Kinga Buraczynska

Monocyte chemoattractant protein-1 (MCP-1) gene polymorphism as a potential risk factor for cardiovascular disease in hemodialyzed patients

AIM Polymorphism in the monocyte chemoattractant protein-1 (MCP-1) gene (A-2518G) has been associated with functional effects. The aim of the present study was to assess the effect of this polymorphism on end-stage renal disease (ESRD) and cardiovascular disease (CVD) in hemodialyzed patients. METHODS A total of 720 patients with ESRD treated with hemodialysis (450 patients with CVD) and 325 healthy control subjects were genotyped for the MCP-1 -2518 polymorphism by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) procedure. RESULTS There was a significant difference in genotype frequencies between entire group of hemodialyzed patients and controls (p<0.01). The odds ratio for the risk allele was 1.85, 95% CI 1.49-2.32 (p<0.01). Hemodialyzed patients were divided into subgroups with CVD (n=450) and without CVD (n=270). The G allele carriers occurred with significantly higher frequency in patients with CVD (62% vs. 38% in patients without CVD and 36% in controls). The odds ratio for the risk allele for patients with CVD vs. those without CVD was 2.17, 95% CI 1.71-2.79. There was no statistically significant difference in the distribution of MCP-1 genotypes between ESRD patients without CVD and healthy controls. CONCLUSION Our results demonstrate for the first time an association between the polymorphism in the regulatory region of the MCP-1 gene and susceptibility to CVD in hemodialyzed patients.

Heat-shock protein gene polymorphisms and the risk of nephropathy in patients with Type 2 diabetes

HSPs (heat-shock proteins) are molecular chaperones synthesized under stress conditions, and are involved in renal cell survival and matrix remodelling in acute and chronic renal diseases. In the present study, we investigated whether the HSP70 gene polymorphisms affect susceptibility to DN (diabetic nephropathy) in patients with T2DM (Type 2 diabetes mellitus). The study group consisted of 452 patients with nephropathy. Two control subgroups involved 340 healthy individuals and 132 patients with T2DM lasting > or =10 years who were free of nephropathy. Subjects were genotyped for the HSP70-1 +190 G/C and -110 A/C, HSP70-2 +1267 A/G and HSP70-hom +2437 T/C polymorphisms by PCR, followed by digestion with restriction endonucleases. There were no statistically significant differences in genotype distribution between patients with T2DM with DN and controls for the HSP70-hom polymorphism. Significant differences were observed for HSP70-1 and HSP70-2 polymorphisms. CC homozygotes of the -110 and +190 HSP70-1 polymorphisms were more frequent in patients with T2DM with DN compared with healthy controls (22 compared with 6% and 15 compared with 6.5% respectively; P<0.01). The OR (odds ratio) for the risk allele was 2.17 [95% CI (confidence interval), 1.73-2.72] for the -110 A/C and 1.74 (95% CI, 1.40-2.15) for +190 G/C polymorphisms. A strong association with DN was found for the +1267 HSP70-2 polymorphism. The GG genotype and the G allele were associated with DN, with the OR for the G allele being 4.77 (95% CI, 3.81-5.96). All GG homozygotes in the patient group had higher LDL (low-density lipoprotein)-cholesterol levels than AA homozygotes (P<0.01), suggesting that the observed effect might be associated with this cardiovascular risk factor. These patients progressed faster to end-stage renal failure than those with other genotypes. In conclusion, our results indicate that the HSP70-1 and HSP70-2 polymorphisms are associated with renal complications in T2DM and may be useful in identifying patients with increased risk of DN.

Monocyte chemoattractant protein (MCP-1) A-2518G gene polymorphism in stroke patients with different comorbidities

OBJECTIVES The aim of our study was to assess the effect of A-2518G polymorphism in the monocyte chemoattractant protein-1 gene on development of stroke. DESIGN AND METHODS A total of 194 patients with stroke and 320 healthy controls were genotyped for the MCP-1 gene -2518 polymorphism. RESULTS There was a significant difference in genotype frequencies between ischemic stroke patients and controls (p=0.01). Stroke patients were subdivided according to gender, presence of renal disease, small-vessel disease, diabetes, atherosclerosis and hyperlipidemia. There were differences in genotype frequencies between stroke patients with atherosclerosis and controls (p=0.03), and in allele frequencies between diabetic patients and controls (p=0.04). In hyperlipidemia, the OR 2.33 for the GG genotype may be due to stroke, because it was found only vs. controls and not vs. group without hyperlipidemia. CONCLUSIONS Our results demonstrate an association between the polymorphism in the regulatory region of MCP-1 gene and susceptibility to ischemic stroke.

