Behçet's disease: from Hippocrates to the third millennium

A Case Report of Neuro-Behçet Syndrome: Frequent Neurological Manifestations Concurrent With Life-Threatening Illnesses

​​​​Behçet disease (BD) is a recurrent, multisystemic autoimmune vasculitis that affects both small and large vessels. A combination of neurological signs and symptoms in BD is called neuro-Behçet syndrome (NBS). We present the case of a 31-year-old male diagnosed with chronic progressive NBS who presented with multiple relapsing episodes concurrent with infective endocarditis due to intravenous drug abuse, drug-induced hepatitis, acute kidney injury, and septic shock that is not related to BD. Neurological relapsing episodes were treated with steroids azathioprine and colchicine. At the same time, concurrent illnesses were managed appropriately. Infective endocarditis needed valve replacement surgery, and sepsis was treated with selected antibiotics. Fortunately, the patient's brain images and laboratory investigation improved accordingly. On average, patients with parenchymal neuro-Behçet syndrome (P-NBS) have a poor prognosis; within 10 years of diagnosis, 50% of those patients are severely disabled as our patient who became aphasic and quadriplegic.

Immunopathogenesis of Behçet's disease

Behçet's disease (BD) is a multi-system inflammatory disorder with vasculitic features. It does not suit any of the current pathogenesis-driven disease classifications well, a unifying concept of its pathogenesis is not unanimously conceivable at present, and its etiology is obscure. Still, evidence from immunogenetic and other studies supports the notion of a complex-polygenic disease with robust innate effector responses, reconstitution of regulatory T cells upon successful treatment, and first clues to the role of an, as of yet, underexplored adaptive immune system and its antigen recognition receptors. Without an attempt to be comprehensive, this review aims to collect and organize impactful parts of this evidence in a way that allows the reader to appreciate the work done and define the efforts needed now. The focus is on literature and notions that drove the field into new directions, whether recent or more remote.

Adamantiades-Behçet disease: Between dermatology and ophthalmology

Adamantiades-Behçet disease is an inflammatory, vascular disease of unknown etiology. The disease is named after two physicians, Benediktos Adamantiades and Hulȗsi Behçet, who both made significant contributions to the study of the disease. It was probably first described by Hippocrates in 500 BCE. Adamantiades-Behçet disease is most common in the region encompassing the ancient trade route known as the Silk Road. In Turkey, the disease is estimated to affect 80 to 370 people per 100,000 inhabitants, and it is also the country with the highest incidence rate. The frequency of the disease associated with the clinical picture differs from the origin of the onset. The disease is characterized by recurrent aphthous ulcers of the mouth, genitals, skin lesions, and eye lesions. The disease process can also involve other organs, including the joints, nervous system, large vessels, heart, and gastrointestinal tract. Aphthous oral ulcers appear as the first harbinger of the disease and affect almost all patients (97%-99%). The scientific interest in Adamantiades-Behçet disease has increased exponentially in the past decade.

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.

Utilizing shear wave elastography for the evaluation of optical nerve involvement in Behçet's disease

In this study, we investigated the elasticity of the optic nerve using shear wave elastography (SWE) in patients with Behçet's Disease (BD) and compare findings with a healthy control group. Optic nerve measurements of 40 eyes in the BD group and 38 eyes in the control group were performed by SWE (SWE-right and SWE-left). The mean age of the individuals in the BD group was higher than controls (p = 0.022). The SWE measurement results in the right eye were significantly higher in the BD group (p = 0.005), while SWE-left values were similar in the two groups (p = 0.206). There was a moderate positive correlation between age and SWE-right (r = 0.347, p = 0.031), there was no correlation between SWE-left and age (p = 0.756). It was found that SWE-right had significant value in distinguishing between BD and healthy controls (sensitivity: 75%, specificity: 78.9%; p = 0.005); whereas, SWE-left did not (p = 0.206). In the multiple logistic regression analysis, after adjusting for age and sex, the performance of SWE-right to distinguish BD patients from controls was found to remain significant (OR: 15.045, 95% CI: 2.33-97.120, p = 0.004). Due to the fact that only SWE-right values appear to have significant discriminatory performance for BD, it is feasible to suggest that the frequency and severity of BD involvement are associated with SWE-related changes in the optic nerve. This finding indicates the need for more comprehensive studies evaluating optic nerve SWE values in this context.

Candidate Drugs Screening for Behcet’s Disease Based on Bioinformatics Analysis and Mouse Experiments

Background

Behcet’s disease (BD) is a chronic immune disease that involves multiple systems. As the pathogenesis of BD is not clear, and new treatments are needed, we used bioinformatics to identify potential drugs and validated them in mouse models.

Methods

Behcet’s disease-related target genes and proteins were screened in the PubMed and UVEOGENE databases. The biological functions and pathways of the target genes were analyzed in detail by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. A protein-protein interaction (PPI) network was constructed by the STRING database, and hub genes were identified by the Cytoscape plug-in CytoHubba. Gene-drug interactions were identified from the DGIdb database. Experimental autoimmune uveitis (EAU) mice were used as an animal model for drug validation.

Results

A total of 249 target genes and proteins with significant differences in BD were screened, and the results of functional enrichment analysis suggested that these genes and proteins were more located on the cell membrane, involved in regulating the production of cytokines and affecting the activity of cytokines. They mainly regulated “Cytokine- Cytokine receptor interaction”, “Inflammatory bowel disease (IBD)” and “IL-17 signaling Pathway”. In addition, 10 hub genes were obtained through PPI network construction and CytoHubba analysis, among which the top 3 hub genes were closely related to BD. The DGIdb analysis enriched seven drugs acting together on the top 3 hub genes, four of which were confirmed for the treatment of BD or its complications. There is no evidence in the research to support the results in omeprazole, rabeprazole, and celastrol. However, animal experiments showed that rabeprazole and celastrol reduced anterior chamber inflammation and retinal inflammation in EAU mice.

Conclusions

The functional analysis of genes and proteins related to BD, identification of hub genes, and validation of potential drugs provide new insights into the disease mechanism and potential for the treatment of BD.

