THE RELATIONSHIP BETWEEN ARGYROPHILIC PROTEINS AND SOME IMMUNOPHENOTYPIC MARKERS IN ACUTE-LEUKEMIA CELLS

This study reports the immunophenotypic features of a series of 62 sel ected acute leukemia patients with increased incidence of argyrophilic proteins (AgNORs) at the time of initial diagnosis. Peripheral blood and bone marrow cells of patients with TALL, B-precursor ALL and AML w ere studied. The method of silver staining was used to determine the n umber of AgNORs per cell. Cell surface markers were detected by a stan dard immunofluorescence assay. To demonstrate the relationship between AgNOR quantity and cell proliferation, the expression of activation a nd proliferation antigens CD38 and CD71 was investigated. To character ize the immunophenotype and the discrete stages of differentiation, th e wide panel of antibodies against lymphoid, myeloid and non-lineage s pecific antigens was used. The number of AgNORs at diagnosis ranged fr om 3.05 to 6.70. Immunophenotypic analysis showed a variation in CD38 and CD71 expression among different leukemia subtypes. CD71 antigen wa s more expressed in TALL than in B-precursor ALL or in AML. Notable wa s the relationship between increased AgNOR quantity and antigens that characterize the immaturity of leukemic cells. The association with CD 7, CD2, CD5 (without CD3 membrane expression) and CD34 in T blasts was evident. High positivity of CD19, CD10, CD34 and HLA-DR in relation t o the increased amount of AgNORs in B-lineage ALL was observed. The va st majority of AML patients with high numbers of AgNORs simultaneously expressed CD13, CD33, CD34 and HLA-DR. One third of AML cases coexpre ssed T cell marker CD7. In conclusion, the presence of increased numbe rs of AgNORs at diagnosis might reflect the dependence on an early sta ge of leukemia cell differentiation.