Polymorphisms of Tumor Necrosis Factor and Myeloperoxidase Genes in Patients with Chronic Renal Failure on Peritoneal Dialysis

AbstractBackground: Analyzing the molecular variants of immunological system genes helps to develop our understanding of the pathogenesis of several diseases. The tumor necrosis factor (TNF) is an important cytokine of cellular response and inflammation. The TNF gene is located within the MHC region on chromosome 6p21.3. Single nucleotide polymorphisms in the TNF gene, such as the one at a position −308, probably have a direct influence on TNF production. Myeloperoxidase, a heme enzyme, participates in micro-organism killing. The myeloperoxidase (MPO) gene is located on chromosome 17. In the promoter region, at position −463, G to A transition has been found, which causes decreased gene expression. Aim: The aim of our study was to analyze the genetic polymorphisms of the TNF and MPO genes in patients with chronic renal failure. Methods: The study included 95 patients with chronic renal failure and 115 healthy individuals. All participants were genotyped for TNF-308 and MPO promoter region polymorphisms by PCR, followed by digestion and gel electrophoresis. Genotype distribution was compared between patients and controls. For statistical analysis the Statistica PL 6.0 program was used. The Kruskal-Wallis and median test were employed; to evaluate relationship between quantitative data chi-square test was used. Results: There were no significant differences in genotype distribution of TNF or MPO polymorphisms between patients and controls. Some differences may be associated with gender because the TNF1/TNF1 genotype was significantly more common in healthy women in comparison with women with chronic renal failure (p < 0.05). In men, no such differences were found. For MPO polymorphism, in men with renal failure the GG genotype was significantly more frequent than in healthy men (p < 0.05). Comparing the MPO genotype distribution in diabetic nephropathy patients and nondiabetic patients, we found a statistically significant difference: GG and AA genotypes were more frequent in diabetic nephropathy than in other renal diseases (73 versus 60% and 10.8 versus 1.7%, respectively; p < 0.05). The genotype distribution in patients with other renal diseases was similar to the control group. There was a correlation between the TNF genotype and the age of onset of glomerulonephritis. For myeloperoxidase, there was a significant association between genotype and the age of onset of renal disease. There was no relationship between the TNF and MPO genotypes and time to end-stage renal disease. Conclusion: Our studies show that the TNF and MPO genes may play a role in chronic renal failure. The relationship observed between polymorphisms of the TNF and MPO genes and chronic renal failure may depend on the pathophysiological changes in different diseases underlying renal failure.

The intercellular adhesion molecule-1 (ICAM-1) gene polymorphism K469E in end-stage renal disease patients with cardiovascular disease.

The intercellular adhesion molecule-1 (ICAM-1) mediates interaction of activated endothelial cells with leukocytes. It plays an important role in the pathogenesis of atherosclerosis. A functionally important polymorphism of the ICAM-1 gene, K469E, has been described. We investigated whether this polymorphism influences the risk of CVD in end-stage renal disease (ESRD) patients. The groups of 1016 ESRD patients and 824 healthy individuals were genotyped by PCR and allele specific oligonucleotide technique. The T allele of the K469E polymorphism was significantly more frequent in ESRD CVD+ patients than CVD- and controls (OR 2.26, 95% CI 1.87-2.72 and 1.82, 95% CI 1.55-2.11, respectively). The TT genotype was also more frequent in CVD+ patients (OR 9.90, 95% CI 6.17-15.88 vs. CVD- subgroup). When patients were stratified according to clinical outcome of CVD, there was a tendency towards higher frequencies of the T allele and TT genotype in patients with myocardial infarction (OR for T allele 1, 57, 95% CI 1.12-2.18 vs. patients without MI). In the multivariate regression analysis the carrier status of T allele of K469E was an independent risk factor of susceptibility to CVD. Our data suggest that the ICAM-1 K469E polymorphism is associated with CVD in ESRD patients.

Matrix metalloproteinase-2 (MMP-2) gene polymorphism and cardiovascular comorbidity in type 2 diabetes patients

OBJECTIVE Matrix metalloproteinases (MMPs) play an important role in pathogenesis of atherosclerosis and vascular disease. We hypothesized that MMP-2 might be a susceptibility gene for cardiovascular disease (CVD) in diabetes. The aim of this study was to evaluate the association between C(-1306)T functional polymorphism in the MMP-2 gene and risk of CVD in type 2 diabetes patients. METHODS We examined 1090 patients with T2DM and 612 controls. All subjects were genotyped for the C(-1306)T polymorphism by polymerase chain reaction (PCR) and restriction analysis. RESULTS A significant decrease of T allele frequency was observed in patients with CVD versus those with no CVD (OR 0.44, 95% CI 0.36-0.52, p<0.0001). In contrast, OR for CC genotype was 2.19 (1.79-2.68, p<0.0001), conferring 2-fold greater odds for CVD. When the distribution of C(-1306)T was compared in subgroups with different clinical phenotypes of CVD, patients with stroke had the lowest frequency of T allele (6% vs. 11%), compared to entire CVD+ group (p<0.05). CONCLUSIONS T2DM patients carrying the T allele of MMP-2 C(-1306)T polymorphism have a significantly reduced risk of CVD. The C(-1306)T polymorphism is associated with susceptibility to stroke in T2DM patients.

