Leucocyte common antigen is present on osteoclasts

Abstract

Using a large panel of monoclonal antibodies which recognize the leucocyte common antigen (LCA), the presence of LCA on osteoclasts in both fetal and adult human bone specimens has been determined by immunohistochemistry. LCA is evident on the surface of fetal human osteoclasts in bone imprints and cryostat sections. LCA was also found on osteoclasts in specimens of fixed, decalcified osteoarthritic bone. The intensity and pattern of osteoclast reactivity were similar to those of foreign-body type macrophage polykaryons in inflammatory lesions. These results favour derivation of osteoclasts and their precursors from the multipotential haemopoietic stem cell which produces peripheral blood leucocytes and argues against their origin from a separate stem cell.