小胶质细胞在人原发性视网膜色素变性中的活化

Activation of microglia in patient with retinitis pigmentosa

目的观察小胶质细胞在原发性视网膜色素变性(RP)患者中的活化表现。方法制备22个原发性RP患者及18个正常人眼的石蜡切片。抗体HLA-DR,CD45及CD68对视网膜小胶质细胞进行免疫标记。结果RP患者赤道部视网膜内层出现大量肥大的活化小胶质细胞,部分向变性的感光细胞层浸润。黄斑区小胶质细胞主要以三种形式存在:在视网膜内层明显活化并向感光细胞层浸润;在视网膜内层活化但很少向外核层浸润;视网膜全层未见小胶质细胞活化。视神经及视网膜前膜均见小胶质细胞活化。结论小胶质细胞的活化是RP的一种独特的炎性反应方式,在感光细胞变性中发挥一定作用。

Objective Photoreceptor degeneration is frequently accompanied by activation of retinal microglia in various animal models of retinal degeneration. The purpose of this study was to identify retinal microglial cells with different markers and observe their activation in the patients with retinitis pigmentosa （RP）. Methods Paraffin sections were prepared from 22 human eyes with RP and 18 normal eyes. Immunolabeling of retinal microglial cells was performed using monoclonal antibodies MHC Class ]I ,CD45 and CD68. Results In the normal retina,few ramified microglial cells distributed in the inner retinal layers. In eyes with RP,numerous hypertrophic activated microglia were noted in the inner retinal layers at the equatorial region. These cells infiltrated the degenerated photoreceptor cell layer. In macula, microglial activation was presented in three manners based on the different degree of RP ： spared of activated microglial cells in the whole retinal layers ; many activated microglial cells in the inner retinal layers but few ones in outer nuclear layer （ONL） ; a lots of activated microglial cells in the inner retina infiltrated ONL. Obvious microglial activation could be seen in the optic nerves,and labeled microglial cells were also noted in the epiretinal membranes. Conclusion Microglial activation in RP is a form of novel inflammatory reaction in response to the retinal degeneration and may play a role in the retinal degeneration in RP patients.