Behçet's syndrome: a family study and the elucidation of a genetic role

Vasculitis and vasculopathy associated with inborn errors of immunity: an overview

Systemic autoinflammatory diseases (SAIDs) are disorders of innate immunity, which are characterized by unprovoked recurrent flares of systemic inflammation often characterized by fever associated with clinical manifestations mainly involving the musculoskeletal, mucocutaneous, gastrointestinal, and nervous systems. Several conditions also present with varied, sometimes prominent, involvement of the vascular system, with features of vasculitis characterized by variable target vessel involvement and organ damage. Here, we report a systematic review of vasculitis and vasculopathy associated with inborn errors of immunity.

Assessment of Cytokine Release against Oral Mucosal Cell Line Culture (TR146) Stimulated by Neutrophil Elastase Associated with Behcet's Disease

Aim

Cytokines and chemokines may be involved in the onset of oral ulcer in Behcet's disease. The aim of our study is to assess the cytotoxic effects of proinflammatory cytokines and chemokines on reconstructed oral mucosal cell line (TR146) when treated with different concentrations of neutrophil elastase (NE).

Objective

For this purpose, a culture of the oral mucosal model (OMM) prepared from a cell line derived from an oral squamous cell carcinoma of buccal mucosa (TR146) is treated with different concentrations of neutrophil elastase. The cultures were incubated for 4- and 24-hour intervals and designed as follows: culture + artificial saliva served as the negative control; culture + 0.01% SLS (sodium lauryl sulphate) served as the positive control; and culture + NE (10, 50, 100, and 200 nM) served as the treated group.

Materials and Methods

We used sandwich ELISA technique to isolate IL-1β (interleukin 1β), IL-8, and TNF-α (tumor necrosis factor).

Results

We found no significant level of IL-8 and TNF-α when treated with different concentrations of neutrophil elastase after 4- and 24-hour incubation. The IL-1β level was slightly higher when treated with 100 and 200 nM NE after 24 hours of incubation although a significantly high level was observed at 100 nM NE after 4 hours of incubation. Hence, we found an increase in the level of IL-1β when stimulating the reconstructed oral mucosal model (OMM) with different concentrations of NE. This is a preliminary in vitro study; however, further research is required to evaluate the cytotoxic effects of cytokines and chemokines released when treated with NE. Moreover, high concentrations of NE are recommended to stimulate the release of cytokines and chemokines against the OMM.

Novel heterozygous C243Y A20/TNFAIP3 gene mutation is responsible for chronic inflammation in autosomal-dominant Behçet's disease

Objective

Although Behçet's disease (BD) is a chronic inflammatory disorder of uncertain aetiology, the existence of familial BD with autosomal-dominant traits suggests that a responsibility gene (or genes) exists. We investigated a Japanese family with a history of BD to search for pathogenic mutations underlying the biological mechanisms of BD.

Methods

6 patients over 4 generations who had suffered from frequent oral ulcers, genital ulcers and erythaema nodosum-like lesions in the skin were assessed. Whole-exome sequencing was performed on genomic DNA, and cytokine production was determined from stimulated mononuclear cells. Inflammatory cytokine secretion and Nod2-mediated NF-κB activation were analysed using the transfected cells.

Results

By whole-exome sequencing, we identified a common heterozygous missense mutation in A20/TNFAIP3, a gene known to regulate NF-κB signalling, for which all affected family members carried a heterozygous C243Y mutation in the ovarian tumour domain. Mononuclear cells obtained from the proband and his mother produced large amounts of interleukin 1β, IL-6 and tumour necrosis factor α (TNF-a) on stimulation as compared with those from normal controls. Although inflammatory cytokine secretion was suppressed by wild-type transfected cells, it was suppressed to a much lesser extent by mutated C243Y A20/TNFAIP3-transfected cells. In addition, impaired suppression of Nod2-mediated NF-κB activation by C243Y A20/TNFAIP3 was observed.