Characterizing the diversity of MHC conserved extended haplotypes using families from the United Arab Emirates

Aside from its anthropological relevance, the characterization of the allele frequencies of genes in the human Major Histocompatibility Complex (MHC) and the combination of these alleles that make up MHC conserved extended haplotypes (CEHs) is necessary for histocompatibility matching in transplantation as well as mapping disease association loci. The structure and content of the MHC region in Middle Eastern populations remain poorly characterized, posing challenges when establishing disease association studies in ethnic groups that inhabit the region and reducing the capacity to translate genetic research into clinical practice. This study was conceived to address a gap of knowledge, aiming to characterize CEHs in the United Arab Emirates (UAE) population through segregation analysis of high-resolution, pedigree-phased, MHC haplotypes derived from 41 families. Twenty per cent (20.5%) of the total haplotype pool derived from this study cohort were identified as putative CEHs in the UAE population. These consisted of CEHs that have been previously detected in other ethnic groups, including the South Asian CEH 8.2 [HLA- C*07:02-B*08:01-DRB1*03:01-DQA1*05:01-DQB1*02:01 (H.F. 0.094)] and the common East Asian CEH 58.1 [HLA- C*03:02-B*58:01-DRB1*03:01- DQA1*05:01-DQB1*02:01 (H.F. 0.024)]. Additionally, three novel CEHs were identified in the current cohort, including HLA- C*15:02-B*40:06-DRB1*16:02-DQB1*05:02 (H.F. 0.035), HLA- C*16:02-B*51:01-DRB1*16:01-DQA1*01:02-DQB1*05:02 (H.F. 0.029), and HLA- C*03:02-B*58:01-DRB1*16:01-DQA1*01:02-DQB1*05:02 (H.F. 0.024). Overall, the results indicate a substantial gene flow with neighbouring ethnic groups in the contemporary UAE population including South Asian, East Asian, African, and European populations. Importantly, alleles and haplotypes that have been previously associated with autoimmune diseases (e.g., Type 1 Diabetes) were also present. In this regard, this study emphasizes that an appreciation for ethnic differences can provide insights into subpopulation-specific disease-related polymorphisms, which has remained a difficult endeavour.

Multimodality Evaluation of Aortic Insufficiency and Aortitis in Rheumatologic Diseases

Aortic insufficiency is commonly observed in rheumatologic diseases such as ankylosing spondylitis, systemic lupus erythematosus, antiphospholipid syndrome, Behçet's disease, granulomatosis with polyangiitis, and Takayasu arteritis. Aortic insufficiency with an underlying rheumatologic disease may be caused by a primary valve pathology (leaflet destruction, prolapse or restriction), annular dilatation due to associated aortitis or a combination of both. Early recognition of characteristic valve and aorta morphology on cardiac imaging has both diagnostic and prognostic importance. Currently, echocardiography remains the primary diagnostic tool for aortic insufficiency. Complementary use of computed tomography, cardiac magnetic resonance imaging and positron emission tomography in these systemic conditions may augment the assessment of underlying mechanism, disease severity and identification of relevant non-valvular/extracardiac pathology. We aim to review common rheumatologic diseases associated with aortic insufficiency and describe their imaging findings that have been reported in the literature.

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.

Uveitis in Children and Adolescents

Childhood noninfectious uveitis leads to sight-threatening complications. Idiopathic chronic anterior uveitis and juvenile idiopathic arthritis-associated uveitis are most common. Inflammation arises from an immune response against antigens within the eye. Ophthalmic work-up evaluates anatomic involvement, disease activity, ocular complications, and disease course. Local and/or systemic glucocorticoids are initial treatment, but not as long-term sole therapy to avoid glucocorticoids-induced toxicity or persistent ocular inflammation. Children with recurrent, refractory, or severe disease require systemic immunosuppression with methotrexate and/or anti-tumor necrosis factor monoclonal antibody medications (adalimumab, infliximab). Goals of early detection and treatment are to optimize vision in childhood uveitis.

Behcet's disease in an adult male from Nepal: A case report

This case report highlights considering Behcet's disease as a diagnosis in orogenital ulcers and uveitis, although its prevalence is unknown in Nepal due to underreporting. Also, collaboration for patient care among relevant specialties is required.

Association of Behçet disease with psoriasis and psoriatic arthritis

Behçet disease (BD) is a debilitating multi-systemic vasculitis with a litany of muco-cutaneous manifestations and potentially lethal complications. Meanwhile, psoriasis (PSO) is a cutaneous and systemic inflammatory disorder marked by hyperplastic epidermis and silvery scales, which may be accompanied by a distinct form of arthropathy called psoriatic arthritis (PsA). While the clinical pictures of these two are quite different, they feature some important similarities, most of which may stem from the autoinflammatory components of BD and PSO. Therefore, the aim of this study was to investigate the prospective link between BD and cutaneous and articular manifestations of psoriasis. BD, PSO, and PsA cohorts were extracted using the National Health Insurance Service of Korea database. Using χ² tests, prevalence of PSO and PsA with respect to BD status was analysed. Relative to non-BD individuals, those with personal history of BD were nearly three times more likely to be diagnosed with PSO. The adjusted odds ratio (aOR) was 2.36 [95% confidence interval (CI), 1.91–2.93, p < 0.001]. Elevated PSO risk was more pronounced in the male BD cohort (aOR = 1.19, 95% CI 1.16–1.23, p < 0.001). In age-group sub-analysis, individuals over 65 years with PSO were one and a half times more likely to be affected with BD, relative to those under 65. The adjusted OR for the older group was 1.51 (95% CI 1.43–1.59, p < 0.001). BD individuals with “healthy” body weight were significantly less likely to be affected by PSO (aOR = 0.59, 95% CI 0.57–0.62, p < 0.001). On the other hand, there was a correlation between BMI and the risk of BD, with the “moderately obese (30–35 kg/m²)” group having an aOR of 1.24 (95% CI 1.12–1.38, p < 0.001). BD patients were also twice more likely to be associated with PsA (aOR = 2.19, 95% CI 1.42–3.38, p < 0.001). However, in contrast to the case of psoriatic disease itself, females were exposed to a greater risk of developing BD compared to the male PsA cohort (aOR = 2.02, 95% CI 1.88–2.16, p < 0.001). As with PSO, older BD patients were exposed to a significantly higher risk of developing PsA (aOR = 3.13, 95% CI 2.90–3.40, p < 0.001). Behçet disease may place an individual at a significantly increased risk of psoriasis, and still greater hazard of being affected with psoriatic arthritis. This added risk was pronounced in the male cohort, and tended to impact senile population, and this phenomenon may be related with the relatively poor prognosis of BD in males and PSO in older patients.

