Gender disparities in Behçet's syndrome: identifying distinct phenotypes through cluster analysis

Behçet's syndrome (BS) is a complex, multi-systemic disorder with a global occurrence, notably concentrated along the Silk Road. This study aimed to investigate gender-specific expressions and clinical phenotypes in BS patients within the Eastern Black Sea Region of Turkey. A total of 290 BS patients were retrospectively analyzed between January 2013 and December 2023. Demographic characteristics, clinical manifestations, medical treatment, and pathergy test results were obtained from a review of medical records. The mean age was 45.79 ± 13.05, with a male-to-female ratio of 48.6:51.4. Male patients had higher papulopustular lesions (p < 0.001) and ocular involvement (p = 0.036), while females showed more frequent genital ulcers (p = 0.032). Medication usage showed gender-based variations, notably higher corticosteroid, azathioprine, and tumor necrosis factor-alpha inhibitor (TNFi) use in males (p < 0.001). Cluster analysis revealed five distinct clusters, each with unique features and gender predominance. Cardiovascular type, ocular type, and skin type predominantly featured male patients, while joint involvement type and neurologic and mucosal involvement type were more prevalent among female patients with BS. This research contributes valuable insights into the gender-related clinical variations of BS within a specific geographic region, fostering a more comprehensive understanding of this challenging syndrome. The identification of distinct clinical phenotypes facilitates the development of tailored treatment strategies, potentially leading to improved outcomes for patients with BS.

Behçet's syndrome

Behçet's syndrome is a rare, chronic multisystemic inflammatory disorder also known as the Silk Route disease due to its geographical distribution. Behçet's syndrome is a multifactorial disease and infectious, genetic, epigenetic, and immunological factors contribute to its pathogenesis. Its heterogeneous spectrum of clinical features include mucocutaneous, articular, ocular, vascular, neurological, and gastrointestinal manifestations that can present with a relapsing and remitting course. Differential diagnosis is often hampered by the non-specific clinical presentation and the absence of laboratory biomarkers or pathognomonic histological features. The therapeutic approach is tailored on the basis of patient-specific manifestations and relies on glucocorticoids, colchicine, and traditional and biological immunosuppressants. Despite progress in the knowledge and management of the disease, unmet needs in diagnostics, monitoring, prediction, and treatment personalisation challenge clinical practice, making Behçet's syndrome a complex disorder associated with an increased risk of morbidity.

Cluster analysis as a clinical and research tool in Behçet's syndrome

PURPOSE OF REVIEW

The purpose of this review was to comprehensively summarize recent phenotype research findings in Behçet's syndrome.

RECENT FINDINGS

Cluster analysis has recently been employed as a phenotype research tool in Behçet's syndrome. Studies reported different clustering patterns caused by biological variation and some degree of artificial heterogeneity. However, some clusters were more consistent than others: 1) oral ulcers, genital ulcers, and skin lesions 2) oral ulcers, genital ulcers, skin lesions, and arthritis 3) oral ulcers, genital ulcers, skin lesions, and uveitis 4) oral ulcers, genital ulcers, skin lesions, and gastrointestinal involvement. A number of loci suggestive of differential risk for individual disease manifestations were proposed. Peripheral blood gene expression profile and plasma proteome exhibited significant differences in patients with different organ involvements and were able to differentiate between disease phenotypes. However, these observations require further validation and functional studies.

SUMMARY

Clustering patterns in Behçet's syndrome is highly heterogeneous. Artificial heterogeneity might obscure the true biological variation of disease expression. Preliminary genetic, transcriptomic and proteomic data suggest that different pathogenetic mechanisms may operate in different phenotypes of Behçet's syndrome.

Behçet Syndrome

Behçet's syndrome is a systemic vasculitis affecting arteries and veins of all sizes as well as recurrent oral, genital, and intestinal ulcers, skin lesions, predominantly posterior uveitis, and parenchymal brain lesions. These can be present in various combinations and sequences over time and diagnosis is made by recognizing the manifestations, as there are no diagnostic biomarkers or genetic tests. Treatment modalities include immunomodulatory agents, immunosuppressives and biologics, tailored according to prognostic factors, disease activity, severity, and patients' preferences.

