Opsonic, cytotoxic, precipitating, blocking of bacterial adherence, and other activities of monoclonal IgE antibody compared with IgA and IgM.

Monoclonal IgE anti-TNP antibodies were compared with monoclonal anti-TNP, IgM and IgA isotypes in different biological reactions. The reaginic activity of IgE antibodies demonstrated in passive cutaneous anaphylaxis reactions and degranulation of mast cells was accompanied by a number of activities known to be associated with other isotypes. The occurrence of relatively high numbers of lymphoid cells and macrophages bearing Fc epsilon receptors suggests a possible role of IgE antibodies in host defence mechanisms acting systematically and/or locally on mucosal surfaces.