of HLA Variants and Graves' Disease and Its Comorbidities Using a High Resolution Imputation System to Examine Electronic Medical Health Records

Hyperthyroidism is a prevalent endocrine disorder, and genetics play a major role in the development of thyroid-associated diseases. In particular, the inheritance of HLA has been demonstrated to induce the highest susceptibility to Graves' disease (GD). However, thus far, no studies have reported the contribution of HLA to the development of GD and the complications that follow. Thus, in the present study, to the best of our knowledge, for the first time, a powerful imputation method, HIBAG, was used to predict the HLA subtypes among populations with available genome-wide SNP array data from the China Medical University Hospital (CMUH). The disease status was extracted from the CMUH electronic medical records; a total of 2,998 subjects with GD were identified as the cases to be tested and 29,083 subjects without any diagnosis of thyroid disorders were randomly selected as the controls. A total of 12 HLA class I genotypes (HLA-A*02:07-*11:01, HLA-B*40:01-*46:01 and *46:01-*46:01, and HLA-C*01:02-*01:02, *01:02-*03:04, and *01:02-*07:02) and 17 HLA class II genotypes (HLA-DPA1*02:02-*02:02, HLA-DPB1*02:01-*05:01, *02:02-*05:01, and *04:01-*05:01, HLA-DQA1*03:02, HLA-DRB1*09:01-*15:01, and *09:01-*09:01) were found to be associated with GD in the Taiwanese population. Moreover, the HLA subtypes HLA-A*11:01, HLA-B*46:01, HLA-DPA1*01:03, and HLA-DPB1*05:01 were found to be associated with heart disease, stroke, diabetes, and hypertension among subjects with GD. Our data suggest that several HLA alleles are markedly associated with GD and its comorbidities, including heart disease, hypertension, and diabetes.

Dysregulation of Rnf 213 gene contributes to T cell response via antigen uptake, processing, and presentation

Growing evidence suggest the association between Moyamoya disease (MMD) and immune systems, such as antigen presenting cells in particular. Rnf213 gene, a susceptibility gene for MMD, is highly expressed in immune tissues, however, its function remains unclear. In addition, the physiological role of RNF213 gene polymorphism c.14576G > A (rs112735431), susceptibility variant for MMD, is also poorly understood. By studying Rnf213-knockout (Rnf213-KO) mice with deletion of largest exon32 and Rnf213-knockin (Rnf213-KI) mice with insertion of single-nucleotide polymorphism corresponding to c.14576G > A mutation in MMD patients, we aimed to investigate the role of RNF213 in dendritic cell development, and antigen processing and presentation. First, we found a high level of Rnf213 gene expression in conventional DCs and monocytes. Second, flow cytometric and confocal microscopic analysis revealed ovalbumin protein-pulsed Rnf213-KO and Rnf213-KI DCs showed impaired antigen uptake, proteolysis and reduced numbers of endosomes and lysosomes, and thereby failed to activate and proliferate antigen-specific T cells efficiently. In addition, Rnf213-KI DCs showed a similar phenotype to that of Rnf213-KO BMDCs. In conclusion, our findings suggest the critical role of RNF213 in antigen uptake, processing and presentation.

