HOST-DONOR CELLULAR INTERACTIONS IN TREATMENT OF EXPERIMENTAL OSTEOPETROSIS

OSTEOPETROSIS is a rare bone disease of man, animals and birds1. A striking feature is the failure of resorption of bone during growth and a reshaping of the skeleton so that the medullary cavities of shaft bones, normally containing only soft Tissue - bone Marrow - are filled with unabsorbed primary spongiosa causing a characteristic opaque radiological appearance that gives the disease its name. The osteoclast, a multi-nucleated giant cell, is considered to be responsible for the resorption of bone2, and it has long been held that osteopetrosis is due to deficient osteoclasts. That the defect had a cellular rather than a humoral basis1 was indicated when it was shown that bony resorption in osteopetrotic mice was resumed after short periods in parabiosis with normal litter mates3,4 (which also showed that a circulating cell was involved) and after infusions of phenotypically normal and histocompatible haematopoietic cells5,6. The subsequent and often rapid disappearance of the calcified material suggested to us that a new and proliferating population of cells was responsible, and to test this donor cells were tracked by a chromosome marker technique7. We now report that only low proportions of donor cells were located. © 1978 Nature Publishing Group.