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

Clinical characteristics of Behçet's disease in China

To evaluate the prevalence of clinical findings in Behçet's disease (BD) in Chinese population. The clinical data of 170 consecutive BD patients were, retrospectively, analyzed and compared with previous reports. The mean age at onset was 34.4 years (range 6-72) and the mean age of diagnosis was 39.1 years (range 8-72). Mean delay in diagnosis was 5.7 years. The male to female ratio was 1.3:1. Recurrent aphthous ulceration (64.7%), skin lesion (18.2%), and genital ulceration (8.2%) were the commonest onset-presentations of the disease. During the disease course, the commonest presenting features were oral ulcer (100%), cutaneous involvement (68.2%), genital ulcer (63.5%), arthritis (37.1%), and ocular lesion (14.1%). As for the minor clinical manifestations, gastrointestinal lesion (10.0%), vascular lesion (8.8%), and cardiac lesion (4.7%) occurred occasionally. The pathergy skin test showed positive in 63.5% of the patients and revealed a higher positive rate in the females (76.7%) than in the males (53.6%). Less ocular lesion and genital ulcer were present in Chinese BD patients.

HLA haplotypes in recurrent aphthous stomatitis: a mode of inheritance?

The aim of this study was to investigate the genetic association between recurrent aphthous stomatitis (RAS) and human leucocyte antigen (HLA) class I and II alleles and HLA haplotypes. Families selected had at least one child suffering from recurrent aphthous stomatitis in addition to one or both of the parents. HLA-A, -B and -DR alleles were typed in 29 families, 27 nuclear and two extended (121 subjects). HLA haplotypes of all family members with RAS were compared with those who were RAS negative. Although major histocompatibility complex class I and II gene analysis failed to demonstrate any significant association between RAS and HLA antigens, the study of HLA haplotypes revealed a significant association between HLA haplotypes and susceptibility to RAS. The results indicate that susceptibility to RAS segregates in families in association with HLA haplotypes.

Killer cell immunoglobulin-like receptor genotypes in Behçet's disease patients: any role for the 3DP1*001/002 pseudogene?

AIMS

Genotypic profiles of the natural killer cell immunoglobulin-like receptors (KIR) have been reported to vary among different ethnic groups and variable clinical entities. This study represents the second report on its distribution among patients with Behçet's disease (BD). We studied 43 unrelated Lebanese Behçet's patients, had their DNA typed using sequence-specific primer technique for the presence of 16 KIR genes and pseudogenes loci, and compared them to the general Lebanese population.

RESULTS

In addition to sharing common features with the general population, the AA genotype was still the most frequent--however, with five new KIR profiles identified. There was no statistically significant distribution of the different KIR genes between the cases (BD patients) and controls (Lebanese population); however, KIR3DP1*001/002 was found to be significantly different between the BD patients and the Lebanese population, but this significance was lost after correction for all KIR loci.

CONCLUSION

The results lead to an interesting future research question of whether or not KIR genotype is involved in the predisposition to or pathogenesis of BD especially that a pseudogene is controversially in question. This is the second report that describes the KIR genotypic profile in such an important clinical disease but the first to shed a light on the possible role of a pseudogene.

Epidemiology and clinical characteristics of Behçet's disease in the US: a population-based study

OBJECTIVE

Behçet's disease (BD) is a rare, multisystem inflammatory disorder of unknown cause. Although well-documented in Eastern populations, epidemiologic data is scarce in North American countries. Here we describe the incidence and prevalence of BD in Olmsted County, Minnesota over 45 years.

METHODS

We identified an incidence cohort of subjects age >/=18 years who had a clinical diagnosis of and/or fulfilled the International Study Group (ISG) criteria for BD from January 1, 1960 to January 1, 2005. Age- and sex-specific incidence and prevalence were estimated and age- and sex-adjusted to the 2000 US total population.

RESULTS

The study population was comprised of 13 subjects with BD; 11 fulfilled ISG criteria between 1960 and 2005. Mean +/- SD age was 31 +/- 9 years, and 69% were white. Point prevalence in 2000 was 5.2 per 100,000 population (95% confidence interval [95% CI] 0.64-9.84). The overall annual age- and sex-adjusted incidence of BD was 0.38 per 100,000 population (95% CI 0.17-0.59), with a higher incidence in women (0.51 per 100,000; 95% CI 0.17-0.84) than in men (0.26 per 100,000; 95% CI 0.004-0.52). Dermatologic lesions included oral ulcers (100%), genital ulcers (62%), erythema nodosum (46%), and papulopustular lesions (54%). Ocular lesions, vascular complications, and central nervous system involvement were present in 8, 3, and 3 subjects, respectively.

CONCLUSION

Our study shows an overall incidence of 0.38 per 100,000 population, which is comparable with other Western populations. The prevalence of 5.2 per 100,000 population is similar to estimates reported in Western countries, but lower than that in countries along the Silk Road.