The Genetic Basis of Moyamoya Disease

Moyamoya disease (MMD) is a rare cerebrovascular disease characterized by progressive spontaneous bilateral occlusion of the intracranial internal cerebral arteries (ICA) and their major branches with compensatory capillary collaterals resembling a “puff of smoke” (Japanese: Moyamoya) on cerebral angiography. These pathological alterations of the vessels are called Moyamoya arteriopathy or vasculopathy and a further distinction is made between primary and secondary MMD. Clinical presentation depends on age and population, with hemorrhage and ischemic infarcts in particular leading to severe neurological dysfunction or even death. Although the diagnostic suspicion can be posed by MRA or CTA, cerebral angiography is mandatory for diagnostic confirmation. Since no therapy to limit the stenotic lesions or the development of a collateral network is available, the only treatment established so far is surgical revascularization. The pathophysiology still remains unknown. Due to the early age of onset, familial cases and the variable incidence rate between different ethnic groups, the focus was put on genetic aspects early on. Several genetic risk loci as well as individual risk genes have been reported; however, few of them could be replicated in independent series. Linkage studies revealed linkage to the 17q25 locus. Multiple studies on the association of SNPs and MMD have been conducted, mainly focussing on the endothelium, smooth muscle cells, cytokines and growth factors. A variant of the RNF213 gene was shown to be strongly associated with MMD with a founder effect in the East Asian population. Although it is unknown how mutations in the RNF213 gene, encoding for a ubiquitously expressed 591 kDa cytosolic protein, lead to clinical features of MMD, RNF213 has been confirmed as a susceptibility gene in several studies with a gene dosage-dependent clinical phenotype, allowing preventive screening and possibly the  development of new therapeutic approaches. This review focuses on the genetic basis of primary MMD only.

Progression in Moyamoya Disease: Clinical Feature, Neuroimaging Evaluation and Treatment

Moyamoya disease (MMD) is a chronic cerebrovascular disease characterized by progressive stenosis of the arteries of the circle of Willis, with the formation of collateral vascular network at the base of the brain. Its clinical manifestations are complicated. Numerous studies have attempted to clarify the clinical features of MMD, including its epidemiology, genetic characteristics, and pathophysiology. With the development of neuroimaging techniques, various neuroimaging modalities with different advantages have deepened the understanding of MMD in terms of structural, functional, spatial, and temporal dimensions. At present, the main treatment for MMD focuses on neurological protection, cerebral blood flow reconstruction, and neurological rehabilitation, such as pharmacological treatment, surgical revascularization, and cognitive rehabilitation. In this review, we discuss recent progress in understanding the clinical features, in the neuroimaging evaluation and treatment of MMD.

Genetic and Proteomic Contributions to the Pathophysiology of Moyamoya Angiopathy and Related Vascular Diseases

RATIONALE

This literature review describes the pathophysiological mechanisms of the current classes of proteins, cells, genes, and signaling pathways relevant to moyamoya angiopathy (MA), along with future research directions and implementation of current knowledge in clinical practice.

OBJECTIVE

This article is intended for physicians diagnosing, treating, and researching MA.

METHODS AND RESULTS

References were identified using a PubMed/Medline systematic computerized search of the medical literature from January 1, 1957, through August 4, 2020, conducted by the authors, using the key words and various combinations of the key words "moyamoya disease," "moyamoya syndrome," "biomarker," "proteome," "genetics," "stroke," "angiogenesis," "cerebral arteriopathy," "pathophysiology," and "etiology." Relevant articles and supplemental basic science articles published in English were included. Intimal hyperplasia, medial thinning, irregular elastic lamina, and creation of moyamoya vessels are the end pathologies of many distinct molecular and genetic processes. Currently, 8 primary classes of proteins are implicated in the pathophysiology of MA: gene-mutation products, enzymes, growth factors, transcription factors, adhesion molecules, inflammatory/coagulation peptides, immune-related factors, and novel biomarker candidate proteins. We anticipate that this article will need to be updated in 5 years.

CONCLUSION

It is increasingly apparent that MA encompasses a variety of distinct pathophysiologic conditions. Continued research into biomarkers, genetics, and signaling pathways associated with MA will improve and refine our understanding of moyamoya's complex pathophysiology. Future efforts will benefit from multicenter studies, family-based analyses, comparative trials, and close collaboration between the clinical setting and laboratory research.

