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

Associations of IL-17 and IL-17 receptor polymorphisms with Behçet's disease in Denizli Province of Turkey

Although the etiopathogenesis of Behçet's disease is not known, studies conducted in different populations show that it is a multifactorial disease that is thought to develop as a result of the interaction of environmental and genetic factors. IL-17 is thought to induce the neutrophilic inflammation and the tissue damage mediated by immune response in patients. Polymorphisms in the gene region encoding IL-17 and IL-17R molecules may play a critical role in the pathogenesis of the disease and contribute to the elucidation of disease mechanism. We aimed to show the association of IL-17A, IL-17F, and IL-17RC polymorphisms and haplotypes in Behçet's disease patients and its clinical features. We genotyped IL-17A (rs4711998 (A/G), rs8193036 (C/T), rs2275913 (A/G), rs3819025 (A/G), rs8193038 (A/G), rs3804513 (A/T), rs1974226 (C/T), rs3748067 (C/T)); IL-17F (rs763780 (T/C), rs2397084 (T/C)); and IL-17R (IL-17RC) (rs708567 (C/T)) polymorphisms in 88 patients with Behçet's disease and 133 healthy controls using PCR-RFLP-based approach. The results of our study showed that polymorphisms of IL-17A, rs8193036 (C/T), rs3819025 (G/A), rs3804513 (A/T), IL-17F rs2397084 (T/C), and IL-17RC rs708567 (C/T) are associated with the susceptibility to the BD. When the haplotype distributions of all loci of IL-17Aand IL-17A/IL-17F together were examined and in contrast to the data obtained from the controls, the GTGGAACC (27.84%) and GTGGAACCTT (25.57%) have the highest frequencies. In conclusion, the allele and genotype frequency differences of the IL-17A, IL-17F, and IL-17R and haplotype frequencies between Behçet's disease and controls indicate that the genetic structure of Behçet's disease may be different.

Association of single nucleotide polymorphisms in CXCR1, CXCR2 and CXCL5 with Behçet disease: a study in the Denizli province of Turkey

BACKGROUND

Behçet disease (BD) is associated with the immune system, especially neutrophilic activity. The CXCR1, CXCR2 and CXCL5 genes mediate the activation and migration of neutrophils.

AIM

To investigate CXCR1, CXCR2 and CXCL5 single nucleotide polymorphisms (SNPs) and examine their association with BD.

METHODS

We studied polymorphic sites in CXCR1 (four sites: rs16858811, rs9282752, rs16858809 and rs16858808), CXCR2 (three sites: rs2230054, rs1126579 and rs1126580) and CXCL5 (one site: rs352046) in 87 patients with BD and 111 healthy controls (HCs), using a PCR restriction-fragment length polymorphism-based approach for genotyping.

RESULTS

We found that the CXCR2 rs2230054 TT genotype and the CXCL5 rs352046 polymorphism might be possible genetic factors responsible for BD. We did not find any association between the development of BD and any of the four CXCR1 polymorphisms or the other two CXCR2 SNPs. In addition, our haplotype analysis results indicated that the haplotypes of the CXCR2 and CXCR1-CXCR2 polymorphic loci were different between the BD and HC groups.

CONCLUSION

Our study suggests that polymorphisms of CXCR1, CXCR2 and CXCL5 may affect susceptibility to BD and increase the risk of developing the disease. These loci need to be studied in larger groups of patients from different geographical areas around the world in order to clarify the genetic background for BD pathogenesis.

The IL-8 Gene Polymorphisms in Behçet's Disease Observed in Denizli Province of Turkey

Behçet's disease is a multisystemic inflammatory disorder as a triad of symptoms including recurrent oral and genital aphthous ulceration and uveitis with unknown pathogenesis. IL-8, a proinflammatory cytokine, has been found increased in the active stage of BD. DNA samples were obtained from 88 patients with BD and 112 healthy control subjects in Denizli province of Turkey. All genotyping experiments of SNPs in IL-8 gene were performed using polymerase chain reaction-restriction fragment polymorphism. We found that IL-8 -845 T > C and -738 T > A sites are non-polymorphic. There were no differences in the polymorphisms of IL-8 +396 G/T, +781 C/T, and +1633 C/T sites except IL-8 -251 T > A in between patients and healthy controls. Analysis of IL-8 polymorphisms indicates that the distribution of frequencies seems to be associated with -251 T > A and gender, -251 T > A and erythema nodosum, -251 T > A and ocular involvement, +781 C > T and erythema nodosum, +396 G > T and pathergy positivity, and +1633 C > T and papulopustular lesion. We demonstrated that the frequencies of IL-8 haplotypes were significantly different with BD patients than control group. We found that the distribution of IL-8 haplotypes was significantly different with genital ulcers, ocular involvement, positive pathergy test, erythema nodosum, papulopustular lesions, and arthritis with BD patients than healthy control individuals. Our study suggests that IL-8 gene polymorphisms may affect susceptibility to BD and increase the risk of developing disease. In order to confirm and assess the association of IL-8 and other cytokine gene polymorphisms in the pathophysiology of BD, large cohort studies are needed.

