CD33

This antibody reacts with the CD33-antigen, which is expressed on human myelomonocytic cells; monocytes, granulocytes (weakly), myeloid progenitors and mast cells. The monoclonal antibody reacts in the bone marrow from myeloblasts up to myelocytes. CD33-antigen is found on CFU-GEMM, CFU-GM, CFU-G, CFU-M and with erythroid CFU-E but not on earlier precursors. CD33 does not react with normal human peripheral B-cells, T-cells and platelets. CD33 reacts weakly with blast cells in 70% of patients with Acute Myeloid Leukaemia (AML) and in 30% of adult patients with Acute Lymphoblastic Leukaemia (ALL).