复方倍他米松对异种角膜板层移植术后免疫排斥反应的影响

目的：观察结膜下注射复方倍他米松对鸵鸟-兔眼板层角膜移植术后免疫排斥反应的缓释治疗作用。

方法：16只6周龄健康新西兰白兔角膜(单眼)行板层角膜移植术，植片应用鸵鸟脱细胞的角膜基质，术后分成两组，实验组术毕及术后结膜下注射复方倍他米松注射液(每隔7d一次)，对照组术毕及术后结膜下注射地塞米松磷酸钠注射液(每隔7d一次)。分别于术后1、2wk， 1、2mo取兔角膜组织做石蜡包埋切片，进行HE染色观察组织特点，同时进行间接免疫荧光法检测CD4⁺、CD8⁺ T淋巴细胞的变化。

结果：术后2mo，实验组角膜植片在位，并保持透明，新生血管极少，组织切片HE染色和间接免疫荧光染色结果显示，仅见少许中性粒细胞浸润，未见CD4⁺、CD8⁺ T淋巴细胞； 对照组炎症反应明显，角膜植片混浊，组织切片HE染色和间接免疫荧光染色结果显示，炎性反应以中性粒细胞浸润为主，可见CD4⁺、CD8⁺ T淋巴细胞。

结论：复方倍他米松作为长效缓释剂可有效抑制鸵鸟-兔板层角膜移植术后免疫排斥反应，延长植片的存活时间。

Effect of compound betamethasone on immunological rejection after xenogeneic corneal lamellar transplantation

AIM: To observe the sustained-release effect of compound betamethasone by subconjunctival injection on immunological rejection after ostrich-rabbit lamellar keratoplasty.

METHODS: Sixteen healthy New Zealand white rabbits with 6wk old received corneal lamellar keratoplasty, and the corneal graft was ostrich acellular corneal stroma. After surgery all subjects were divided into two groups, Group A(experimental group)were administrated with subconjunctival injection of compound betamethasone injection(once every 7d), and Group B(control group)were administrated with subconjunctival injection of dexamethasone sodium phosphate(once every 7d). At 1,2wk, 1, 2mo after the surgery, rabbit corneas were taken for paraffin sections, and were observed with H-E staining, in the meantime changes of CD4⁺ and CD8⁺ T lymphocytes were observed by immunofluorescence.

RESULTS: Two months after surgery, in Group A corneal grafts remained transparenct, and showed little neovascularization; HE staining and indirect immunofluorescence showed that only a few neutrophil infiltration, no CD4⁺ and CD8⁺T lymphocytes. In Group B, the inflammatory reaction was observable at different time points, the corneal graft was turbid; and the tissue sections and indirect immunofluorescence staining showed that neutrophil infiltration was predominant, and CD4⁺, CD8⁺T lymphocytes were also seen.

CONCLUSION: Compound betamethasone is able to inhibit the ostrich-rabbit corneal transplantation immune rejection, prolong the survival time of the grafts. The present study lay the foundation for further research and clinical application.