Cerebral Hyperperfusion and Concomitant Reversible Lesion at the Splenium after Direct Revascularization Surgery for Adult Moyamoya Disease: Possible Involvement of MERS and Watershed Shift Phenomenon

Superficial temporal artery (STA)–middle cerebral artery (MCA) bypass is the standard surgical treatment for moyamoya disease (MMD). Local cerebral hyperperfusion (CHP) is one of the potential complications, which could enhance intrinsic inflammation and oxidative stress in MMD patients and accompany concomitant watershed shift (WS) phenomenon, defined as the paradoxical decrease in the cerebral blood flow (CBF) near the site of CHP. However, CHP and simultaneous remote reversible lesion at the splenium have never been reported. A 22-year-old man with ischemic-onset MMD underwent left STA–MCA bypass. Although asymptomatic, local CHP and a paradoxical CBF decrease at the splenium were evident on N-isopropyl-p-[¹²³I] iodoamphetamine single-photon emission computed tomography 1 day after surgery. The patient was maintained under strict blood pressure control, but he subsequently developed transient delirium 4 days after surgery. MRI revealed a high-signal-intensity lesion with a low apparent diffusion coefficient at the splenium. After continued intensive management, the splenial lesion disappeared 14 days after surgery. The patient was discharged without neurological deficits. Catheter angiography 2 months later confirmed marked regression of posterior-to-anterior collaterals via the posterior pericallosal artery, suggesting dynamic watershed shift between blood flow supplies from the posterior and anterior circulation. Mild encephalitis/encephalopathy with a reversible splenial lesion could explain the pathophysiology of the postoperative splenial lesion in this case, which is associated with generation of oxidative stress, enhanced inflammation, and metabolic abnormalities. Rapid postoperative hemodynamic changes, including local CHP and concomitant WS phenomenon, might participate in the formation of the splenial lesion.

Capillary microscopy in Europeans with idiopathic Moyamoya angiopathy

OBJECTIVE

In Europe, MMA is a very rare non-inflammatory vasculopathy. MMA is an important differential diagnosis of cerebral vasculitis. Systemic manifestations, such as livedo racemosa or renal artery stenosis, associated with Moyamoya variants suggest the involvement also of non-cerebral vessels. Hypothetically, capillary microscopy could be a promising non-invasive screening method to visualize microcirculation, for example prior to cerebral angiography.

METHODS

Standardized capillary microscopic images were taken in European patients with MMA and subsequently evaluated in a blinded analysis, using data obtained from a large NP cohort and a large SLE cohort by the same blinded Investigator as controls.

RESULTS

Twenty-four European MMD patients and 14 healthy accompanying controls were included in this study. The results were compared to 116 SLE patients and 754 NP subjects. In MMD patients, no capillary morphological differences were found in comparison with NP, in particular no density reduction or increased neoangiogenesis. The pattern observed in the SLE cohort was clearly distinct from NP and MMD with regard to vascular density, vascular damage, and neoangiogenesis.

CONCLUSIONS

MMD is not associated with microvascular changes of the nailfold capillaries. In this respect, it is clearly distinct from SLE.

Identification of HLA-DRB1*04:10 allele as risk allele for Japanese moyamoya disease and its association with autoimmune thyroid disease: A case-control study

Background and purpose

Moyamoya disease (MMD) is a progressive cerebrovascular disease with unknown etiology. Growing evidence suggest its involvement of autoimmune and genetic mechanisms in the pathogenesis of MMD. This study aims to clarify the association between HLA allele and MMD.

Methods

Case-control study: the DNA of 136 MMD patients in Japan was extracted and the genotype of human leukocyte antigen (HLA) from this DNA was determined by super-high-resolution single-molecule sequence-based typing using next-generation sequencing. Next, the frequency of each HLA allele (HLA-A, HLA-B, HLA-C, HLA-DRB1, HLA-DQB1, and HLA-DPB1) was compared with those in the Japanese control database. In addition, haplotype estimation was performed using the expectation maximization algorithm.

Results

The frequencies of the HLA-DRB1*04:10 allele (4.77% vs. 1.47% in the control group; P = 1.7 × 10⁻³; odds ratio [OR] = 3.35) and of the HLA-DRB1*04:10–HLA-DQB1*04:02 haplotype (haplotype frequency 4.41% vs. 1.35% in the control group; P = 2.0 × 10⁻³; OR = 3.37) significantly increased. The frequency of thyroid diseases, such as Graves’ disease and Hashimoto thyroiditis, increased in HLA-DRB1*04:10-positive MMD patients compared with that in HLA-DRB1*04:10-negative MMD patients.