Conclusions

A C243Y mutation in A20/TNFAIP3 was likely responsible for increased production of human inflammatory cytokines by reduced suppression of NF-κB activation, and may have accounted for the autosomal-dominant Mendelian mode of BD transmission in this family.

Genetic variants in the JAK1 gene confer higher risk of Behcet's disease with ocular involvement in Han Chinese

Recent surveys have identified SLC22A4, SLC22A5, RUNX1, JAK1 as susceptibility genes for various immune-related diseases. An association study was performed in 738 Behcet's patients with ocular involvement and 1,873 controls using the iPLEX system method. The first-stage study for 30 SNPs showed that SNPs rs2780815, rs310241, rs3790532 in JAK1 were associated with Behcet's disease in Han Chinese (Pc(Bonferroni correction) = 0.022-7.7 × 10(-3)). The G allele and AA genotype of SNP rs2834643 in RUNX1 (Pc = 0.041-1.75 × 10(-3)), but none of the other SNPs, were associated with Behcet's disease. Haplotype analysis for the SLC22A4, SLC22A5 genes showed an increased tendency for AGTCTGCCGC frequency in patients compared with controls; however, the significance was lost after Bonferroni correction (P = 0.004, Pc > 0.05). Subsequently, we further replicated the significantly associated SNPs using another independent cohort. Replication and combining studies showed that three SNPs rs2780815, rs310241, rs3790532 in JAK1, but not SNP rs2834643 in RUNX1, were consistently associated with Behcet's disease (replication: Pc = 0.012-9.60 × 10(-4); combining: Pc = 0.030-1.90 × 10(-4)). SNPs rs2780815, rs310241, rs3790532 were estimated to confer a population attributable risk of 35.0, 28.0, 27.0 %, respectively. We found a strong association between HLA-B51 with Behcet's disease in Chinese Han population (P = 1.35 × 10(-73); OR = 5.15; 95 % CI 4.28-6.19). GMDR analysis showed that no gene-gene interaction was detectable between JAK1 and HLA-B51. Logistic analysis indicated that the JAK1 gene was an independent risk factor for Behcet's disease (P > 0.05). Real-time PCR analysis showed that no difference on the expression of JAK1 in PBMCs or LPS-stimulated PBMCs between individuals with the different rs1762780815 genotypes studied (P > 0.05). In conclusion, this study suggests that JAK1, but not SLC22A4, SLC22A5 and RUNX1, contributes to the genetic susceptibility to Behcet's disease with ocular involvement.

[Behçet's disease in obstetrics and gynecology]

Behçet's disease is a multisystemic disease of unknown origin characterized by a recurrent bipolar aphtosis (oral and genital) associated with vascular, digestive or articular symptoms. Gynecologists can be faced to this disease at any time of the life of their patients, including during the pregnancy. Given that the first demonstrations of the disease can be genital, they are in the front line to evoke this diagnosis. They thus have to know the main characteristics of the disease to make the diagnosis and to organize a multidisciplinary management. During pregnancy, the treatment of the disease is to be adapted to avoid teratogenic drugs, and adapt the doses of the treatment.

Behçet's syndrome in pregnancy

Behçet's syndrome (BS), a systemic inflammatory disease characterized by oral and genital ulceration, eye inflammation and arthritis, usually presents in the third and fourth decades of life, but is rare in pregnancy. BS is not usually associated with a detrimental effect on pregnancy outcome. In most women BS is reported to improve in pregnancy, although it may not always follow a similar course in successive pregnancies and it is not possible to predict the course of BS in a particular pregnancy. Many of the drug therapies used to treat BS are safe to use in pregnancy and in the breastfeeding mother. These include corticosteroids, azathioprine, calcineurin inhibitors and probably colchicine. Experience with use of biologics in pregnancy is increasing. Drugs used in the management of BS that should be avoided in women planning a pregnancy include methotrexate, mycophenolate mofetil, thalidomide, cyclophosphamide and chlorambucil.

