Abstract: Disclosed are gene constructs of anti-IgE antibodies or fragments thereof for therapy for allergic diseases. Upon introduction into suitable host, anti-IgE antibody gene constructs will direct the synthesis of an antibody (or its fragments) capable of binding to free IgE in serum but not binding to IgE bound to the high affinity receptor (Fc&egr;RI), or not binding to IgE bound to both the high affinity receptor and the low affinity receptor (Fc&egr;RII or CD23). The antibody (or fragments) which are synthesized may also inhibit IgE binding to the high affinity receptor or the low affinity receptor, or to both.