Platelet activation in ocular Behçet's patients with posterior segment involvement

PURPOSE:

The aim of the present study was to assess platelet activation by analyzing three platelet activation parameters in ocular Behçet's disease (BD): mean platelet volume (MPV), platelet distribution width (PDW), and plateletcrit (PCT).

METHODS:

Twenty-nine patients with active ocular BD (Group 1), 40 patients with inactive ocular BD (Group 2), and 40 healthy adult individuals serving as controls (Group 3) were evaluated. All of the individuals had been performed the complete ophthalmologic evaluation. The levels of MPV, PDW, and PCT were measured in each group.

RESULTS:

The mean MPV level was 8.40 ± 0.97 in Group 1, 8.32 ± 1.04 in Group 2, and 7.77 ± 0.72 in Group 3. The mean PDW level was 15.12 ± 1.09 in Group 1, 14.97 ± 1.02 in Group 2, and 14.52 ± 0.82 in Group 3. The mean PCT level was 0.23 ± 0.07 in Group 1, 0.21 ± 0.04 in Group 2, and 0.18 ± 0.03 in Group 3. MPV, PDW, and PCT levels were significantly higher in ocular BD patients than controls (P < 0.05).

CONCLUSION:

Platelet activation may affect vascular occlusion in ocular Behçet's patients with posterior segment involvement. This result may be important in evaluating ocular BD patients.

Behçet disease in Emergency Department: a rare case presenting with haemoptysis and massive pulmonary arterial aneurysms

Behçet disease (BD) is a systemic disorder caused by underlying vasculitis of unknown origin. In this paper we present a case of a 26-year-old male patient who was admitted at our Emergency Department with massive haemoptysis due to pulmonary arterial involvement in BD. The discussion of this case helps to remember that BD is the main cause of aneurysm of the pulmonary arteries and a cause of haemoptysis in young patients. Therefore, the radiologist plays a key role in the identification of intrathoracic alterations with chest computed tomography. The knowledge of clinical manifestations and distinctive elements of BD allow an accurate diagnosis and let the patient to be directed towards an appropriate treatment, in order to avoid the onset of life-threatening complications.

The protective function of invariant natural killer T cells in the relapse of experimental autoimmune uveoretinitis

Experimental autoimmune uveoretinitis (EAU) in mice provides a useful platform to study the pathogenesis and experimental therapeutics of human uveitis. One often used EAU model employs C57BL/6 (B6) mice sensitized with a peptide residue having 1 to 20 amino acids of human interphotoreceptor retinoid binding protein (hIRBP_1-20). The model using the B6 background has permitted a liberal use of genetically engineered strains and has provided insights for understanding uveoretinitis. However, this is usually acute/monophasic and does not represent human uveoretinitis that is characterized as a chronic/recurrent disease. Several chronic/recurrent EAU models have been developed; of these, we employed administration of staphylococcal enterotoxin B (SEB) for relapse in the present study, and found that recurrence was induced at day 24 after primary immunization, which is thought to be the convalescent phase. We reported the activation of invariant natural killer T (iNKT)-cells upon primary immunization of the EAU model mice with the ligand RCAI-56, which was found to mitigate the disease in our previous study. Here, we first attempted to ameliorate EAU in the relapse model using a preventive regimen by activating iNKT cells at the same time relapse induction (day 24) or in a regimen after 3 days of relapse induction (day 27). The preventive as well as post-inductive regimens were successful in reducing histopathological scores by inhibiting the Ag-specific Th17-biased response. Collectively, activation of iNKT cells may be useful to mitigate the relapse response of EAU induced with SEB.

Neutrophil elastase and endogenous inhibitors in Behçet's disease saliva

Behçet's disease (BD) is a vasculitis of unknown aetiology typified by chronic recurrent oral ulcers and systemic inflammatory manifestations. Neutrophils, and specifically their protease neutrophil elastase (NE), have been implicated in its pathology. Although NE is an effective anti-microbial, excessive NE can damage host tissue. Recurrent oral ulceration is a primary BD symptom, therefore we hypothesized that excessive neutrophil infiltration evidenced by increased NE and a reduction in specific endogenous inhibitors, secretory leucocyte protease inhibitor (SLPI) and alpha1-anti-trypsin (α1AT) contributes to BD mucosal instability. NE, SLPI and α1AT were quantified in saliva from BD patients with active oral ulcers (BDa) and quiet without ulcers (BDq), recurrent aphthous stomatitis (RASa; RASq) and healthy controls (HC). Although BDq saliva had marginally higher median NE levels (1112 ng/ml) compared to both RASq (1043 ng/ml) and HC (999 ng/ml), SLPI was significantly reduced in BDq (P < 0·01). Despite decreased SLPI protein, mRNA expression was significantly increased in BDq buccal epithelial swabs compared to RASq and HC (P < 0·05, P < 0·001). NE remained enzymatically active, although α1AT levels were at least eight times higher than SLPI in all groups, suggesting that α1AT does not have a primary role in counteracting NE in saliva. Furthermore, NE levels in BDa patients medicated with both azathioprine (AZA) and colchicine (COLC) were significantly lower than those on COLC (P = 0·0008) or neither (P = 0·02), indicating that combining AZA + COLC may help to regulate excessive NE during ulceration. This study showed that enzymatically active NE coupled with reduced SLPI in BD saliva may contribute to recurrent oral ulcerations.