Phenotypic abnormalities of peripheral blood mononuclear cells in patients with Behçet's disease and association with HLA-B51 expression

The aim of this study was to investigate the subclasses and the immunophenotypic profile of peripheral mononuclear cells in patients with Behçet's disease (BD) and to assess associations between the expression of HLA-B51 antigen and that of other cell markers. Thirty healthy volunteer blood donors and forty patients with BD were enrolled into this study. Phenotyping was performed using two color flow cytometry. HLA-B51 typing was performed using the complement dependent microlymphocytotoxicity assay. Unlike controls, patients with BD presented a modified immunophenotypic profile of lymphocytes. Compared to those in the remission phase, patients with active BD showed an increased mean of MFI ratio of CD56 on CD16+CD56+ cells (32.47 ± 14.26 versus 23.87 ± 10.3; p = 0.032), increased absolute numbers of CD4(-)CD8(bright) and CD4(+)CD8(+) cells (657.1 ± 463.6 cells/µL versus 319.24 ± 116.4 cells/µL; p = 0.017 and 40.77 ± 36.41 cells/µL versus 10.77 ± 9.78 cells/µL; p < 0.0001, respectively) and an elevated mean of MFI ratio of CD19 on B cells (252.3 ± 56.7 versus 205.67 ± 32.3; p = 0.021). However, expression of HLA-B51 was not associated with any specific immunophenotypic profile. In conclusion, abnormal immunophenotypic profile of peripheral lymphocytes was found in patients with BD, especially in active phase, reflecting an immune dysregulation. Moreover, HLA-B51 expression was not found to be related to the expression of other cell markers.

Analyses of functional IL10 and TNF-α genotypes in Behçet's syndrome

We aim to ascertain the possible involvement of functional IL10 and TNF-α promoter polymorphisms on the susceptibility to Behçet's syndrome (BS), to examine whether IL10 and TNF-α genotypes might work synergistically influencing susceptibility to BS. IL10 -1082G/A, -819C/T and -592C/A and TNF -308G/A polymorphisms were analyzed in 102 Turkish patients with BS and 102 healthy subjects by using amplification refractory mutation system-polymerase chain reaction (ARMS-PCR). We have found no significant associations between IL10 -1082G/A, -819C/T, -592C/A, TNF-α -308G/A polymorphisms and BS. Also, no significant correlation was found between IL10 GCC, ACC, ATA haplotypes, GCC(+)/GCC(+), GCC(+)/GCC(-), GCC(-)/GCC(-) genotypes. There was no significant association between combined TNF-α/IL10 genotypes and BS. Our study indicates that functional TNF-α, IL10 genotypes or combined TNF-α, IL10 genotypes do not play a role in BS susceptibility in Turkish BS patients.

HLA-B51/B5 and the risk of Behçet's disease: a systematic review and meta-analysis of case-control genetic association studies

OBJECTIVE

To quantify by meta-analysis the genetic effect of the HLA-B5 or HLA-B51 (HLA-B51/B5) allele on the risk of developing Behçet's disease (BD) and to look for potential effect modifiers.

METHODS

Relevant studies were identified using the PubMed Medline database and manual searches of the literature. Pooled odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated by using the random-effects model. Subgroup meta-analyses and meta-regression analyses were undertaken to investigate the effects of selected study-level parameters on the pooled OR. Heterogeneity was assessed using the I2 statistic. Pooled results were used to calculate population-attributable risks (PAR) for BD in relationship to HLA-B51/B5.

RESULTS

A total of 4,800 patients with BD and 16,289 controls from 78 independent studies (published 1975-2007) were selected. The pooled OR of HLA-B51/B5 allele carriers to develop BD compared with noncarriers was 5.78 (95% CI 5.00-6.67), with moderate between-study heterogeneity (I2 = 61%). The subgroup analyses stratifying studies by geographic locations (Eastern Asia, Middle East/North Africa, Southern Europe, Northern/Eastern Europe) yielded consistent OR ranges (5.31-7.20), with I2 ranges of 52-70%. Univariate random-effects meta-regression indicated the percentage of male BD cases (P = 0.008) as a source of heterogeneity. The PAR within the various geographic areas were estimated at 32-52%.

CONCLUSION

The strength of the association between BD and HLA-B51/B5, and its consistency across populations of various ethnicities, lends further support to this allele being a primary and causal risk determinant for BD. Variations according to sex support an interaction of this allele with BD characteristics.

HLA-B27 and HLA-B51 determination in Tunisian healthy subjects and patients with suspected ankylosing spondylitis and Behçet's disease

The aim of this retrospective study is to assess the frequency of HLA-B27 and HLA-B51 in healthy subjects from the center of Tunisia and to investigate their usefulness in the diagnosis of ankylosing spondylitis (AS) and Behçet's disease (BD), respectively. Microlymphocytotoxicity test was used to perform serologic HLA typing in a group of 124 healthy volunteers and a group of 365 patients suffering from clinical manifestations of AS and/or BD. HLA-B27 was found in 3.2% of healthy subjects and in 42.9% of patients with AS (P < 0.00006). HLA-B51 is, however, found in 16.1% of healthy subjects and in 30.0% of patients with BD (P > 0.05). Unlike HLA-B51, which seems to be as frequent in Tunisian patients with BD as in healthy subjects, HLA-B27 is more frequent in patients with AS than in controls. This highlights the usefulness of HLA-B27, rather than that of HLA-B51, in the diagnosis of the respective diseases.