Purpose:
The purpose of this study was to use a new monoclonal antibody against the lymphatic endothelial marker, D2-40, to determine if the human cornea can undergo lymphangiogenesis and in what pathological settings this occurs. A variety of pathologies lead can lead to corneal decompensation and the need for transplantation. However, it is not well understood what specific factors lead to graft failure. 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. The use of the anti-D2-40 antibody has allowed for detection of lymphatics in other tissues; the current study will illustrate its use in detection of corneal lymphatic vessels.
Methods:
Thirty-one corneal buttons were randomly selected from the cases submitted for routine pathology between 2001-2003 to the Department of Ocular Pathology of the Scheie Eye Institute. These underwent immunohistochemical staining with a monoclonal antibody against D2-40 to detect the presence/absence of lymphatics by light microscopy. In addition to pathology reports reviewed to ascertain diagnoses, the charts of the above subjects were reviewed to confirm the preoperative clinical diagnosis.
Results:
Eighteen (58%) corneas contained lymphatic vessels as evidenced by D2-40 staining (brown coloration shown in figures) of thin-walled endothelial cell-lined vessels within corneal stroma. Within the group of corneal buttons that contained lymphatics, 50% (n=9) had been given a histopathologic and clinical diagnosis of bullous keratopathy (including pseudophakic and aphakic types), while in the D2-40 negative group, only 2/13 (15%) had such a diagnosis.
Conclusions:
While the presence of D2-40 positive vessels in corneal buttons is supported by previous work, the current study represents a novel finding of increased D2-40 expression and therefore, lymphatic vessel growth in a common, non-inflammatory condition that leads to penetrating keratoplasty.
Keywords: cornea: basic science