Behçet's disease, the Silk Road and HLA-B51: historical and geographical perspectives

Genome-wide association analysis reveals the associations of NPHP4, TYW1-AUTS2 and SEMA6D for Behçet's disease and HLA-B*46:01 for its intestinal involvement

BACKGROUND

Intestinal involvement in Behçet's disease (BD) is associated with poor prognosis and is more prevalent in East Asian than in Mediterranean populations. Identifying the genetic causes of intestinal BD is important for understanding the pathogenesis and for appropriate treatment of BD patients.

METHODS

We performed genome-wide association studies (GWAS) and imputation/replication genotyping of human leukocyte antigen (HLA) alleles for 1,689 Korean and Turkish patients with BD (including 379 patients with intestinal BD) and 2,327 healthy controls, followed by replication using 593 Japanese patients with BD (101 patients with intestinal BD) and 737 healthy controls. Stratified cross-phenotype analyses were performed for 1) overall BD, 2) intestinal BD, and 3) intestinal BD without association of overall BD.

RESULTS

We identified three novel genome-wide significant susceptibility loci including NPHP4 (rs74566205; P=1.36 × 10-8), TYW1-AUTS2 (rs60021986; P=1.14 × 10-9), and SEMA6D (rs4143322; P=5.54 × 10-9) for overall BD, and a new association with HLA-B*46:01 for intestinal BD (P=1.67 × 10-8) but not for BD without intestinal involvement. HLA peptide binding analysis revealed that Mycobacterial peptides, have a stronger binding affinity to HLA-B*46:01 compared to the known risk allele HLA-B*51:01.

CONCLUSIONS

HLA-B*46:01 is associated with the development of intestinal BD; NPHP4, TYW1-AUTS2, and SEMA6D are susceptibility loci for overall BD.

Novel genetic variants of HLA gene associated with Thai Behcet's disease (BD) patients using next generation sequencing technology

Behçet's disease (BD) manifests as an autoimmune disorder featuring recurrent ulcers and multi-organ involvement, influenced by genetic factors associated with both HLA and non-HLA genes, including TNF-α and ERAP1. The study investigated the susceptible alleles of both Class I and II molecules of the HLA gene in 56 Thai BD patients and 192 healthy controls through next-generation sequencing using a PacBio kit. The study assessed 56 BD patients, primarily females (58.9%), revealing diverse manifestations including ocular (41.1%), vascular (35.7%), skin (55.4%), CNS (5.4%), and GI system (10.7%) involvement. This study found associations between BD and HLA-A*26:01:01 (OR 3.285, 95% CI 1.135-9.504, P-value 0.028), HLA-B*39:01:01 (OR 6.176, 95% CI 1.428-26.712, P-value 0.015), HLA-B*51:01:01 (OR 3.033, 95% CI 1.135-8.103, P-value 0.027), HLA-B*51:01:02 (OR 6.176, 95% CI 1.428-26.712, P-value 0.015), HLA-C*14:02:01 (OR 3.485, 95% CI 1.339-9.065, P-value 0.01), HLA-DRB1*14:54:01 (OR 1.924, 95% CI 1.051-3.522, P-value 0.034), and HLA-DQB1*05:03:01 (OR 3.00, 95% CI 1.323-6.798, P-value 0.008). However, after Bonferroni correction none of these alleles were found to be associated with BD. In haplotype analysis, we found a strong linkage disequilibrium in HLA-B*51:01:01, HLA-C*14:02:01 (P-value 0.0, Pc-value 0.02). Regarding the phenotype, a significant association was found between HLA-DRB1*14:54:01 (OR 11.67, 95% CI 2.86-47.57, P-value 0.001) and BD with ocular involvement, apart from this, no distinct phenotype-HLA association was documented. In summary, our study identifies specific HLA associations in BD. Although limited by a small sample size, we acknowledge the need for further investigation into HLA relationships with CNS, GI, and neurological phenotypes in the Thai population.

Characterization and Management of Amicrobial Pustulosis of the Folds, Aseptic Abscess Syndrome, Behçet Disease, Neutrophilic Eccrine Hidradenitis, and Pyostomatitis Vegetans-Pyodermatitis Vegetans

Neutrophilic dermatoses are a broadly heterogeneous group of inflammatory skin disorders. This article reviews 5 conditions: amicrobial pustulosis of the folds, aseptic abscess syndrome, Behçet disease, neutrophilic eccrine hidradenitis, and pyostomatitis vegetans-pyodermatitis vegetans.The authors include up-to-date information about their epidemiology, pathogenesis, clinicopathologic features, diagnosis, and management.

Behçet's Disease, Pathogenesis, Clinical Features, and Treatment Approaches: A Comprehensive Review

Behçet's disease is a systemic inflammatory disorder of unknown etiology. The disease manifests with diverse clinical symptoms, most commonly recurrent oral and genital ulcers, skin lesions, and uveitis, though it can affect multiple organ systems. Diagnosis is primarily clinical due to the lack of a definitive diagnostic test, and management involves a multidisciplinary approach to control inflammation and manage symptoms. Current treatment strategies involve corticosteroids, immunosuppressive agents, and, increasingly, biological therapies. Behçet's disease exhibits a higher prevalence along the Silk Road, suggesting a role of environmental and genetic factors. Despite significant progress in understanding its clinical characteristics and treatment approaches, gaps remain in our understanding of its pathogenesis. Future research is needed to elucidate the disease's pathophysiology and optimize treatment strategies.

An Exploration of Some Predictors of Quality of Life-Related to the Innate Immune System, Inflammation, and Disease Activity in Patients with Behcet's Syndrome: An Analytical Cross-sectional Study

BACKGROUND

Behçet's disease (BD) has a growing prevalence in Silk Road countries. The aim of our cross-sectional study was to explore the clinical and molecular predictors of quality of life in BD patients.

MATERIALS AND METHODS

One hundred and fifty consecutive Iranian BD patients with an age range between 20-50 years were included. The Leeds Behçet's disease quality of life (BDQoL) in Persian form was fulfilled to evaluate the quality of life. Anthropometric measurements were carried out using the calibrated scales. Iranian Behcet's Disease Dynamic Activity Measure (IBDDAM), Behcet's disease current activity form (BDCAF), and Total Inflammatory Activity Index (TIAI) were used to assess BD activity. mRNA expression of toll-like receptors 2 and 4 (TLR2 and TLR4) and tumor-necrosis-factor-alpha (TNF-α) levels in serum were measured by real-time polymerase chain reaction (PCR) and ELISA, respectively. Multiple linear backward regression at P = 0.1 was used to study the potential predictors of quality of life.

RESULTS

TLR2 and BDCAF were shown to be the most important predictors of quality of life in BD patients by 22%. There were positive associations between them (β = 0.326, p = 0.013 for BDCAF; β = 0.366, p = 0.006 for TLR2) and BDQoL value.

CONCLUSION

Higher TLR2 expression as a key protein in recognizing pathogens by innate immunity and BDCAF value as a comprehensive BD assessing scale contribute to poor quality of life among BD patients. Emphasizing therapeutically, approaches associated with lower TLR2 expression and BDCAF value can be considered in future studies.

When it looks like Behçet's syndrome but is something else: differential diagnosis of Behçet's syndrome: a two-centre retrospective analysis

OBJECTIVE

To investigate the differential diagnostic spectrum in patients with suspected Behçet's syndrome (BS) in low prevalence regions. In addition, the number of patients fulfilling the ICBD criteria despite not having BS was evaluated.

METHODS

This retrospective analysis was performed in two referral centres for BS. Patients with confirmed BS (clinical diagnosis with fulfilment of ISG criteria or a score of ≥5 points in the ICBD criteria) were excluded. The remaining patients were divided into 11 differential diagnosis categories. If no definitive alternative diagnosis could be established, patients were termed 'probable BS' in case of (i) relapsing orogenital aphthosis in the absence of other causes and either HLA-B51 positivity, or origin from an endemic area or presence of an additional typical BS symptom that is not part of the classification criteria, or (ii) with 3-4 points scored in the ICBD criteria.

RESULTS

In total 202 patients were included and categorized as follows: 58 patients (28.7%) as 'probable BS', 57 (28.2%) skin disease, 26 (12.9%) chronic pain syndrome, 14 (6.9%) eye disease, 11 (5.4%) spondyloarthropathy, 9 (4.5%) gastrointestinal disease, 7 (3.5%) neurological disease, 4 (2%) arthritis, 3 (1.5%) auto-inflammation, 3 (1.5%) connective tissue disease and 10 (5.0%) miscellaneous disease. HLA-B51 was positive in 55/132 (41.7%); 75/202 (37.1%) of the patients fulfilled the ICBD criteria.

