title: Circulating macrophage colony-stimulating factor is not reduced in malignant osteopetrosis.
abstract: Malignant osteopetrosis is a disorder characterized by a deficiency in osteoclast number or function. In one animal model of osteopetrosis, the op/op mouse, macrophage colony-stimulating factor (M-CSF) is absent, and the administration of M-CSF corrects the defects. We evaluated the serum of 13 patients with malignant osteopetrosis by an M-CSF radioimmunoassay to determine if a quantitative M-CSF deficiency existed in these patients. All patients had M-CSF present in levels equal to or higher than control serum. In addition, serum from 6 osteopetrotic patients was tested in a bioassay to determine if the M-CSF present is biologically active, and in all cases there was demonstrable activity in these samples. We provide evidence that deficiency of circulating M-CSF is unlikely to be a major contributor to the etiologic basis for the majority of children with malignant osteopetrosis.
authors.affiliation: Department of Pediatrics, University of Minnesota Hospital and Clinics, Minneapolis 55455.
authors.forename: P J
authors.initials: PJ
authors.lastname: Orchard
authors.forename: N
authors.initials: N
authors.lastname: Dahl
authors.forename: S L
authors.initials: SL
authors.lastname: Aukerman
authors.forename: B R
authors.initials: BR
authors.lastname: Blazar
authors.forename: L L
authors.initials: LL
authors.lastname: Key
mesh_terms: D002675:Child, Preschool; D006801:Humans; D007223:Infant; D016173:Macrophage Colony-Stimulating Factor / Q000097:blood* / Q000172:deficiency; D010022:Osteopetrosis / Q000097:blood* / Q000209:etiology; D011863:Radioimmunoassay
chemical_list: D016173:Macrophage Colony-Stimulating Factor