The Influence Of -308 TNF Alpha Polymorphisms In The Pathogenesis Of Ischemic Heart Failure

INTRODUCTION AND OBJECTIVES: Heart failure (HF) is the end-stage of all kind of heart diseases ,but it is not that all the patients with heart disease progress to HF. Proinflammatory cytokine play an important role in the pathogenesis of HF,characterized by an inflammatory status. Tumor necrosis factor-alpha (TNF-alpha),one number of the proinflammatory cytokines, has been strongly implicated in the pathogenesis of heart failure. Not only TNF-alpha plays an important role in the pathogenesis of HF, but alsoit is still to be defined that TNF-alpha level in blood plasma is relevant to genetic polymorphisms of TNF-alpha. We hypothesized that there are relationship between single-nucleotide polymorphisms (SNPs) in TNF-alpha genes and HF.PATIENTS AND METHODS:Seventy-eight consecutive inpatients with coronary heart disease were enrolled in the study. Cardiac function was assessed according to the NYHA classification and these patients were divided into two groups:36 patients with HF whose cardiac function were NYHAⅡ-Ⅳ(64.05±7.28years, 42% males) and 41 controls whose cardiac function were all NYHAⅠ(67.24±7.45 years, 61% males). Blood samples were mixed with EDTA and stored at -80°C before further processing .Blood lipid and blood glucose were assaied in the clinic lab.Echocardiography were also performed in these studied patients. Genomic DNA was prepared from peripheral blood leukocytes of patients. Special kit was used Specific oligonucleotide primers were designed for the TNF-a -308 polymorphism, based on the published sequence:5′-AGGCAATAGGTTTTGAGGGCCAT-3′and5′-TCCTCCCTGCTCCGATTCCG-3′.Lyophilised oligonucleotide were manufactured by Songon. Gene Amp PCR kit was used. PCR was performed using the mode PTC-100, programmed for 35 cycles of 95°C and 60°C for 15 and 60 s, respectively. The genotype was identified by running the PCR products through 2% agarose gel containing 5 mg/100 ml ethidium bromide. The PCR product size was 117 base pairs. Restriction enzyme digestion with Ncol of the PCR-amplified product and subsequent electrophoresis on a 2% agarose gel discriminated between two alleles; GG showed two fragments of 97 bps and 20 bps, while its homologue AA was undigested and resulted in a single band of 117 bps. Heterozygous individuals GA were detected by the presence of all three fragments. The data were tested for their fit to the Hardy–Weinberg equilibrium by calculating the expected frequencies of each genotype and comparing them to the observed values. A X 2 test was used to determine the significance of the difference between the observed and expected values.RESULTS: There were no significant differences between the general clinic data of the two groups, such as age,sex,blood pressure,ratio of atrial fibrilation,diabetes mellitus,old myocardial infarction. (P>0.05).There were significant differences between the two groups in some parameters,representing systolic function of heart,such as left ventricle ejection fraction (EF,P<0.001) and left ventricle shortening fraction (FS,P=0.001), value of EF and FS in HF group were less than that in control group. Results of geometry morphological parameters were significant different between the two groups,such as left atrial diameter(LA,P=0.007)and left ventricular diastole diameter(LVD,P<0.001),.value of LA and LVD in HF group were greater than that in control group. These differences were consistent with the change of HF. There were no significant differences in TG (P=0.137),HDL(P=0.190),LDL-C(P=0.119) and APOB(P=0.753)between patients with HF when compared to controls .(P=0.001). There were significant difference in CHO(P=0.01) and APOA (P=0.011) between patients with HF when compared to controls ,.value of CHO and APOA in HF group were greater than that in control group. There was a significant difference in distribution of phenotypes of the -308 polymorphism between patients with HF when compared to controls (P = 0.036).The A -308 allele occurred more frequently in HF patients, P=0.022 (odd ratio: 2.493; 95% confidence interval: 1.153–5.392)Conclusion: The A-308 allele appears to be associated with HF and therefore, could be used as a genetic marker for disease mapping. In fact HF is a complex disease, therefore, a single gene could not be responsible for the diagnosis of HF. This is a pilot study variation of gene in patients with HF. We think that it is a base for establishing the diagnostic plateform for HF in the future.