Abstract
Purpose :
Ocular graft versus host disease (oGVHD) presents in ~50% of allogeneic bone marrow transplant recipients with dry eye symptoms, decreased vision and in some cases corneal perforation. The pathogenesis of oGVHD remains incompletely understood. The objective of this study is to understand the histological and clinical findings of an experimental murine model of oGVHD. The study tested the hypothesis that with increasing clinical severity of oGVHD there would be increased histological changes.
Methods :
We studied a haploidentical murine model of oGVHD (donor C57Bl/6; host B6D2F1). All mice (n=15) underwent total body irradiation followed by injection of donor T and B cell depleted bone marrow +/- increasing doses of splenocytes to provoke more severe disease (1x106, 2x106, 5x106 cells). Control (n=3/group) mice did not receive splenocytes. Systemic GVHD and oGVHD scoring was performed weekly. Immunohistochemistry staining for CD3 polyclonal rabbit antibodies was performed for one mouse within each group at the end of the experiment (Day 40).
Results :
The mice that received 2x106 splenocytes had a significantly higher oGVHD score than control mice that received no splenocytes (p=0.008). Systemic GVHD scores were highest in the mice that received 5x106 splenocytes. Three mice in the 5x106 splenocyte group died prior to Day 40 due to severe GVHD. CD3 immunohistochemical staining of the corneas revealed the most lymphocytic infiltration occurred in the 5x106 splenocyte mouse with a total of 29 lymphocytes in the corneal epithelium. In the epithelial layer of the cornea, there were 9 central lymphocytes and 15 peripheral lymphocytes. In the stromal layer, there were 2 central and 3 peripheral lymphocytes. All other mice had 1 to 2 lymphocytes within the cornea.
Conclusions :
The findings support our hypothesis that with increased clinical severity there is increased inflammatory cells in the cornea which we hypothesize is correlated with the increased clinical severity noted on ocular GVHD score. This study provides the foundation to further study oGVHD, better understand the disease mechanism, and uncover new therapeutic targets.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.