Conclusions

HLA-DRB1*04:10 is a risk allele and HLA-DRB1*04:10–HLA-DQB1*04:02 a risk haplotype for MMD. In addition, HLA-DRB1*04:10 is associated with thyroid disease in MMD patients.

Etiology and pathogenesis of Moyamoya Disease: An update on disease prevalence

Moyamoya disease is a chronic cerebrovascular occlusive disease that is characterized by progressive stenosis of the terminal portion of the internal carotid artery and its main branches. The occurrence of Moyamoya disease is related to immune, genetic, and other factors. Though the research of Moyamoya disease has made great strides in the past 60 years, the etiology and pathogenesis are largely unknown. This review will focus on the genetic pathogenic and inflammation factors of Moyamoya disease.

Moyamoya syndrome causing stroke in young women with type 1 diabetes

CONTEXT

Moyamoya syndrome is an idiopathic brain vasculopathy characterized by stenosis of major intracranial arteries. It often presents in patients with type 1 diabetes or thyroid disease and may have an autoimmune etiology. Moyamoya-related stroke poses a diagnostic challenge as initial symptoms and deficits vary greatly from classic ischemic stroke to encephalopathy, psychiatric, or seizure disorder.

CASE DESCRIPTION

We report 4 patients with type 1 diabetes and other autoimmune diseases who developed moyamoya-related stroke at a young age. Despite having long-term diabetes, these patients exhibited no evidence of dyslipidemia or other typical risk factors for atherosclerosis which might contribute to premature stroke. Three of the four patients underwent revascularization surgery while one patient received conservative management. All patients had improved neurologic function after treatment, some with residual deficits.

CONCLUSION

We highlight the importance of recognizing moyamoya syndrome in patients with pre-existing autoimmune diseases such as type 1 diabetes, as prompt diagnosis and treatment can have major impact on patient outcome and quality of life.

A Recent Update of Clinical and Research Topics Concerning Adult Moyamoya Disease

A better understanding of moyamoya disease (MMD), such as natural clinical course, surgical outcomes and research, has been obtained. This review article focuses on an giving an update for adult MMD in the Korean population. In this paper, we mainly discuss the results of our domestic investigations including meta-analysis, and related subjects from other countries.

Single Nucleotide Polymorphism in Patients with Moyamoya Disease

Moyamoya disease (MMD) is a chronic, progressive, cerebrovascular occlusive disorder that displays various clinical features and results in cerebral infarct or hemorrhagic stroke. Specific genes associated with the disease have not yet been identified, making identification of at-risk patients difficult before clinical manifestation. Familial MMD is not uncommon, with as many as 15% of MMD patients having a family history of the disease, suggesting a genetic etiology. Studies of single nucleotide polymorphisms (SNPs) in MMD have mostly focused on mechanical stress on vessels, endothelium, and the relationship to atherosclerosis. In this review, we discuss SNPs studies targeting the genetic etiology of MMD. Genetic analyses in familial MMD and genome-wide association studies represent promising strategies for elucidating the pathophysiology of this condition. This review also discusses future research directions, not only to offer new insights into the origin of MMD, but also to enhance our understanding of the genetic aspects of MMD. There have been several SNP studies of MMD. Current SNP studies suggest a genetic contribution to MMD, but further reliable and replicable data are needed. A large cohort or family-based design would be important. Modern SNP studies of MMD depend on novel genetic, experimental, and database methods that will hopefully hasten the arrival of a consensus conclusion.

