Antigen details
CD45RA /CD4 is intended for use in flow cytometry. Measurement of the relative as well as the absolute number of CD4- positive cells in peripheral blood is critically important in assessing the immunological status of a patient. The CD4 antigen is is present on most T helper cells and normal thymocytes. The cytoplasmic portion of CD4 is associated with p56lck tyrosine kinase. CD45 Leukocyte Common Antigen (LCA) belongs to the family of at least four isoforms of membrane glycoproteins (220, 205, 190, 180 kDa) expressed on hematopoietic cell lines but absent on non-hematopoietic cell lines, normal and malignant, non-hematopoietic tissues. The intracellular portion of these molecules have protein phosphatase activity and are involved in regulation of transmembrane signals. CD45RA is expressed on approximately 75% of CD8 lymphocytes and 50% of CD4 lymphocytes, all B cells and NK Cells. CD45RA antigen is expressed on naive T lymphocytes, antigen density decreases upon in vitro activation. A decrease antigen density has been demonstrated for CD4+CD45RA+subset with active multiple sclerosis.