CONCLUSION

In a low disease prevalence setting, the straightforward application of the ICBD criteria may lead to overdiagnosis of BS. The differential diagnosis of BS is enormously broad. Clinicians should be aware that HLA-B51 positivity is still not considered as a diagnostic feature in BS.

The relationship between HLA-B*51 subtypes, clinical manifestations and severity of Behçet's syndrome: a large Italian cohort study

Objectives

Behçet's syndrome (BS) is a chronic multisystemic inflammatory disorder of unclear aetiology. The predominant BS susceptibility locus was identified within HLA-B*51. HLA-B*51 subtypes were previously studied as disease susceptibility markers. Few data are now available about the relationship between B*51 subtypes and clinical phenotype. The aim of this study was to genotype HLA-B*51 subtypes in a series of Italian BS patients and to test the association with clinical manifestations and disease severity (Krause's index).

Methods

HLA-B*51 subtype genotyping for 63 alleles (B*51:01-B*51:63) was performed by PCR after DNA extraction from whole blood of BS patients. The correlation of disease clinical manifestations and severity (Krause's index) with the HLA-B*51 allele and its subtypes was analysed.

Results

We enrolled 241 (140 male and 101 female) BS patients, and HLA-B*51 frequency was 62.7% (151 of 241). One hundred and eight of the HLA-B*51-positive patients carried the B*51:01 subtype (108 of 151, 71.5%), 39 of 151 (25.8%) the B*51:08 subtype, 2 of 151 (1.3%) the B*51:02 subtype, 1 of 151 (0.7%) the B*51:05 subtype, and 1 of 151 (0.7%) the B*51:07 subtype. We found that ocular involvement was statistically associated with HLA-B*51 positivity and with B*51:01 and B*51:08 subtypes (P < 0.05). We also found that disease severity was higher in HLA-B*51-positive patients than in negative patients, but without statistical significance (median Krause's index 5.1 vs 4.1, P > 0.05).

Conclusion

Here, we confirm a high frequency of the HLA-B*51 allele in our group of BS patients. B*51:01 and B*51:08 were found to be the most common subtypes, and an association of both subtypes with ocular involvement was also underlined.

Neurological involvement by Behçet's syndrome: clinical features, diagnosis, treatment and outcome

Neurological involvement in Behçet's syndrome arises predominately through an inflammatory meningoencephalitis characterised by perivenular inflammation due to activation of Th-17 immunological pathways. The brainstem is involved in 50% of cases, the diencephalon and other areas of the brain in 30%, and the spinal cord in 10%. Movement disorders and epilepsy may occur. Psychiatric syndromes may arise with brain and brainstem involvement, and cognitive disorders relate to the brain disease, to circulating inflammatory factors, and to fatigue and despondency. Eighty per cent of cases begin with a relapsing disease course, of whom 70% have only one attack, and 30% have a progressive disease course either from onset or following an initially relapsing course. Venous thrombosis leading to intracranial hypertension and cerebral venous infarction is less common and caused by inflammation in affected veins and a circulating prothrombotic state. Arterial involvement is rare and relates to an arteritis affecting large-sized and medium-sized vessels within the brain leading to infarction, subarachnoid and parenchymal haemorrhage, aneurysm formation and arterial dissection. There is a newly recognised disorder of cerebral cortical hypoperfusion. Cranial neuropathy, peripheral neuropathy and myositis are rare. There has been significant progress in understanding the pathophysiology and treatment of the systemic disease, leading to improved outcomes, but there has been no randomised trial of treatment in the neurological disorder.

Characteristics of Patients With Behçet Disease From the Van Province, Eastern Turkey: Definition of Disease Clusters in a Tertiary Referral Center

BACKGROUND

Behçet disease (BD) is a chronic inflammatory systemic disease that affects skin mucosa, joints, eyes, and blood vessels. Behçet disease shows some clinical differences in terms of disease manifestations and prognosis among the Silk Road countries, as well as various ethnicities even in the same country. In this study, we aimed to evaluate the clinical features and disease course of BD using cluster analysis in Van province, Eastern Turkey.

METHODS

This study was carried out in a tertiary referral center in Van province, by reviewing medical records. Seven disease manifestations were included to the cluster analysis as follows: mucocutaneous findings (oral ulcer, genital ulcer, erythema nodosum-like lesions, pseudofolliculitis), uveitis, superficial thrombophlebitis, musculoskeletal involvement, gastrointestinal system involvement, vascular involvement, and parenchymal central nervous system involvement.

RESULTS

We identified 467 patients. After the exclusion of 6 patients who had missing data and 17 patients who did not live in Van, 444 patients (59.2% male) included into the study. Meeting the International Study Group and the International Criteria for Behçet Disease criteria were 91.6% and 96%, respectively, and 91.3% (n = 379/415) of these patients met both criteria. Four clusters were identified in the analyses: 132 patients (31.2%) in vascular (C1), 66 patients (15.6%) in ocular (C2), 60 patients (14.2%) in musculoskeletal (C3), and 165 patients (39%) in mucocutaneous (C4) clusters. Male gender ( p = 0.002; odds ratio [OR], 6.5; 95% confidence interval [CI], 2-21.4), superficial thrombophlebitis ( p = 0.001; OR, 4.7; 95% CI, 1.9-11.4), and uveitis ( p = 0.01; OR, 3.6; 95% CI, 1.3-9.9) were associated with vascular involvement in multivariate analysis.

CONCLUSIONS

In our study, 4 clusters were detected in patients with BD from Van province. The prevalence of severe manifestations of BD may be related to genetic or environmental factors, such as differences in ethnicity and/or geographical differences. Despite the higher proportion of patients with a more severe disease, a favorable outcome was observed in our cohort.

Case report: A case of neuro-Behçet's syndrome presenting as brain stem mass lesions

Neuro-Behçet's syndrome, a severe and rare manifestation of Behçet's disease (BD), can be misdiagnosed due to its challenging clinical presentation. This article presents the case of a 20-year-old cis-gender male with intermittent fever, bilateral uveitis, and neurological symptoms who was found to have multiple brain stem mass lesions on brain imaging. A careful medical history elicited recurrent painful oral and genital ulcerations which were important in making the correct diagnosis. As there are no validated criteria or definite set of tests available to confirm neuro-Behçet's disease, the diagnosis is often established by exclusion after ruling out other potential etiologies. In our case, after an extensive negative workup for infectious, neuro-degenerative and malignant etiologies combined with the patient's medical history, a diagnosis of Behçet's disease with neurological involvement (neuro-Behçet's syndrome) was made. High doses of steroids were given, and the patient had a favorable outcome. Repeated magnetic resonance imaging of the brain 2 years later showed no new brain lesions. Neuro-Behçet's disease should be included as a differential diagnosis of unexplained brain stem lesions in the right clinical context. In these situations, providers should obtain medical histories related to genital and oral ulcers and eye problems as these may help to narrow down the diagnosis. The clinical presentation and challenges of this uncommon presentation of BD including a brief literature review of neuro-Behçet's disease with brain stem mass lesions are discussed in this case study.

Innate immune responses in Behçet disease and relapsing polychondritis

Behçet disease (BD) and relapsing polychondritis (RP) are chronic multisystem disorders characterized by recurrent flare-ups of tissue inflammation. Major clinical manifestations of BD are oral aphthae, genital aphthous ulcers, skin lesions, arthritis, and uveitis. Patients with BD may develop rare but serious neural, intestinal, and vascular complications, with high relapse rates. Meanwhile, RP is characterized by the inflammation of the cartilaginous tissues of the ears, nose, peripheral joints, and tracheobronchial tree. Additionally, it affects the proteoglycan-rich structures in the eyes, inner ear, heart, blood vessels, and kidneys. The mouth and genital ulcers with inflamed cartilage (MAGIC) syndrome is a common characteristic of BD and RP. The immunopathology of these two diseases may be closely related. It is established that the genetic predisposition to BD is related to the human leukocyte antigen (HLA)-B51 gene. Skin histopathology demonstrates the overactivation of innate immunity, such as neutrophilic dermatitis/panniculitis, in patients with BD. Monocytes and neutrophils frequently infiltrate cartilaginous tissues of patients with RP. Somatic mutations in UBA1, which encodes a ubiquitylation-related enzyme, cause vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic syndrome (VEXAS) with severe systemic inflammation and activation of myeloid cells. VEXAS prompts auricular and/or nasal chondritis, with neutrophilic infiltration around the cartilage in 52-60% of patients. Thus, innate immune cells may play an important role in the initiation of inflammatory processes underlying both diseases. This review summarizes the recent advances in our understanding of the innate cell-mediated immunopathology of BD and RP, with a focus on the common and distinct features of these mechanisms.

