Anti-K562 cell monoclonal antibody RTF8X recognizes tumor-associated
antigen of erythroid lineage
T Sakurai, H Hara and K Nagai
Department of Internal Medicine, Hyogo College of Medicine, Japan.
A new anti-K562 cell monoclonal antibody, RTF8X, a cytotoxic IgM,
recognized a surface antigen on erythroblasts from patients with
erythroleukemia and polycythemia vera. RTF8X, which is highly specific to
K562 cells, did not react with the other 14 hematopoietic cell lines and
the seven nonhematopoietic cell lines. RTF8X antigen was not detected in
normal peripheral blood, but was found in less than 1% of normal marrow
cells. RTF8X did not inhibit in vitro colony formation of CFU-E and BFU-E
in a complement-dependent cytotoxicity assay. Cell- sorting analysis showed
that, morphologically, the RTF8X-positive marrow cells from the patients
and normal volunteers contained more than 60% erythroblasts and that CFU-E
and BFU-E were not demonstrated in cells with RTF8X antigen. Enzyme
treatment suggested that RTF8X antigen was a sialoglycolipid. These results
indicate that RTF8X may recognize the surface antigen found increasingly in
association with tumors of erythroid lineage. RTF8X should be useful for
studies of erythroid differentiation and proliferation in patients.
Volume 72,
Issue 5,
pp. 1487-1491,
11/01/1988
Copyright © 1988 by The American Society of Hematology