HLA-B51 and haplotypic diversity of B-Cw associations: implications for matching in unrelated hematopoietic stem cell transplantation

In unrelated hematopoietic stem cell transplantation (HSCT), human leukocyte antigen (HLA)-C locus incompatibilities occur frequently and are associated with increased risk of posttransplant complications. Because HLA-B51 is associated with a high rate of Cw disparities, we performed a comprehensive four-digit typing analysis of 140 ABCDRB1 B51 genotypes proven by pedigree analysis and 311 unrelated donors selected for 75 B51-positive patients. In addition, 145 A1/Ax-B8/B51-DR3/DRx donors were HLA typed at a high-resolution level and tested for three microsatellite (Msat) polymorphisms located in the HLA class I and III regions. Based on these data sets, 182 different ABCDR haplotypes with 14 different B-Cw associations were detected. Rates of Cw mismatches were shown to be highly correlated with the ABDRB1 haplotypes. We have computed 21 B51 haplotypes that disclose a high probability of HLA-C allele matching and 30 haplotypes with a low (<25%) probability. The HLA-C allele frequency profiles were quite different in these two groups, with a more heterogeneous distribution in the low matching probability group. HLA-Cw*1502 was inversely correlated with the likelihood to identify a Cw-mismatched donor: it was present in 61% of the high vs 18% of the low probability group (P < 0.0001). The analysis of three Msats in the class I and III regions showed a higher allelic diversity in B51-positive haplotypes compared with the conserved A1-B8-DR3 haplotype. HLA-B51 haplotypes therefore exhibit a high diversity at the level of B-Cw associations and of non-HLA polymorphisms in the class I and III regions. Such heterogeneity negatively impacts on overall matching in HSCT.

Behçet's disease--a contemporary review

Behçet's disease (BD) is a systemic vasculitis disorder of unknown etiology, characterized by relapsing episodes of oral aphthous ulcers, genital ulcers, skin lesions and ocular lesions. It can affect other systems including vascular, gastrointestinal and neurological systems. It occurs most frequently in an area that coincides with the Old Silk Route (between latitudes 30 degrees and 45 degrees north in Asia and Europe). BD is slightly more frequent and has a worse clinical course in men. It is believed to be due to an auto-immune process triggered by an infectious or environmental agent in a genetically predisposed individual. HLA-B51 is the most strongly associated risk factor. The International Study Group (ISG) for Behçet's Disease created a set of criteria for the diagnosis of BD. Available treatments include corticosteroids, azathioprine, cychlophosphamide, cyclosporine A, interferon-alpha, anti-tumour necrosis factor alpha agents, among others. BD has a variable course characterized by relapses and remissions. Prognosis depends on the clinical involvement. Loss of visual acuity and neurological disease are major causes of morbidity and disability.

Population-based prevalence study of Behçet's disease: differences by ethnic origin and low variation by age at immigration

OBJECTIVE

To estimate the prevalence of Behçet's disease (BD) in a multiethnic population living in France, with particular focus on disease risk among immigrants.

METHODS

The study was conducted in a county in the Paris metropolitan area that is home to 1,094,412 adults (ages > or =15 years), of whom 26% are of non-European ancestry. Patients with BD living in this area during 2003 were identified using 3 sources (hospitals, community physicians, and the National Health Insurance database), and diagnoses were verified using the International Study Group criteria. Standardized, year-2003 prevalence rates were computed for the overall population and for each ethnic group. Stratified prevalence rates according to age at immigration to France were calculated to investigate the relationship between age at immigration and BD risk.

RESULTS

Seventy-nine subjects fulfilled our search criteria. The overall prevalence per 100,000 adults was 7.1 (95% confidence interval [95% CI] 3.5-14.4), and the prevalence for populations of European, North African, and Asian ancestry was 2.4 (95% CI 0.6-7.2), 34.6 (95% CI 24.4-47.5), and 17.5 (95% CI 10.7-27.2), respectively. Within the migrant population of either North African or Asian ancestry, BD prevalences were similar for residents born in France, residents <15 years old at immigration, and residents > or =15 years old at immigration.

CONCLUSION

Our findings indicate that the prevalence of BD among immigrants of North African or Asian ancestry is significantly higher than that in the European-origin population, and comparable with rates reported from North Africa and Asia. Moreover, our results suggest that BD risk is not related to age at immigration. These findings support the hypothesis that BD has a primarily hereditary basis.

Behçet's syndrome

Recent epidemiological work suggests that genetic background overrides environmental factors in the pathogenesis of Behçet's syndrome (BS). There are at least two clusters of disease expression. The first is the cluster of superficial vein thrombosis, deep vein thrombosis and dural sinus thrombi; the second cluster is that of acne, arthritis and enthesitis. The association of antibodies to anti-Saccharomyces cerevisiae antibodies and the presence of inflammatory bowel disease is perhaps another such cluster. The presence of such clusters suggests that there might be more than one disease mechanism operative in this complex disorder. There is a recent trend to classify BS with the autoinflammatory disorders. However, practically all autoinflammatory conditions are recurrent fever syndromes of children, and are genetically linked to well-defined loci; none of this is true for BS. Recent guidelines from the European League Against Rheumatism are quite useful for the management of the disease in organ systems other than the vascular, neurological and gastrointestinal systems, because of the lack of controlled studies related to these latter pathologies.

The unique features of vasculitis in Behçet's syndrome

The presence of a true vasculitis is difficult to discern in some of the more common manifestations of Behçet's syndrome, like the papulopustular lesions of the skin. On the other hand, a true vasculitis is seen in all vessel sizes in the majority of the patients. The pathogenesis is not yet known. A Th1-type inflammatory reaction is seen like in some other primary vasculitides. However, in contrast to other vasculitides, granuloma formation is absent. Behçet's syndrome is unique among the vasculitides with its differing geographic distribution in disease expression, the distinctly more severe disease among the male, the predominance of venous disease, and the generally abating disease course with lack of associated increased atherosclerosis.

Behcet's disease with uveitis in Taiwan

BACKGROUND

Behcet's disease is a multisystemic inflammatory disease which may lead to blindness. The purpose of this study was to describe and compare the clinical features and visual outcome of Behcet's uveitis in Taiwan.

METHODS

The medical charts of 227 consecutive patients (414 eyes) with Behcet's uveitis who were seen in the Uveitis Clinic of Taipei Veterans General Hospital were reviewed: 96 patients (group A) between 1984 and 1993 and 131 (group B) between 1994 and 2003.