Identification of the immune-related biomarkers in Behcet's disease by plasma proteomic analysis

BACKGROUND

This study aimed to investigate the expression profile of immune response-related proteins of Behcet's disease (BD) patients and identify potential biomarkers for this disease.

METHODS

Plasma was collected from BD patients and healthy controls (HC). Immune response-related proteins were measured using the Olink Immune Response Panel. Differentially expressed proteins (DEPs) were used to construct prediction models via five machine learning algorithms: naive Bayes, support vector machine, extreme gradient boosting, random forest, and neural network. The prediction performance of the five models was assessed using the area under the curve (AUC) value, recall (sensitivity), specificity, precision, accuracy, F1 score, and residual distribution. Subtype analysis of BD was performed using the consensus clustering method.

RESULTS

Proteomics results showed 43 DEPs between BD patients and HC (P < 0.05). These DEPs were mainly involved in the Toll-like receptor 9 and NF-κB signaling pathways. Five models were constructed using DEPs [interleukin 10 (IL10), Fc receptor like 3 (FCRL3), Mannan-binding lectin serine peptidase 1 (MASP1), NF2, moesin-ezrin-radixin like (MERLIN) tumor suppressor (NF2), FAM3 metabolism regulating signaling molecule B (FAM3B), and O-6-methylguanine-DNA methyltransferase (MGMT)]. Among these models, the neural network model showed the best performance (AUC = 0.856, recall: 0.692, specificity: 0.857, precision: 0.900, accuracy: 0.750, F1 score: 0.783). BD patients were divided into two subtypes according to the consensus clustering method: one with high disease activity in association with higher expression of tripartite motif-containing 5 (TRIM5), SH2 domain-containing 1A (SH2D1A), phosphoinositide-3-kinase adaptor protein 1 (PIK3AP1), hematopoietic cell-specific Lyn substrate 1 (HCLS1), and DNA fragmentation factor subunit alpha (DFFA) and the other with low disease activity in association with higher expression of C-C motif chemokine ligand 11 (CCL11).

CONCLUSIONS

Our study not only revealed a distinctive immune response-related protein profile for BD but also showed that IL10, FCRL3, MASP1, NF2, FAM3B, and MGMT could serve as potential immune biomarkers for this disease. Additionally, a novel molecular disease classification model was constructed to identify subsets of BD.

Case of elderly onset possible neuro-Behçet's disease with HLA-B51 homozygosity

Behçet's disease commonly affects 20-40-year-old men and shows ophthalmo-dermatological manifestations. Here, we report a man in his 70s with acute onset of dysarthria, dysphagia and hemiplegia showing brainstem and subcortical lesions, which responded to steroid and colchicine therapy. He had a history of uveitis and was homozygous for the human leucocyte antigen-B51 allele, and we clinically diagnosed him with acute neuro-Behçet's disease. Old-age onset neuro-Behçet's disease is uncommon, and as far as we know, this is the oldest case of the first attack of neuro-Behçet's disease. Clinicians should consider Behçet's disease even for elderly patients.

Behçet disease, familial Mediterranean fever and MEFV variations: More than just an association

Behçet disease (BD) and familial Mediterranean fever (FMF) are two inflammatory disorders that share many features including historical background, ethnical distribution and inflammatory characteristics. Several studies suggested that BD and FMF might occur in the same individual more commonly than expected. Additionally, the pathogenic MEFV gene variants, especially p.Met694Val, activating the inflammasome complex have been shown to increase the risk for BD in regions where both FMF and BD are prevalent. Whether these variants are associated with certain disease subtypes and whether they may help in the planning of treatment need to be explored. This review provides a recent overview of the plausible association between FMF and BD and the role of MEFV variants in the pathogenesis of BD.

Evaluation of HLA-B51 frequency and its relationship with clinical findings in patients with Behçet’s disease: 4-year analysis in a single center

Background

The clinical findings of Behçet’s disease (BD) differ according to the country and race investigated. The most important genetic factor known in the pathogenesis of BD is HLA-B51, and this positivity is high in countries on the “Silk Road” where BD is as frequent as it is in Turkey. Although the positivity of HLA B51 is proven to be high in Turkey, there are no studies in the area of the western Black sea demonstrating its relation to the demographic. We aimed to investigate the association of HLA-B51 positivity in Turkish patients diagnosed as having BD and the relationship between the demographic and clinical findings of the patients.

Results

In this descriptive, cross-sectional study, a convenience sample of adults with BD was obtained from an outpatient clinic of a university hospital in Turkey between January 2018 and January 2022. Patients were diagnosed as having BD according to the criteria of the International BD Study Group, and the patients’ sociodemographic and clinical characteristics were recorded retrospectively. Demographic data and the frequency of clinical findings were compared between patients who were HLA-B51-positive and HLA-B51-negative. Sixty patients (55.6%) were HLA-B51-positive. Oral ulceration, genital ulceration, thrombophlebitis, and family history of BD were found to be higher in patients who were HLA-B51-positive. Erythema nodosum, papulopustular eruption, pathergy positivity, arthritis, and ocular involvement were less frequent in patients with HLA-B51 positivity. However, there were no statistically significant differences according to the frequency of clinical findings between the HLA-B51-positive and HLA-B51-negative groups.

Conclusions

HLA B51 positivity is not diagnostic of BD; however, it may affect clinical phenotypes. Although oral and genital ulcerations, thrombophlebitis, and positive family history of BD were found to be common in patients with HLA-B51 positivity, this relationship could not reach statistical significance.

SNP rs7130280 in lncRNA NONHSAT159216.1 confers susceptibility to Behçet's disease uveitis in a Chinese Han population

OBJECTIVE

Long noncoding RNA (lncRNA) plays a crucial role in the process of immune-mediated diseases. However, the defined involvement of lncRNA on Behçet's disease (BD) is not well known. The aim of this study was to investigate the effects of lncRNA-related single nucleotide polymorphisms (SNPs) on BD susceptibility in Chinese populations.

METHODS

A two-stage case-control association study was conducted in a cohort of 1152 BD individuals and 1152 healthy controls. Genotyping was performed by a MassARRAY System. Quantified expression of the lncRNA-miRNA-mRNA molecular axis was detected by real-time PCR and western blot. The cell proliferation was measured by CCK-8 assay.

RESULTS

Two-stage association analysis showed a significantly decreased frequency of A allele of SNP rs7130280 in BD patients compared with healthy controls [OR 0.72 (95% CI 0.64, 0.81), Pc = 1.15 × 10-6]. Functionally, SNP rs7130280 could influence the secondary structure and relative expression of NONHSAT159216.1 in human THP-1/U937 macrophages and in peripheral blood mononuclear cells from healthy volunteers. In vitro, overexpression of the rs7130280 A allele also suppressed cell proliferation. Mechanistically, rs7130280 A allele could inhibit the expression of miR-6778-5p, thus enhancing its downstream molecular RPS6KA4/IL10 in a competing endogenous RNA sponge manner.

CONCLUSION

Our findings suggest that NONHSAT159216.1 rs7130280 G>A might be associated with a low risk of BD and participates in a potential lncRNA-miRNA-mRNA regulatory network.

A comprehensive guide for managing the reproductive health of patients with vasculitis

Vasculitides and their therapies affect all areas of the reproductive life cycle. The ACR, EULAR and the Drugs and Lactation database offer guidance on the management of the reproductive health of patients with rheumatic diseases; however, these guidelines do not address patients with vasculitis specifically. This Review discusses the guidance from multiple expert panels and how these recommendations might apply to men and women with vasculitis, including the safety of contraception, use of assisted reproductive technology, preservation of fertility during cyclophosphamide therapy, disease management in pregnancy and the use of medications compatible with pregnancy and lactation. These discussions are augmented by the existing literature on vasculitis in pregnancy to enable physicians to provide comprehensive, precise and high quality care to patients with vasculitis. The contents of this Review, in conjunction with educational tools, serve to empower patients and physicians to participate in shared decision-making regarding pregnancy prevention, planning and management.

This Review discusses how best to manage the reproductive health of patients with vasculitis, including the safety of contraception, the use of assisted reproductive technology, preservation of fertility during therapy, disease management in pregnancy and the use of medications compatible with pregnancy and lactation.

Rheumatologists have the opportunity to initiate discussions with patients with vasculitis regarding family planning to make proactive decisions leading to improved pregnancy planning, management and outcomes.