Musculoskeletal manifestations in children with Behçet's syndrome: data from the AIDA Network Behçet's Syndrome Registry

This study aims to describe musculoskeletal manifestations (MSM) in children with Behçet's syndrome (BS), their association with other disease manifestations, response to therapy, and long-term prognosis. Data were retrieved from the AIDA Network Behçet's Syndrome Registry. Out of a total of 141 patients with juvenile BS, 37 had MSM at disease onset (26.2%). The median age at onset was 10.0 years (IQR 7.7). The median follow-up duration was 21.8 years (IQR 23.3). Recurrent oral (100%) and genital ulcers (67.6%) and pseudofolliculitis (56.8%) were the most common symptoms associated with MSM. At disease onset, 31 subjects had arthritis (83.8%), 33 arthralgia (89.2%), and 14 myalgia (37.8%). Arthritis was monoarticular in 9/31 cases (29%), oligoarticular in 10 (32.3%), polyarticular in 5 (16.1%), axial in 7 (22.6%). Over time, arthritis became chronic-recurrent in 67.7% of cases and 7/31 patients had joint erosions (22.6%). The median Behçet's Syndrome Overall Damage Index was 0 (range 0-4). Colchicine was inefficacious for MSM in 4/14 cases (28.6%), independently from the type of MSM (p = 0.46) or the concomitant therapy (p = 0.30 for cDMARDs, p = 1.00 for glucocorticoids); cDMARDs and bDMARDs were inefficacious for MSM in 6/19 (31.4%) and 5/12 (41.7%) cases. The presence of myalgia was associated with bDMARDs inefficacy (p = 0.014). To conclude, MSM in children with BS are frequently associated with recurrent ulcers and pseudofolliculitis. Arthritis is mostly mono- or oligoarticular, but sacroiliitis is not unusual. Prognosis of this subset of BS is overall favorable, though the presence of myalgia negatively affects response to biologic therapies. ClinicalTrials.gov Identifier: NCT05200715 (registered on December 18, 2021).

Proteomics Landscape Mapping of Organ-Resolved Behçet's Disease Using In-Depth Plasma Proteomics for Identifying Hyaluronic Binding Protein 2 Expression Associated With Vascular Involvement

OBJECTIVE

This study was undertaken to elucidate the pathogenesis and heterogeneity of Behçet's disease (BD) involving different organs using in-depth proteomics to identify the biomarkers for clinical assessment and treatment of patients with BD.

METHODS

We measured the expression levels of proteins in plasma samples from 98 patients with BD and from 31 healthy controls using our in-depth proteomics platform with a data-independent acquisition mass spectrometer and antibody microarray. We performed bioinformatics analyses of the biologic processes and signaling pathways that were changed in the BD group and constructed a proteomics landscape of organ-resolved BD pathogenesis. We then validated the biomarkers of disease severity and the vascular subset in an independent cohort of 108 BD patients and 29 healthy controls using an enzyme-linked immunosorbent assay.

RESULTS

The BD group had 220 differentially expressed proteins, which discriminated between BD patients (88.6%) and healthy controls (95.5%). The bioinformatics analyses revealed different biologic processes associated with BD pathogeneses, including complement activation, wound healing, angiogenesis, and leukocyte-mediated immunity. Furthermore, the constructed proteomics landscape of organ-resolved BD identified proteomics features of BD associated with different organs and protein targets that could be used for the development of therapeutic treatment. Hyaluronic binding protein 2, tenascin, and serpin A3 were validated as potential biomarkers for the clinical assessment of vascular BD and treatment targets.

CONCLUSION

Our results provide valuable insight into the pathogenesis of organ-resolved BD in terms of proteomics characteristics and potential biomarkers for clinical assessment and potential therapies for vascular BD.

