Department of Ophthalmology, Flinders University, Adelaide, South Australia, Australia.
Cell Transplant. 2014 Jan;23(1):133-8. doi: 10.3727/096368912X659835. Epub 2012 Dec 4.
Lamellar (component cell) corneal transplantation is replacing penetrating keratoplasty for some corneal disorders in humans, but the relative risks of immunological graft rejection for the two procedures remain uncertain. A model of component endothelial cell keratoplasty (endokeratoplasty) was developed in outbred sheep. Clinical and histological graft outcomes after endokeratoplasty were then compared with contemporaneous penetrating corneal allografts. No topical or systemic immunosuppression was administered to any recipient sheep. Endothelial cell allografts (n = 10) took significantly longer to achieve perfect transparency following surgery than did penetrating corneal grafts (n = 7) (day 10 vs. day 4; p = 0.003; two-tailed Mann-Whitney U test). The median day to rejection of penetrating grafts was postoperative day 18; for endothelial cell grafts, it was day 48 (p = 0.04; two-tailed Mann-Whitney U test). The clinical courses of the two procedures were therefore quite different. Penetrating grafts gained clarity quickly but exhibited rapid graft neovascularization. Clinical rejection was preceded by inflammation in the anterior segment. Endothelial cell grafts exhibited a fluctuating, more indolent course of opacification, although all did eventually fail. Histological analysis confirmed immunological rejection in all failed grafts, but with different patterns of leukocytic infiltration in endokeratoplasties compared with penetrating keratoplasties. Inflammatory cells in endothelial cell grafts were generally fewer in number and were more often found in the posterior stroma. We conclude that, in the absence of immunosuppression, all endothelial cell allografts do undergo immunological rejection, albeit at a slower rate than penetrating grafts.
板层（成分细胞）角膜移植术正在取代穿透性角膜移植术，用于治疗人类的某些角膜疾病，但这两种手术的免疫移植物排斥的相对风险仍不确定。我们在杂种绵羊中建立了成分内皮细胞角膜移植术（内皮角膜移植术）的模型。然后，将内皮角膜移植术后的临床和组织学移植物结果与同期穿透性角膜同种异体移植物进行比较。没有给任何受体绵羊使用局部或全身免疫抑制药物。内皮细胞同种异体移植物（n = 10）在手术后达到完全透明的时间明显长于穿透性角膜移植物（n = 7）（第 10 天对第 4 天；p = 0.003；双侧曼-惠特尼 U 检验）。穿透性移植物排斥的中位数时间为术后第 18 天；内皮细胞移植物为第 48 天（p = 0.04；双侧曼-惠特尼 U 检验）。因此，这两种手术的临床过程有很大的不同。穿透性移植物迅速恢复透明，但迅速发生移植物新生血管化。临床排斥反应之前是前段炎症。内皮细胞移植物表现出混浊的波动、更缓慢的过程，尽管所有移植物最终都失败了。组织学分析证实所有失败的移植物均发生免疫排斥反应，但内皮角膜移植术与穿透性角膜移植术相比，白细胞浸润的模式不同。在内皮细胞移植物中，炎性细胞的数量通常较少，并且更常在后基质中发现。我们得出结论，在没有免疫抑制的情况下，所有内皮细胞同种异体移植物都会发生免疫排斥反应，尽管其速度比穿透性移植物慢。