RESULTS

The male-to-female ratio was 1.6. The mean age at the time of uveitis onset was 30.8 years. Males were most affected in the 3rd and 4th decades and females in the 2nd to 5th decades. There were more skin and gastrointestinal lesions in males, and less skin and genital lesions in group B. HLA-B51 antigen was found in 35.7% of patients. Treatment with cyclosporin, azathioprine and methotrexate was more frequent in group B. Uveitis occurred bilaterally in 83.9% of patients. At the first visit, potential visual acuity (VA) was 0.1 or less in 24.7% of eyes in males and 11.4% in females. The mean time from presentation to loss of useful vision (> 0.1) was 51 months in 19.1% of eyes. Kaplan-Meier survival analysis estimated the risks of losing useful vision at 5, 10 and 15 years as being 22.6%, 43.0% and 58.5%, respectively. VA at the first and last visits were better and VA deterioration slower in group B.

CONCLUSION

Visual outcome is poorer in males than in females and has improved in the recent decade, but still a significant proportion of patients lose their vision quickly. The number of new patients has not decreased.

New insights of HLA class I association to Behçet's disease in Portuguese patients

Human leukocyte antigen (HLA)-B*51 is a well-known genetic factor associated with Behçet's disease (BD). To analyse the influence of HLA-B*51 and other HLA class I alleles in BD susceptibility in a Portuguese population and its association with disease severity, we studied 78 BD patients and 208 healthy controls. The patients were classified into two severity groups as described by Gul et al. As expected, a higher frequency of HLA-B*51 was found. The frequency of HLA-Cw*16 alleles was significantly higher in patients. Regarding severity, HLA-B*27 frequency was higher in the severe group compared with controls and with the mild group. Thus, HLA-B*51 and HLA-Cw*16 seem to confer susceptibility to BD in this patients. HLA-B*27 may be important as a prognostic factor.

The genetics of Adamantiades-Behcet's disease

Adamanitiades-Behcet's disease (ABD) is a relapsing systemic vasculitis that may involve the eyes, skin, and almost all other organ systems. Current research on the pathogenesis of ABD suggests a genetic basis for the disease, with certain MHC genes such as those coding for HLA-B51 being the most obvious candidates. Environmental factors such as infectious disease are thought to be responsible for triggering an immunological reaction and systemic features of the disease in genetically susceptible individuals. Identification of genes responsible for this susceptibility may lead to more definitive diagnostic tests and new approaches to the management of this potentially blinding condition.

Ocular features of Behcet's disease: an international collaborative study

OBJECTIVE

To investigate the clinical features of ocular lesions in Behçet's disease in different countries.

METHODS

A descriptive questionnaire survey was performed.

RESULTS

25 eye centres in 14 countries returned questionnaires on prevalent cases in 2006. Clinical data were analysed on 1,465 patients with ocular lesions. Recurrent oral aphthous ulcers were reported in 94.5%, skin lesions in 69.5% and genital ulcers in 61.4%. Most of the patients had bilateral and recurrent intraocular inflammation. Poor visual acuity was seen in 18.9% in women, but 24.8% in men (p<0.01). Panuveitis was seen more in men than in women (p<0.01). 23% of the patients had visual acuity equal to or worse than 20/200 at the final visit. The patients with poor vision were more frequently in India, Iran and Japan than in other countries (p<0.01).

CONCLUSIONS

We report the largest contemporary international case series of patients with ocular involvement in Behçet's disease. Panuveitis was significantly more frequent in men than women, and men tended to have a worse visual prognosis. There were some differences in the clinical pattern of Behçet's disease in different countries. Despite modern treatment, the disease still carries a poor visual prognosis with one-quarter of the patients blind.

Autoinflammatory syndromes with a dermatological perspective

The term autoinflammatory syndromes describes a distinct group of systemic inflammatory diseases apparently different from infectious, autoimmune, allergic and immunodeficient ones. Originally, it was almost synonymous with clinically defined hereditary periodic fever syndromes, including familial Mediterranean fever, hyper immunoglobulin D syndrome with periodic fever and tumor necrosis factor receptor-associated periodic syndrome. Similar but distinct periodic fever syndromes accompanied by urticarial rash, familial cold autoinflammatory syndrome, Muckle-Wells syndrome and chronic infantile neurological cutaneous articular syndrome, have all been reportedly associated with CIAS1 mutations and are collectively called cryopyrin-associated periodic syndromes. Consequently, the concept of autoinflammatory syndromes has been spread to contain other systemic inflammatory diseases: rare hereditary diseases with or without periodic fevers, such as pyogenic sterile arthritis, pyoderma gangrenosum and acne syndrome, Blau syndrome and chronic recurrent multifocal osteomyelitis, and the more common collagen disease-like diseases, such as Behcet's disease, Crohn's disease, sarcoidosis and psoriatic arthritis. These diseases are all caused by or associated with mutations of genes regulating innate immunity and have common clinical features accompanied with activation of neutrophils and/or monocytes/macrophages. In this review, major autoinflammatory syndromes are summarized and the pathophysiology of related skin disorders is discussed in association with dysregulated innate immune signaling.

No association of KIR genes with Behcet's disease

Behcet's disease (BD) is thought to be caused by multiple genetic, environmental and immunological factors, one of the most prominent being the strong association with human leucocyte antigen (HLA)-Bw51, an HLA-Bw4-associated allele. We examined the presence/absence of 14 killer cell immunoglobulin-like receptors (KIRs) and their ligands in 134 Turkish individuals with BD and compared the results with those of 154 ethnically matched controls. Although KIR3DL1 with its ligand (HLA-Bw4) was significantly increased in the patients with BD (P = 0.0003), this no longer applied when the patients and controls were categorised by HLA-Bw51 status. Thus, no association was identified between presence or absence of any of the 14 KIR genes studied and BD. In addition, we did not find any associations of KIR with various manifestations of the disease nor with gender or age of onset.

