Immunophenotyping Of Acute Leukemias Using A Cell Microarray

ObjectiveLeukemias are characterized by a maturation arrest of the malignant clone, with accumulation of immature cells and inhibition of normal hema-topoiesis . The main types of leukemias are ALL derived from immature T - or B - lymphocytes, AML from immature myeloid cells , Accurate diagnosis of hematological malignancies enables selection of the most effective treatment protocol. Current diagnosis of acute leukemias is based on the morphology and cytochemistry of the blast cells according to the WHO classification released recently and the FAB classification used previously, usually supplemented with karyotyping and limited immunophenotyping . Flow cytometric analysis of leukemias with panels of monoclonal antibodies now provides 90% accuracy for distinguishing acute leukemias of myeloid and lymphoid origin. The expression of CD antigens on leukocytes is currently determined by flow cytometry , which is expensive and labor - intensive, requiring 5 -20μl quantities of fluorescently labeled antibodies and allowing concurrent analysis for a limited number of CD antigens, usually three to four. We have developed a rapid , simple procedure , which enables concurrent determination of more CD antigens on leukocytes or leukemia cells in a single analysis for immunophenotyping of leukemia . A suspension of cells is applied to the array and cells only bind to antibody dots for which they express the corresponding; CD antigen. The microarray enables extensive immunophenotyping ,and the intact cells captured on anti-body dots can be further characterized .MethodsAntibodies of CD1, CD2, CD3, CD4, CD5, CD7, CD10, CD11 , CD13, CD14,CD15, CD19, CD20, CD22, CD23, CD30, CD33, CD34, CD38, CD41, CD45RO, CD79, HLA - DR were spotted on the aldehyde slide . A suspension of cells is applied to the array and cells only bind to antibody dots for which they express the corresponding CD antigen. The cell microarrays were dyed with Wrights.Results30 acute leukemia patients were classified according to FAB -types,25 cases of AML,5 cases of ALL. The arrays showed in AML which were taken from 25 cases almost expressed myeloid antigens:CD 13, CD15,CD33. However,M4, M5 expressed CD14. M3 didn't express HLA - DR . 5cases of ALL there were 2 cases B - ALL:CD10,CD19;3 cases T - ALL: CD5,CD7.ConclusionPrecursor cells from different lineages express different subsets of surface molecules ,many of which are now difined by Cluster of Differentiation antigens. The cell microarray lies in according different cell membrane antigens to identify and distinguish the cells. These haematological malignancies arise from precursor cells of T - or B - lymphocytic , or myeloid lineages of hematopoiesis . The dot patterns obtained from patients are distinct from those of peripheral blood leukocytes from subjects. The cell microarray can be analysed by the scanner to realize high - throughput analysis . The result can be directly observed by means of the common optics microscope. Cell microarray is rapid , simple procedure and low cost and this technology becomes to be widely used. The microarray now contains more CD antibodies and a scanner for imaging dot patterns provide an extensive...