Birth control options and infertility interventions for women with vasculitis depend on their risk of thrombosis, serological profile and comorbid conditions.

The majority of pregnancies in patients with vasculitis can be successful with the use of advanced family planning, medications compatible with pregnancy and lactation, and multidisciplinary collaboration among specialists.

Vasculitis exacerbations and pregnancy complications can present with similar and overlapping clinical manifestations.

Multiple expert panels provide guidelines and risk stratification regarding medication use in pregnancy and breastfeeding that can be applied to patients with vasculitis.

Sex-specific analysis in Behçet's disease reveals higher genetic risk in male patients

OBJECTIVES

Behçet's disease tends to be more severe in men than women. This study was undertaken to investigate sex-specific genetic effects in Behçet's disease.

METHODS

A total of 1762 male and 1216 female patients with Behçet's disease from six diverse populations were studied, with the majority of patients of Turkish origin. Genotyping was performed using an Infinium ImmunoArray-24 BeadChip, or extracted from available genotyping data. Following imputation and extensive quality control measures, genome-wide association analysis was performed comparing male to female patients in the Turkish cohort, followed by a meta-analysis of significant results in all six populations. In addition, a weighted genetic risk score for Behçet's disease was calculated and compared between male and female patients.

RESULTS

Genetic association analysis comparing male to female patients with Behçet's disease from Turkey revealed an association with male sex in HLA-B/MICA within the HLA region with a GWAS level of significance (rs2848712, OR = 1.46, P = 1.22 × 10-8). Meta-analysis of the effect in rs2848712 across six populations confirmed these results. Genetic risk score for Behçet's disease was significantly higher in male compared to female patients from Turkey. Higher genetic risk for Behçet's disease was observed in male patients in HLA-B/MICA (rs116799036, OR = 1.45, P = 1.95 × 10-8), HLA-C (rs12525170, OR = 1.46, P = 5.66 × 10-7), and KLRC4 (rs2617170, OR = 1.20, P = 0.019). In contrast, IFNGR1 (rs4896243, OR = 0.86, P = 0.011) was shown to confer higher genetic risk in female patients.

CONCLUSIONS

Male patients with Behçet's disease are characterized by higher genetic risk compared to female patients. This genetic difference, primarily derived from our Turkish cohort, is largely explained by risk within the HLA region. These data suggest that genetic factors might contribute to differences in disease presentation between men and women with Behçet's disease.

Association of miRNA-146a Gene Polymorphism Rs2910164 with Behcet's Disease: A Meta-analysis

BACKGROUND

A meta-analysis was performed by summarizing relevant researches to evaluate the relationship between miRNA-146a gene polymorphism rs2910164 and Behcet's disease (BD).

METHODS

A systematic search of published studies was conducted in PubMed and Embase. Five eligible studies involving 1167 BD cases and 1662 controls were included in the current meta-analysis.

RESULTS

The results suggested that the polymorphism rs2910164 was correlated with BD susceptibility in all genetic models. In subgroup analysis according to ethnicity, the relationship between this polymorphism and BD was more significant in Caucasians (allele model: OR = 0.49, 95% CI 0.39-0.61; heterozygote model: OR = 0.35, 95% CI 0.26-0.47; homozygote model: OR = 0.29, 95% CI 0.16-0.53; dominant model: OR = 0.34, 95% CI 0.25-0.45; recessive model: OR = 0.56, 95% CI 0.50-0.72) than that in Asians.

CONCLUSION

In conclusion, this meta-analysis indicates that miRNA-146a gene polymorphism rs2910164 G allele confers BD susceptibility, especially in Caucasians.

Diverse selection pressures shaping the genetic architecture of behçet disease susceptibility

Behçet disease (BD) is a polygenic, multifactorial, multisystem inflammatory condition with unknown etiology. Global distribution of BD is geographically structured, highest prevalence observed among East Asian, Middle Eastern, and Mediterranean populations. Although adaptive selection on a few BD susceptibility loci is speculated, a thorough evolutionary analysis on the genetic architecture of BD is lacking. We aimed to understand whether increased BD risk in the human populations with high prevalence is due to past selection on BD associated genes. We performed population genetics analyses with East Asian (high BD prevalence), European (low/very low BD prevalence), and African (very low/no BD prevalence) populations. Comparison of ancestral and derived alleles’ frequencies versus their reported susceptible or protective effect on BD showed both derived and ancestral alleles are associated with increased BD risk. Variants showing higher risk to and more significant association with BD had smaller allele frequency differences, and showed less population differentiation compared to variants that showed smaller risk and less significant association with BD. Results suggest BD alleles are not unique to East Asians but are also found in other world populations at appreciable frequencies, and argue against selection favoring these variants only in populations with high BD prevalence. BD associated gene analyses showed similar evolutionary histories driven by neutral processes for many genes or balancing selection for HLA (Human Leukocyte Antigen) genes in all three populations studied. However, nucleotide diversity in several HLA region genes was much higher in East Asians suggesting selection for high nucleotide and haplotype diversity in East Asians. Recent selective sweep for genes involved in antigen recognition, peptide processing, immune and cellular differentiation regulation was observed only in East Asians. We conclude that the evolutionary processes shaping the genetic diversity in BD risk genes are diverse, and elucidating the underlying specific selection mechanisms is complex. Several of the genes examined in this study are risk factors (such as ERAP1, IL23R, HLA-G) for other inflammatory diseases. Thus, our conclusions are not only limited to BD but may have broader implications for other inflammatory diseases.

Risk for Behçet's disease gauged via high-density lipoprotein cholesterol: a nationwide population-based study in Korea

Behçet’s disease (BD) is a chronic inflammatory disease. Low levels of plasma high-density lipoprotein cholesterol (HDL-C) are associated with Crohn’s disease, another chronic inflammatory disease. However, the effects of low HDL-C levels on BD are unclear. We investigated the effects of HDL-C levels, and variability therein, on the risk for BD. We used the Korean National Health Insurance System database to identify 5,587,754 adults without a history of BD who underwent ≥ 3 medical examinations between 2010 and 2013. Mean HDL-C levels at each visit were used to calculate variability independent of the mean (VIM) and the coefficient of variation (CV). There were 676 new cases of BD (0.012%). The risk for BD was increased in participants with highly variable and low mean HDL-C levels. In a multivariate-adjusted model, the hazard ratios (95% confidence intervals) for BD incidence were 1.335 (1.058–1.684) in a high mean/high VIM group, 1.527 (1.211–1.925) in a low mean/low VIM group, and 2.096 (1.67–2.63) in a low mean/high VIM group compared to a high mean/low VIM group. Low mean HDL-C levels, and high variability therein, are independent risk factors for BD.

Macrophage-like Cells Characterized by En Face Optical Coherence Tomography was Associated with Fluorescein Vascular Leakage in Behçet's Uveitis

PURPOSE

To investigate the features of macrophage-like cell (MLC) characterized by en face optical coherence tomography (OCT) in Behçet's uveitis (BU).

METHODS

The extent of fluorescein vascular leakage (FVL) was graded on a scale of 0-3 (0=none, 1=mild, 2=moderate, 3=severe) for the optic nerve head (ONH), macula and peripheral retina. The 3μm en face OCT slabs on inner limiting membrane of ONH or macular region was used to visualize the MLCs.

RESULTS

The MLC densities of BU group in ONH and macular region were significantly higher than the control group (both p<0.001). The ONH and macular MLC density were significantly higher in eyes with higher FVL grade and they were positively correlated with FVL score (all p<0.001).

CONCLUSION

MLC density was elevated in Behçet's uveitis and it may serve as a noninvasive indicator for the severity of fluorescein leakage and retinal inflammation in Behcet's uveitis.

Population Genetics and Signatures of Selection in Early Neolithic European Farmers

Human expansion in the course of the Neolithic transition in western Eurasia has been one of the major topics in ancient DNA research in the last 10 years. Multiple studies have shown that the spread of agriculture and animal husbandry from the Near East across Europe was accompanied by large-scale human expansions. Moreover, changes in subsistence and migration associated with the Neolithic transition have been hypothesized to involve genetic adaptation. Here, we present high quality genome-wide data from the Linear Pottery Culture site Derenburg-Meerenstieg II (DER) (N = 32 individuals) in Central Germany. Population genetic analyses show that the DER individuals carried predominantly Anatolian Neolithic-like ancestry and a very limited degree of local hunter-gatherer admixture, similar to other early European farmers. Increasing the Linear Pottery culture cohort size to ∼100 individuals allowed us to perform various frequency- and haplotype-based analyses to investigate signatures of selection associated with changes following the adoption of the Neolithic lifestyle. In addition, we developed a new method called Admixture-informed Maximum-likelihood Estimation for Selection Scans that allowed us test for selection signatures in an admixture-aware fashion. Focusing on the intersection of results from these selection scans, we identified various loci associated with immune function (JAK1, HLA-DQB1) and metabolism (LMF1, LEPR, SORBS1), as well as skin color (SLC24A5, CD82) and folate synthesis (MTHFR, NBPF3). Our findings shed light on the evolutionary pressures, such as infectious disease and changing diet, that were faced by the early farmers of Western Eurasia.