The association of the PTPN22 620W polymorphism with Behcet's disease

OBJECTIVES

A single nucleotide polymorphism (SNP) of the gene encoding protein tyrosine phosphatase type 22 (PTPN22 620W) has recently been described as a strong common genetic risk factor for human autoimmune disease. We have analysed the association of PTPN22 620W in patients with Behçet's disease (BD).

METHODS

Genomic DNA was obtained from 270 patients with BD from the UK and the Middle East. Normal controls (n = 203) were collected from the same populations. Patients with idiopathic retinal vasculitis from the UK (n = 136) were used as disease controls. PTPN22 620W was detected by SSP-PCR analysis and agarose gel electrophoresis.

RESULTS

The results showed an inverse correlation between the presence of PTPN22 620W and Behçet's disease in either patient group tested. There was a greatly reduced prevalence in Middle Eastern compared to UK patients and controls. Finally, there was no association with either UK patients with retinal vasculitis compared with UK controls.

CONCLUSIONS

The presence of PTPN22 620W was inversely associated with BD and the distribution of the SNP in the Middle East supports previous findings in the global prevalence.

HLA-B51 gene and its expression in association with Behçet’s Disease in Denizli Province of Turkey

Behçet's Disease (BD) is a multisystemic inflammatory disorder as a triad of symptoms including recurrent oral and genital aphthous ulceration, and uveitis with unknown pathogenesis. Many researchers have tried to investigate the association of HLA-B51 gene with the BD. We aimed to investigate the association of the HLA-B51 gene and its expression, also polymorphic structure by PCR, RT-PCR and sequence specific oligonucleotide primers and probes in BD patients (n: 35) and control group (n: 50). According to our results, we did not observe any association in between HLA-B51 gene, its polymorphism, expression and BD patients.

A study of ten Japanese patients with seronegative spondylarthropathy: a tentative proposal

We reviewed ten patients with seronegative spondylarthropathy (SNSA), who all fulfilled the European Spondylarthropathy Study Group criteria for spondylarthropathy (SpA); seven patients also met the Amor criteria for SpA. Seronegative spondylarthropathy was not a uniform syndrome but rather a wide spectrum of complex disease with characteristics of sacroiliitis and enthesopathy. The most frequent symptom at diagnosis of SNSA was inflammatory low back pain, followed by asymmetric oligoarthralgia and Achilles tendonitis and/or plantar fasciitis. Systemic complications were revealed as eye and skin involvement. Imaging methods including pelvic radiography, scintigraphy, and computed tomography scanning were useful in detecting spondylarthropathic changes, which were characteristic of SNSA. Human leukocyte antigen (HLA) typing showed various patterns among patients, in which HLA-B27 was positive in three patients with ankylosing spondylitis. HLA-B51, which is a well-known genetic factor associated with Behçet's disease (BD), was positive in two patients who were apparently distinct from BD. Two patients with palmoplantar pustulosis showed symptoms and signs characteristic of SNSA. Although we have few SNSA patients in the present study, we would like to propose that HLA-B51 positive SpA would be considered as a subset of SNSA, and that pustulotic SpA also would be classified as a member of SNSA. This led us to suggest the possibility to change the concept of SNSA proposed by Moll et al. The optimal treatment remains to be defined, but sulfasalazine was effectively used with almost all patients in combination with nonsteroidal anti-inflammatory drugs.

Epidemiology and clinical course of Behçet's disease in the Reggio Emilia area of Northern Italy: A seventeen-year population-based study

OBJECTIVE

To investigate the epidemiology and clinical course of Behçet's disease (BD) over a 17-year period in a defined area of northern Italy.

METHODS

All patients with incident BD diagnosed over a 17-year period (from January 1, 1988 to December 31, 2004) living in the Reggio Emilia area were identified through the following sources: physicians at Reggio Emilia Hospital, medical practitioners, and community-based specialists. We identified all patients registered in a centralized index and in the Reggio Emilia district database for rare diseases. Patients were followed up from the time of diagnosis until either their death or April 1, 2005.

RESULTS

Eighteen patients (9 men and 9 women) had complete BD. Mean +/- SD age at diagnosis was 33 +/- 7 years. The incidence rate of BD was 0.24 per 100,000. The prevalence of BD on January 1, 2005 was 3.8 per 100,000. No patients died during the followup period. Although all patients developed oral ulceration during the disease course, 22.2% had no oral lesions at disease onset. Eye disease occurred in 55.6%. Ocular disease was more common in men and appeared at disease onset or within the first few years of disease onset (median 3 years). Only 1 patient had loss of useful vision in at least 1 eye at the end of followup. In all affected patients, visual acuity improved once treatment was started.

CONCLUSION

This population-based study is the first to report the prevalence and incidence of BD in Italy. In Italian patients, BD is nonfatal and the prognosis of eye disease is good.

Physiopathologie de la maladie de Behçet

SUBJECT

Pathophysiology of Behçet's disease (BD) is complex. Recent experimental data shed new light on the mechanisms leading to organ lesions.

MAIN ISSUES

Neutrophils and cytotoxic lymphocytes are now recognized as key effector cells in BD. Genetic susceptibility, environmental factors (virus and/or bacterial infections), inflammatory response abnormalities (heat shock proteins, dysregulated NO production) and abnormal immune response play also a major role in BD pathogeny.

PERSPECTIVES

Better understanding of the BD pathophysiology will allow the development of new therapies more specific of BD.