Research Progress of Moyamoya Disease in Children

During the onset of Moyamoya disease (MMD), progressive occlusion occurs at the end of the intracranial internal carotid artery, and compensatory net-like abnormal vessels develop in the skull base, generating the corresponding clinical symptoms. MMD can affect both children and adults, but MMD in pediatric patients exhibits distinct clinical features, and the treatment prognoses are different from adult patients. Children are the group at highest risk for MMD. In children, the disease mainly manifests as ischemia, while bleeding is the primary symptom in adults. The pathogenesis of MMD in children is still unknown, and some factors are distinct from those in adults. MMD in children could result in progressive, irreversible nerve functional impairment, and an earlier the onset corresponds to a worse prognosis. Therefore, active treatment at an early stage is highly recommended. The treatment methods for MMD in children mainly include indirect and direct surgeries. Indirect surgeries mainly include multiple burr-hole surgery (MBHS), encephalomyosynangiosis (EMS), and encephaloduroarteriosynangiosis (EDAS); direct surgeries mainly include intra- and extracranial vascular reconstructions that primarily consist of superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis. Indirect surgery, as a treatment for MMD in children, has shown a certain level of efficacy. However, a standard treatment approach should combine both indirect and direct procedures. Compared to MMD in adults, the treatment and prognosis of MMD in children has higher clinical significance. If the treatment is adequate, a satisfactory outcome is often achieved.

Moyamoya Biomarkers

Moyamoya disease (MMD) is an arteriopathy of the intracranial circulation predominantly affecting the branches of the internal carotid arteries. Heterogeneity in presentation, progression and response to therapy has prompted intense study to improve the diagnosis and prognosis of this disease. Recent progress in the development of moyamoya-related biomarkers has stimulated marked interest in this field. Biomarkers can be defined as biologically derived agents-such as specific molecules or unique patterns on imaging-that can identify the presence of disease or help to predict its course. This article reviews the current categories of biomarkers relevant to MMD-including proteins, cells and genes-along with potential limitations and applications for their use.

Moyamoya disease and syndromes: from genetics to clinical management

Moyamoya angiopathy is characterized by a progressive stenosis of the terminal portion of the internal carotid arteries and the development of a network of abnormal collateral vessels. This chronic cerebral angiopathy is observed in children and adults. It mainly leads to brain ischemic events in children, and to ischemic and hemorrhagic events in adults. This is a rare condition, with a marked prevalence gradient between Asian countries and Western countries. Two main nosological entities are identified. On the one hand, moyamoya disease corresponds to isolated moyamoya angiopathy, defined as being “idiopathic” according to the Guidelines of the Research Committee on the Pathology and Treatment of Spontaneous Occlusion of the Circle of Willis. This entity is probably multifactorial and polygenic in most patients. On the other hand, moyamoya syndrome is a moyamoya angiopathy associated with an underlying condition and forms a very heterogeneous group with various clinical presentations, various modes of inheritance, and a variable penetrance of the cerebrovascular phenotype. Diagnostic and evaluation techniques rely on magnetic resonance imaging (MRI), magnetic resonance angiography (MRA) conventional angiography, and cerebral hemodynamics measurements. Revascularization surgery can be indicated, with several techniques. Characteristics of genetic moyamoya syndromes are presented, with a focus on recently reported mutations in BRCC3/MTCP1 and GUCY1A3 genes. Identification of the genes involved in moyamoya disease and several monogenic moyamoya syndromes unraveled different pathways involved in the development of this angiopathy. Studying genes and pathways involved in monogenic moyamoya syndromes may help to give insights into pathophysiological models and discover potential candidates for medical treatment strategies.

Review of past research and current concepts on the etiology of moyamoya disease

Research on moyamoya disease has progressed remarkably in the past several decades. Indeed, many new facts concerning the epidemiology of the disease have been revealed and surgical treatments have been drastically improved. However, despite extensive research, the mechanism of moyamoya disease is still unknown. Consequently, the cardinal treatment of this disease has not yet been developed. For further clarification of its etiology, innovative studies are therefore indispensable. The aim of this paper is to review research on the pathogenesis of moyamoya disease to identify milestones in the direction of its true solution. Many hypotheses of the pathogenesis of moyamoya disease have been proposed in the past half century, including infection (viral and bacterial), autoimmune disorders, proteins abnormality, and gene abnormality. Some of these are now considered to be historical achievements. Others, however, can be still subjected to contemporary research. Currently, several genetic abnormalities are considered to offer the most probable hypothesis. In addition, interesting papers have been presented on the role of the endothelial progenitor cell on the pathogenesis of moyamoya disease. Intuitively, however, it appears that a single theory cannot always explain the pathogenesis of this disease adequately. In other words, the complex mechanism of several factors may comprehensively explain the formation of moyamoya disease. The "double hit hypothesis" is probably the best explanation for the complicated pathology and epidemiology of this disease.

