| ObjectiveA number of monoclonal antibodies against leukocyte surface differentiation antigens became available in the early 1980s and the number has been increasing quite rapiadly since then. Precursor cells from different lineages express different subsets of surface molecules, many of which are now difined by Cluster of Differentiation(CD) antigens. CD antigens associated with the plasma membranes of leukocytes may be molecules involved in a variety of functions. Leukemias are characterized by a maturation arrest of the malignant clone, with accumulation of immature cells and inhibition of normal hematopoiesis. For lymphocytic leukemia, immunophenotyping plays a central role in defining clinically relevant subsets. The WHO classification states that acute lymphocytic leukemia (ALL) should be classified by the pattern of reactivity of cell to a panel of lineage - associated antibodies and , where possible , genetic abnormalities. The expression of CD antigens on leukocytes is currently determined by flow cytimertry, which is expensive and labor - intensive, requiring 5 - 20ul quantities of fluores-cently labeled antibodies and allowing concurrent analysis for a limited number of CD antigens, usually three to four. From clinical point of view, an efficient method is required for analysis of a large number of samples in a single experiment. We developed the cell microarray, which enables concurrent determination of 21 CD antigens on leuko-cytes or leukemia cells in a single analysis for immunophenotyping of leukemias,described here.MethodsAntibodies of CD2, CD3 , CD4, CD5, CD7, CD8, CD9, CD10, GD11a, CD13, CD14, CD15, CD19, CD20, CD22, CD30, CD33, CD34, CD44, CD44v6, CD45, CD45RA, CD66e, CD68, HLA - DR were spotted on the aldehyde slide . A suspension of cells is applied to the array, and cells onlybind to antibody dots for which they express the corresponding CD antigen. The cell microarrys were dyed with Trypan Blue , Wrights , three colors fluorescence and Papanicolaou strained.ResultsLeukocyte samples from 20 ALL patients showed predictably and distinctly different dot patterns from samples from 20 normal subjects. It is monoclonal malignant hyperplasia that is the main character of a-cute leukemia. Only one antibody can capture malignant leukemic cells,just as acute leukemias characterized by a maturation arrest of the malignant clone. The arrays showed in T - ALL which were taken from 8 patients were three CD3 + , two CD4 + , two CD7 + and one CDS +. Among 12 B - ALL patients there were two CD10 + , five CD19 + , two CD20 + and two HLA - DR + . Anti - CD3 and anti -CD4 dots of one patient showed significant difference using optics microscope observed. These cells were characterized by regular shape with dense chromatin on the anti - CD3. And the cells were irregular shapes, different sizes and loose chromatins on the anti - CD4. The same situations appeared in other lukemia patients.ConclusionBiochip is a general term for miniaturised components used to denote the combination of microfabrication technology and life sciences . Microarrays sport vast numbers of selected molecules, e. g. DNA, which are spotted or printed onto a glass or plormer substrate. The DNA microarrays become important for the identification of biochemical targets that are involved in disease processes. But the gene mi-croarray has been limited to use in clinical laboratory because of its high cost and special equipments required. As we known , there are some peculiar proteins in malignant tumor cells due to the gene mutation. And such proteins can appear on different parts of a cell. So cy-tological examination is much necessary in diagnosis and therapy of malignant tumor. At present, immunohistochemistry is routine procedure for histopathological examination of tumors. Fluorescence in situ hybridization (FISH) , which is applicable to interphase cells and met-aphase spreads, is widely used in both research and clinical analyses. But when many samples have to be examined , such a one - by - one proced...
|
PDF Full Text Request