Vascular Behçet syndrome: from pathogenesis to treatment

Behçet syndrome is a rare, chronic inflammatory disease of unknown aetiopathogenesis, most commonly presenting with mucocutaneous and ocular manifestations. Vascular involvement, most frequently superficial vein and deep vein thrombosis, can occur in up to 50% of patients with Behçet syndrome. Venous thrombosis at atypical sites (inferior and superior vena cava, suprahepatic veins with Budd-Chiari syndrome, portal vein, cerebral sinuses and right atrium and/or ventricle) and arterial involvement (mostly in situ thrombosis and aneurysms of the pulmonary arteries, as well as aneurysms of the abdominal aorta, and peripheral and visceral arteries) are also unique features of Behçet syndrome. Behçet syndrome is considered a natural model of inflammation-induced thrombosis in humans, with an impaired immune-inflammatory response rather than traditional cardiovascular risk factors contributing to thrombogenesis. Specifically, neutrophil hyperactivation and neutrophil-mediated mechanisms of damage directly promote endothelial dysfunction, platelet activation and thrombogenesis in Behçet syndrome. This unusual pathogenesis directly determines the treatment approach, which relies mostly on immunosuppressants rather than anticoagulants for treatment of thrombosis and for secondary prevention. This Review discusses the main histopathological, pathogenetic and clinical aspects of vascular Behçet syndrome, addressing their implications for therapeutic management. Future perspectives in terms of pathogenetic studies, disease monitoring and treatment strategies are also discussed.

Current pharmacological solutions for Behçet's syndrome

INTRODUCTION

Behçet's syndrome (BS) has a heterogeneous clinical phenotype, and its clinical manifestations may respond differently to drugs commonly used to treat BS. The type, dose, and duration of immunomodulatory, immunosuppressive, and biologic agents should be tailored individually.

AREAS COVERED

We reviewed the literature for articles on BS management that were published until June 2022 and summarized the management options in BS for each type of organ involvement. We aimed to cover all currently available pharmacological agents used in BS, as well as surgical and interventional options, focusing on recent evidence.

EXPERT OPINION

The management aims in BS are to preserve function and quality of life and to avoid damage. The choice of treatment modalities depends on the organs that are actively involved, the severity of that involvement, and prognostic factors. A treat-to-attack strategy would help improve long-term outcomes in BS.

Clusters in Behçet’s syndrome

Clustering is an important clinical feature of Behçet’s syndrome (BS) and may have pathogenetic and therapeutic implications. Recent and previous studies on BS phenotype differ substantially in terms of methodology. Correlation matrices and factor analyses were not efficient enough to uncover clusters. Clustering patterns may change according to demographic factors such as age and sex. Clustering patterns may also be profoundly influenced by the misperception of symptoms that are assumed to be secondary to BS, when, in fact, they represent manifestations of BD mimics. This can give rise to misleading conclusions and should be kept in mind when interpreting data obtained by clustering or other phenotype analyses of BS. A true geographical/racial variability in disease expression could be studied in a multinational consensus cohort. Pathogenetic studies in separate clusters of BS have still been lacking.

Cluster Analysis of Pediatric Behçet's Disease: Data from The Pediatric Rheumatology Academy (PeRA)-Research Group (RG)

OBJECTIVES

Behçet's Disease (BD) is a systemic vasculitis affecting many organ systems with the involvement of all sized arteries and veins. Patients with BD may present with varying features. The study aims to determine the main characteristics of pediatric BD patients and also analyze the clustering phenotypes in a large multicentric cohort.

METHODS

Demographic data, clinical manifestations, laboratory features, treatment schedules, and disease outcomes were achieved from patients' charts retrospectively. A cluster analysis was performed according to phenotype.

RESULTS

A total of 225 (109 male/ 116 female) patients with BD were enrolled in the study. The median age of disease onset and diagnosis was 131 (36-151) and 156 (36-192) months, respectively. The median time between the onset of symptoms and diagnosis was 23.5 (0-45) months. According to cluster analysis; 132 (58.6%) patients belonged to the mucocutaneous-only cluster (C1) while 35 (15.6%) patients fitted to articular type (C2), 25 (11.1%) %) were in ocular cluster (C3), 26 (11.6%) were in vascular cluster (C4) and 7 (3.1%) belonged to the gastrointestinal cluster (C5). Ocular and vascular clusters were more common in boys (p<0.001), while girls usually presented with the mucocutaneous-only cluster. The clusters had comparable ages upon diagnosis. The disease activity at the diagnosis and the last control was higher in ocular, vascular, and gastrointestinal clusters.

