Development of bone marrow immunoscintigraphy using a Tc-99m labeled anti-NCA-95 monoclonal antibody.

We evaluated the monoclonal antibody CEA-79.4 against carcinoembryonic antigen as an immunoscintigraphic agent for assessing the state of the bone marrow. Western blotting of human granulocyte extracts with the antibody could confirm that the binding was with the epitope of NCA-95. Immunocytochemical staining of bone marrow aspirates revealed specific uptake of this antibody by granulopoietic cells. The affinity constant was 2-9 x 10(9) L/mol. Immunoscintigraphy using 99mTc-labeled CEA-79.4 in a normal volunteer revealed high uptake in the bone marrow as compared to other organs.