Membrane receptors of human leukaemic myeloid cells: sequential expression of the gamma Fc receptor.

An immunological surface marker study was performed on 13 patients with a variety of myeloid leukaemias. It was shown that expression of the receptor for the Fc of IgG (gamma FcR) starts to take place at the promyelocyte stage, and that the receptor is present on more mature granulocytic cells, but is absent from myeloblasts. Myeloblasts and promyelocytes are negative for the complement receptor CR2. Monoblasts, unlike myelobasts, were shown to express a gamma FcR and, to a lesser extent, CR2. Receptor expression therefore appears to be an earlier event in monocytic development. The possible diagnostic value of immunological marker studies in myeloid disorders is considered.