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

Purpose 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. 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 (Pa <
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.