Characterization of osteopenia in feline mucopolysaccharidosis VI and evaluation of bone marrow transplantation therapy.

Studies on a feline model of MPS VI demonstrated a marked osteopenia in iliac crest bone samples from young adult animals with fewer, finer trabeculae. In the absence of significant differences in bone remodeling, this was considered due to defects in endochondral ossification and the formation of fewer trabeculae. Cell-level bone formation was normal despite the presence of vacuolated osteoblasts. Affected animals had vacuolated osteocytes in larger lacunae. Cats of the same age who had received a bone marrow transplant 12 months prior as young kittens, had significantly more trabecular bone with thicker trabeculae. The presence of smaller osteocyte lacunae in these animals as compared to their untreated MPS VI cats appeared to be a direct effect of bone marrow transplantation and a useful parameter to monitor its efficacy.