KIR Variation in Iranians Combines High Haplotype and Allotype Diversity With an Abundance of Functional Inhibitory Receptors

Natural killer (NK) cells are innate lymphocytes that eliminate infected and transformed cells. They discriminate healthy from diseased tissue through killer cell Ig-like receptor (KIR) recognition of HLA class I ligands. Directly impacting NK cell function, KIR polymorphism associates with infection control and multiple autoimmune and pregnancy syndromes. Here we analyze KIR diversity of 241 individuals from five groups of Iranians. These five populations represent Baloch, Kurd, and Lur, together comprising 15% of the ethnically diverse Iranian population. We identified 159 KIR alleles, including 11 not previously characterized. We also identified 170 centromeric and 94 telomeric haplotypes, and 15 different KIR haplotypes carrying either a deletion or duplication encompassing one or more complete KIR genes. As expected, comparing our data with those representing major worldwide populations revealed the greatest similarity between Iranians and Europeans. Despite this similarity we observed higher frequencies of KIR3DL1^*001 in Iran than any other population, and the highest frequency of HLA-B^*51, a Bw4-containing allotype that acts as a strong educator of KIR3DL1^*001⁺ NK cells. Compared to Europeans, the Iranians we studied also have a reduced frequency of 3DL1^*004, which encodes an allotype that is not expressed at the NK cell surface. Concurrent with the resulting high frequency of strong viable interactions between inhibitory KIR and polymorphic HLA class I, the majority of KIR-A haplotypes characterized do not express a functional activating receptor. By contrast, the most frequent KIR-B haplotype in Iran expresses only one functional inhibitory KIR and the maximum number of activating KIR. This first complete, high-resolution, characterization of the KIR locus of Iranians will form a valuable reference for future clinical and population studies.

The roles of ERAP1 and ERAP2 in autoimmunity and cancer immunity: New insights and perspective

Autoimmunity and cancer affect millions worldwide and both, in principal, result from dysregulated immune responses. There are many well-known molecules involved in immunological process playing as a double-edged sword, by which associating autoimmune diseases and cancer. In this regard, Endoplasmic reticulum aminopeptidases (ERAP) 1, which belongs to the M1 family of aminopeptidases, plays a central role as a "molecular ruler", proteolyzing of N-terminal of the antigenic peptides before their loading onto HLA-I molecules for antigen presentation in the Endoplasmic Reticulum (ER). Several genome-wide association studies (GWAS) highlighted the significance of ERAP1 and ERAP2 in autoimmune diseases, including Ankylosing spondylitis, Psoriasis, Bechet's disease, and Birdshot chorioretinopathy, as well as in cancers. The expression of ERAP1/2 is mostly altered in different cancers compared to normal cells, but how this affects anti-cancer immune responses and cancer growth has been little explored. Recent studies on the immunological outcomes and the catalytic functions of ERAP1 and ERAP2 have provided a better understanding of their potential pathogenetic role in autoimmunity and cancer. In this review, we summarize the role of ERAP1 and ERAP2 in the autoimmune diseases and cancer immunity based on the recent advances in GWAS studies.

Vascular Behçet's syndrome: an update

Behçet's syndrome (BS) is a complex vasculitis, characterised by peculiar histological, pathogenetic and clinical features. Superficial venous thrombosis (SVT) and deep vein thrombosis (DVT) are the most frequent vascular involvements, affecting altogether 15-40% of BS patients. Atypical thrombosis is also an important clinical feature of BS, involving the vascular districts of the inferior and superior vena cava, suprahepatic veins with Budd-Chiari syndrome, portal vein, cerebral sinuses and right ventricle. On the other hand, arterial involvement, although affecting only 3-5% of patients, represents a unique feature of BS, with aneurysms potentially affecting peripheral, visceral and pulmonary arteries. Vascular events in BS are promoted by inflammation, with neutrophils playing a key role in the pathogenesis of thrombotic events; in turn, coagulative components such as fibrinogen, thrombin, factor Xa and factor VIIa amplify the inflammatory cascade. Understanding the contribution of inflammatory and coagulation components in the pathogenesis of BS vascular events is crucial to define the most effective therapeutic strategy. Control of vascular thrombosis is achieved with immunosuppressants drugs rather than anticoagulants. In particular, use of azathioprine and cyclosporine in association with low-dose corticosteroids should be considered in DVT and SVT cases, while treatment with cyclophosphamide together with anti-TNF-α agents can be effectively used in arterial involvement. More recently, the anti-TNF-α drugs have also been reported as a valid alternative for the treatment also of venous events, especially DVT. An exception to the use of anticoagulant in BS could be represented by cerebral veins thrombosis. In this review, we will depict the main characteristics of the vascular involvement in BS, briefly describing histological and pathogenetic features, while focusing on the clinical and therapeutical approaches of the vascular manifestations of BS.

HLA class I allele lineages and haplotype frequencies in Arabs of the United Arab Emirates

The high degree of polymorphism of the HLA system provides suitable genetic markers to study the diversity and migration of different world populations and is beneficial for forensic identification, anthropology, transplantation and disease associations. Although the United Arab Emirates (UAE) population of about nine million people is heterogeneous, information is limited for the HLA class I allele and haplotype frequencies of the Bedouin ethnic group. We performed low-resolution PCR-SSP genotyping of three HLA class I loci at HLA-A, -B and -C for 95 unrelated healthy Bedouins from the cities of Al Ain and Abu Dhabi in the UAE. A total of 54 HLA allele lineages were detected; the most frequent low-resolution allele lineages at each HLA locus were A*02 (0.268), B*51 (0.163) and C*07 (0.216). The inferred estimates for the two most frequent HLA-A and HLA-B haplotypes were HLA-A*02 ~ HLA-B*50 (0.070) and HLA-A*02 ~ HLA-B*51 (0.051), and the most frequent 3-locus haplotype was HLA-A*02 ~ HLA-B*50 ~ HLA-C*06 (0.068). The HLA allele lineage frequencies of the UAE Arabs were compared to those previously reported for 70 other world populations, and a strong genetic similarity was detected between the UAE Arabs and the Saudi Arabians from the west with evidence of a limited gene flow between the UAE Arabs and Pakistani across the Gulf from the east, and the UAE Arabs and Omani from the south of the Gulf Peninsula.

