FMC7 antigen expression on normal and malignant B-cells can be predicted by expression of CD20.
Most antibody panels proposed for flow cytometric immunophenotyping of non-Hodgkin's lymphomas and chronic lymphoid leukemias include anti-CD20 and FMC7 antibodies. As in our experience, reactivity of B-cells with these antibodies seemed to be correlated, we evaluated whether the simultaneous use of anti-CD20 and FMC7 antibodies is justified. Using flow cytometry, we measured the binding of these 2 antibodies to the B-cells of 67 bone marrow aspirates, 31 lymph node biopsies, 18 peripheral blood specimens, and 12 tissue samples from other locations. The diagnoses included 50 cases without overt abnormalities, 5 reactive lymphadenopathies, 56 lymphomas and chronic lymphoid neoplasias, and 17 cases with other malignancies. Although CD20 expression was consistently higher, we observed a significant and strong correlation between CD20 and FMC7 antigen expression on B-lymphocytes, irrespective of the nature of the sample or disease (r=0.910; P < 0.001). Moreover, FMC7 antigen expression on B-cells could be predicted by CD20 expression with a sensitivity of 96%, a specificity of 94% and an efficiency of 96%. Our results show that although differing in intensity, expression of CD20 on B-cells closely parallels that of FMC7 antigen. We, therefore, conclude that little additional information is revealed by using FMC7 in immunophenotyping of non-Hodgkin's lymphomas or chronic lymphoid leukemias if intensity of CD20 expression is taken into consideration.
Hübl
W
W
Department of Pathology, University of Florida College of Medicine, and Shands Hospital, Gainesville 32610-0275, USA.
Iturraspe
J
J
Braylan
R C
RC
D000911:Antibodies, Monoclonal / Q000276:immunology; D018951:Antigens, CD20 / Q000096:biosynthesis* / Q000276:immunology; D000951:Antigens, Neoplasm / Q000096:biosynthesis* / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology*; D006023:Glycoproteins / Q000096:biosynthesis*; D006801:Humans; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000097:blood / Q000276:immunology*; D008228:Lymphoma, Non-Hodgkin / Q000097:blood / Q000276:immunology*; D011237:Predictive Value of Tests
D000911:Antibodies, Monoclonal; D018951:Antigens, CD20; D000951:Antigens, Neoplasm; D006023:Glycoproteins; C112523:MS4A1 protein, human