Strong expression of Fc-receptors on leukemic cells in hairy cell leukemia.

The neoplastic cells of a patient with hairy cell leukemia were found to express a high Fc-receptor actitivy on their surface. When the Fc-receptors were determined quantitatively by measuring the uptake of 125I-labelled aggregated IgG under saturation conditions, it was found that the hariy cells bound approximately 3 times more aggregated IgG than normal adherent mononuclear cells. The bound 125I-Agg. IgG was evenly distributed on the cell surface when the cells were labelled at 4 degrees C and was rapidly redistributed in form of a cap at one cell pole during incubation at 20 degrees C.