Diagnosis of B-cell chronic lymphoid leukemia by means of two-colour flow cytofluorimetry.

Immunophenotype of peripheral blood lymphocytes was studied in 39 patients with mature-cell lymphoproliferative diseases. Density of surface antigenes CD45, CD23, CD19, CD5, CD3, CD10, CD22, cappa and lambda chains, CD20, CD4 , CD8, CD16+56, CD34, HLA-DR was determined. Consequently, the diagnosis wa s specified in 8 patients. In all cases of B-cell chronic lymphoid leukemia CD45 concentration on the surface of leukemic lymphocytes was Father low. In the other B-cell well differentiated lymphoproliferative diseases this d ecrease was not found. This fact may be important for more definite selecti on of B-CLL from the whole spectrum of chronic lymphoproliferative diseases basing on immunophenotyping. In monitoring effectiveness of B-CLL treatmen t simultaneous detection of lymphocytes with low density CD45+CD19+ may app ear a more sensitive indicator for identification of a small leukemic cell number after chemotherapy than estimation of CD19+CD5+ lymphocytes. Moreove r, simultaneous evaluation of CD45 and CD23 density and CD19+CD5+ coexpress ion may at once give a definite diagnosis of B-CLL and mantle cell lymphoma .