Tumour necrosis factor-alpha gene promoter region-308 and -376 G -> A polymorphisms in Behcet's disease

Objective. Contribution of HLA-B51 to the genetic susceptibility for Behcet's disease is well documented and recent studies suggest involvement of other genes. Tumour necrosis factor (TNF) genes are located in the vicinity of the HLA-B locus. Polymorphisms in the promoter region of TNF-alpha gene has been found to be associated with altered TNF secretion, and it may have a prominent role in the increased inflammatory responses of Behcet's disease

Polymorphisms of the IL-8 and CXCR2 genes are not associated with Behcet's disease

Objective. Genetic susceptibility to Behcet's disease (BD) is well documented for HLA-B51; however, contribution of other genetic polymorphisms is estimated to be substantial. Interleukin 8 (IL-8), a potent chemoattractant for neutrophils, has been found to be elevated in BD serum, and the serum concentrations correlate with disease activity. Novel polymorphisms in IL-8 (CXCL8) and in one of its receptors, CXCR2 gene, may have a role in enhanced IL-8 activity in BD

Evaluation of KIR3DL1/KIR3DS1 polymorphism in Behcet's disease

The Behcet's disease (BD)-associated human leukocyte antigen (HLA) allele, HLA-B*51 (B*51), encodes a ligand for a pair of allelic killer immunoglobulin-like receptors (KIR) present on cytotoxic cells-KIR3DL1, which inhibits their cytotoxicity, and KIR3DS1, which activates their cytotoxic activity. We tested whether KIR-regulated mechanisms contribute to BD by testing for association of KIR3DL1/KIR3DS1 genotypes with disease in 1799 BD patients and 1710 healthy controls from Turkey, as well as in different subsets of individuals with HLA-type-defined ligands for the KIR3D receptors. HLA types were imputed from single nucleotide polymorphism genotypes determined with the Immunochip. The presence of inhibitory KIR3DL1 or activating KIR3DS1 alleles did not differ significantly between cases and controls (KIR3DL1: 92.9% vs 93.4%, P-dominant = 0.55; KIR3DS1: 42.7% vs 41.0%, Pdominant = 0.29). The KIR3DL1/KIR3DS1 alleles were also present at similar frequencies among cases and controls bearing HLA-B with a Bw4 motif; HLA-B with a Bw4 motif with isoleucine at position 80; and HLA-B*51. Our results suggest that pathogenic mechanisms associated with HLA-B*51 do not primarily involve differential interactions with KIR3DL1 and KIR3DS1 receptors. However, due to the complexity of this locus (that is, sequence variation and copy number variation), we cannot exclude a role for other types of KIR variation in the pathogenesis of BD

The role of HLA-DRB1 shared epitope alleles in predicting short-term response to leflunomide in rheumatoid arthritis

WOS: 000251197900020PubMed ID: 18032542Objectives. To investigate the role of shared epitope (SE) alleles in the short-term clinical response to leflunomide for the treatment of active RA. Methods. In an open-label, multi-centre study of 16-weeks duration, 93 patients (82% female) fulfilling ARA 1987 RA criteria were treated with leflunomide (100 mg loading dose for 3 days, then 20 mg/day as the maintenance dose). The primary efficacy criterion was the response status according to the European League Against Rheumatism (EULAR) response criteria using Disease Activity Score-28 (DAS28) activity measure. SE determinations have been undertaken by polymerase chain reaction and sequencespecific oligonucleotide genotyping methods. Results. The mean (S.D) Disease Activity Score-28 (DAS28) was 5.1 (1.3) before the treatment, which was significantly decreased after 16 weeks [3.0 (1.1), P < 0.001]. According to the EULAR response criteria, 55 patients (59.1%) were classified as good responders. SE was positive in 51 (54.8) of the patients, with 13 (13.9%) having SE homozygosity or carrying any two SE alleles. Among SE-positive patients, 68.6% (35/51) were good responders, compared with 47.6% (20/42) in SE negatives (P < 0.04). No difference was present according to SE hetero- or homozygosity (68.4 vs 69.2%). RF was also present significantly more frequently in the SE-positive group compared with negatives (78.4 vs 57.1%, P = 0.03). However, no significant difference was observed in the prevalence of RF positivity in patients with a good clinical response (72.7 vs 63.2%, P = 0.32). Conclusions. The results suggest that HLA-DRB1 SE presence may favourably affect the outcome of leflunomide monotherapy in an unselected group of RA patients with an active disease and naive to leflunomide