Phenotypes in Behçet's syndrome

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.

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.

Changes in the proportion of clinical clusters contribute to the phenotypic evolution of Behçet's disease in Japan

Background

We hypothesized that Behçet’s disease (BD) consists of several clinical subtypes with different severity, resulting in heterogeneity of the disease. Here, we conducted a study to identify clinical clusters of BD.

Methods

A total of 657 patients registered in the Yokohama City University (YCU) regional BD registry between 1990 and 2018, as well as 6754 patients who were initially registered in the Japanese Ministry of Health, Labour and Welfare (MHLW) database between 2003 and 2014, were investigated. The YCU registry data regarding the clinical manifestations of BD, human leukocyte antigen (HLA) status, treatments, and hospitalizations were analyzed first, followed by similar analyses of the MHLW for validation. A hierarchical cluster analysis was independently performed in both patient groups.

Results

A hierarchical cluster analysis determined five independent clinical clusters in the YCU cohort. Individual counterparts of the YCU clusters were confirmed in the MHLW registry. Recent phenotypical evolutions of BD in Japan, such as increased gastrointestinal (GI) involvement, reduced complete type according to the Japan Criteria, and reduced HLA-B51 positivity were associated with chronologically changing proportions of the clinical clusters.

Conclusions

In this study, we identified independent clinical clusters among BD patients in Japan and found that the proportion of each cluster varied over time. We propose five independent clusters namely “mucocutaneous”, “mucocutaneous with arthritis”, “neuro”, “GI”, and “eye.”

Cluster analysis of phenotypes of patients with Behçet's syndrome: a large cohort study from a referral center in China

INTRODUCTION

Behcet's syndrome (BS) is a complex, heterogeneous disorder. However, classification of its subgroups is still debated. The purpose of this study was to investigate the clinical features and aggregation of patients with BS in China, based on manifestations and organ involvements.

METHODS

This was a cross-sectional study of BS patients in Huadong Hospital of Fudan University between September 2012 and January 2020. We calculated relative risks (RRs) of clinical variables according to sex. Moreover, we conducted a hierarchical cluster analysis applied according to eighteen variables to determine subgroups of patients.

RESULTS

A total of 860 BS patients were included. Male sex was associated with ocular involvement (RR 2.32, 95% CI 1.67, 3.22, P < 0.0001), vascular involvement (RR 2.00, 95% CI 1.23, 3.23, P = 0.004), cardiac lesion (RR 5.46, 95% CI 2.33, 12.77, P < 0.0001), and central nervous system involvement (RR 2.95, 95% CI 1.07, 6.78, P = 0.007) and was negatively associated with genital ulcers (RR 0.84, 95% CI 0.79, 0.91, P < 0.0001). Five clusters (C1-C5) were observed. C1 (n = 307) showed the skin and mucosa type. In C2 (n = 124), all had articular involvement, barely having major organ involvement except for 18 cases with intestinal lesions. In C3 (n = 156), the gastrointestinal type, 144 patients presented with intestinal involvement, and 36 patients with esophageal ulcers. In C4 (n = 142), all subjects presented with uveitis. C5 (n = 131) consisted of 44 patients with cardiac lesions, 58 with vascular involvement, and 26 cases having central nervous system involvement.

CONCLUSION

Our analysis confirmed sex differences in phenotypes of BS. Cluster analysis identified gastrointestinal, uveitis, and cardiovascular involvement cluster separately in different subsets, which represents the most commonly involved organs. Further research is required to replicate and clarify the patterns of phenotype in BS.

