Co-Authors:
Steinitz, M., Department of Pathology, Hebrew University, Hadassah Medical School, Post Office Box 1172 Jerusalem, Israel
Tamir, S., Department of Pathology, Hebrew University, Hadassah Medical School, Post Office Box 1172 Jerusalem, Israel
Sela, S.B., Department of Pathology, Hebrew University, Hadassah Medical School, Post Office Box 1172 Jerusalem, Israel
Rosenmann, E., Department of Pathology, Hebrew University, Hadassah Medical School, Post Office Box 1172 Jerusalem, Israel
Abstract:
Polyclonal anti-human IgE reagents were earlier shown to contain variable amounts of non-isotype-specific antibodies depending on the strategy used for their preparation. The presence of these antibodies in two commercial anti-IgE reagents was demonstrated in this work by (a) their binding to human Ig-surface-positive lymphoblastoid cells specifically selected by one of the polyclonal anti-human IgE reagents and (b) their binding to the non-IgE immunoglobulins secreted by those lymphoblastoid cells. Peripheral blood B lymphocytes from two normal and two atopic patients were immortalized with Epstein-Barr virus (EBV) and then selected for cells that rosette with anti-IgE-coated erythrocytes. Selection was repeated four times and cells were then cloned. The cloned cells formed rosettes and their supernatants agglutinated erythrocytes coated with rabbit anti-IgE. The immunoglobulins of these clones were positive in an ELISA for IgE, using two different polyclonal anti-human IgE reagents. They were shown, however, to be 19 S IgMs. This discrepancy was due apparently to substantial contamination of anti-non-IgE-isotype-specific antibodies in the polyclonal anti-IgE reagents used both in the selection of cells and in the ELISA. The human monoclonal B-cell lines which were applied here as targets amplified the non-IgE-isotype specific antibody contamination present in the polyclonal anti-human IgE reagents. Because of the normally very low frequency of IgE-positive cells, the use of polyclonal anti-IgE reagents to detect these cells has to be carefully evaluated. © 1988.