CONCLUSIONS

We identified five different subtypes in juvenile BD patients. These subtypes express different phenotypes with different outcomes. Our analysis may help clinicians to identify the disease subtypes accurately and to arrange personalized treatment.

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.

Patients characteristics in Behçet's Syndrome and their associations with major organ involvement: a single-centre experience of 2118 cases

Objectives: To evaluate the demographic and clinical characteristics of patients with Behçet's syndrome (BS), and to define their associations with the presence of major organ involvement (MOI).Method: Medical records of 2118 patients (964 males, 1154 females) were analysed retrospectively. MOI was defined as the presence of at least one of vascular, eye, nervous, or gastrointestinal system involvement. Univariable and multivariable binary and ordinal logistic regression analyses were applied to assess the factors that were potentially associated with MOI.Results: The mean ± sd age at diagnosis was 30.5 ± 9.4 years. Genital ulcer and joint involvement were more common in females (both p < 0.001), while MOI was more frequent in males (p < 0.001). Genital ulcer (p < 0.001) and vascular involvement (p = 0.006) were more common in patients with a younger age at diagnosis, while joint involvement was more common in older patients. A total of 1097 patients (51.8%) had at least one MOI, 322 (15.2%) at least two MOIs, and 48 (2.3%) at least three MOIs. Male gender, smoking history, and absence of genital ulcer were significantly associated with MOI in multivariable binary logistic regression. Multivariable ordinal regression analyses confirmed the association between MOI and male gender and smoking, but not the protective effect of genital ulcers. In both regression analyses, we found no significant effects of age, human leucocyte antigen-B51, skin involvement, or joint involvement on MOI.Conclusion: Male gender and positive smoking history have a significant influence on the presence of MOI in patients with BS.

[Behçet's disease : Description and analysis of a French single-center retrospective study of 51 patients]

PURPOSE

To evaluate if the presence of uveitis in Behçet's disease (BD) is associated with a particular clinical phenotype and to analyze the prognostic impact of a missed diagnosis of BD at the time the uveitis is diagnosed.

MATERIEL AND METHODS

Ophthalmologic and systemic clinical features of 51 patients with BD were recorded retrospectively. We compared the clinical phenotype of patients with ocular manifestations with those without ocular manifestations. The patients were divided into two groups depending on the progression of their visual acuity: "decreased visual acuity" versus "stable or improved visual acuity."

RESULTS

In the group of patients with ocular involvement, there was a mean 2.3 systemic manifestations, vs. 3.2 in the group without ocular manifestations (P=0.004). When BD was diagnosed prior to the onset of uveitis, we counted fewer patients in the "decreased visual acuity" group in comparison with the patients who had no prior diagnosis of BD at the onset of the uveitis (91.3% in the "decreased visual acuity" group, P=0.04). The time before initiation of immunosuppressive treatment or a biological agent was shorter for these patients (4.4 vs. 39.3 months, P=0.007).

CONCLUSION

It appears that different phenotypes exist according to whether or not the BD patient has ocular involvement. Moreover, the visual prognosis is better if the uveitis occurs in patients who have already been diagnosed with BD, due to earlier initiation of immunosuppressive therapy.

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.

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.

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.

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.

Long-Term Outcome of Ustekinumab Therapy for Behçet's Disease

OBJECTIVE

Oral ulcers, the hallmark lesion of Behçet's disease (BD), can be disabling and resistant to conventional treatment, and there is a need for safe and effective treatment. We undertook this study to investigate the long-term safety and efficacy of ustekinumab therapy for BD-related oral ulcers that are resistant to colchicine.

METHODS

This multicenter, prospective, open-label study included 30 patients who fulfilled the criteria of the International Study Group for BD and who were diagnosed as having active oral ulcers resistant to colchicine. Patients were treated subcutaneously with ustekinumab 90 mg at inclusion, at week 4, and then once every 12 weeks. Each patient was assessed longitudinally for the presence and number of oral ulcers, and median numbers of oral ulcers (with interquartile range [IQR]) were calculated. The primary efficacy end point was the proportion of patients at week 12 who experienced complete response, defined as having no oral ulcers.

