Aberrant markers expression in T- and B-lymphoid and myeloid leukemia cells of different differentiation stages.

The aim of the study was to ascertain if in T acute lymphoblastic leukemia (T-ALL), B acute lymphoblastic leukemia (B-ALL) and acute myeloid leukemia (AML) of different differentiation stages the coexistence of aberrant markers correlate with the degree of leukemic blasts maturation. We evaluated the results of surface and intracellular markers in 42 T-ALL, 86 B-ALL and 71 AML cases. A large panel of monoclonal antibodies (MoAbs) against T-cell, B-cell, myeloid cell and non-lineage specific structures has been used. Patients had dual-color flow cytometric immunophenotyping performed by FACStar flow cytometer. The correct immunological diagnosis of followed new cases before any treatment has been performed and simultaneously the presence of atypical/aberrant phenotypes has been studied and correlated with leukemia cells differentiation stage. A great deal of T-ALL and AML, in opposite to B-ALL cases, revealed a high proportion of atypical phenotypes (55, 75 and 36%, respectively), which are absent in nonleukemic cells. We found out that these atypical phenotypes were present in T-ALL, AML (not clearly in B-ALL) through all differentiation stages and so we obtained an evidence that they might represent an abnormal/atypical rather than an immature phenotype, as it was postulated till now by several authors.