[Quantitative immunoautoradiography for the diagnosis of leukemias]

A quantitative autoradiographic method is presented for determining absolute amounts of 125I-labelled compounds on the surface of individual cells. Autoradiographic evaluation of single cell radioactivity is accomplished by comparing the silver grain densities over the specimen and a radioactive standard being exposed simultaneously. The application of microphotometry of grain densities permits to determine semi-automatically the content of surface antigens or receptors of single cells in immunoautoradiographs. Hereby, the expression of various surface markers was measured on single lymphocytes and leukaemia cells. It was demonstrated that the variation of surface immunoglobulins or T cell antigens is restricted in density in the situation of leukaemia. This fits the concept that leukaemic cell clones are arrested at certain stages of cell differentiation. An immunological classification of acute and chronic forms of lymphatic leukaemias is given in relation to the differentiation degree of the neoplastic cell.