Prevalence and clinical aspects of Behcet's disease in the north of Israel

Behcet's disease (BD) has a higher prevalence in countries along the ancient silk route, but the actual prevalence in Israel is unknown. We evaluated the occurrence and clinical expression of BD in the northern region of Israel: in the whole population and by ethnic groups. The sample included all adult patients with BD (International Study Group criteria) treated at three medical centers in northern Israel. Patient data were collected by file review and physician survey. Relevant demographic data for the population served by the medical centers were obtained from the official Israeli authorities. A total of 112 patients were identified. The overall prevalence of BD was 15.2/100,000 and was similar in men and women. The prevalence rates among the Jewish, Arab, and Druze populations were 8.6, 26.2, and 146.4 per 100,000, respectively. Age at disease onset was similar in all ethnic groups and significantly lower in males (28.6+/-9.7 vs 32.9+/-11.3, p=0.03). There were no differences in disease manifestations by sex or ethnicity. All Druze patients were HLA-B5 positive, compared to 80.8% of the Arab patients and 72.0% of the Jewish patients. Recurrent oral ulcers in family members were more common in Arab patients (p=0.004). The BD severity index was significantly lower in Druze patients (p=0.05), mainly in males (p=0.03). This study confirms the high prevalence of BD in Israel and the variability in disease rates and expression by ethnic origin. Our findings, particularly regarding the Druze population, call for further field surveys and genetic studies.

Four-digit allele genotyping of the HLA-A and HLA-B genes in Japanese patients with Behcet's disease by a PCR-SSOP-Luminex method

The present study represents the first four-digit allele genotyping of HLA-A and -B in Japanese Behcet's disease (BD) patients and controls using a new genotyping method (named the PCR-SSOP-Luminex method) to determine the association of certain HLA-A or -B alleles with BD. Peripheral blood lymphocytes were collected from 180 Japanese BD patients and 170 healthy controls. The genotype frequency of HLA-B*5101 was significantly increased in the patients (61.7%) as compared with the controls (15.9%) (Pc = 1 x 10(-16), OR = 8.5). When we recalculated the phenotype frequencies after excluding the HLA-B*51-positive patients and controls to account for the effects of the linkage disequilibrium and the abundance of the HLA-B*51 allele, the frequencies of HLA-A*2602 and HLA-B*3901 had a weak association in the patient group without HLA-B*51 as compared with the control group without HLA-B*51 (A*2602; Pc = 0.130, OR = 4.3, B*3901; Pc = 0.099, OR = 3.5). This study confirmed on the basis of using a new and more accurate genotyping method that Japanese BD patients have a strong primary association with HLA-B*5101. The significant increase of HLA-A*2602 and B*3901 in the patient group without HLA-B*51 suggests that these two alleles might also have some secondary influence on the onset of BD.

Microsatellite polymorphisms of the MICA gene among Japanese patients with Behçet's disease

BACKGROUND

Behçet's disease (BD) is a multisystemic inflammatory disease of unknown origin. Because some researchers have recently suggested a primary association of BD with the A6 allele of the human major histocompatibility complex class I chain-related A (MICA) gene, we investigated microsatellite polymorphisms of the MICA gene in subjects with and without BD.

METHODS

This was a case-control study of 23 Japanese patients with BD and 23 Japanese volunteers without BD who were compared for MICA microsatellite polymorphisms using the polymerase chain reaction (PCR). We also analysed associations between 5 MICA alleles and the clinical features of patients.

RESULTS

There was no significant difference between case patients and control subjects in phenotype frequencies. The MICA-A6 allele showed the strongest positive correlation with the human leukocyte antigen allele HLA-B51. Allele A5 showed a strong positive correlation with age at onset and a strong negative correlation with iridocyclitis and HLA-B51. A4 showed a strong negative correlation with ocular lesions and HLA-B51. Patients with the MICA-A6 allele had significantly higher HLA positivity than patients without the allele.

INTERPRETATION

While the MICA-A6 allele had no significant association with BD, it showed a strong association with HLA-B51. This finding suggests that an association between MICA-A6 and BD may be a secondary phenomenon related to HLA-B51. As several associations with MICA alleles and clinical features have been found, further investigation is expected to elucidate the biological mechanism of action of the MICA protein relative to disease onset.

Hereditary auto-inflammatory disorders and biologics

The term auto-inflammatory disorders has been coined to describe a group of conditions characterized by spontaneously relapsing and remitting bouts of systemic inflammation without apparent involvement of antigen-specific T cells or significant production of auto-antibodies. The hereditary periodic fever syndromes are considered as the prototypic auto-inflammatory diseases, and genetic studies have yielded important new insights into innate immunity. DNA analysis has greatly enhanced the clinical characterization of these conditions, and elucidation of their molecular aetiopathogenesis has suggested that therapies may be aimed at specific targets within the immune cascade. The availability of biologic response modifiers such as inhibitors of tumour necrosis factor (TNF) and interleukin-1beta has greatly improved the outlook for some of these disorders, although effective therapies remain elusive in patients with certain conditions, including hyperimmunoglobulinaemia-D with periodic fever syndrome (HIDS) and a proportion of those with TNF-receptor associated periodic syndrome (TRAPS). Indeed, outstanding challenges and the unique potential to further elucidate molecular mechanisms in innate immunity are illustrated by the dashed early hope that TNF blockade would be a panacea for TRAPS: not only is etanercept (Enbrel) ineffective in some cases, but there are anecdotal reports of this condition being greatly exacerbated by infliximab (Remicade).