The Greek (Hellenic) rheumatology over the years: from ancient to modern times

Rheumatology has its roots in ancient Greece. Hippocrates and other prominent Greek (Hellenes) physicians in ancient times, Hellenistic, Roman, and Byzantine period were acute observers of disease course and of patients and were able to define many disorders. They wrote books on various aspects of medicine and these writings were the basis of medical practice and education in Europe and the Arabic world well into the seventeenth century. In 1821, Greece emerged from a long occupation by the Turks. In 1930, Adamantiades, a Greek Ophthalmologist, before Behcet of Turkey, described what is known as (Adamantiades)-Behcet disease. The first scientific Hellenic Society for Rheumatology (ERE) was established in 1960 and today ERE having been merged with the Professional Union of Greek rheumatologists (EPERE) is known as ERE-EPERE. Rheumatology is a strong specialty with 348 rheumatologists for a population of around 11 million. Greek rheumatologists have contributed to rheumatology science and practice, and are active physicians participating in the American College of Rheumatology and the EULAR annual congresses and in many educational postgraduate courses. ERE-EPERE formed therapeutic protocols for inflammatory and autoimmune rheumatic diseases which were incorporated in the electronic National prescription system. Rheumatologists are authorized to use this platform to prescribe biologicals free of charge for patients. ERE-EPERE publishes a peer-reviewed English language journal, the Mediterranean Journal of Rheumatology (MJR), an open access journal with no publication fees. MJR is a quarterly journal with international Editorial Board.

The main aspects of retinal vein occlusion etiopathogenisis in young adults. Part I. Neuroretinovasculitis (prothrombotic potential, clinical manifestations)

This review is dedicated to the neuroretinovasculitis, which is the leading cause of retinal vein occlusion in young adults. Presumed etiological factors, possible pathogenic mechanisms, and clinical manifestation are analyzed. Advisability of multidisciplinary approach in management and individual approach in treatment of patients with neuroretinovasculitis with secondary retinal vein occlusion are justified.

Epidemiology of Behcet's Disease in Taiwan: A Population-Based Study

PURPOSE

To study the incidence and epidemiology of Behcet's disease in Taiwan.

METHODS

This retrospective cohort study was conducted using the nationwide reimbursement database in Taiwan. One million registered beneficiaries of the Taiwan National Health Insurance system in 2000 were randomly selected. All medical claims of these persons were collected. The definition of having Behcet's disease was based on diagnostic codes. Persons who had incomplete registry data or diagnoses prior to 2001 were excluded. Annual incidence between 2001 and 2011 was calculated and risk factors for incidence were explored using the Cox proportional regression model. Characteristics of patients with Behcet's disease with and without uveitis were compared.

RESULTS

A total of 236 newly diagnosed patients with Behcet's disease were found between 2001 and 2011. The average incidence was 2.40 cases per 100,000 person-years (ranging from 1.29 to 3.53). Female patients and those aged between 40 and 65 years were at the highest risk of Behcet's disease. Only 18.2% of the patients had also suffered from uveitis. The subspecialties of doctors making initial diagnoses and the number of prescribed immunomodulatory agents differed significantly between the patients with and without uveitis (p < 0.001 and <0.05, respectively).

CONCLUSION

Incidence of Behcet's disease was not high in Taiwan and relatively few of the patients developed uveitis. Patients of working age or who were female were more likely to have Behcet's disease. However, age of onset and clinical severity differed between patients with and without uveitis.

Treatment of severe generalized chronic periodontitis in a patient with Behçet's disease: A case report

Behçet’s disease is a systemic disorder of unknown etiology. It involves multiple organ systems and is characterized by recurring episodes of oral ulcers as well as ocular, genital, and skin lesions. Oral ulcers can affect tooth brushing and impair proper oral hygiene. As a result, a dental biofilm accumulates, and the condition of the teeth and periodontal tissue deteriorates. The aim of this case report is to highlight the efficacy of periodontal treatment for patients with Behçet’s disease. A 51-year-old man with Behçet’s disease presented with generalized severe periodontitis. After basic treatment of the periodontal tissues, periodontal surgery was performed at several sites with bony defects. However, the patient developed severe stomatitis in the oral mucosa and gingiva after periodontal surgery. Administration of the antimicrobial agent cefdinir had little effect on recovery; however, subsequent administration of sitafloxacin resulted in significant improvement of the stomatitis. This case demonstrates that periodontal therapy is very useful for alleviating the oral signs and symptoms of Behçet’s disease. Systemic antibiotic treatment with sitafloxacin (but not cefdinir) and mechanical debridement were effective in preventing the recurrence of aphthous ulcer outbreaks after periodontal surgery.

Role of Human Leukocyte Antigens (HLA) in Autoimmune Diseases

Since the discovery of HLA 60 years ago, it has contributed to the understanding of the immune system as well as of the pathogenesis of several diseases. Aside from its essential role in determining donor-recipient immune compatibility in organ transplantation, HLA genotyping is meanwhile performed routinely as part of the diagnostic work-up of certain autoimmune diseases. Considering the ability of HLA to influence thymic selection as well as peripheral anergy of T cells, its role in the pathogenesis of autoimmunity is understandable. The aim of this paper is to provide a brief overview of the role and current clinical relevance of HLA-B27 in spondyloarthritis and HLA-B51 in Behçet's disease as well as HLA-DQ2/DQ8 in celiac disease and HLA-DRB1 in rheumatoid arthritis and to discuss possible future implications.

Role of Human Leukocyte Antigens (HLA) in Autoimmune Diseases

The aim of this review is to provide a brief overview of the role and current clinical relevance of HLA-B27 in spondyloarthritis and HLA-B51 in Behcet's disease as well as HLA-DQ2/DQ8 in celiac disease and HLA-DRB1 in rheumatoid arthritis and to discuss possible future implications.

Investigation of the arterial intima-media thickness in Behcet’s disease patients without vascular complaints

Objectives

Behcet’s disease is a multisystemic, inflammatory disease. Various factors have been implicated in the disease, including genetics, infections, immunoglobulins, immune complexes, antibodies, and oxidative stress. However, the underlying etiopathogenesis remains unclear. Behcet’s disease can occur with or without vascular involvement. This prospective study investigated the relationship between the intima-media thickness of the major arteries, in addition to other factors affecting the disease process, in Behcet’s disease without vascular involvement.