Interleukin 1α: a comprehensive review on the role of IL-1α in the pathogenesis and treatment of autoimmune and inflammatory diseases

The interleukin (IL)-1 family member IL-1α is a ubiquitous and pivotal pro-inflammatory cytokine. The IL-1α precursor is constitutively present in nearly all cell types in health, but is released upon necrotic cell death as a bioactive mediator. IL-1α is also expressed by infiltrating myeloid cells within injured tissues. The cytokine binds the IL-1 receptor 1 (IL-1R1), as does IL-1β, and induces the same pro-inflammatory effects. Being a bioactive precursor released upon tissue damage and necrotic cell death, IL-1α is central to the pathogenesis of numerous conditions characterized by organ or tissue inflammation. These include conditions affecting the lung and respiratory tract, dermatoses and inflammatory skin disorders, systemic sclerosis, myocarditis, pericarditis, myocardial infarction, coronary artery disease, inflammatory thrombosis, as well as complex multifactorial conditions such as COVID-19, vasculitis and Kawasaki disease, Behcet's syndrome, Sjogren Syndrome, and cancer. This review illustrates the clinical relevance of IL-1α to the pathogenesis of inflammatory diseases, as well as the rationale for the targeted inhibition of this cytokine for treatment of these conditions. Three biologics are available to reduce the activities of IL-1α; the monoclonal antibody bermekimab, the IL-1 soluble receptor rilonacept, and the IL-1 receptor antagonist anakinra. These advances in mechanistic understanding and therapeutic management make it incumbent on physicians to be aware of IL-1α and of the opportunity for therapeutic inhibition of this cytokine in a broad spectrum of diseases.

Characteristics and phenotype heterogeneity in late-onset Behçet's syndrome: a cohort from a referral center in China

OBJECTIVES

To evaluate the demographics, clinical aspects, and major organ involvement of patients with late-onset Behçet's syndrome (BS) in a tertiary center in China.

METHODS

We conducted a cross-sectional study of consecutive BS patients in Huadong Hospital of Fudan University from September 2012 to January 2020. We compared clinical variables between patients with disease onset before and after 40 years of age. The relative risks (RRs) of clinical variables were calculated between the two age groups. Moreover, a hierarchical cluster analysis was conducted according to 29 variables to determine homogeneous subgroups in patients with late-onset BS.

RESULTS

We enrolled 152 late-onset BS patients, with a median age at onset of 47 years (interquartile range, IQR: 43-52 years). There is a higher prevalence of intestinal ulcers in late-onset BS than in early-onset BS (RR 1.47), but a lower prevalence of ocular involvements (RR 0.54) and folliculitis (RR 0.46). Female sex was associated with genital ulcers, erythema nodosum, and arthritis. Four clusters (C1-C4) were formed. C1 (n = 71), the largest cluster, was defined as the mucocutaneous group, C2 (n = 20) as the arthritis group, C3 (n = 39) as the gastrointestinal group, in which all patients presented with intestinal lesions, and five cases with esophageal ulcers. In C4 (n = 22), showing a mixture of uveitis and vascular lesions, 15 patients presented with uveitis and 8 had vascular lesions, and 1 case had central nervous system lesions.

CONCLUSION

Four phenotype clusters were identified. Patients with skin lesions comprised the largest cluster, while gastrointestinal, panuveitis, and cardiovascular clusters are the most commonly involved organs in late-onset BS patients. Key Points • Our analysis demonstrated the phenotype discrepancy between early and late onset groups. • Four phenotype clusters were identified, with gastrointestinal, panuveitis and cardiovascular clusters representing commonly involved organs.

Succinivibrionaceae is dominant family in fecal microbiota of Behçet's Syndrome patients with uveitis