Incidence of ophthalmic involvement in Behçet's disease in the United Kingdom: a British Ophthalmic Surveillance Unit (BOSU) study

BACKGROUND

Behçet's disease (BD) is a relapsing-remitting vasculitis, which can manifest in different organ systems including the eyes. There is currently limited published data describing the incidence of ophthalmic disease within the United Kingdom. The primary aim of this study was to survey the incidence and manifestations of ophthalmic BD prospectively, with a secondary aim of reviewing treatment modalities initiated in first-line therapy.

METHODS

Using the British Ophthalmic Surveillance Unit reporting system between October 2016 and November 2018, we prospectively surveyed the number of cases of BD presenting to UK ophthalmologists. A total of 89 cases of ophthalmic manifestations of BD were reported and complete information was collected on 58 patients.

RESULTS

93 eyes of 58 patients were affected. The median age of reported cases was 31 years (range 13-55 years) who were born in 15 different countries. Most cases (n = 35, 60%) had bilateral involvement. Vitritis was the most common ocular manifestation (68%; n = 63) followed by anterior uveitis (46%; n = 43). The greatest causes of visual morbidity were cystoid macular oedema, vitritis and retinal ischaemia. Most patients were prescribed either topical or oral corticosteroids (59%; n = 34), with some given intravitreal or intravenous corticosteroids. Five patients (8.6%) were initiated on disease-modifying anti-rheumatic drugs and one given an anti-TNF monoclonal antibody.

CONCLUSIONS

This is the first prospective study to analyse the incidence of ophthalmic involvement in BD over a 2-year period, finding an annual incidence of 0.04 per 100,000 individuals in the UK.

Uveitis Patterns and Severity: An Epidemiologic Study from a Tertiary Care Private Referral Center in Buenos Aires, Argentina

PURPOSE

To report uveitis' spectrum in a private practice cohort in the city of Buenos Aires, Argentina.

METHODS

Retrospective review at Instituto de la Visión (November 2011-October 2015). Standard demographics, ethnicity and Native American aboriginal ancestry were recorded.

RESULTS

Among 212 patients, median age 45 (6-97), 10% pediatric, 35% bilateral, 72% non-idiopathic, 36% infectious. Anterior uveitis presented in 50%, followed by posterior (32%), intermediate (9%) and panuveitis (8%). Frequent visits (≥ 6 per year) needed by 29%: posterior, non-idiopathic disease with 79% systemic immunosuppression requirement was their main presentation. Native American aboriginal ancestry was reported by 22.64% of the whole cohort and 37% of frequent visits' subgroup.

CONCLUSIONS

Unilateral, non-idiopathic, non-infectious anterior uveitis was the most frequent presentation, in agreement with reports coming from western developed cities. The multi-racial Argentinian population with specific Native American aboriginal ancestry might contribute to certain forms of posterior uveitis and their response to treatment.

SMALL BOWEL IS LARGELY AFFECTED IN BEHÇET’S DISEASE: A LONG-TERM FOLLOW-UP OF GASTROINTESTINAL SYMPTOMS

ABSTRACT Background Behçet’s disease is a rare immune-mediated disorder that can affect the gastrointestinal tract. The prevalence and extension of small bowel involvement is largely unknown. Objective The aim of this study was to describe the small bowel lesions diagnosed by double-balloon enteroscopy (DBE) and to verify if these findings were associated to the presence of gastrointestinal symptoms and disease activity after long-term follow-up. Methods This study included 19 Behçet’s disease patients who underwent DBE. After a mean follow-up of 15 years the endoscopic findings were associated to the presence of gastrointestinal symptoms, disease activity and current therapy through collection of electronic medical records. Results A total of 63.2% patients were female and the mean age was 37 years at the time of DBE. Mean disease duration at baseline was 24 years. 11 patients had no gastrointestinal symptoms and eight patients presented either abdominal pain, gastrointestinal bleeding or diarrhea. The average procedure time was 1 hour and 30 minutes and the ileum was achieved in all patients but one. Small bowel ulcers were diagnosed in 78.9%, with 63.1% of jejunal involvement. Two patients presented only small bowel edema and two were normal by DBE. Eight patients had concomitant gastric ulcers. Gastrointestinal symptoms prior to DBE were present in 36.8% of the patients and, after follow-up, all of them persisted with some of the symptoms. Bleeding was reported by three patients at baseline and persisted in only one patient. The frequency of treatment with steroids and immunomodulators was 31.6% and 57.9% at baseline, respectively, and 21% in both at the end of the follow-up. No patient was treated with biologics at the time of the DBE procedure and the current rate of biologic use is 21%. Conclusion Small bowel involvement in Behçet’s disease was frequently demonstrated by DBE even in asymptomatic patients. Understanding clinical evolution of the disease over the years and the impact of such diagnosis still represents a challenge, possibly with the need for novel treatment.

Anesthetic Management of an Obstetric Patient with Behçet’s Disease Complicated by Transverse Myelitis

Transverse myelitis is an acute inflammation of the spinal cord. Its annual incidence is 1–8 per million. Behçet disease is also a rare autoimmune disease. Transverse myelitis can be a manifestation of neuro-Behçet’s disease. For those two rare diseases to present in one patient sets a challenge in anesthetic management. Up to our knowledge, our approach to managing these cases has not been reported in the literature. We present the case of a 37-year-old female patient in her 34th week of pregnancy, showing manifestations of neuro-Behçet’s disease and recurrent transverse myelitis. She presented to the preanesthesia clinic on a wheelchair with worsening of baseline right lower limb weakness. The patient elected for neuroaxial anesthesia, and the procedure was conducted without complications. The patient was followed up for 6 months. The neuroaxial approach was successful. Patients with neuro-Behçet’s disease and transverse myelitis can be safely managed with epidural anesthesia.

Vascular complications of Behçet disease

Behçet disease is a multi-systemic complex vasculitis with unknown etiology characterized by different clinical involvements, including mucocutaneous, ocular, vascular, articular, neurological, and gastrointestinal manifestations. Growing evidence supports that different phenotypes, characterized by clusters of co-existing involvements, can be distinguished. Namely, the vascular phenotype identifies a specific group of patients who suffer from recurrent inflammatory thrombosis and arterial involvement. Vascular disease develops in up to 40% with a definite male preponderance and is usually an early manifestation. Venous involvement is significantly more common than arterial disease, and lower extremity deep vein thrombosis is its most frequent manifestation. Arterial disease involves mostly pulmonary arteries and aorta and manifests mainly in the form of aneurysms. Glucocorticoids and immunosuppressants are the recommended first-line treatments in vasculo-Behçet. Furthermore, controlled trials are still needed to assess the role of adding anticoagulation to the treatment regimen, with an accent on new oral anticoagulants. Treatment with anti-TNF alpha agents seems promising, but the management strategies are not clear yet.