Dexamethasone, colchicine and iodine-lithium-α-dextrin act differentially on the oxidative burst and endotoxin tolerance induction in vitro in patients with Behçet's disease

Pro-inflammatory activation of innate immune cells, such as macrophages, and neutrophils in patients with Behçet's disease (BD) results in increased production of reactive oxygen species and enhanced adhesion to endothelial cells due to increased expression of adhesion receptors. We investigated the influence of dexamethasone (DEX), colchicine (Col), and iodine-lithium-alpha-dextrin (ILalphaD), during BD, on the respiratory burst of whole blood neutrophils and monocytes, CD11a/CD18 surface expression, monocyte endotoxin tolerance and cytokine synthesis in vitro. In BD patients we observed an increase of the spontaneous, N-formyl-Met-Leu-Phe- and LPS-induced respiratory burst of monocytes and neutrophils as well as up-regulation of neutrophil CD11a/CD18 surface expression. DEX, Col and ILalphaD in vitro differentially affected the stimulus-dependent oxidative burst of BD and caused the down-regulation of CD11a/CD18 surface expression in neutrophils but not monocytes. LPS homologous tolerance induction is not altered in BD. However, DEX and Col increased tolerance to LPS-induced TNF-alpha synthesis. ILalphaD down-regulated N-formyl-Met-Leu-Phe- and LPS-induced oxidative burst and CD14 receptor expression and increased monocyte cross-tolerance to LPS. DEX induced LPS-tolerance by restoring the ratio of INF-gamma and IL-4 production, while Col caused a dramatic increase in IL-4 synthesis by monocytes. DEX, Col and ILalphaD may limit the overwhelming inflammation by differentially affecting the monocyte activation program, shifting them from ''classically" into "alternatively'' activated monocytes and may have important implications for the treatment of BD.

Number VII Behcet's disease (Adamantiades syndrome)

Behçet's syndrome (BS; Adamantiades syndrome) is the association of the triple symptom complex of recurrent aphthous stomatitis (RAS) with genital ulceration, and eye disease (especially iridocyclitis) though a number of other systemic manifestations may also be seen. BS mainly affects young adult males, and there is an association with HLA-B5 and HLA-B51 (B5101). Features such as arthralgia and leucocytoclastic vasculitis suggest an immune-complex mediated basis, which is supported by finding circulating immune complexes and, although the antigen responsible is unidentified, heat shock proteins have been implicated. An inflammatory disorder, BS is now considered as a systemic vasculitis, characterised by a very wide spectrum of clinical features and by unpredictable exacerbations and remissions.

Whole-genome screening for susceptibility genes in multicase families with Behçet's disease

OBJECTIVE

Behçet's disease is generally considered to be a multifactorial disease with important genetic and environmental components. A strong association between an HLA class I antigen, HLA-B51, and Behçet's disease has long been known. However, analysis of multicase families has suggested a substantial contribution of non-HLA loci. The aim of this study was to perform a whole-genome linkage analysis for identification of other susceptibility loci for Behçet's disease in multicase families.

METHODS

The study group comprised a total of 193 individuals (90 male, 103 female) from 28 multicase families of Turkish origin; 83 of the subjects (50 males, 33 females) fulfilled the International Study Group criteria for Behçet's disease. Three hundred ninety-five highly informative microsatellite markers spanning the genome were genotyped using fluorescent polymerase chain reaction primers and a fully automated electrophoresis platform. After the first analysis, 33 additional markers that were located close to the peak linkage areas were genotyped in all individuals. Nonparametric multipoint linkage analysis was carried out using GeneHunter version 2.1 software.

RESULTS

Evidence for linkage (P < or = 0.05) was obtained in 16 chromosome regions: 1p36, 4p15, 5q12, 5q23, 6p22-24, 6q16, 6q25-26, 7p21, 10q24, 12p12-13, 12q13, 16q12, 16q21-23, 17p13, 20q12-13, and Xq26-28. After the addition of further markers, the maximum nonparametric linkage score increased from 3.5 to 3.94 at 12p12-13 (D12S77; P = 0.0002) and from 3.07 to 3.70 at 6p22-24 (D6S285; P = 0.0005).

CONCLUSION

This study is the first systematic genome screen in Behçet's disease and provides evidence of linkage to several non-HLA susceptibility loci in a cohort of Turkish multicase families. This represents the first step toward the identification of novel Behçet's disease susceptibility genes.

Lack of association of tumor necrosis factor-alpha gene polymorphisms with disease susceptibility and severity in Behçet’s disease

Although it has been reported that the MHC class I molecule, HLA-B51, is a risk factor for Behçet's disease (BD), contribution of the tumor necrosis factor (TNF) genes, which are located in the vicinity of the HLA-B locus, to the genetic susceptibility for BD has yet to be elucidated. The purpose of this study was to analyze the effect of TNF-alpha promoter polymorphisms at positions -308, -238 and -376 on the susceptibility, severity and clinical features of BD. The TNF-alpha gene sequences from 107 patients with BD and 102 healthy subjects were amplified by the polymerase chain reaction. Sequence analysis of the TNF-alpha gene locus, which contains promoter polymorphisms at positions -376, -308, and -238, was performed with a DNA sequencing kit on automated sequencer. The patients were classified according to disease severity and clinical features. Serum TNF-alpha level in the study groups was measured by sandwich enzyme immunoassay. In patients with BD the frequencies of TNF-alpha -308 (19.4% vs 18.4%), -238 (3.7% vs 5.9%), and -376 (0.9% vs 2.9%) gene polymorphisms were not found to be significantly different from those in healthy subjects. The TNF-alpha gene polymorphisms did not show any association with disease severity or clinical features. Serum TNF-alpha level was significantly higher in patients with BD than in healthy controls (3.10 +/- 1.45 pg/ml vs 2.43 +/- 1.94 pg/ml, P < 0.01). Serum TNF-alpha level was not found to be significantly associated with disease severity, activity, clinical findings and TNF-alpha genotypes. The results of this study suggest that the TNF-alpha gene polymorphisms are unlikely to play an important role in the pathogenesis and severity of BD.

