Congenitally osteopetrotic (oplop) mice are not cured by transplants of spleen or bone marrow cells from normal littermates.

Congenital mammalian osteopetrosis is characterized by a generalized skeletal sclerosis due to reduced bone resorption by osteoclasts. This condition can be cured in several mutant strains of mice and rats by transplantation of spleen or bone marrow cells from normal littermates. The ability of this regimen to cure osteopetrosis in oplop mice was examined in 23 mice treated with spleen or bone marrow cells from normal littermates and followed for up to 80 days. In no instance was there radiographic or histologic evidence of removal of the excessive skeletal mass characteristic of the disease. These data show that spleen or bone marrow cells do not cure osteopetrosis in this mutation. Recent demonstrations that not all children with congenital osteopetrosis are cured by bone marrow transplants from HLA-matched donors suggest that the oplop mouse mutation may be a useful model system in which to develop alternate treatments.