Lymphangiogenesis Concurrent with Haemangiogenesis in the Human Cornea

Background: Corneal transplant rejection can occur with and without neovascularization; therefore, it is necessary to elucidate what other factors allow for rejection. It has been suggested that the lymphatic system may play a role in graft failure, but it has also been held that the cornea is devoid of lymphatics. Use of a new monoclonal antibody against a lymphatic endothelial marker, D2-40, has been used to detect lymphatics in other tissues. The purpose of this study was to use this new tool to determine if the human cornea can undergo lymphangiogenesis.

Methods: Twelve corneal buttons submitted for routine pathology were subjected to immunohistochemical staining with a monoclonal antibody against D2-40 to detect the presence/absence of lymphatics by light microscopy.

Results: By the criteria defined, lymphatic vessels were identified in seven out of 12 corneal buttons. In these cases, there was also evidence of neovascularization. Lymphatic positive buttons included four cases where there were histological markers of inflammation. There were no identifiable lymphatics in the remaining five cases and no sign of vascularization.

Conclusions: Corneal lymphatics were identified in association with corneal neovascularization, via the use of a monoclonal antibody against D2-40. In non-vascularized corneas, lymphatics were absent.