Methods

Twenty-four patients (average age: 38.50 ± 10.931) without vascular involvement or any vascular complaints who were diagnosed with Behcet’s disease were included in the study. Sixteen healthy subjects (average age: 39.75 ± 7.793) were included as a control group. Demographic information and medical histories were recorded, and routine blood tests were performed in both groups. The intima-media thickness of the subclavian, axillary, femoral, and carotid arteries of all the participants were recorded using Doppler ultrasonography. The data were then subjected to intergroup statistical and correlation analyses.

Results

There were no significant differences between the arterial intima-media thickness values of the Behcet’s disease patients and those of the control group ( p > 0.05). However, there was a significant difference between the neutrophil–lymphocyte ratio ( p = 0.004), low-density lipoprotein ( p = 0.007), and triglyceride ( p = 0042) levels of the two groups. Significant correlations were found between intima-media thickness and neutrophil–lymphocyte ratio levels ( p = 0.012) and the disease duration ( p = 0.030). There was also a significant correlation between the intima-media thickness of the femoral artery and disease duration ( p = 0.014).

Conclusions

The results showed that the duration of illness had a significant effect on arterial intima-media thickness in Behcet’s disease. Blood neutrophil–lymphocyte ratio levels were also associated with increased intima-media thickness.

Soluble CD40L is associated with increased oxidative burst and neutrophil extracellular trap release in Behçet's disease

Background

Studies have suggested that soluble factors in plasma from patients with active (aBD) and inactive (iBD) Behçet’s disease (BD) stimulate neutrophil function. Soluble CD40 ligand (sCD40L) is an important mediator of inflammation in BD. Its expression and effect on neutrophil oxidative burst and neutrophil extracellular trap (NET) release have not been characterized. In this study, we sought to investigate the role of plasma and the CD40L pathway on NET release and the oxidative burst profile in patients with aBD and iBD.

Methods

Neutrophils and peripheral blood mononuclear cells (PBMCs) were obtained from patients with aBD (n = 30), patients with iBD (n = 31), and healthy control subjects (HCs; n = 30). sCD40L plasma concentration was determined in individual samples. A pool of plasma for each group was created. In some experiments, plasma pools were treated with recombinant CD40 (rhCD40-muIg) for sCD40L blockade. NET release and H₂O₂/O₂⁻ production were determined after stimulation with phorbol 12-myristate 13-acetate, sCD40L, or plasma pool. Flow cytometric analysis was performed to evaluate the expression of (1) CD40, Mac-1, and phosphorylated NF-κB p65 on neutrophils and monocytes and (2) CD40L on activated T cells and platelets. CD40L gene expression in PBMCs was determined by qRT-PCR.

Results

sCD40L plasma levels were significantly higher in patients with iBD (median 17,234, range 2346–19,279 pg/ml) and patients with aBD (median 18,289, range 413–19,883 pg/ml) than in HCs (median 47.5, range 33.7–26.7 pg/ml; p < 0.001). NET release was constitutively increased in BD compared with HC. NET release and H₂O₂/O₂⁻ were higher after stimulation with sCD40L or BD plasma and decreased after sCD40L blockade. Mac-1 expression was constitutively increased in neutrophils of patients with aBD (88.7 ± 13.2% of cells) and patients with iBD (89.2 ± 20.1% of cells) compared with HC (27.1 ± 18.8% of cells; p < 0.01). CD40 expression on phagocytes and CD40L expression on platelets were similar in the three groups. PBMCs as well as nonactivated and activated CD4⁺ T cells from patients with BD showed higher CD40L expression.

Conclusions

Plasma from patients with aBD exerts a stimulus on NET release and oxidative burst, probably induced by sCD40L.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-017-1443-5) contains supplementary material, which is available to authorized users.

Long-Term Efficacy and Safety of Interferon Alpha-2a in the Treatment of Chinese Patients with Behçet's Uveitis Not Responding to Conventional Therapy

PURPOSE

To investigate the long-term efficacy and safety of interferon alpha-2a (IFNα-2a) in Chinese patients with Behçet's uveitis (BU) refractory to conventional therapy.

METHODS

In a prospective observational cohort study, 127 patients were treated with an initial dosage of 3 million units per day in the first three months, followed by gradual tapering of the dose.

RESULTS

After 3 months of treatment, IFNα-2a was shown to be effective in 115 cases (91%). At the end of the 1-year follow-up, the frequency of ocular relapses decreased to 1.59 ± 1.68 per year (ranging 0-6) (p < 0.001), as compared to 5.09 ± 2.51 per year (ranging 3-15). Moreover, the frequency of oral ulcer relapses also decreased to 2.49 ± 1.84 per year (ranging 0-6) (p < 0.001), as compared to 8.20 ± 3.72 per year (ranging 2-10). Visual improvement or stability was observed in 32 patients (59%) in these 54 patients. During a mean follow-up of 11 months (range 3-33), the mean final VA (logMAR) had progressed from 1.0 logMAR to 0.8 logMAR in all treated patients.

CONCLUSIONS

Long-term low dose of IFNα-2a is useful in treating Chinese BU patients who do not respond adequately to conventional therapy.

Behcet's DiseaseA Case Report

Behcet's disease is a rare autoimmune systemic vasculitis. It usually presents with a symptom complex involving primarily mucocutaneous lesions, genital lesions, and uveitis. When it involves the lower extremity, venous and arterial disease predominates, and joint involvement occurs in approximately 50% of patients. We present a patient with Behcet's disease who was initially referred to us for chronic toenail pathology.

Conjunctival Cytological Alterations in Ocular Behçet Disease

PURPOSE

To evaluate the ocular surface alterations and tear film functions in patients with ocular Behçet disease (BD).

METHODS

This study included 48 eyes of 48 patients with inactive BD and a control group of 33 age- and sex-matched subjects. Schirmer I and tear break-up time (TBUT) tests were used to evaluate the tear film of the subjects. Impression cytology was used to evaluate morphological changes of the conjunctival surface epithelial cells.

