The impact of smoking on clinical features of Behçet's disease patients with glutathione S-transferase polymorphisms.

OBJECTIVES: Various cancer studies have suggested that polymorphism of GSTM1 may influence the ability to detoxify chemicals in cigarette smoke. In the present study the effect of smoking on clinical features of Behçet's disease were investigated in patients having GST-M1 and/or -T1 null polymorphisms. METHODS: Ninety-seven patients meeting International Study Group Criteria for Behçet's disease (63 male, 34 female) and 172 healthy controls (94 male, 78 female) were included into the study. GST-M1 and -T1 polymorphisms were investigated using polymerase chain reaction-restriction fragment length polymorphism technique. RESULTS: Frequency of GSTM1- and/or GSTT1-null polymorphisms were comparable between the Behçet and the control groups. Smoking patients with GSTM1 null-polymorphism have decreased risk of developing papulopustuler lesions (OR=0.227 [0.063-0.818], χ2=5.463, p=0.019). Non-smoking patients with GSTM1 null-polymorphism has increased risk for having chronic arthritis (OR=5.988 [0.845-43.478]) but smoking patients with GSTM1 null-polymorphism have decreased risk (OR=0.741 [0.593-0.926]). GSTT1 null-polymorphism is associated with the presence of venous insufficiency (χ2=6.273, p=0.012, OR=2.740 [1.224-6.135]); smoking further increases the risk (χ2=7.840, OR=3.333 [1.412-7.874], p=0.005). GSTM1 null-polymorphism seemed to effect development of large vessel vasculitis (OR=1.158 [0.981-1.367], χ2=4.760, p=0.029). Male smoker Behçet patients even have more risk (OR=1.250 [0.971-1.610]). CONCLUSIONS: Several manifestations of Behçet's disease may be influenced by smoking, and this effect can be augmented in patients carrying GST gene polymorphism, which code enzymes crucial for the detoxification of chemicals.

Analysis of vascular endothelial growth factor gene 936 C/T polymorphism in patients with familial Mediterranean fever.

Vascular endothelial growth factor (VEGF) is a cytokine that promotes endothelial cell proliferation, leucocyte chemotaxis and expression of adhesion molecules and is a major mediator of vascular permeability. It has been demonstrated that VEGF directly activates neutrophils and it could promote acute recruitment of leucocytes. It is known that neutrophils are the major cell population involved in acute inflammation in familial Mediterranean fever (FMF) and the role of VEGF in these cells may be crucial. The aim of this study was to investigate whether the 936 C/T functional polymorphism of the VEGF gene is associated with susceptibility to FMF and its relationship with the main clinical features of the disease. Polymerase chain reaction-restriction fragment length polymorphism technique was used to determine 936 C/T polymorphism within the VEGF gene in 75 patients with FMF and 122 non-related healthy controls. Genotype and allele frequencies of the VEGF 936 C/T polymorphism between patients with FMF and healthy control groups were not significantly different (OR = 0.74, 95% CI = 0.40-1.37, P = 0.335 for CT genotype; OR = 1.11, 95% CI = 0.67-1.83, P = 0.700, for T allele). Although VEGF 936 TT genotype was found to be more frequent in patients with FMF than in healthy controls (6.7% vs. 1.6%, respectively), the difference was not significant (OR = 4.28, 95% CI = 0.81-22.67, P = 0.108). No associations were found between the studied polymorphism and either the clinical features such as arthritis, abdominal pain, pleuritis, myalgia, arthralgia and erysipelas-like erythema of the disease or the four common studied exon 10 mutations (M694V, M680I, V726A, M694I) of the Mediterranean fever gene. Present results suggest that VEGF gene 936 C/T polymorphism does not seem to be associated with susceptibility to FMF and its clinical manifestations.

Analysis of CD28 and CTLA-4 gene polymorphisms in Turkish patients with Behcet's disease.

In this study we aimed to investigate IVS3 +17T/C single nucleotide polymorphism (SNP) of CD28 gene, +49A/G and -318C/T SNPs of CTLA-4 gene in patients with Behçet's disease (BD) and their potential association to the main clinical features of the disease. These polymorphisms were investigated in a Turkish population of 123 patients with BD and 179 healthy controls, by using PCR-RFLP technique. HLA-B*51 genotype was also studied in both groups by using PCR-SSP. The frequency of IVS3 +17TC genotype of the CD28 gene was significantly increased in BD patients compared to controls (43.6% vs. 31.2%, OR = 1.663, 95% CI = 1.033-2.679, P = 0.039). CTLA-4 +49GG genotype frequency was found to be significantly lower in patients with BD than those of healthy controls (4% vs. 10.6%, OR = 0.357, 95% CI = 0.130-0.983, P = 0.05). Genotype and allele frequencies of the CTLA-4-318C/T polymorphism between the BD and healthy control groups were not significantly different (12.2% vs. 10.6%, OR = 1.170, 95% CI = 0.570-2.402, P = 0.713). There were no associations between the studied polymorphisms and the main clinical features of BD. The frequencies of HLA-B*51 were 60.3% and 30.7% in BD and control groups, respectively (OR = 3.429, 95% CI = 2.115-5.559, P = 0.0001). Association between HLA-B*51 and each studied polymorphism did not reach to significant levels (OR = 0.479, 95% CI = 0.228-1.004, P = 0.064 for CD28 IVS3 +17TT genotype; OR = 2.180, 95% CI = 1.025-4.639, P = 0.061 for TC genotype; OR = 1.570, 95% CI = 0.870-2.836, P = 0.146 for C allele). These results may suggest that CD28 IVS3 +17TC genotype may be a risk factor for the development of BD, on the contrary CTLA-4 +49GG genotype may be protective in the studied Turkish population.