RESULTS

The median number of oral ulcers per patient during ustekinumab therapy was significantly lower at week 12 compared to baseline (0 [IQR 0-1] versus 2 [IQR 2-3]; P < 0.0001). Complete response was achieved in 60.0% and 88.9% of patients at weeks 12 and 24, respectively. The median Behçet's Syndrome Activity Score (in which higher scores indicate more active disease) was significantly lower at weeks 12 and 24 (17.5 [IQR 10-42.5] and 10 [IQR 8-11], respectively) versus baseline (70 [IQR 50-70]; P < 0.0001). After a median follow-up of 12 months (IQR 6-16 months), 26 patients (86.7%) were still receiving ustekinumab treatment. Reasons for ustekinumab discontinuation included BD flare (n = 3) and side effects (n = 1). Seven patients (23.3%) experienced adverse events, including headaches (n = 4) and asthenia (n = 2), with no serious side effects.

CONCLUSION

Ustekinumab seems to be effective in treating BD-related oral ulcers that are resistant to treatment with colchicine.

Phenotypes in Behçet's syndrome

Behçet syndrome (BS) is a multi-systemic complex disorder with unknown etiology and a unique geographic distribution. It could not be possible to include it into specific classification schemes and it is certainly not a uniform disease. Several cluster and association studies revealed that it has been composed of multiple phenotypes ascribing the principal problem such as skin-mucosa, joint, eye, vascular, neurological and gastrointestinal involvement. Each phenotype has its own characteristic demographic and clinical features as such their management strategies and prognosis differ substantially. Actually, the concept of phenotyping has been well known for some time and is considered one of the basic elements of the still continuing debate whether to call this entity 'disease' or 'syndrome'. Further supporting evidence comes from the observation of the geographical differences of disease expression. In this setting, BS resembles rather a construction made of several dynamic and interactive LEGO pieces of different shapes and colors. These pieces presenting phenotypes with their own disease mechanism have presumably different genetic determinants. The analysis of phenotyping could help us to identify this disorder and hence could contribute to find better ways of treatment.

The ocular involvement did not accompany with the genital ulcer or the gastrointestinal symptoms at the early stage of Behçet's disease

OBJECTIVES

This study aimed to identify patients with high-probability of ocular involvement of Behçet's disease (BD).

METHODS

The Japanese Ministry of Health, Labour and Welfare provided dataset of ongoing nationwide BD registration project. A patient who had confirmed BD and who was suspected to have BD was registered. We mainly analyzed newly registered patients who had the data for all demographic and diagnostic parameters regardless of fulfilment of any diagnostic criteria.

RESULTS

Among 3213 patients with confirmed or possible BD, 1382 (43.0%) were men and 1831 (57.0%) were women with a median age of 38 years (interquartile range (IQR) 30-49 years). The median duration between onset and registration was 0 year (IQR 0-3). A binomial multivariable logistic regression analysis revealed that being female (odds ratio (OR) 0.63, 95% confidence interval (CI) 0.53-0.75, p < .001), duration since onset (OR 1.33 per 10 years, 95% CI 1.18-1.51, p < .001), genital ulceration (OR 0.28, 95% CI 0.23-0.34, p < .001), and gastrointestinal symptoms (OR 0.36, 95% CI 0.30-0.44, p < .001) were related to the ocular lesion. Analyses based on data of 2800 patients who satisfied International criteria of BD, age-, sex-, duration-based subgroup analyses, analyses targeting iridocyclitis and retino-uveitis, and analysis including patients with missing data confirmed that the four factors were associated with the probability of eye involvement.

CONCLUSION

The ocular involvement did not accompany with genital ulcer or gastrointestinal symptoms at the early stage of BD.

Behçet's syndrome: providing integrated care

Behçet’s syndrome (BS) is a multisystem vasculitis that presents with a variety of mucocutaneous manifestations such as oral and genital ulcers, papulopustular lesions and erythema nodosum as well as ocular, vascular, gastrointestinal and nervous system involvement. Although it occurs worldwide, it is especially prevalent in the Far East and around the Mediterranean Sea. Male gender and younger age at disease onset are associated with a more severe disease course. The management of BS depends on the severity of symptoms. If untreated, morbidity and mortality are considerably high in patients with major organ involvement. Multidisciplinary patient care is essential for the management of BS, as it is for other multisystem diseases. Rheumatologists, dermatologists, ophthalmologists, neurologists, cardiovascular surgeons and gastroenterologists are members of the multidisciplinary team. In this study, we reviewed the epidemiology, etiology, diagnostic criteria sets, clinical findings and treatment of BS and highlighted the importance of the multidisciplinary team in the management of BS.

