Iriyama Aya, Chen Yi-Ning, Tamaki Yasuhiro, Yanagi Yasuo
Department of Ophthalmology, University of Tokyo School of Medicine, Tokyo 113-8655, Japan.
Br J Ophthalmol. 2007 Sep;91(9):1230-3. doi: 10.1136/bjo.2007.117309. Epub 2007 May 2.
Intravitreal injection of anti-vascular endothelial growth factor (VEGF) antibody (bevacizumab, Avastin) has become one of the chief choices for the treatment of macular oedema and neovascular age-related macular degeneration. However, the effect of blocking the VEGF function has not been thoroughly explored in vivo. A previous study has reported that intravitreal injection of bevacizumab had no retinal toxicity on rats; however, bevacizumab is human-specific and does not react with rat VEGF. In this study, the authors examined the effect of anti-rat VEGF antibody and bevacizumab on rat retina in vivo and in vitro, especially focusing on retinal ganglion cells (RGCs).
In vitro, rat RGCs were purified by a two-step immunopanning procedure, and incubated in the presence of VEGF, bevacizumab, anti-rat VEGF antibody, and control-IgG for three days. The number of viable RGCs was counted. In vivo, after intravitreal injections of bevacizumab, anti-rat VEGF antibody, and control-IgG, viable RGCs were visualised by retrolabelling with Fluo-gold and enumerated to examine the toxicity.
In vivo, the mean (standard deviation) number of viable RGCs in the VEGF-treated group (0.99 (0.29) vs control), the bevacizumab-treated group (1.0 (0.23) vs control), the anti-rat VEGF antibody-treated group (0.98 (0.18) vs control) and the control IgG-treated group (0.98 (0.19) vs control) was not statistically different from that of the control group after 3 days. In vitro, the mean (SD) number of viable RGCs in the bevacizumab-treated group (2613 (230)/mm(2)), the anti-rat VEGF antibody-treated group (2600 (140)/mm(2)) and the control IgG-treated group (2656 (150)/mm(2)) was not statistically different from that of the control group (2656 (150)/mm(2)) after 7 days. There were no apparent histological abnormalities.
This study suggests that bevacizumab and anti-rat VEGF antibody have no short-term, direct retinal toxicity using the rat model. Intravitreal injection of bevacizumab shows no short-term, direct toxicity on RGCs.
玻璃体内注射抗血管内皮生长因子（VEGF）抗体（贝伐单抗，阿瓦斯汀）已成为治疗黄斑水肿和新生血管性年龄相关性黄斑变性的主要选择之一。然而，阻断VEGF功能的效果在体内尚未得到充分研究。先前的一项研究报道玻璃体内注射贝伐单抗对大鼠无视网膜毒性；然而，贝伐单抗是针对人类的，不与大鼠VEGF发生反应。在本研究中，作者在体内和体外研究了抗大鼠VEGF抗体和贝伐单抗对大鼠视网膜的影响，尤其关注视网膜神经节细胞（RGCs）。
在体外，通过两步免疫淘选法纯化大鼠RGCs，并在VEGF、贝伐单抗、抗大鼠VEGF抗体和对照IgG存在的情况下孵育三天。对存活的RGCs数量进行计数。在体内，玻璃体内注射贝伐单抗、抗大鼠VEGF抗体和对照IgG后，用荧光金逆行标记使存活的RGCs可视化并计数以检测毒性。
在体内，3天后，VEGF治疗组（0.99（0.29）对对照组）、贝伐单抗治疗组（1.0（0.23）对对照组）、抗大鼠VEGF抗体治疗组（0.98（0.18）对对照组）和对照IgG治疗组（0.98（0.19）对对照组）存活RGCs的平均（标准差）数量与对照组相比无统计学差异。在体外，7天后，贝伐单抗治疗组（2613（230）/mm²）、抗大鼠VEGF抗体治疗组（2600（140）/mm²）和对照IgG治疗组（2656（150）/mm²）存活RGCs的平均（标准差）数量与对照组（2656（150）/mm²）相比无统计学差异。未观察到明显的组织学异常。
本研究表明，使用大鼠模型，贝伐单抗和抗大鼠VEGF抗体无短期直接视网膜毒性。玻璃体内注射贝伐单抗对RGCs无短期直接毒性。