HLA antigens in a family with Behçet's syndrome

A family is described in which 3 of 12 members suffered from Behçet's syndrome. Four members, including the three patients with Behçet's syndrome suffered from recurrent aphthous stomatitis. These four family members possessed the HLA-haplotype HLA A2, B15, Cw3, DR4. However, one relative had inherited the same HLA-haplotype without showing any symptoms of the disease. Genetic influence from the actual HLA-haplotype may interact in manifestation of the syndrome.

Behçet's disease and pregnancy

BACKGROUND

Behçet's disease (BD) is a multisystem inflammatory chronic disorder, which is characterized by relapsing oral and genital ulceration and iridocyclitis. While being of unknown etiology, vasculitic changes of possible autoimmune origin are common to all involved organs, and thrombotic complications, which may adversely affect gestation, are frequently seen. Very little is known to date about the reciprocal influence of BD and pregnancy. We have undertaken to explore the mutual effect of BD and pregnancy with emphasis on maternal and fetal complications.

METHODS

In this case-control study, we have evaluated pregnancies that occurred in women suffering from BD, who were treated in our institution during the last 25 years. All records were reviewed, and data were confirmed by a telephone interview and compared with a matched control group. To review the current knowledge, a Medline search together with a manual search of selected articles was performed.

RESULTS

Thirty-one Behçet's patients who had 135 pregnancies were studied. Remissions were significantly more frequent during both pregnancy and postpartum periods, while exacerbations were observed only in one-sixth of the patients (P < 0.001). Pregnancy complications (P < 0.001), cesarean section (P < 0.001), and miscarriage (P < 0.02) rates, however, were significantly higher in the study group.

CONCLUSIONS

Our study suggests that pregnancy does not have a deleterious effect on the course of BD and may possibly ameliorate its course. However, it seems that BD may adversely affect pregnancy. The miscarriage rate was higher, and the pregnancy complications and cesarean section rates were significantly elevated.

Identification of an autosomal recessive mode of inheritance in paediatric Behçet's families by segregation analysis

We have conducted a segregation analysis in order to characterise the transmission of Behçet Disease (BD), a multifactorial condition with a strong genetic component. Complete information about BD status and pedigree was obtained on 104 probands from our database. We used the criteria of the International Study Group for BD (ISBD) to delineate the clinical status of the sibs: possible BD (patients meeting two criteria), or ascertained BD (patients meeting at least three criteria). A proband was defined as "paediatric" when he/she completed ISBD criteria before/by the age of 16 years. Families were distinguished as paediatric (n = 67) (ascertained through a paediatric proband), and non-paediatric (n = 37) ones. An Expectation Maximization (EM) algorithm was used to estimate the Mendelian segregation ratio P in nuclear families (two parents and their offspring). The maximum likelihood estimate: Pcirc; = 0.248, calculated in the paediatric data set, was consistent with the theoretical value of P = (1/4) for autosomal recessive inheritance, whereas the Pcirc; value was 0.08 when using the non-paediatric data set. Our work provides the first evidence of genetic heterogeneity in BD, and of the existence of a Mendelian entity in the paediatric BD subgroup. Previous studies failed to show any simple mode of inheritance in BD, probably because they were performed on the whole BD population.

High frequency of sister chromatid exchanges in lymphocytes of the patients with Behçet's disease

Behçet's disease (BD) (OMIM 109650) is an immunogenetically based multisystem disease, characterized by iridocyclitis, arthritis, orogenital ulcerations and pustular skin lesions. Viral and autoimmune etiologies have been suggested and HLA-B5 has been found to predominate in BD. The disease is most seen in Turkey and Japan. Although familial cases have been reported, the mode of inheritance is not clear. To determine the genetic instability in BD, sister chromatid exchange (SCE) analysis has been performed on peripheral lymphocytes in 23 patients and 20 healthy controls. We found significantly higher SCE rates in the patient group (p < 0.0001). Our results may indicate that genetic impairment and genetic instability may play an important part in the etiology of BD.

