Impact of vascular endothelial growth factor single nucleotide polymorphism association on acute renal allograft rejection

Association of Vascular Endothelial Growth Factor 936 C/T Gene Polymorphism with Renal Allograft Outcome: A Study from North India

The significance of vascular endothelial growth factor (VEGF) and its polymorphisms in renal allograft rejection has recently become the subject of extensive research. Recently, some studies have shown some role of VEGF in rejection episodes and graft survival. VEGF +936 C>T polymorphism is significant in the transcription regulation of VEGF. Herein, we report the results of a prospective, single-center study seeking an association of VEGF +936 C/T gene polymorphism and allograft rejection. One hundred and forty-seven kidney transplant recipients with age-and sex-matched controls were included in this study. VEGF 936 C/T genes were studied using restriction fragment length polymorphism analysis of the blood specimen of these patients. All patients were studied for allograft rejection, response to treatment, and overall graft survival. We found that CT genotype and T allele carrier state were associated with good graft outcomes (P = 0.008 and 0.002, respectively). There was a lower number of rejection episodes with T allele, although it was not a significant finding (P = 0.880). Our findings suggest that good graft outcome in kidney transplant recipients is associated with an increased frequency of the VEGF 936 CT genotype and T allele, and that determination of the T allele might be helpful for the identification of recipients with overall good graft survival.

Association of VEGF -2549 I/D and VEGF +936 C/T Polymorphisms with Chronic Kidney Disease in North-West Indian Patients

Introduction

Chronic kidney disease (CKD) is a complex multifactorial disease in which both genetic and environmental factors influence the onset, development and progression of disease. The genetic variations in the vascular endothelial growth factor (VEGF) can influence levels of VEGF protein expression, and thus, susceptibility to progression of kidney diseases. The aim of the present study was to evaluate the association of VEGF-2549 I/D and VEGF +936 C/T polymorphisms in CKD stage V patients from North-West India.

Methods

In this case-control study, 166 patients and 166 controls were analyzed. DNA samples were screened for VEGF -2549I/D and VEGF +936 C/T polymorphisms using polymerase chain reaction-based (PCR) methods.

Results

The genotype frequency of VEGF -2549 I/D was significantly different between patients and controls (P < 0.05). ID genotype of VEGF -2549 I/D polymorphism was significantly associated with decreased risk of CKD (P = 0.009). Genetic model analysis of VEGF -2549 I/D polymorphism revealed a significantly decreased risk of CKD in co-dominant (P = 0.009), dominant (P = 0.021), and over-dominant (P = 0.012) models. Genotype and allele frequency of VEGF +936 C/T polymorphism was not significantly different between the patient and control groups. Genotype combination analysis revealed that ID-CT genotype combination of VEGF -2549 I/D and VEGF +936 C/T polymorphisms was associated with decreased CKD risk (P = 0.047).

Conclusion

VEGF -2549 ID genotype and ID-CT genotype combination of VEGF -2549 I/D and VEGF +936 C/T polymorphisms was significantly associated with reduced CKD risk in North-West Indians.

Influence of polymorphisms in the vascular endothelial growth factor gene on allograft rejection after kidney transplantation: a meta-analysis

Background: Reported associations of allograft rejection in kidney transplant patients with VEGF single nucleotide polymorphisms (SNPs) have been inconsistent between studies, which prompted a meta-analysis to obtain more precise estimates. Methods: Using the PICO elements, kidney transplant patients (P) were compared by genotype data between rejectors (I) and non-rejectors (C) in order to determine the risk of allograft rejection (O) attributed to the VEGF SNPs. Literature search of four databases yielded seven articles. To calculate risks for allograft rejection, four SNPs were examined. Using the allele-genotype model we compared the variant ( var) with the wild-type ( wt) and heterozygous ( var- wt) alleles. Meta-analysis treatments included outlier and subgroup analyses, the latter was based on ethnicity (Indians/Caucasians) and rejection type (acute/chronic). Multiple comparisons were corrected with the Bonferroni test. Results: Five highly significant outcomes (P a < 0.01) survived Bonferroni correction, one of which showed reduced risk for the var allele (OR 0.61, 95% CI 0.45-0.82). The remaining four indicated increased risk for the wt allele where the chronic rejection (OR 2.10, 95% CI 1.36-3.24) and Indian (OR 1.44, 95% CI 1.13-1.84) subgroups were accorded susceptibility status. Conclusions: Risk associations for renal allograft rejection were increased and reduced on account of the wt and var alleles, respectively. These findings could render the VEGF polymorphisms useful in the clinical genetics of kidney transplantation.

Vascular Endothelial Growth Factor Gene Polymorphism Is Associated With Long-term Kidney Allograft Outcomes

Introduction

Vascular endothelial growth factor (VEGF) regulates vasculogenesis in physiological and pathological states. We evaluated the role of VEGF single-nucleotide polymorphisms (SNPs) −1154 G/A, −2578 C/A, +936 C/T, and −2549 Ins/Del in chronic allograft nephropathy.

Methods

Blood samples were collected before renal transplantation, and DNA was extracted. Genotyping of VEGF SNPs −1154 G/A (rs1570360), −2578 C/A (rs699947), +936 C/T (rs112005313), and −2549 Ins/Del (18bpindel) polymorphisms were carried out. Relative quantification of VEGF-A mRNA expression for 4 VEGF SNPs were quantified by the 2^−ΔΔCt algorithm. Kidney allografts were categorized into graft loss (n = 98) and normally functioning (n = 174) groups. Genotype frequencies were calculated using additive, dominant, and recessive models. Hardy−Weinberg Equilibrium was assessed between outcome groups by standard procedure using χ² analysis. The cumulative allograft survival was estimated by Kaplan−Meier analysis and compared among VEGF genotypes by the log-rank test. Study limitations were the lack of VEGF serum levels, donor-specific antigens, and protocol biopsies.

Results

There was an association of AA (hazard ratio = 2.42, P = 0.0001) and CA (hazard ratio = 1.83, P = 0.009) genotypes of −2578 C/A SNP with graft loss. After adjustment for transplant-related covariates, associations of VEGF SNPs −2578 C/A and −2549 Ins/Del with graft failure were found to be significant. There was prolonged graft survival for cases with the CC genotype of VEGF −2578 C/A SNP. The carrier −2578*CC, −1154*GG, and +936*CC genotypes were shown to have a strongly protective association. There was no association with posttransplantation lymphomas.

Conclusion

Recipients of kidney allografts possessing low-producing VEGF genotypes are associated with less prolonged graft survival.