First Author: M.Losada SPAIN
Co Author(s): P. Zafrilla N. Manresa J. Mulero 0 0 0 0 0 0 0 0 0
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Neovascularization (CNV) is a common pathological process in various retinal vascular disorders including diabetic retinopathy and AMD. The development of neovascular vessels may lead to complications such as vitreous hemorrhage, fibrovascular tissue formation, and traction retinal detachments. Various proangiogenic factors are involved in these complex processes. The aim of this study was to analyze the effect of antiangiogenic treatments on biomarkers of oxidative stress in patients with age related macular degeneration
A total of 43 patients with exudative AMD with no previous anti-VEGF treatment (age group of 55–82 years with the mean age of 71 years (20M and 23 F) were recruited for the study. The following parameters were determined: reduced and oxidized Glutathione (GSH/GSSH) and protein carbonyl groups.
Blood sampling: Blood samples were collected from the median cubital vein and placed in EDTA-containing vials. Blood is centrifuged to obtain serum at 3000x g for 15 min at room temperature within 1 h of collection and stores at - 80º C until the assays were performed. Reduced and oxidized Glutathione (GSH/GSSH) were determined by colorimetric determination (OxisResearch TM Bioxytech GSH/GSSH-412 TM Burlingame, USA) according to the manufacturer’s intruccions. Protein carbonyl groups were determined by an ELISA kit (Biocell Corporation Ltd, New Zealand) according to the manufacturer`s intruccions. Statistical analysis: All data were analyzed by using SPSS 17.0 statistical software (SPSS Inc., Chicago, IL). Descriptive statistic is presented as mean ± standard deviation. Means were compared by the variance test of repeated means. Analysis of variance (ANOVA) was used to examine significant differences in the protein carbonyl groups and GSH/GSSH ratio, of the two groups of study. A probability of less than 0.05 (p<0.05) was considered statistically significant.
Oxidative stress mediated toxicity is common to several sight-threatening ocular conditions, in which VEGF plays both a pathologic and protective role. Exogenous ROS stimulate the induction of VEGF expression in various cell types, such as endothelial cells, smooth muscle cells, and macrophages, whereas VEGF induces endothelial cell migration an proliferation through an increase of intracellular ROS19. According to the GSH/GSSH results, initial average values were higher in patients treated with Pegaptanib (8,2 ±1,4 µM) than in patientstreated with Ranibizumab (6,2 ±1,1µM); significant differences were found. After antiangiogenic therapies these values decreased slightly but there were no significant differences (7,9±1,6µM) in patients treated with Pegaptanib and (5,8±2,1 µM) in patients treated with Ranibizumab. Average values of carbonyl groups were higher in patients in patients treated with Pegaptanib than in patients treated with Ranibizumab (72,1±7,0 µmol/mg vs 68,3 ±4,1 µmol/mg) and significant differences were found. After antiangiogenic therapies these values increased but significant differences were not observed (75,1±8,1Ug/Hb Pegaptanib vs 71.8±5,8 Ug/Hb Ranibizumab).
The anti-VEGF therapies didn’t change the parameters studied of oxidative stress but they are very new therapies and have to continue investigating them.