Adamantiadis-Behçet's disease in sisters

Two sisters with documented Adamantiadis-Behçet's disease of different severity, associated with HLA-B51, are described. Although the overall incidence of this complex disease is not different between sexes, only 4 female siblings, versus 14 male, that fulfill the 1990's International Study Group for Behçet's Disease criteria have been reported in the literature.

Clinical analysis of 40 cases of childhood-onset Behçet's disease

Behçet's disease is a chronic, relapsing, idiopathic, multi-system condition characterized by mucocutaneous, ocular, gastrointestinal, articular, vascular, urogenital, and neurologic involvement. Usually the onset occurs between 20 and 30 years of age; it is very uncommon in children. We analyzed 40 cases of childhood-onset Behçet's disease. The male:female ratio was 0.67. The most frequent major sign was oral ulceration, appearing in all patients. Other major signs were genital ulcers (33 patients), skin lesions (29), and ocular lesions (11). The average time interval between the initial oral ulceration and the second major manifestation was 8.8 years. After the second major manifestation, the third and fourth features rapidly developed within one to two years. The most frequent minor sign was arthritis, occurring in 11 of 40 patients. Intestinal, neurologic, and renal involvement was also present. From our results, we concluded that oral ulceration, which is the most common initial manifestation, should not be neglected in children, since it may signal Behçet's disease.

Pediatric onset of Behçet's syndrome with myositis: case report and literature review illustrating unusual features

We report a case of Behçet's syndrome with myositis in a pediatric patient, emphasizing the importance of muscle involvement in the differential diagnosis of calf pain and swelling in Behçet's syndrome. A review of the English-language literature from 1965 to the present suggests that the clinical picture of Behçet's syndrome in children differs from that in adults, in that there is a lower frequency of ocular disease, and unusual manifestations appear to be more common.

Behçet's syndrome involving the gastrointestinal tract--a diagnostic dilemma in childhood

Behçet's syndrome is very rare in children, especially those under 10 years of age. Clinical and radiological features are described in 4 children, including 2 under the age of 5 years, with the syndrome. As in other pediatric cases reported, the incomplete form of Behçet's syndrome was present in each case. All 4 patients had oral and genital mucosal effects, arthritis and gastrointestinal and dermatological manifestations. Ophthalmological symptoms occurred in only 1 patient. Radiologically, the 4 cases demonstrated the spectrum of gastrointestinal involvement, from minimal irregularity and thickening of the terminal ileum to gross irregularity and deformity of the terminal ileum and cecum. Because of the difficulty in differentiating Behçet's syndrome from other forms of inflammatory bowel disease it is suggested that in children with gastrointestinal involvement, 3 major criteria be present before the diagnosis of Behçet's syndrome is made.

Fetal arterial involvement in Behcet's disease: an electron microscope study

A fetus, 16 weeks old, was removed by hysterotomy from a patient suffering from Behcet's disease. The patient received systemic steroids during pregnancy. Electron microscopy of the fetal thoracic aorta revealed edema of the sub-endothelial space and of the luminal part of the tunica media, as well as a pronounced rarefaction and disarrangement of the smooth-muscle cells. Results obtained from two human fetal aortae used as controls suggest that the fetal aortic lesions were caused by the maternal disease and not by the exposure to steroids.

Neonatal Behçet's syndrome in an infant of a mother with the disease

Behçet's disease is reported in a newborn infant of a mother with the disease. The mother had recurrent orogenital ulcers, pustulonecrotic skin lesions, arthritis, thrombophlebitis, and colonic ulcers. Shortly after birth the infant presented with transient orogenital ulcerations and pustular cutaneous lesions. On healing, depressed scars developed which were very similar to those of the mother. The finding of circulating immune complexes in the mother's serum gives some support to the hypothesis that the infant's transient illness was caused by transplacental passage of maternal antibodies.