RESULTS

The mean Schirmer I test result was 11.6 ± 5.9 mm/5 minutes and 16.1 ± 4.6 mm/5 minutes in the Behçet and control groups, respectively. The mean TBUT test result was 9.8 ± 5.6 seconds and 13.2 ± 5.7 seconds in the study and control groups, respectively. The Schirmer and TBUT test results were significantly lower in the study group than in the controls (P = 0.001 and P = 0.011, respectively). The mean impression cytology score was 1.3 ± 0.9 in the study group and significantly higher than the control group value of 0.4 ± 0.6 (P = 0.001).

CONCLUSIONS

Tear film functions and conjunctival surface epithelial morphology were significantly altered in patients with ocular BD.

Behcet’s disease: from heat shock proteins to infections

Background: Behcet’s disease (BD) is a chronic, inflammatory multisystemic condition of unknown etiology. Although the cause of BD is not clear, it is believed to be the result of an autoimmune process triggered by an infectious or environmental agent (possibly local to a geographic region) in a genetically predisposed individual.

Objective: To detail current knowledge of the role of microorganisms in the pathogenesis of BD and review the infectious etiology of this disease.

Methods: The review based on publication in SCOPUS, Science direct, and PubMed.

Results: A microbial infection has been implicated in the development of the disease to explain the strong inflammatory reactions observed, the activation of monocytes and macrophages, and the induction of proinflammatory cytokines and chemokines detected. Common factors linking some of the possible pathogenetic agents are extrinsically induced tissue stress or heat shock proteins, which react with host tissues and elicit significant T-helper type 1 cell responses.

Conclusion: Based on collected data, we conclude that the microorganisms discussed seem to participate and, at least in part, act as triggers during the course of BD. By clarifying the microbial associations of BD and finding its etiology, particularly the causative antigens leading to BD, it would be easier to suggest more effective treatment and preventive strategies for this disease.

Polymorphisms of Promoter Region of TNF-α Gene in Iranian Azeri Turkish Patients with Behçet's Disease

Behçet's disease (BD) is a complex chronic relapsing inflammatory disorder of unknown etiology. Alterations of the tumor necrosis factor (TNF) expression related to the polymorphic alleles of TNF gene may implicate a pathogenetic role in increased activity of this cytokine in BD. A current study aimed at investigating the possible association between BD and its clinical features in Iranian Azeri Turks with two functional TNF-α gene polymorphisms (at the positions of -238 and -857). A total number of 166 Iranian subjects were enrolled into two different groups; patients with BD (n = 64), and ethnically matched healthy controls (n = 101). The genotype distributions of BD patients and healthy controls were determined. The frequency of TNF-α -857C allele was significantly higher in Behçet's patients than that of healthy controls (P = 0.001; odds ratio [OR] = 2.616; 95% confidence interval [CI] = 1.129-6.160), whereas the frequency of TNF-α -238A allele was similar in both groups. The sole TNF-α haplotype-857C-1031C, was associated with an increase in the risk of developing BD. The TNF-α -857C allele was considerably associated with BD in this cohort. The findings of this study, collectively, indicate that TNF-α -857C-1031C haplotype located in the promoter region of the gene could exert major influence on the susceptibility to BD.

Can Pentraxin-3 be a Candidate Marker in the Follow-Up of the Patients With Behçet's Disease?

Objectives

This study aims to assess the level of pentraxin-3 (PTX-3) as an inflammatory marker and compare it with C-reactive protein (CRP) levels in patients with Behçet's disease (BD).

Patients and methods

Forty-two patients with BD (15 males, 27 females; mean age 39.7±8.6 years; range 20 to 64 years) and 42 age- and sex- matched healthy controls (14 males, 28 females; mean age 40.8±8.2 year; range 25 to 60 years) were included in the study. Serum CRP and plasma PTX-3 levels were measured. Subgroup analyses were performed according to clinical manifestations of patients with BD.

Results

Both PTX-3 and CRP levels were significantly higher in patients with BD than controls (1.33±0.29 vs 0.85±0.12, p<0.05 for PTX-3 and 0.71±0.13 vs 0.27±0.03, p<0.001 for CRP, respectively). Area under the curve was 0.633±0.062 vs 0.729±0.05, respectively. Mean PTX-3 and CRP levels were 1.1 vs 1.5, p=0.5; 0.5 vs 0.9, p=0.5; respectively, in patients with mucocutaneous involvement alone and with other involvements, whereas they were 0.9 vs 1.6, p=0.1; 0.5 vs 0.8, p=0.3; respectively, in patients with and without peripheral arthritis, and were 1.7 vs 0.9, p=0.06; 1.0 vs 0.5, p=0.07; respectively, in patients with and without uveitis.

Conclusion

Although PTX-3 levels were higher in patients with BD than healthy controls, sensitivity and specificity of PTX-3 was not different than CRP in patients with BD.

Successful Laparoscopic Treatment for Refractory Rectovaginal Fistula of Behçet's Disease: A Case Report and Review of the Literature

Rectovaginal fistula caused by Behçet's disease is extremely rare, and the clinical course is very unfavorable. We describe rectovaginal fistula of Behçet's disease with successful laparoscopic treatment and review the literature. A 30-year-old woman with Behçet's disease was diagnosed with rectovaginal fistula and treated medically after fecal diversion colostomy. However, the fistula remained, and she underwent radical surgery. Laparoscopically, after mobilization of the rectum, the fistula was removed. The rectum was transected on the anal side of the fistula and removed after extraction through the vaginal incision. The vaginal incision was repaired by suturing, and rectal anastomosis was performed using a double-stapling technique. The omentum was fixed between the rectum and vagina, and the operation was completed. Six months after the laparoscopic surgery, no evidence of fistula recurrence has been seen on colonoscopy. We have reported a rare case of rectovaginal fistula of Behçet's disease treated with an altogether new surgical approach that might prove effective for refractory rectovaginal fistula.

