Abstract
Purpose: :
Young recipient age is a risk factor for immune rejections after perforating keratoplasty. The establishment of a functional lymphatic vascular drainage from the donor tissue is of great importance for the induction of corneal allogeneic transplant rejections. In this study we investigated a potential age-dependency of the limbal lymphatic vascular response after an inflammatory stimulus.
Methods: :
Three interrupted 11-0 sutures were placed into the corneal stroma of young (6-8 weeks) and old (9-12 months) BALB/c mice and left in place for one week. Outgrowth of pathologic lymphatic vessels was analyzed histomorphometrically (using LYVE-1 as a lymphatic endothelial specific marker) after one week. Additionally, centrally directed lymphatic extensions from the main limbal lymphatic vessels of untreated young and old mice were counted.
Results: :
Old mice had a 44 ± 12 % reduced corneal ingrowths of lymphatic vessels after a stromal suture-induced inflammatory stimulus compared with young mice (p<0.03). Old untreated mice showed a markedly reduced number of centrally directed corneal lymphatics compared to young mice (4.8 ± 0.5 vs. 10.4 ± 1.1; p<0.001).
Conclusions: :
A reduced capacity for early and rapid lymphatic vessel ingrowths into the cornea towards the donor tissue in older mice could contribute to the higher risk of immune rejections in young recipients of corneal grafts.
Keywords: cornea: basic science • neovascularization • inflammation