T-cell lineage differentiation antigens and T-cell maturation sequence in the management of T-acute leukemia patients.

The multiparametric flow cytometry analysis was performed for exact definition of membrane and intracellular (cytoplasmic and nuclear) markers of acute leukemia and lymphoma cells of T-phenotype.. The main aim was concerned to more proper T-ALL/T-NHL diagnosis and stage definition and identification of the prognostic factors and the useful markers for the follow-up of T-ALL/T-NHL in remission. New knowledge of the T-cell maturation stages of hematopoietic cells in bone marrow and thymus has been applied, as each T-acute leukemia clone is representative of one blocked stage through maturation. Patients with more favorable prognosis (i.e. those of cortical stage) could have been already differentiated at diagnosis from those, allocated to pro-T stage, with very immature phenotypes and an unfavorable clinical course. These patients had very distinctive immunophenotypes, CD1a and CD8 markers completely negative, CD7 and cytCD3 positive; CD5 was weakly expressed and myeloid markers CD13 and CD33 were coexpressed.