Low prevalence of juvenile-onset Behcet's disease with uveitis in East/South Asian people.

AIM: There is little information on the demographic and clinical characteristics of Behçet's disease in children in different parts of the world. We sought to provide this information through a questionnaire survey of specialist eye centres. METHODS: Descriptive questionnaires were collected from 25 eye centres in 14 countries. The questionnaire surveyed details of juvenile-onset Behçet's disease with uveitis. Ethnic groups, clinical features, treatments and prognosis of paediatric-age Behçet's disease were examined on a worldwide scale. RESULTS: The clinical data of 135 juvenile-onset and 1227 adult-onset patients with uveitis were collected. The average age of disease diagnosis in the children was 11.7 years old. Of the ethnic groups identified 54% were from Middle East, 43% from Europe, but only 2% from East/South Asian countries. By contrast, 19.2% of adult patients were from East or South Asia. The frequency of genital ulcers in juvenile patients was 38.7%, which was significantly lower than in adult cases (53.5%; p<0.01). CONCLUSIONS: Behçet's disease with uveitis was less common in children than in adults in East/South Asia. Although the clinical features of the systemic disease were similar in children and adults, there was a lower frequency of genital ulceration in children.

Re-evaluation of heterogeneity in HLA-B*510101 associated with Behçet's disease.

Behçet's disease (BD) is a chronic inflammatory disease characterized by oral aphthous ulcers, genital ulcers, uveitis and skin lesions. Etiology and pathogenesis of BD are not fully elucidated, but the association with human leukocyte antigen (HLA)-B51 or B*5101 has been repeatedly reported. Previous studies have shown that there are few sequence variations in the protein-coding region of B51, while there is a report on many variations in the 5'-flanking region and intron. In this study, HLA-B*5101 gene from 37 individuals including Japanese, Turkish, Jordanian and Iranian patients and healthy controls were fully sequenced to further clarify the B*5101 gene in association with BD. We found that all the patients and healthy controls carried B*510101 with no variation in the 5'-flanking region, exon and intron. However, seven polymorphisms were found in the 3'-flanking region. These polymorphisms composed of six haplotypes that were shared and stretched over the ethnic groups, suggesting that the susceptibility to BD was conferred by the B*510101 itself and not by any genes in linkage disequilibrium with B*510101. In addition, phylogenetic analyses of B*510101 showed that the 3'-flanking sequences followed an evolutional divergence differently from that of the other regions, implying that a unifying selection might operate to conserve B*510101.

Evaluation of the effect of acetazolamide on cystoid macular oedema in patients with Behcet's disease.

AIM: To study the effect of acetazolamide on cystoid macular oedema (CMO) in patients with Behcet's disease. PATIENTS AND METHODS: A total of 67 eyes of 35 Behcet's patients with chronic, but well-controlled uveitis, and CMO were randomised into a double-masked, crossover trial comparing the effect of acetazolamide vs placebo. The patients received an initial 4-week course of either 250 mg acetazolamide twice daily (b.i.d.) or placebo, followed by a 4-week washout period. They then received a 4-week course of the reverse study medication. An improvement in visual acuity and fundus fluorescein angiographic findings was assessed. RESULTS: In total, 29 patients (55 eyes) completed the trial and were available for analysis. Of the 29, 16 men and 13 were women. The age range was 13-50 years (mean 33.6 years). Patients on acetazolamide showed a slightly better improvement of angiographic signs (at least by one grade improvement) over that of placebo (12 vs five eyes). They also had less deterioration of angiographic signs over that of placebo (three vs seven eyes). However, these findings were not statistically significant (P=0.99). Acetazolamide had no statistically significant effect (P=0.53) on the improvement of visual acuity of patients over that of placebo (13 vs eight eyes), nor on the deterioration of visual acuity (three vs 11 eyes). CONCLUSION: Despite seemingly favourable results, the 4-week course of acetazolamide (250 mg b.i.d.) has no statistically significant effect on the improvement of the visual acuity and the fluorescein angiographic findings in Behcet's patients with CMO.

Topical aminocaproic acid to prevent rebleeding in cases of traumatic hyphema.

