CYTOPLASMIC AND SURFACE-MEMBRANE PHENOTYPIC MARKERS IN CELLS OF B-CELL CHRONIC LYMPHOCYTIC-LEUKEMIA

Peripheral blood cells of twenty-six patients with B cell chronic lymp hocytic leukemia (B-CLL) were characterized for their surface membrane and cytoplasmic marker profiles using flow cytometry and fluorescence microscopy. According to surface membrane marker analysis three disti nct immunophenotypic subgroups of B-CLL were identified: group I (SIg, MR+, CD5+, B Ag+, T Ag-; 19 cases), group II (SIg+, MR+, CD5+, B Ag, T Ag+; 3 cases), group III (SIg-, MR+, CD5+, B Ag+, T Ag-; 4 cases). Cells from all patients were positive for the CD19 antigen and at lea st one of other B Cell antigens. Cells from all patients expressed als o CD5 and HLA-DR antigens and formed mouse rosettes (MR). Great hetero geneity was found in the membrane and cytoplasmic marking by anti-CD22 MoAb. In four of 23 patients tested, CD22 antigen was expressed in th e cytoplasm of CLL cells while it was absent on surface membrane of th ese cells This finding was discussed from the point of certain cell he terogeneity in the followed B-CLL cases. Cytoplasmic immunoglobulin (C yIg) detection showed to be very important especially in group III of followed B-CLL cases with undetectable surface immunoglobulins (SIg). Cytoplasmic antigens and immunoglobulin determinations are useful in p henotyping every B-CLL patient, as well as in the immunological study of different maturation stages of B lymphocytes.