目的：对生物工程角膜移植术后发生免疫排斥反应患者进行激光共焦显微镜观察和免疫病理研究，初步探究生物工程角膜移植排斥反应的发生机制。

方法：回顾性病例研究。纳入2018-09/2020-12我院收治的感染性角膜炎行生物工程角膜移植术后发生免疫排斥患者5例5眼。裂隙灯检查角膜透明度、角膜新生血管； 激光共焦显微镜对角膜进行动态观察，记录免疫排斥反应后角膜上皮下朗格罕氏细胞和基质炎症细胞密度，并以对侧眼作为对照进行统计分析。行同种异体角膜移植时取下生物工程角膜，免疫组织化学染色后对CD4⁺细胞和CD8⁺细胞及炎症细胞的浸润和分布进行观察。

结果：激光共焦显微镜显示，术眼角膜上皮下可见大量活化郎格罕氏细胞，其活化比例与对侧眼比较有差异(χ²=38.29，P<0.001)。基质层大量炎症细胞，与对侧眼比较具有差异(t=32.5，P<0.05)。对生物工程角膜组织进行免疫组织化学染色和HE染色，角膜基质层均可见CD4⁺细胞和CD8⁺细胞，仅1眼角膜基质层可见大量嗜酸性粒细胞。

结论：生物工程角膜移植术后免疫排斥反应经免疫病理证实以T细胞介导的细胞免疫在发病机制中具有重要作用，对异种抗原的超敏反应可能参与其中。

METHODS: Retrospective case study. Five patients(5 eyes)who underwent bioengineered keratoplasty for infectious keratitis from Sep.2018 to Dec.2020 and were immunologically rejected included. All observers were monocular. Slit-lamp was used to examine corneal transparency and corneal neovascularization. The cornea was dynamically observed under laser confocal microscopy, the density of subepithelial langerhans cells and stromal inflammatory cells was recorded after graft rejection, and the contralateral eye was used as the control group for statistical analysis. The infiltration and distribution of CD4⁺ cells, CD8⁺ cells and inflammatory cells were observed after immunohistochemical staining of bioengineered corneas during corneal allograft.

RESULTS: Confocal laser microscopy showed that a large number of langerhans cells were activated under the corneal epithelium of the intraoperative eye, and the activation ratio was significantly different from that of the contralateral eye(χ²=38.29, P<0.001). The stromal layer was rich in inflammatory cells, which was significantly different from that of the contralateral eye(t=32.5, P<0.05). Immunohistochemical staining and HE staining were performed on the bioengineering corneal tissue. CD4⁺ and CD8⁺ cells were observed in all corneal stromal layers, and only one case had a large number of eosinophils.

CONCLUSION: Immunopathology of rejection after bioengineered keratoplasty confirmed that T-cell-mediated cellular immunity plays an important role in the pathogenesis, and hypersensitivity to xenoantigen may be involved in it.