Saliva and Serum Cytokine Profiles During Oral Ulceration in Behçet's Disease

Behçet's disease (BD) is a chronic, multi-systemic disorder of unknown aetiology typified by recurrent oral and genital mucocutaneous lesions, uveitis and vasculitis. Innate and adaptive immune system dysregulation has been implicated in pathogenesis with alterations in serum cytokine profiles. Few studies have investigated salivary cytokines in BD, despite more than 90% of BD patients first presenting with oral ulceration. The aim of this pilot study was twofold; firstly to investigate whether cytokine levels in matched serum and saliva samples show a differential profile in BD (with and without oral ulcers), recurrent aphthous stomatitis (RAS) and healthy controls (HCs), and secondly, to explore if any differential profiles in serum and/or saliva could provide a panel of cytokines with diagnostic and therapeutic potential for BD. Concentrations of 12 cytokines (IL-1β, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12p70, IL-17A, IFN-γ, TNF-α, TNF-β) were measured using the Human Th1/Th2 11-Plex FlowCytomix™ kit with IL-17A, in BD (N=20), RAS (N=6) and HCs (N=10). A differential range of cytokines was detected in serum and saliva with the majority of cytokine levels higher in saliva. The most prevalent salivary cytokines were IL-1β, IL-2, IL-8, IL-10 and TNF-α present in all samples in contrast to serum where the most prevalent cytokine detected was IL-8 (91.9%). The least abundant cytokine was IFN-γ in both saliva (43.2%) and serum (2.7%). After normalizing saliva for protein content, BD patients with oral ulcers (BD-MA) had significantly higher levels of salivary IL-1β (p=0.01), IL-8 (p=0.02), TNF-α (p=0.004) and IL-6 (p=0.01) than HCs. Notably, BD patients without oral ulcers (BD-MQ) also had significantly higher salivary IL-1β, IL-8 and TNF-α (p ≤ 0.05) than HCs. During relapsed (BD-RE) and quiet (BD-Q) systemic episodes, salivary IL-β and TNF-α were also significantly increased with IL-8 significantly higher only in BD-Q (p=0.02). BD oral ulcers signify a potential reactivation of systemic inflammation. Identifying cytokines released during asymptomatic episodes and oral ulceration might lead to targeted drug therapy to prevent recurrent oral ulcers and possible disease relapse. This is the first study to report salivary cytokine levels in BD. The detectable levels suggests cytokine profiling of BD saliva may provide an alternative, less invasive, sensitive procedure for frequent monitoring of disease activity and progression.

The association of Behçet's syndrome with HLA-B51 as understood in 2021

PURPOSE OF REVIEW

To discuss clinical and pathogenic roles of HLA-B∗51 in Behçet's syndrome.

RECENT FINDINGS

HLA-B∗51 remains the most important genetic factor in Behçet's syndrome, despite the recent identification of several susceptibility genes. The prevalence of HLA-B∗51 has been shown to differ among phenotype-based clinical clusters in the same patient population. HLA-B∗51 shows epistatic interaction with the susceptible allele of endoplasmic reticulum aminopeptidase (ERAP)1 encoding the Hap10 allotype, which has the lowest trimming activity of the MHC-Class I binding peptides. Subsequent molecular studies have suggested that the disease-associated Hap10 allotype is implicated in the generation and selection of the disease protective or promoting peptides loading onto HLA-B∗51, although these pathogenic peptides have yet to be identified.

SUMMARY

HLA-B∗51 is a hallmark of Behçet's syndrome but genetic markers are not very useful in the diagnosis of Behçet's syndrome. Rather, it is considered an important factor in determining clinical phenotypes in this heterogeneous condition. The epigenetic interaction of HLA-B∗51 with ERAP1 sheds light on pathogenesis.

Cardiac magnetic resonance imaging in patients with Behçet's disease

BACKGROUND

Behçet's disease (BD) is a multisystemic vasculitis that may affect the heart. However, the incidence and nature of cardiac involvement in BD have not been clearly documented yet. The aim of this study was to delineate the cardiac magnetic resonance imaging (MRI) appearances of cardiac involvement in BD patients.

METHODS

This cross-sectional observational study was carried out 30 BD patients without known cardiac disease. Patients were subjected to history taking, physical examination, echocardiography and cardiac MRI.

RESULTS

At least one abnormality on cardiac MRI was observed in 20/30 patients (66.67%). Myocardial oedema was observed in 3 patients (10%) and late gadolinium enhancement in 1 patient (3.3%). Pericardial effusion was found in 3 patients (10.0%), global hypokinesia in 6 patients (20.0%) and intra-cardiac thrombosis in only 1 patient (3.3%). Pulmonary artery was dilated in 4 patients (13.3%). Left ventricular (LV) and right ventricular (RV) end diastolic volume were altered in 4 patients (13.3%) and 7 patients (23.3%) respectively. LV and RV end systolic volume were abnormal in 7 patients (23.3%) and 5 patients (16.7%) respectively. There was aortic valve regurge in 2 patients (6.7%), tricuspid valve regurge in 9 patients (30%), and mitral valve regurge in 9 patients (30%). Dilated left main coronary artery was found in 2 patients (6.7%) and arrhythmogenic right ventricular dysplasia in only one patient 1 patient (3.3%). On logistic regression analysis, BD activity index score was a significant predictor of cardiac abnormalities.

CONCLUSION

BD may cause cardiac abnormalities without clinical manifestations and cardiac MRI may represent a tool for early detection of these subtle abnormalities. Higher BD activity index scores are strongly linked to cardiac problems.

A Tale of 2 Aneurysms: Cardiogenic Shock Secondary to Vascular Behçet's Syndrome

A patient with vascular Behçet’s syndrome (BS), a subtype of BS with mainly venous/arterial manifestations, presented with a left main aneurysm/thrombus and cardiogenic shock. The clinical diagnosis of BS includes mucocutaneous, vascular, and neurologic criteria. It is important to consider vascular BS as a nonatherosclerotic cause of coronary aneurysms. (Level of Difficulty: Intermediate.)

C-reactive protein is associated with postoperative outcomes in patients with intestinal Behçet's disease

BACKGROUND

Patients with intestinal Behçet's disease (BD) frequently undergo intestinal resections, which significantly affects postoperative morbidity and mortality. The aim of this study was to identify the association between C-reactive protein (CRP) levels and postoperative outcomes in patients with intestinal BD who underwent surgical bowel resection.

METHODS

Patients who were diagnosed with intestinal BD and underwent intestinal surgery due to BD at Severance Hospital between November 2005 and April 2018 were retrospectively investigated. Clinical relapse was defined as a disease activity index of BD (DAIBD) > 40, existence of newly added medications, re-hospitalization, or re-operation related to intestinal BD. The relationship between CRP level and postoperative outcomes was analyzed, and a receiver operating characteristic (ROC) curve was drawn to specify a cut-off value.

RESULTS

Ninety patients with intestinal BD were included. Among them, 44 were male (48.9%), and the median age at diagnosis was 38 years (range, 11-69 years). The median total disease follow-up duration was 130 months (range, 3-460 months). Forty patients (44.4%) underwent laparoscopic surgery. A higher CRP level immediately after surgery was significantly associated with postoperative complications (OR 1.01, 95% CI 1.004-1.018, p < 0.01), re-operation (hazard ratio [HR] 1.01, 95% CI 1.005-1.020, p < 0.01), and re-admission (HR 1.01, 95% CI 1.006-1.017 p < 0.01). The ROC curve showed that CRP predicts the risk of postoperative complications (p < 0.01) at a cut-off value of 41.9% with a sensitivity of 60.0% and specificity of 67.7%.

CONCLUSIONS

Postoperative CRP levels in patients with intestinal BD undergoing surgical resection were associated with postoperative outcomes.

Behçet syndrome

Behçet syndrome is a systemic vasculitis with an unknown aetiology affecting the small and large vessels of the venous and arterial systems. The presence of symptom clusters, regional differences in disease expression and similarities with, for example, Crohn's disease suggest that multiple pathological pathways are involved in Behçet syndrome. These disease features also make formulating disease criteria difficult. Genetic studies have identified HLA-B*51 as a genetic risk factor. However, the low prevalence of HLA-B*51 in many patients with bona fide disease, especially in non-endemic regions, suggests that other factors must also be operative in Behçet syndrome. Despite lacking a clear aetiological mechanism and definition, management of manifestations that include major vascular disease, eye disease and central nervous system involvement has improved with the help of new technology. Furthermore, even with our incomplete understanding of disease mechanisms, the prognoses of patients with Behçet syndrome, including those with eye disease, continue to improve. New treatment options and a better understanding of the underlying pathogenesis for various manifestations of this condition are required to further improve the management of the disease, which will improve patient quality of life.

Using hierarchical similarity to examine the genetics of Behçet's disease

OBJECTIVE

Behçet's disease (BD) is a multisystem inflammatory disease that affects patients along the historic silk road. Thus far, the pathogenesis of the disease has proved elusive due to the complex genetic interactions of the disease. In this paper, we seek to clarify the genetic factors of the disease while also uncovering other diseases of interest that present with a similar genotype as BD.

RESULTS

To do this, we employ a convergent functional genomics approach by leveraging the hierarchical similarity tool available in Geneweaver. Through our analysis, we were able to ascertain 7 BD consensus genes and 16 autoimmune diseases with genetic overlap with BD. The results of our study will inform further research into the pathogenesis of Behçet's disease.

Post-remission retinal microvascular and choroidal thickness changes in eyes with Behḉet's disease posterior uveitis: an OCTA longitudinal study

PURPOSE

To investigate the retinal microvascular and choroidal thickness changes in eyes with active Behḉet's disease posterior uveitis and post-remission.