Cogan and Behcet syndromes

Cogan and Behcet syndromes are considered large vessel vasculitides. Both are rare diseases, with varied clinical manifestations affecting multiple organ systems. Although both have hallmark symptoms (ocular and vestibuloauditory inflammation in Cogan syndrome and aphthous ulcers in Behcet syndrome), neither has confirmatory diagnostic testing. Delayed diagnosis can result in poor outcomes. In both syndromes, large vessel arterial inflammation may result in severe morbidity and mortality. Treatment strategies in both syndromes vary based on organ system involvement and severity of manifestations. In this article, the epidemiology, proposed pathogenesis, manifestations, and the most current treatment paradigms for these syndromes are reviewed.

Update on the diagnosis and management of Behçet's disease

Behçet’s disease is a multi-organ disorder that is more common in countries around the Silk Road, and manifests as mucosal ulcers and skin lesions, and with ocular involvement. As a systemic disease, it can also involve gastrointestinal organs and the central nervous or cardiovascular systems. Although the etiology of Behçet’s disease is not clearly identified, the pathogenesis of the disease is most commonly hypothesized as a profound inflammatory response triggered by an infectious agent in a genetically susceptible host. As there are no single specific manifestations or specific diagnostic tests, various diagnostic criteria have been proposed around the world, and, among them, the International Study Group criteria have been most commonly used. As the clinical expression of Behçet’s disease is heterogeneous, the treatment should be individualized based on involved organs, severity of the disease, and patient’s background. The choice of therapeutic agents is limited by lack of clinical trials and is based largely on case reports, case series, and several open-label clinical trials. Corticosteroids, colchicine, and traditional immunosuppressive agents, including azathioprine and cyclosporine, have been used for the treatment of Behçet’s disease. Recently, tumor necrosis factor (TNF) inhibitors have become available for several rheumatic diseases, and considerable published data suggest that TNF inhibitors represent an important therapeutic advance for patients with severe and resistant disease, as well as for those with contraindications or intolerance to these treatments.

Genetics of Behçet's disease: lessons learned from genomewide association studies

PURPOSE OF REVIEW

Behçet's disease is a complex disease, and genetic susceptibility plays a critical role. This review aimed to discuss the recent genomewide association study (GWAS) findings and their implications to the pathogenesis of Behçet's disease.

RECENT FINDINGS

GWAS data confirmed the major role of HLA-B51 in Behçet's disease susceptibility, and the discovery of epistatic interactions between HLA-B51 and ERAP1 variants provided some hints about its possible pathogenic mechanisms. Investigation of human leukocyte antigen (HLA) Class I region showed weaker but independent associations around HLA-A and HLA-C regions. Genomewide studies also established associations with IL10, IL23R, CCR1, STAT4, KLRC4, GIMAP2/GIMAP4, and UBAC2 genes in Behçet's disease patients of different ethnicities. Deep resequencing of targeted genes identified additional associations with rare variants in TLR4, MEFV, and NOD2 genes.

SUMMARY

GWAS data established a major step forward by providing insights into the underlying mechanisms in Behçet's disease with the discovery of new susceptibility genes. These variations may implicate defects in the sensing and processing of microbial and endogenous danger signals as well as in the regulation of innate and adaptive immune responses in Behçet's disease. Association findings with HLA Class I antigens as well as IL23R, ERAP1, IL10, and MEFV genes also suggest shared inflammatory pathways with spondyloarthropathies.

Behçet's syndrome

Behçet's syndrome (BS) shows a peculiar distribution, with a much higher prevalence in countries along the ancient Silk Road compared with rest of the world. BS also seems to follow a more severe course in ethnic groups with higher prevalence. Diagnosis depends on clinical findings. Criteria sets may not help in patients with less frequent types of involvement. Management strategies should be modified according to the age and sex of the patient and the organs involved. Being a serious health problem in endemic areas, BS also attracts global attention as a model to study inflammatory diseases of unknown cause.