Lymphangiogenesis Occurring in Transplanted Corneas

Immunological rejection is the major cause ofcorneal allograft failure .Corneal newblood vessels(hemangiogenesis) and lymphatic vessels (lym-phangiogenesis) are well-known high-risk factorsin corneal transplantation. Although i mmunosup-pressive-agents have been used systematically andlocally ,survival rate of corneal grafts placed intovascularized recipient beds is only 51 %1].In con-trast to the studies with respect to processes ofblood vessel proliferation,the reports on corneallymphangiog…

Lymphangiogenesis occurring in transplanted corneas

To study corneal lymphangiogenesis after corneal transplantation, corneal allogenic transplantation models were established in rats. 8 female Wister rats were used as donors, and 16 Sprague Dawley (SD) rats were used as recipients and 2 SD served as controls. Corneal lymphangiogenesis and hemangiogenesis was examined by electron microscopy 1 and 2 weeks after corneal penetrating transplantation, and the expression of lymphatic vessel endothelial receptor (LYVE-1) was examined 1, 3, 7, 14 days after the transplantation respectively. In addition, 19 allograft failed human corneas were examined by 5'-nase-alkaline phosphatase (5'-NA-ALP) double-enzyme-histochemistry staining to detect corneal lymphangiogenesis and hemangiogenesis. By immunohistochemistry for LYVE-1, it was found that blown lymphatics were localized in the stroma 3 days after the corneal transplantation. With electron microscopy, new lymphatic vessels and blood vessels were found 1 and 2 weeks after the corneal transplantation. By 5'-NA-ALP enzyme-histochemistry, corneal hemangiogenesis was found in all allograft failed human corneas and 5 of 19 (26.3 %) cases had developed corneal lymphangiogenesis. It is concluded that corneal lymphangiogenesis is present after corneal transplantation, which may play an important role in allograft rejection.