PATIENTS AND METHODS

A prospective longitudinal observational analytic study where patients with active Behḉet's posterior uveitis (BU) were assessed by optical coherence tomography angiography (OCTA) and enhanced depth imaging OCT during activity and after remission, for retinal microvascular and subfoveal choroidal thickness (SFCT) changes.

RESULTS

26 eyes of 20 patients were included. With remission of active posterior uveitis, capillary density in both layers increased, only being significant in the superficial capillary plexus (SCP) 1.81 ± 3.57% (p = 0.025), while the foveal avascular zone (FAZ) area increased by 0.036 ± 0.069 mm (p = 0.023).

CONCLUSION

OCTA can be used to monitor the activity of Behḉet's posterior uveitis. Comparing the retinal microvascular changes during activity and after remission, the superficial capillary plexus was found to be more indicative of the activity status, while the deep capillary plexus and foveal avascular zone area-being more irreversible-are more useful as prognostic indicators. Subfoveal choroidal thickness, on the other hand, proved to be a consistent indictor of visual function; however, its change doesn't accurately reflect the activity status.

Pathogenesis and management of gastrointestinal inflammation and fibrosis: from inflammatory bowel diseases to endoscopic surgery

Gastrointestinal fibrosis is a state of accumulated biological entropy caused by a dysregulated tissue repair response. Acute or chronic inflammation in the gastrointestinal tract, including inflammatory bowel disease, particularly Crohn’s disease, induces fibrosis and strictures, which often require surgical or endoscopic intervention. Recent technical advances in endoscopic surgical techniques raise the possibility of gastrointestinal stricture after an extended resection. Compared to recent progress in controlling inflammation, our understanding of the pathogenesis of gastrointestinal fibrosis is limited, which requires the development of prevention and treatment strategies. Here, we focus on gastrointestinal fibrosis in Crohn’s disease and post-endoscopic submucosal dissection (ESD) stricture, and we review the relevant literature.

Genetic Association of a Gain-of-Function IFNGR1 Polymorphism and the Intergenic Region LNCAROD/DKK1 With Behçet's Disease

OBJECTIVE

Behçet's disease is a complex systemic inflammatory vasculitis of incompletely understood etiology. This study was undertaken to investigate genetic associations with Behçet's disease in a diverse multiethnic population.

METHODS

A total of 9,444 patients and controls from 7 different populations were included in this study. Genotyping was performed using an Infinium ImmunoArray-24 v.1.0 or v.2.0 BeadChip. Analysis of expression data from stimulated monocytes, and epigenetic and chromatin interaction analyses were performed.

RESULTS

We identified 2 novel genetic susceptibility loci for Behçet's disease, including a risk locus in IFNGR1 (rs4896243) (odds ratio [OR] 1.25; P = 2.42 × 10-9 ) and within the intergenic region LNCAROD/DKK1 (rs1660760) (OR 0.78; P = 2.75 × 10-8 ). The risk variants in IFNGR1 significantly increased IFNGR1 messenger RNA expression in lipopolysaccharide-stimulated monocytes. In addition, our results replicated the association (P < 5 × 10-8 ) of 6 previously identified susceptibility loci in Behçet's disease: IL10, IL23R, IL12A-AS1, CCR3, ADO, and LACC1, reinforcing the notion that these loci are strong genetic factors in Behçet's disease shared across ancestries. We also identified >30 genetic susceptibility loci with a suggestive level of association (P < 5 × 10-5 ), which will require replication. Finally, functional annotation of genetic susceptibility loci in Behçet's disease revealed their possible regulatory roles and suggested potential causal genes and molecular mechanisms that could be further investigated.

CONCLUSION

We performed the largest genetic association study in Behçet's disease to date. Our findings reveal novel putative functional variants associated with the disease and replicate and extend the genetic associations in other loci across multiple ancestries.

A Darwinian View of Behçet's Disease

Behçet's disease (BD) is a multisystem inflammatory disorder of unknown etiology, characterized by oral and genital ulceration, with other complications including eye, skin, joint, and central nervous system (CNS) lesions. Diagnosis is based on clinical findings, which may differ between patients. There is a strong genetic basis for BD; however, only a few genes have been associated with the disease across the geographical spread of BD. In this article, we discuss the history and combination of genes involved in this complex disease in relation to the geographical range and present our view that the disease has developed from a Darwinian perspective, with different gene polymorphisms that affect the same biological pathway. Moreover, these mutations individually are protective mechanisms against the disease relevant to each region, which affected both archaic and modern humans.

Adalimumab in Treatment of Uveitis in Pediatric Behcet's Disease-a Case Report

Introduction

Behcet's Disease (BD) is an inflammatory disease characterized by multisystemic involvement and featured by a chronic, relapsing disease course. Recurrent ocular inflammation and macular involvement may lead to severe loss of visual acuity. Prolonged use of local and systemic corticosteroids lead to numerous side effects and complications. Very often other immunosuppressive therapies are needed. Biologic agents are promising for the treatment of Behcet's disease-associated uveitis.

Aim

To report successful treatment of paediatric uveitis due to incomplete Behçet's disease with administration of adalimumab, after failing to react to all other modalities of treatment.

Case report

We present the case of a 15-year-old girl who was treated for reccurent uveitis in both eyes with developed complications on anterior and posterior ocular segment. She was earlier treated with topical and systemic steroids for uveitis, laser photocoagulation and methotrexate, however, relapses occurred inspite all treatment modalities. Patient was diagnosed with incomplete Behcet's disease, and adalimumab therapy was initiated. Inflammation was well-controlled by adalimumab administration without need for local or systemic corticosteroids.

Conclusion

Adalimumab is effective for treating children with Behcet's disease-associated uveitis. Control of ocular inflammation in our case was achieved without need for continuing local or systemic corticosteroids, thus preventing further complications and possible significant vision loss.

An uncommon disease included commonly in the differential diagnosis of neurological diseases: Neuro-Behçet's syndrome

Behçet's Syndrome (BS) may present with different neurological problems, related either directly (primary) or indirectly (secondary) to BS. Primary neurological involvement is named as neuro-Behcet's syndrome (NBS), and its two major subtypes that are classified mainly on the clinical and MRI findings are (1) Parenchymal-NBS (p-NBS) and (2) Extra parenchymal neuro-vascular involvement mostly seen as cerebral dural venous sinus thrombosis (CVST). The less commonly seen forms of NBS are cognitive and behavioral syndromes and peripheral nervous system involvement. Parenchymal-NBS is the most common clinical neurological presentation of BS. It is a rare disease with distinct MRI features and is often included in the differential diagnosis of neuro-vascular and neuro-inflammatory disorders. The most commonly affected neuro-anatomical site in p-NBS is the meso-diencephalic junction (MDJ), followed by the ponto-bulbar and thalamic regions, the basal ganglia, and the spinal cord. These varied locations may explain to a certain extent why BS is considered in the differential of so many neurological disorders. The other relatively common form of NBS that results in CVST may also be confused with other conditions resulting in CVST, especially when the systemic clinical features suggestive of BS are missed.

Isolated brachial artery aneurysm: a rare presentation of paediatric Behçet's disease

Behçet's disease is a rare disease characterised by recurrent oral ulcers, with systemic manifestations including genital ulcers, ocular disease, skin lesions, gastrointestinal disease, neurologic disease, vascular disease and arthritis. Most clinical manifestations of Behçet's disease are believed to be due to vasculitis. The heterogeneous clinical spectrum is influenced by sex, ethnicity and country of residence. Vascular manifestation in the form of isolated large brachial artery aneurysm is rare in children. Treatment involves aneurysmorrhaphy to avoid rupture or ischaemic sequelae in addition to lifelong medical management to control vasculitis.

HLA-B*51 allelic and carrier frequency in Kazakhstan: insights into Behçet's disease prevalence in Central Asia

Behçet's disease (BD) is a systemic vasculitis whose prevalence varies according to the ethnicity. HLA-B*51 is a well-known genetic factor predisposing to BD: populations with higher HLA-B*51 allelic frequencies are also those with a greater disease prevalence, as occurs in the Silk Road countries. However, the BD prevalence is unknown in many countries, including Kazakhstan and, in general, Central Asia, despite the location on or near the Silk Road. Due to the lack of clinical studies from this area, we analyzed the bone marrow donors registry in Kazakhstan, in order to assess the HLA-B*51 allelic and carrier frequencies, which resulted to be 8.14 and 15.28%, respectively. Through a comparison with the same parameters in other countries (by performing a data search in the medical literature and in the Allele Frequency Net Database), we might speculate a BD prevalence in Kazakhstan of 10-15/100.000 at least. This result should prompt a greater clinical consideration of this disease in Central Asia, as well as the publication of clinical data from this geographic area.