HLA class I variation in Iranian Lur and Kurd populations: high haplotype and allotype diversity with an abundance of KIR ligands

HLA-A, -B and -C alleles of 285 individuals, representing three Iranian Lur populations and one Iranian Kurd population were sequenced completely, yielding human leukocyte antigen (HLA) class I genotypes at high resolution and filling four fields of the official HLA nomenclature. Each population has 87-99 alleles, evenly distributed between the three HLA class I genes, 145 alleles being identified in total. These alleles were already known, named and deposited in the HLA database. The alleles form 316 different HLA A-B-C haplotypes, with each population having between 80 and 112 haplotypes. The four Iranian populations form a related group that is distinguished from other populations, including other Iranians. All four KIR ligands - the A3/11, Bw4, C1 and C2 epitopes - are well represented, particularly Bw4, which is carried by three high-frequency allotypes: HLA-A*24:02, HLA-A*32:01 and HLA-B*51:01. In the Lur and Kurd populations, between 82% and 94% of individuals have the Bw4 epitope, the ligand for KIR3DL1. HLA-B*51:01 is likely of Neandertal origin and associated with Behcet's disease, also known as the Silk Road disease. The Lordegan Lur have the highest frequency of HLA-B*51:01 in the world. This allele is present on 46 Lur and Kurd haplotypes. Present at lower frequency is HLA-B*51:08, which is also associated with Behcet's disease. In the four Iranian populations, 31 haplotypes encode both Bw4(+) HLA-A and Bw4(+) HLA-B, a dual combination of Bw4 epitopes that is relatively rare in other populations, worldwide. This study both demonstrates and emphasizes the value of studying HLA class I polymorphism at highest resolution in anthropologically well-defined populations.

A 30-year-old female Behçet's disease patient with recurrent pleural and pericardial effusion and elevated adenosine deaminase levels: case report

Behçet's disease is a systemic disease which may involve various organs. We describe a case of a patient diagnosed as pleuropericardial involvement of Behçet's disease. A 30-year-old woman visited our clinic presented with left pleuritic chest pain for s days. She had been diagnosed as Behçet's disease and admitted to our clinic due to pericardial and pleural effusion repeatedly in past two years. In the previous studies, effusion analysis revealed to be lympho-dominant exudate with high adenosine deaminase level. Acid-fast bacilli (AFB) culture and polymerase chain reaction (PCR) for mycobacterial tuberculosis (M.TB) were negative in the pericardial tissue, and pathologic finding showed mild endothelitis with micro-thrombi formation in the lumen. The patient had been treated with antituberculous medication for a year. In the current admission, chest computed tomography (CT) again showed left pleural effusion without other significant lesion. Pleural fluid analysis was similar with the previous study. Video-assisted thoracoscopic pleural biopsy was performed to obtain the definite diagnosis. Pathology confirmed the diagnosis as pleuropericardial involvement of Behçet's disease, and we treated the patient with oral steroid in the out-patient department. Pleuropericardial involvement of Behçet's disease may mimic TB pleurisy or pericarditis due to high adenosine deaminase (ADA) level in effusion analysis. Clinicians should keep in mind that Behçet's disease may manifest as pleural or pericardial effusion, and pathologic confirmation could be helpful for the definite diagnosis.

Periodontal Health Status among Patients with Behçet's Disease

We aimed to evaluate the relationship of individual periodontal parameters with the severity of Behçet's disease (BD) and attempt to find the correlation between chronic periodontitis and BD. In this study, 74 registered subjects attending Behçet's clinic with BD symptoms were recruited. The diagnosis was based on the criteria presented by the international study group for BD (ISG) and the total clinical severity score was determined for each patient. All individuals underwent clinical examination to assess oral and periodontal status and presence of oral ulcers. Periodontal clinical parameters of bleeding on probing (BOP), probing depth (PD), and clinical attachment level (CAL) and also hygiene index (HI) and decayed, missing, and filled (DMF) teeth were noted and analyzed to assess the correlation with severity of BD. There was no significant correlation between DMF and severity of BD. The strong association was found between periodontal parameters (BOP, PD, and CAL) and the severity of BD (P < 0.001). It seems that relation of BD to oral health is higher up in severe forms of BD and periodontal diseases. Clinical association between the diseases might be due to a common underlying etiopathogenesis of periodontitis and BD.

Behcet's Disease: Is There Geographical Variation? A Review Far from the Silk Road

Behcet's Disease (BD) is a systemic vasculitis characterized by the triad of recurrent mouth and genital ulcers with eye involvement. To date there are no laboratory tests specific for the disease and diagnosis continues to remain on clinical grounds. Multiple criteria have been created as guides for diagnosis; however, given the wide spectrum of organ involvement, some cases remain undiagnosed. The diagnosis of Behcet's Disease may only be made over time as the clinical manifestations emerge sometimes separated by months and even years. With an increased recognition of this disease it has become apparent that there is geographical variation in clinical manifestations. In particular cardiac manifestations are not seen commonly in Caucasians compared to Asian and Middle Eastern patients, while neurological manifestations are more common in Caucasians. Use of immunosuppressive and immunomodulatory drugs to suppress inflammation remains the cornerstone of treatment.

'MHC-I-opathy'-unified concept for spondyloarthritis and Behçet disease

The spondyloarthropathies comprise ankylosing spondylitis (AS), reactive arthritis, psoriatic arthritis (PsA) and arthritis associated with inflammatory bowel disease. In this Perspectives article, we describe how Behçet disease and several clinically distinct spondyloarthropathies-all associated with MHC class I (MHC-I) alleles such as HLA-B(*)51, HLA-C(*)0602 and HLA-B(*)27 and epistatic ERAP-1 interactions-have a shared immunopathogenetic basis. As a unifying concept, we propose that barrier dysfunction in environmentally exposed organs such as the skin, and aberrant innate immune reactions at sites of mechanical stress, can often trigger secondary adaptive immune CD8(+) T-cell responses with prominent neutrophilic inflammation that culminate in exacerbation and recurrence of these diseases. Of note, these 'MHC-I-opathies' show a differential immunopathology, probably reflecting antigenic differences within target tissues: HLA-B(*)51 is linked to ocular and mucocutaneous disease but not gut involvement, and HLA-C(*)0602 is linked to type I psoriasis but not scalp or nail disease.