Analysis of human leucocyte antigen genes in Caucasian patients with idiopathic moyamoya angiopathy

BACKGROUND

The etiology and genetic susceptibility of Moyamoya angiopathy (MMA) (Moyamoya disease, Moyamoya syndrome and unilateral type of MMA) still remain unclear. In Asian patient cohorts several HLA markers were described to be associated with MMA, but in Caucasians very little is known about genetic susceptibility of this angiopathy.

METHOD

We analysed DNA of 33 Caucasian patients with MMA for HLA-A, HLA-B, HLA-DRB1, and HLA-DQB1 markers, respectively. HLA frequencies of all 33 patients with MMA were compared with HLA-frequencies of Caucasian controls. Additionally, subgroup analysis of 22 patients with Moyamoya disease (MMD) and 11 patients with unilateral type of MMA was performed.

FINDINGS

Significant association was observed for HLA-DRB1*03 and HLA-DRB1*13 in all 33 patients (P (c) < 0.001 and P (c) < 0.001, respectively). Moreover, HLA-A*02 (P (c) = 0.009); HLA-B*08 (P (c) = 0.009), and HLA-DQB1*03 (P (c) = 0.003) frequencies were higher in all patients with MMA when compared with the controls. In addition, in 22 patients with MMD a higher frequency of HLA-DRB1*03 (P (c) < 0.001) was observed when compared with controls.

CONCLUSIONS

The results of this study indicate a putative association of HLA markers with MMA in Caucasian patients. Further studies are needed to elucidate the role of human MHC in the pathogenesis of this angiopathy.

Genetics of Moyamoya disease

Moyamoya disease (MMD) is a disease pattern consisting of bilateral stenosis of the intracranial internal carotid arteries (ICA) accompanied by a network of abnormal collateral vessels that bypass the stenosis. Once symptomatic, insufficient cerebral blood flow or rupture of the fragile collaterals may cause stroke or hemorrhage, resulting in severe neurological dysfunction or death. The etiology of MMD is still unknown, although few associations with other diseases and environmental factors have been described. Strong regional differences in epidemiological data, as well as known familial cases, turned the focus to genetics for the insight into the disease's pathogenesis. Thus far, several reports have suggested specific genetic loci and individual genes as predisposing to MMD, but none have demonstrated reproducible results in independent cohorts. Small sample sizes, as well as a likely multifactorial origin, seem to be the most challenging tasks in identifying the disease-causing mechanisms. Once identified, susceptibility genes may allow preventive screening and a possible development of novel therapeutic options.

Comparative analysis of serum proteomes of moyamoya disease and normal controls

OBJECTIVE

The etiology and pathogenesis of moyamoya disease remain unclear. Furthermore, the definitive diagnostic protein-biomarkers for moyamoya disease are still unknown. The present study analyzed serum proteomes from normal controls and moyamoya patients to identify novel serological biomarkers for diagnosing moyamoya disease.

METHODS

We compared the two-dimensional electrophoresis patterns of sera from moyamoya disease patients and normal controls and identified the differentially-expressed spots by matrix-assisted laser desorption/ionization-time-of flight mass spectrometry and electrospray ionization quadruple time-of-flight mass spectrometry.

RESULTS

We found and analyzed 22 differently-expressed proteomes. Two proteins were up-regulated. Twenty proteins were down-regulated. Complement C1 inhibitor protein and apolipoprotein C-III showed predominantly changed expressions (complement C1 inhibitor protein averaged a 7.23-fold expression in moyamoya patients as compared to controls, while apolipoprotein C-III averaged a 0.066-fold expression).

CONCLUSION

Although our study had a small sample size, our proteomic data provide serologic clue proteins for understanding moyamoya disease.