Bone marrow-derived cells are present in Mooren's ulcer.

To investigate whether bone marrow-derived cells are present in Mooren's ulcer and involved in its destructive and regenerative disease course, tissue specimens were collected from 3 eyes of 3 patients with Mooren's ulcer that underwent lamellar keratectomy. Three normal donor limbal corneoscleras served as controls. Immunohistochemical staining patterns were analyzed by using the following antibodies: CD34 (a marker of hematopoietic progenitor cells and endothelium), c-kit (a marker of hematopoietic and stromal progenitor cells) and STRO-1 (a differentiation antigen present on bone marrow fibroblast cells and on various nonhematopoietic progenitor cells). Strong positive CD34, c-kit and STRO-1 cells were revealed in Mooren's ulcer specimens, especially in the superficial stroma. A few weakly expressed CD34 stromal cells were seen in normal limbal cornea, but no immunoreactivity for c-kit and STRO-1 was found. Bone marrow-derived cells are present in Mooren's ulcer and contribute to its destructive and regeneration process by synergizing with other factors. Specific therapeutic strategies that target the role of these cells in Mooren's ulcer are anticipated.