Late cutaneous reactions due to IgE antibodies

IgE antibodies can produce a late inflammatory response 6--12 h after allergen challenge which is characterized by diffuse edema, erythema, pruritus, tenderness and heat. That IgE is involved in inducing the late reaction was shown by the abolition of both immediate and late responses by passive transfer tests: (1) by heating atopic serum at 56 degrees C for 4 h; (2) by removing IgE from the atopic serum by a solid phase anti-IgE immunoabsorbent, and (3) by competitively inhibiting the binding of IgE antibodies to cells by an IgE myeloma protein. Also, both responses were induced by affinity chromatography-purified IgE antibody followed by antigenic challenge. Very similar lesions could be induced by intradermal injection of Compound 48/80. The late phase is characterized by edema and a mixed cellular infiltration, predominantly lymphocytic but also containing eosinophils, neutrophils and basophils. Direct immunofluorescent staining did not show deposition of immunoglobulins or complement components, except IgM in two of 15 and C3 in one of 15 patients, respectively.