Behçet’s Syndrome (BS) is a multisystem vasculitis with various clinical manifestations. Pathogenesis is unclear, but studies have shown genetic factors, innate immunity and autoinflammation to have an important role in the disease course. Diversity in the microbial community of gut microbiota may significantly contribute to the activation of the innate immune system. The clinical features of BS present themselves in clusters and each cluster may be a consequence of different disease mechanisms. For this reason we aimed to investigate the gut microbiota of BS patients with uveitis. In addition to healthy controls, we have aimed to compare the gut microbiota of BS with that of Familial Mediterranean Fever (FMF) and Crohn’s Disease (CD) as both diseases have innate and autoinflammatory features in their pathogenesis. Seven patients with BS, 12 patients with FMF, 9 patients with CD and 16 healthy controls (HC) were included in the study. Total genomic DNAs were isolated from fecal samples of the patients. Partial 16S rRNA gene was sequenced using the PGM Ion Torrent (Thermo Fisher Scientific, Waltham, MA, USA) for microbiota analysis. Statistical analysis showed that significant differences were detected on the microbial community of four groups. Succinivibrionaceae is dominant and the signature family, whereas Bacteroides was absent in BS patients.

[Behçet's syndrome : Current diagnostics and treatment]

Behçet's syndrome (BS) in our latitude is a rare vasculitis of various vessels. It mainly consists of oral and genital aphthous ulcers, skin lesions, oligoarthritis and ocular manifestations, mostly a posterior uveitis with occlusive retinal vasculitis. This review article summarizes the diagnostic and classification criteria as well as possible differential diagnoses and current treatment recommendations.

Behçet disease (BD) and BD-like clinical phenotypes: NF-κB pathway in mucosal ulcerating diseases

Behçet's disease (BD) is a heterogeneous multi-organ disorder in search of a unified pathophysiological theory and classification. The disease frequently has overlapping features resembling other disease clusters, such as vasculitides, spondyloarthritides and thrombophilias with similar genetic risk variants, namely HLA-B*51, ERAP1, IL-10, IL-23R. Many of the BD manifestations, such as unprovoked recurrent episodes of inflammation and increased expression of IL-1, IL-6 and TNFα, overlap with those of the hereditary monogenic autoinflammatory syndromes, positioning BD at the crossroads between autoimmune and autoinflammatory syndromes. BD-like disease associates with various inborn errors of immunity, including familial Mediterranean fever, conditions related to dysregulated NF-κB activation (eg TNFAIP3, NFKB1, OTULIN, RELA, IKBKG) and either constitutional trisomy 8 or acquired trisomy 8 in myelodysplastic syndromes. We review here the recent advances in the immunopathology of BD, BD-like diseases and the NF-κB pathway suggesting new elements in the elusive BD etiopathogenesis.

Behçet's syndrome in Italy: a detailed retrospective analysis of 396 cases seen in 3 tertiary referral clinics

Behçet's syndrome (BS) is a multisystemic disorder displaying a marked variability across different geographic areas. The main aim of this study was to analyze demographic and clinical features of a cohort of BS patients diagnosed in three tertiary referral centers in Italy and detect potential associations between the different manifestations. Medical records of 396 patients (218 females, 178 males) were retrospectively analyzed. Mean age at onset was 30.00 ± 18.75 years with a female-to-male ratio of 1.22:1. Mucocutaneous features were the most frequent starting manifestations of BS, followed by eye inflammation. Erythema nodosum (p = 0.007), arthritis/arthralgias (p = 0.0115), and central nervous system (CNS) signs (p = 0.014) were significantly over-represented in female patients, whereas male gender was associated with lower mean age at onset (p = 0.031), higher frequency of pseudofollicular lesions, and uveitis (p = 0.00134 and p < 0.0001 respectively), particularly for posterior segment involvement and panuveitis (p < 0.0001). Regarding the association between disease features, genital ulcers were negatively associated with uveitis (p < 0.0001) and vascular involvement (p < 0.0001). Other negative associations were detected between uveitis and gastrointestinal involvement (p = 0.008), pseudofolliculitis and CNS signs (p = 0.031), vascular involvement (p = 0.002) and erythema nodosum (p = 0.013). Logistic regression identified male gender and genital ulcers, respectively, with a higher (OR 2.199 [1.397-3.461], p < 0.001) and lower risk (OR 0.157 [0.090-0.273], p < 0.0001) of developing major organ involvement. Our evaluations found that the disease had started mostly in the second and third decade with most severe features in the male gender, and that patients presenting with mucocutaneous manifestations were less prone to develop major organ involvement.

