Abstract
Purpose: :
PVR is one of the major causes of failure in retinal detachment (RD) surgery, affecting 5% to 10% of patients. PVR is considered a multifactorial disease, resulting in an excessive inflammatory and scarring process of the retina. Studies to identify those patients at high risk of developing PVR have been based on the analysis of clinical features; however results have not been satisfactory. Our group is exploring the genetic contribution of this process and we have already described the potential contribution of TGFβ and LTA. (Ophthalmology 2010, 117:2417-2423)Tumour protein p53 (Tp53) codon 72 polymorphism has been studied as a risk factor for many diseases, involving apoptosis. After RD, retina suffers from ischemia and p53 levels are increased. Photoreceptor death and visual decline has been thought to be caused by apoptosis and the presence of soluble apoptosis molecules has been recently implicated in PVR.The purpose of this work has been to assess the distribution of Tp53 polymorphism among primary RD and PVR secondary in an European blood sample.
Methods: :
As a component of the Retina 4 project (European multicentric study for analysing the genetic component of PVR), 550 blood samples from patients with PVR (n: 134) secondary to a primary RD (cases) and Non PVR (n: 416) (controls) were analyzed for p53 polymorphisms (rs1042522; a G→C substitution at codon 72 in exon 4) using allele specific primer PCR. Genotypic and allelic frequencies were compared between cases and controls. The proportions of genotypes between sub-samples from different countries were analyzed.
Results: :
A significant difference (p<0.05, Fisher test) was observed regarding the p53 genotype frequencies at codon 72 between the PVR cases (GG: 30.59%, GC: 43.28%, CC: 26.11 %) and Non PVR controls (GG: 39.66%, GC: 52.64%, CC: 7.69%). The odd ratio of Proline variant was 4.3 (95% CI: 2.52 to 7.20).The comparison of proportions of genotypes between sub-samples from different countries showed also a significant difference between cases group and controls group in Spain and Portugal, but not in UK and Holland. However, when we analyze the Pro homozygote group between cases and controls revealed differences in Spain[29.01-42.18]/[2.29-10.20], Portugal [10.49-29.50]/[1.35-8.89]and Holland [16.49-31.70]/[4.51-15.09]but, again there was no differences in UK [7.68-18.1]/[4.85-13.94] p>0.05.
Conclusions: :
Results indicate that the Pro variant in rs1042522 of p53 gene could be a risk factor for PVR development after a primary RD. Genotype Pro/Pro could be related to a higher inflammatory process after RD. Further studies are necessary to establish the real role of this polymorphism in the development of PVR
Keywords: proliferative vitreoretinopathy • clinical (human) or epidemiologic studies: risk factor assessment • genetics