Acute Leukemias: Immunophenotypic Differences between Blast Cells and Their Nonneoplastic Analogues in Bone Marrow

Flow cytometry immunophenotyping of bone marrow tumor blasts is one of the principal methods used for acute leukemia (AL) diagnosing. Normal lymphopoietic and myelopoietic progenitors have very similar antigenic profile with leukemic cells, thus, making the AL diagnosing more difficult. Genetic disorders resulting in formation of a tumor clone contribute to development of an immunophenotype that differs from normal cells. Aberrant expression of markers detected in AL blast cells alone forms a so-called leukemia-associated immunophenotype. The leukemia-associated immunophenotype detection by multicolor flow cytometry permits distinguishing between normal and neoplastic cells. This requires simultaneous assessment of many markers on the same cells, which is possible only if multicolor flow cytometry with well-designed and well-established antibodies panels is used. Moreover, correct interpretation of the cell population location on dot plot requires adequate cytometer setup, standardized sample preparation and enough experienced personnel. That is why correct immunophenotyping is often possible only in large laboratories performing reference immunophenotyping within the frames of multicenter trials