Clinical features and management of venous thromboembolism in patients with Behçet's syndrome: a single-center case-control study

Almost one third of patients with Behçet's syndrome (BS) display vascular involvement. However, data regarding the prevalence and management of venous thromboembolism (VTE) in BS are scanty. We assessed the differential characteristics between patients with and without VTE and the factors associated with VTE incidence. A case-control study in a cohort of patients with BS was performed. 57 patients were included (56.1% women) with a mean follow-up of 10.56 (± 10.7) years. Mean age at diagnosis of BS and diagnosis of the first VTE episode was 34.7 (± 12.1) and 31.2 (± 8.9) years, respectively. Erythema nodosum (OR 4.6, CI 95% 1.2-18.1) and fever (OR 8.2, CI 95% 1.6-42.1) were associated with a higher risk of VTE. 26 episodes of VTE were registered in 12/57 (21%) patients. 83.3% of patients were not diagnosed with BS when the first episode of VTE occurred and, among them, the episode of VTE led to the diagnosis of BS in 40% of cases. Half of patients had at least one VTE recurrence. The absence of immunosuppressive treatment was associated with a higher risk of developing a first episode of VTE (OR 20 CI 95% 19.2-166.6). All patients were treated with anticoagulation and 75% were treated with immunosuppressants after the first VTE event. The diagnosis of VTE usually precedes that of BS, with a high frequency of VTE recurrence. Erythema nodosum and fever were associated with a higher risk of VTE, while the immunosuppressants showed a protective role for the development of VTE.

Clusters in Pediatric Rheumatic Diseases

PURPOSE OF THE REVIEW

Rheumatic diseases usually have very diverse and complex pathophysiology resulting in different clinical phenotypes. Some certain phenotypes cluster together with a common presentation, course, and outcome. Our primary aim is to review the known disease clusters in certain rheumatological conditions.

RECENT FINDINGS

Cluster analysis has been reported in several rheumatic diseases, Behcet disease being the most common. Five individual clusters together with some clinical associations have been reported in Behcet patients. Certain antibody-phenotype associations and damage clusters have been reported in systemic lupus erythematosus (SLE) patients as well. Although there is no proper cluster analysis, two distinct phenotypes are evident in deficiency of ADA2 (DADA2): those with a polyarteritis nodosa-like vasculopathy and hematological involvement with pure red cell aplasia or bone marrow failure. The variants are claimed to be different regions of this gene for these 2 phenotypes. Lastly, there is a recent paper grouping ANCA-associated vasculitis according to disease phenotype and antibody associations. There are distinct clusters in certain rheumatic diseases which might help us to predict comorbidities, disease course, and treatment response.

Long-term effectiveness and safety of secukinumab for treatment of refractory mucosal and articular Behçet's phenotype: a multicentre study

OBJECTIVE

To evaluate the effectiveness and safety of secukinumab in patients with a mucosal and articular Behçet's phenotype resistant to conventional and biologic treatment.

METHODS

A multicentre retrospective study was performed on 15 patients with a mucosal and articular phenotype of Behçet's syndrome fulfilling the International Criteria for Behçet's Disease and refractory to treatment with colchicine, disease-modifying antirheumatic drugs and at least one antitumour necrosis factor-α agent. Minimum follow-up was set at 6 months. Six patients with a polyarticular involvement were treated with secukinumab 300 mg/month, while all other cases received secukinumab 150 mg/month. Dose increase from 150 to 300 mg per month and shortening of administration frequency were allowed for poor disease control. Response evaluation was based on the number of oral ulcers in the previous 28 days and Disease Activity Score-28 for articular manifestations.