Genetics of Behçet's Disease: Functional Genetic Analysis and Estimating Disease Heritability

Behçet's disease is a chronic multisystemic inflammatory disorder characterized by recurrent oral and genital ulcers. Although its etiology remains unclear, it is thought that both genetic and environmental factors contribute to the onset and progression of Behçet's disease. Here, we provide an updated view of the genetic landscape and architecture of Behçet's disease. Large-scale genetic studies performed to date revealed 21 genetic susceptibility loci associated with the disease at a GWAS level of significance (p-value = 5 × 10⁻⁸). We performed epigenetic pattern enrichment analysis in Behçet's disease associated loci, providing new insights into the molecular mechanisms underlying its pathophysiology. Our data suggest the crucial involvement of several immune cell types, including natural killer cells, monocytes, and B cells in the pathogenesis of the disease. Pathway enrichment analysis identified important biological processes involved. Using large-scale genetic data available from ~200 immune-related loci (Immunochip), we estimate Behçet's disease heritability to be at least 16%. We further used the same approach to estimate the heritability explained by the known Behçet's disease-associated loci, suggesting that they explain ~ 60% of the genetic component underlying Behçet's disease. These results indicate a significant role of non-genetic factors in causing Behçet's disease and that additional genetic variation influencing the risk of Behçet's disease remains to be identified. Finally, we calculated a cumulative genetic risk score across populations reinforcing the link between geographic variations in disease prevalence with its genetic component.

Behçet: the syndrome

Behçet's syndrome (BS) is a systemic vasculitis characterized by a relapsing and remitting course. It can involve the skin, mucosa, joints, vessels (arteries and/or veins), eyes, and nervous and gastrointestinal systems, and so is referred to as a syndrome rather than as a unique and nosologically distinct condition. These involvements may present alone or co-exist in the same patient. Although all the possible combinations of the above-mentioned manifestations may occur, clusters of commonly co-existing involvements (also referred to as 'disease phenotypes') have been suggested, namely 'mucocutaneous and articular', 'peripheral vascular and extra-parenchymal neurological' and 'parenchymal neurological and ocular' phenotypes have been described. Patient-specific demographic and genetic features have been described as positively or negatively associated with specific disease phenotypes. This review will focus on the different clinical features of Behçet's syndrome, summarizing current evidence on the distinct disease manifestations as well as the major phenotypes.

Pediatric Behçet's Disease

Behçet's Disease (BD) is a systemic vasculitis firstly described as a disorder causing aphthous lesion in oral and genital mucosae and uveitis. The disease has an extremely unique distribution characterized by the highest incidence in communities living along the historical Silk road. Although our understanding of the etiopathogenesis of BD has expanded over time, there are still lots of unidentified points in the underlying mechanisms of the disease. The accepted opinion in the light of the current knowledge is that various identified and/or unidentified infectious and/or environmental triggers can take a role as a trigger in individuals with genetic susceptibility. Although the disease usually develops in young adulthood, it is reported that about 15-20% of all Behçet's patients develop in childhood. Pediatric BD differs from adult BD not only with the age of onset but also in the frequency and distribution of clinical findings, disease severity and outcome. While gastrointestinal system involvement, neurological findings, arthralgia and positive family history are more common in children, genital lesions and vascular lesions are more common in adult patients. In addition, a better disease outcome with lower severity score and activity index has been reported in children. The diagnosis of the disease is made according to clinical findings. It can be challenging to diagnose the disease due to the absence of a specific diagnostic test, and the long time interval from the first finding of the disease to the full-blown disease phenotype in pediatric cases. Therefore, many classification criteria have been proposed so far. The widely accepted ones are proposed by the International Study Group. The new sets of classification criteria which is the only one for pediatric BD were also developed for pediatric cases by the PEDBD group. The primary goal for the treatment is preventing the organ damages by suppressing the ongoing inflammation and forestalling the disease flares. The treatment of the BD can be onerous due to its multisystemic nature and a multidisciplinary approach is essential for the management of the patients. In this review article, the definition, clinical findings, epidemiology, etiopathogenesis, and treatment will be discussed.

Mimicking Behçet's disease: GM-CSF gain of function mutation in a family suffering from a Behçet's disease-like disorder marked by extreme pathergy

Behçet's disease (BD) is an inflammatory disease mainly affecting men along the ancient Silk Route. In the present study we describe a Dutch family suffering from BD-like disease with extreme pathergic responses, but without systemic inflammation. Genetic assessment revealed a combination of the human leukocyte antigen (HLA)-B*51 risk-allele together with a rare heterozygous variant in the CSF2 gene (c.130A>C, p.N44H) encoding for granulocyte-macrophage colony-stimulating factor (GM-CSF) found by whole exome sequencing. We utilized an over-expression vector system in a human hepatocyte cell line to produce the aberrant variant of GM-CSF. Biological activity of the protein was measured by signal transducer and activator of transcription 5 (STAT-5) phosphorylation, a downstream molecule of the GM-CSF receptor, in wild-type peripheral mononuclear cells (PBMCs) using flow cytometry. Increased STAT-5 phosphorylation was observed in response to mutated GM-CSF when compared to the wild-type or recombinant protein. CSF2 p.N44H results in disruption of one of the protein's two N-glycosylation sites. Enzymatically deglycosylated wild-type GM-CSF also enhanced STAT-5 phosphorylation. The patient responded well to anti-tumor necrosis factor (TNF)-α treatment, which may be linked to the capacity of TNF-α to induce GM-CSF in phorbol 12-myristate 13-acetate (PMA)-treated PBMCs, while GM-CSF itself only induced dose-dependent interleukin (IL)-1Ra production. The identified CSF2 pathway could provide novel insights into the pathergic response of BD-like disease and offer new opportunities for personalized treatment.

Diagnosis of Behçet's disease: clinical characteristics, diagnostic criteria, and differential diagnoses

BACKGROUND

The diagnosis of Behçet disease (BD) is challenging in many cases. The purpose of this study was to describe the clinical characteristics of patients at a referral BD clinic.

METHODS

In a retrospective study, we collected data from patients at a national referral Behçet clinic from November 2018-August 2019. A BD diagnosis was confirmed (BD group) or ruled out (Non-BD group), and the two groups were compared for differences.

RESULTS

A total of 238 patients satisfied the inclusion criteria. Forty patients (16.8%) were finally diagnosed with BD. Ocular and genital lesions were significantly more prevalent in the BD group. A positive pathergy test and HLA-B51 were also significantly more common in BD. However, oral lesions, articular involvement, and gastrointestinal manifestations were similar between groups. Also, patients with BD were significantly more likely to have multi-organ (≥2 organ systems) involvement.

CONCLUSIONS

Being the first study to evaluate the clinical characteristics of patients who are visited at a referral BD clinic and are believed to have a high probability of Behçet, the results of this study are important from an epidemiological standpoint. Also, the findings of this study could be used by referral Behçet clinics, which evaluate and diagnose patients with a high pretest probability and atypical presentations of BD on a daily basis. The alternative diagnoses established in this study could be used as the list of the most common differential diagnoses for Behçet's disease.

A comprehensive overview on the genetics of Behçet's disease

Behçet's disease (BD) is a systemic and inflammatory disease, characterized mainly by recurrent oral and genital ulcers, eye involvement, and skin lesions. Although the exact etiopathogenesis of BD remains unrevealed, a bulk of studies have implicated the genetic contributing factors as critical players in disease predisposition. In countries along the Silk Road, human leukocyte antigen (HLA)-B51 has been reported as the strongest genetically associated factor for BD. Genome-wide association studies, local genetic polymorphism studies, and meta-analysis of combined data from Turkish, Iranian, and Japanese populations have also identified new genetic associations with BD. Among these, other HLA alleles such as HLA-B*15, HLA-B*27, HLA-B*57, and HLA-A*26 have been found as independent risk factors for BD, whereas HLA-B*49 and HLA-A*03 are independent protective alleles for BD. Moreover, other genes have also reached the genome-wide significance level of association with BD susceptibility, including IL10, IL23R-IL12RB2, IL12A, CCR1-CCR3, STAT4, TNFAIP3, ERAP1, KLRC4, and FUT2. Also, several rare nonsynonymous variants in TLR4, IL23R, NOD2, and MEFV genes have been reported to be involved in BD pathogenesis. According to genetic determinants in the loci outside the MHC region that are contributed to the host defense, immunity, and inflammation pathways, it is suggested that immune responses to the pathogen as an important environmental factor and mucosal immunity contribute to BD susceptibility.