PURPOSE: To determine the effect of topical aminocaproic acid on the incidence of rebleeding after traumatic hyphema. PATIENTS AND METHODS: This randomized double blind clinical trial investigated 132 consecutive cases of traumatic hyphema referred to the emergency room of Farabi Eye Hospital in 1998-1999. The patients were randomly divided into three groups: Group 1 received cycloplegic drops only. Group 2 received cycloplegic drops and 2% carboxy polymethylene (CPM) gel as placebo. Group 3 was treated with cycloplegic drops and 25% aminocaproic acid (ACA) in CPM gel (supplied by Messrs. Sina Darou). All patients were treated for five days on an outpatient basis, with a two-week follow-up. The incidence of rebleeding, time needed for clot absorption, and complications of hyphema were recorded and analyzed using the chi-square and Student's t-tests and logistic regression modeling. RESULTS: Rebleeding occurred in 8 eyes of 52 patients in group 1 (15.4%), 7 eyes of the 39 patients in group 2 (17.9%) and 5 eyes of the 41 patients in group 3 (12.2%). This difference was not significant. The time needed for clot absorption in groups 1, 2 and 3 was respectively 9.5 +/- 3.9, 9.3 +/- 4.2 and 11.15 +/- 4.7 days, the difference between group 3 and the other two groups being statistically significant (p<0.04). CONCLUSIONS: Topical 25% ACA is not effective in reducing the incidence of rebleeding and lengthens the time needed for clot absorption.

Analysis of microsatellite polymorphism around the HLA-B locus in Iranian patients with Behçet's disease.

We have previously suggested that in a Japanese population the susceptible locus for Behçet's disease (BD) is HLA-B51 itself. To confirm this finding in another population, we performed HLA class I typing using the PCR-SSP method and analyzed eight polymorphic markers distributed within 1100 kb around the HLA-B gene using automated sequencer and subsequent automated fragment detection by fluorescent-based technology with the DNA samples of 84 Iranian patients with BD and 87 healthy ethnically matched controls. As a result, three microsatellite alleles (MICA-A6, MIB-348, C1-4-1-217) and HLA-B51 were found to be strongly associated with BD. Of these alleles HLA-B51 is the most strongly associated allele. There were no alleles that were increased in allele frequency at any microsatellite loci centromeric of MICA or telomeric of HLA-B51. Therefore, HLA-B51 was confirmed to be by far the most strongly associated gene with BD in an Iranian population.

HLA class I genotyping including HLA-B*51 allele typing in the Iranian patients with Behçet's disease.

It is well known that Behçet's disease (BD) is strongly associated with human leukocyte antigen (HLA) B51 in many ethnic groups. However, there has been no published report as yet with respect to this association among the Iranian people. Furthermore, since it is now known that the B51 antigen can be encoded by 21 alleles, B*5101-B*5121, we performed HLA-B*51 allele typing as well as HLA class I genotyping of 48 Iranian patients with this disease. As a result, the frequency of the B*51 allele was significantly higher (62.1%) in the patient group as compared with the ethnically matched control group (31.8%) (Pc=0.067, R.R.=3.51). In the genotyping of B*51 alleles, 33 out of the 36 B*51-positive patients possessed B*5101 and the remaining 3 carried B*5108. This study revealed that Iranian patients with BD also had a strong association with HLA-B51. In addition, this significantly high incidence of HLA-B*51 was found to be caused by an increase in both the HLA-B*5101 and HLA-B*5108 alleles. However, there was no significant difference in the HLA-B*51 allelic distribution between the patient and control groups.

Trinucleotide repeat polymorphism within exon 5 of the MICA gene (MHC class I chain-related gene A): allele frequency data in the nine population groups Japanese, Northern Han, Hui, Uygur, Kazakhstan, Iranian, Saudi Arabian, Greek and Italian.

We recently identified a trinucleotide repeat polymorphism, (GCT)n, within the transmembrane (TM) segment of the human MHC class I MICA gene (MHC class I chain-related gene A). Five distinct alleles (A4, A5, A5.1, A6, A9) corresponding to 4, 5, 5 with one nucleotide insertion, 6 and 9 repetitions, respectively, have been detected in various HLA-homozygous B cell lines. Here we present allele frequencies for this trimeric short tandem repeat (STR) in 604 unrelated individuals collected from nine human populations (Japanese, Northern Han, Hui, Uygur, Kazakhstan, Iranian, Saudi Arabian, Greek and Italian) determined using the polymerase chain reaction (PCR) combined with fluorescent-based automated fragment detection technology. All alleles were present in each population, but allelic distributions varied from one population to another. No new alleles (such as A7 or A8) were identified. The evolutionary and structural significance of these data as well as the potential application to forensic medicine is discussed.

[Behçet's disease. Apropos of 32 cases]. / La maladie de Behçet. A propos de 32 cas.

The study of 32 cases of Behçet's disease has enabled the authors to ascertain that the disease presents no particular characteristics in Lebanon, except certain variations in the frequency of the symptoms. Their study includes two familial cases, or approximately 3 p. cent and confirms the severity of these forms. Colchicine proves to be an effective treatment able to cure cutaneous and articular symptoms and perhaps stabilize the ocular lesions. The long-term efficacy of steroid therapy in ocular manifestations is not certain. Chlorambucil caused a stabilization of ocular lesions in four patients.