RESULTS

At 3 months of follow-up, nine (66.7%) patients achieved a response (complete or partial), and this proportion further increased to 86.7% at 6 months, 76.9% at 12 months, 90.0% at 18 months and 100.0% after 24 months. Notably, all patients who started with secukinumab 300 mg/month achieved complete response by month 6. Seven (46.7%) patients could achieve a response only after switching to a higher dosage.

CONCLUSIONS

Our study suggests that secukinumab at a dose of 150 and 300 mg per month is safe and effective for the long-term treatment of patients with Behçet's syndrome with a mucosal and articular phenotype refractory to previous treatments. Notably, secukinumab 300 mg/month resulted in superior complete mucosal and articular responses with no serious or dose-related adverse effects.

Pediatric Behçet's disease - clinical aspects and current concepts

Behçet's Disease was first described by a Turkish dermatologist, Hulusi Behçet, in 1937 as a triple symptom complex; aphthous stomatitis, genital ulcers, and uveitis. Today, in light of current trials and experiments, we know that the disease may have a wider involvement with a multisystemic recurrent course, causing significant morbidity and mortality. However, there are still unanswered questions, particularly about Pediatric Behçet's Disease. Although several immunological and genetic associations have been demonstrated, the real etiologic mechanism of the disease is unclear. The diagnosis is difficult due to its rarity in childhood, the lack of validation of the diagnostic criteria obtained from adult studies, and the inadequacy of large case-controlled studies. Also, the management is challenging and controversial due to the various geographic distribution of clinical spectrum. New therapeutic options under development in light of pathogenetic hypothesis seem to be promising.

Treating the Different Phenotypes of Behçet's Syndrome

Behçet's syndrome (BS) is a multisystemic vasculitis, characterized by different clinical involvements, including mucocutaneous, ocular, vascular, neurological, and gastrointestinal manifestations. Based on this heterogeneity, BS can be hardly considered as a single clinical entity. Growing evidence supports that, within BS, different phenotypes, characterized by clusters of co-existing involvements, can be distinguished. Namely, three major BS phenotypes have been reported: (a) the mucocutaneous and articular phenotype, (b) the extra-parenchymal neurological and peripheral vascular phenotype, and (c) the parenchymal neurological and ocular phenotype. To date, guidelines for the management of BS have been focused on the pharmacological treatment of each specific BS manifestation. However, tailoring the treatments on patient's specific phenotype, rather than on single disease manifestation, could represent a valid strategy for a personalized therapeutic approach to BS. In the present literature review, we summarize current evidence on the pharmacological treatments for the first-, second-, and third-line treatment of the major BS phenotypes.

Venous involvement in inflammatory disorders

PURPOSE OF REVIEW

To review the association of venous thrombosis and inflammatory disorders.

RECENT FINDINGS

Various systemic inflammatory diseases of which Behçet's syndrome is the prototype are associated with an increased risk of venous thrombosis. Recent data indicate that venous wall thickness is increased among Behçet's syndrome patients with no history of venous thrombosis and thrombosis in Behçet's syndrome could be a unique model of inflammation-induced thrombosis. Patients with inflammatory bowel disease (IBD) have a two to three time-fold increased risk of developing thromboembolic complications compared with general population. The risk of venous thrombosis is increased after surgical interventions and is higher in ulcerative colitis compared with Crohn's disease. Despite similarities with Behçet's syndrome, anticoagulation is advised as the main treatment in IBD, while there is uncertainty about the duration of antithrombotic prophylaxis. Antineutrophil cytoplasmic antibody-associated vasculitides and ankylosing spondylitis are also other inflammatory disorders associated with a thrombotic risk.

SUMMARY

Underlying mechanisms of venous thrombosis in inflammatory disorders are not clearly understood. How we might prevent thrombosis, should we screen asymptomatic patients, what should we use for the treatment (immunosuppression or anticoagulation or both) and what should be the duration of this treatment also need to be addressed. Finally, the link between inflammation and thrombosis should be more intensively studied.