HLA class I and class II genotyping in patients with Behcet's disease: a regional study of eastern part of Turkey

Class I human leucocyte antigen (HLA)-B51 is well known to be associated with Behcet's disease in many ethnic groups. However, there has been no published paper with respect to its association with HLA class I and class II among the Turkish people who live in the eastern region of Turkey. Moreover, as it is known that B51 antigen is encoded by 21 alleles, B*5101-5121, HLA-B51 allele typing was performed, as well as HLA class I and class II genotyping of 75 patients with the disease and the 54 individuals in the matched control group. The result shows that the HLA-B51 frequency was significantly higher (58.66%) in the patient group, compared to that in the control group (18.51%) (OR = 6.245). In the subtyping of B51 alleles, 44 B51-positive patients possessed B*5101 (45.5%), B*5108 (25%), B*5105 (9.1%) and B*5104 (4.5%). There was no significant difference in the HLA-B51 allelic distribution between the patient group and the control group. However, homozygous carriers of HLA-B51 showed considerably high risk (OR = 2.647) in the patient group, compared to that in the control group. In the genotyping of class II HLA alleles, while HLA-DRB1*04 (45.3%) and HLA-DRB1*07 (24%) were the predominant alleles in the patient group, DRB1*11 (50%) appeared to be more common in the control group.

The use of interferon alpha in Behçet disease: review of the literature

OBJECTIVES

To evaluate the efficacy and safety of interferon (IFN) alpha for the treatment of Behçet's disease (BD) and discuss its possible mechanisms of action.

METHODS

Reports published until July 2002 in all languages were identified by the PubMed Database and the BD conference proceedings and abstract booklets. The indexing terms used were "Behçet" and "interferon."

RESULTS

Thirty-two original reports and 4 selected abstracts were included in the analysis. Systemic IFN-alpha was administered to 338 patients. One hundred eighty-two patients with acute ocular disease were treated with IFN-alpha. Two hundred sixty-four patients received IFN-alpha2a, and 74 received IFN-alpha2b. Eighty-six percent of the patients with mucocutaneous symptoms, 96% with arthritis, and 94% with uveitis exhibited a partial or complete response. Higher IFN doses were more effective than low-dose regimens and led to up to 56% long-term remissions after discontinuation of IFN-alpha were reported. IFN-alpha2a apparently was superior to IFN-alpha2b, with more complete remissions, but this probably was the result of a bias caused by the larger number of patients treated with IFN-alpha2a. Side effects were dose-dependent and similar to those noted in patients with hepatitis C.

CONCLUSIONS

Although the comparability of the studies is hampered because of different study designs, IFN-alpha is effective for the treatment of BD. It was beneficial even in resistant posterior uveitis, in which long-term remissions with preservation of visual acuity was achieved. In contrast, mostly partial remissions were reported for mucocutaneous symptoms.

Analysis of the CC chemokine receptor 5 (CCR5) Delta32 polymorphism in Behcet's disease

Chemokines are important determinants of the early inflammatory response. The CC chemokine receptor 5 (CCR5) Delta32 variant results in a non-functional form of the chemokine receptor, and has been implicated in a variety of immune-mediated diseases. To investigate its role in the pathogenesis of Behçet's disease, we studied 350 patients and 519 healthy controls from three ethnic groups. While significant inter-ethnic variation in allele frequency was observed, no association was identified with disease, even when data were stratified by the known susceptibility gene HLA-B*51.

Prevalence of Behçet's disease in Istanbul, Turkey

BACKGROUND

The prevalence of Behçet's disease (BD) is much higher in countries along the ancient Silk Route, extending from Japan to Mediterranean countries including Turkey, than in northern Europe and the USA. Three previous epidemiologic surveys have been carried out in different regions of Turkey.

PATIENTS AND METHODS

This study investigated the cross-sectional prevalence of BD in individuals aged > 12 years in Istanbul, Turkey, in two stages. The first stage aimed to identify individuals with recurrent oral ulcers (ROUs) by visiting them in their homes, and the second stage aimed to further examine those with ROUs for the presence of other BD-related manifestations under hospital conditions. The sample size was determined to be 24,000 with an expected BD prevalence rate of 1/1000 and a sampling error of 4/10,000, with a 95% confidence interval (CI) of 6-14/10,000. The number of individuals to be screened in each district was determined in proportion to the population of all districts in Istanbul.

RESULTS

The standard questionnaire was applied to a total of 23,986 individuals at their homes. A history of ROU was recorded in 2289 individuals (9.5%), and a previous diagnosis of BD was recorded in 47. The diagnosis of ROU was confirmed in 700, and the diagnosis of BD was established in 101 according to the International Study Group criteria. The prevalence rate of BD was estimated as 42/10,000 (95% CI, 34-51/10,000) in Istanbul, Turkey.

CONCLUSIONS

This survey conducted in Istanbul, the largest cosmopolitan city in Turkey with immigrants from all over the country, has a larger sample size than other previous studies, and therefore the reported prevalence rate of BD has a more acceptable confidence interval. This study aids in the estimation of the prevalence of BD in Turkey, and supports previous findings that Turkey has the highest prevalence rate of the disease in the world.