Receptor for advanced glycation end products (RAGE) gene polymorphism and cardiovascular disease in end-stage renal disease patients.

BACKGROUND/OBJECTIVES Receptor for advanced glycation end products (RAGE) contributes to the pathogenesis of vascular and inflammatory diseases. We investigated whether the functional polymorphism in the promoter region of the RAGE gene (-374 T/A) influences development of cardiovascular disease in the end-stage renal disease (ESRD) patients. METHODS The cohorts of 1866 ESRD patients and 1143 healthy subjects were genotyped by polymerase chain reaction (PCR) for the RAGE variant rs1800624. RESULTS The genotype and allele frequencies did not differ significantly between ESRD patients and controls. There was no significant difference in the genotype distribution when patients with CVD were compared to those without it (p for A allele = 0.62). After stratifying CVD patients according to CVD clinical phenotype, the ESRD patients with stroke had a lower frequency of A allele than patients without CVD (0.12 vs. 0.21, p = 0.027). To confirm this finding, we genotyped 163 patients with ischemic stroke but without renal disease. In this group, the AA/TA genotypes were also significantly associated with lower risk of stroke (OR 0.46, p = 0.0002). CONCLUSION Our data suggest that the presence of the A allele of -374 T/A polymorphism in the RAGE gene has a protective effect against stroke.

Interleukin-4 Gene Intron 3 VNTR Polymorphism in Type 2 Diabetes Patients with Peripheral Neuropathy

ABSTRACT Objective: Diabetic peripheral neuropathy (DPN) is one of late complications of diabetes mellitus. The aim of this study was to evaluate the association between variable number tandem repeat (VNTR) polymorphism in intron 3 of interleukin-4 gene and risk of DPN. Methods: We examined 926 T2DM patients and 420 healthy controls. In the patient group, 44% had DPN. Genomic DNA was isolated from all subjects and genotyped for the IL-4 VNTR polymorphism by polymerase chain reaction (PCR). Results: No significant difference was observed in the frequency of minor P1 allele between T2DM patients and controls (OR 1.00, 95% CI 0.81–1.23, p = 0.988). The distribution of IL-4 VNTR polymorphism was compared between patients with DPN and those without it. The polymorphism was not significantly associated with DPN in studied subjects. In comparison of 406 T2DM patients with DPN and 520 patients without it, the OR (95% CI) for P1 allele was 0.82 (0.65–1.04), p = 0.10 and for P1P1 genotype 1.00 (0.53–1.89), p = 0.991. When two subgroups of patients with DPN, those with cardiovascular disease (CVD) and without CVD, were compared, subgroup with coexisting CVD had significantly higher frequency of P1 allele than patients without CVD, with odds ratio for the P1 allele 3.27 (95% CI 1.83–5.83), p = 0.0001. Conclusion: Our results demonstrated that VNTR polymorphism in the IL-4 gene is associated with DPN in type 2 diabetes patients with coexisting CVD.

Predictors of intracranial cerebral artery stenosis in patients before cardiac surgery and its impact on perioperative and long-term stroke risk

BACKGROUND The aim of this prospective study was to determine the prevalence of stenosis within intracranial and extracranial arteries in patients before coronary artery bypass surgery (CABG), to evaluate the influence of intracranial artery stenosis on neurological outcome and to identify preoperative risk factors for these patients. METHODS One hundred and seventy-five patients (71% males, mean age=66.1) scheduled for CABG were enrolled for extracranial Doppler duplex sonography, transcranial color-coded duplex sonography (TCCS) and transcranial Doppler (TCD) examination. RESULTS Twenty-six patients (14.7%) had extracranial stenosis or occlusion and 13 patients (7.3%) intracranial vascular disease. Six patients (3.5%) had both extra- and intracranial artery disease. The presence of peripheral artery disease and diabetes mellitus was a strong risk factor for extracranial artery stenosis but not for intracranial artery stenosis, which occurred independently also of typical atherosclerotic risk factors like age >70, male sex, hypertension, hyperlipidemia, hyperhomocysteinemia, smoking habit, obesity (BMI>30) and waist to hip ratio >1. Functional neurological outcome of the patients with intracranial arterial disease evaluated 7 days after CABG was the same as the patients without extra- and intracranial stenosis. However, 12-months neurological follow-up revealed significantly more ischemic strokes in patients with intracranial artery stenosis compared to patients without intracranial stenosis (p=0.015). CONCLUSION The occurrence of intracranial artery stenosis in CABG patients cannot be predicted by well-known atherosclerotic risk factors and seems not to be associated with perioperative stroke.