Behçet's disease: from Hippocrates to the third millennium

Behçet's disease (BD) is characterised by recurrent episodes of orogenital aphthae, systemic vasculitis, and systemic and retinal venous thrombosis. An association between HLA-B51 and BD was first identified over 20 years ago, but recently identified gene associations implicate regions both within and without the MHC in the immunological events underlying the lesions in BD. These include allelic variants within the tumour necrosis factor gene region and within the MHC class I chain related gene region, the factor V Leiden mutation, which is associated with retinal vascular occlusion, and alleles of the intercellular adhesion molecule gene. No single causative gene for BD has emerged; the evidence indicates that the underlying immune events in BD are triggered by a microbial antigen and subsequently driven by genetic influences which control leucocyte behaviour and the coagulation pathways. Knowledge of these risk factors may permit a more accurate prognosis for a given patient, and identify new pathways for more targeted intervention than is currently available.

Behçet's disease in patients of west African and Afro-Caribbean origin

AIM

To report the presence of Behçet's disease with ocular involvement in patients of west African or Afro-Caribbean origin.

METHODS

Case series of eight patients reporting to a tertiary uveitis service.

RESULTS

Eight patients with typical features of the disease are presented. Six of the eight patients were tested and found to be HLA-B51 negative.

CONCLUSION

Behçet's disease has only been reported in sporadic case reports in the indigenous west African and Afro-Caribbean populations, in whom the incidence of HLA B51 is also very low. A series of patients from the London region presented with the typical symptoms and signs of disease, most of whom were also HLA B51 negative. The presence of disease in this population, when absent in the indigenous population, suggests either that ascertainment of disease is poor in the indigenous population or that acquired factors may be important in the aetiology of the disease.

HLA-DRB1*, -DQB1* in Piramalai Kallars and Yadhavas, two Dravidian-speaking castes of Tamil Nadu, South India

Two Dravidian-speaking castes of Tamil Nadu, Piramalai Kallars (PKs, n = 205) and Yadhavas (YDs, n = 239) and a random panel (84) were studied for HLA-DRB1* and -DQB1* polymorphisms by DNA-SSOP typing methods. XI and XII International Histocompatibility primers and non-radioactive-labelled oligo probes were employed to identify the alleles. Results revealed that PKs possessed >0.1 allele frequencies of HLA-DRB1*15011, 0301, -DQB1*0201, 0501 and 0601; YDs, HLA-DRB1*0301, 0401, 07 and -DQB1*0601; and the random panel, DRB1*15021, 0401, 07, -DQB1 0201, 0301, 0302 and 0501. The highest frequency of DRB1*1501 in the world (GF = 0.225) was found in PKs. The most frequent two-locus haplotype (>500/10,000) in all the study samples was DRB1*10-DQB1*0501, while 1501-0601 was frequent in PKs and YDs. Comparison of the HLA-DRB1* data with Eastern European and South-East Asian populations suggested migration as the prime cause of the observed diversity in DRB1* allele frequencies. Nonetheless, the heterozygocity test and Watterson's homozygosity test indicated that balancing selection still operates on HLA-DRB1* locus, in this endemic region of various infectious diseases. This and spatial autocorrelation analysis support the view that selection may be a cause of "generating" new variants and allelic diversity in different ancient settlements. The study suggested that South Indian, inbred, endogamous, sympatrically isolated castes or similar well-defined breeding isolates around the world, living under the same milieu-epidemiology, may be ideal models to test the immunogenetic basis of disease susceptibility.

Mapping the HLA association in Behçet's disease: a role for tumor necrosis factor polymorphisms?

OBJECTIVE

Experimental evidence suggests that inappropriate regulation of tumor necrosis factor alpha (TNF alpha) may play a role in the pathogenesis of Behçet's disease (BD). This is supported by recent reports highlighting the efficacy of anti-TNF alpha agents in the treatment of this disease. The TNF gene is encoded in the class III region of the HLA complex adjacent to HLA-B. This genetic proximity to a gene that is already widely implicated in disease susceptibility led us to investigate the association between TNF promoter polymorphisms and susceptibility to BD.

METHODS

We studied 133 UK white Caucasoid patients with BD and 354 healthy controls. We attempted to dissect the contribution of individual polymorphisms in this gene-dense region by linkage disequilibrium mapping across 6 adjacent genes.

RESULTS

We report a novel association with the TNF promoter allele TNF-1031C. Subsequent analysis identified 2 extended HLA haplotypes associated with BD. One of them contained the previously recognized susceptibility gene HLA-B*51, while the other was defined by HLA-B*5701. Both of these haplotypes contained the TNF promoter polymorphism -1031C, an allele that was associated with disease even in individuals who did not carry either HLA-B*51 or HLA-B*5701.

CONCLUSION

The TNF-1031C allele is independently associated with susceptibility to BD in Caucasoid patients. Further studies will be required to determine the functional effects of this polymorphism, its influence in disease pathogenesis, and its role in other ethnic groups.

HLA-B phenotype modifies the course of Behçet's disease in Moroccan patients

In Moroccan patients, predisposition to Behçet's disease is associated with HLA-B*51, mostly in males with young age at disease onset. In addition, the disease is associated with B*15 both in females and in males with late disease onset. We analyzed the clinical presentation, the severity and the course of the disease in 86 Moroccan patients according to their HLA-B phenotype. The presence of the B*51 or B*15 did not predispose to a particular clinical manifestation, nor to a more severe presentation of the disease. By contrast, outcome of the disease significantly differed depending on HLA-B phenotype, with an increase of symptoms in most B*51+ patients and in half of B*15 patients, and a remission or a decrease of symptoms in all B*51-B*15- patients. This variable course was mostly observed for ocular lesions, skin lesions, articular symptoms, and neurological symptoms. These data may suggest that treatment should be given early in the course of the disease in B*51 or B*15-positive patients in order to stabilize the inflammatory process.