title: Generalized urticaria to cyclophosphamide: Type I hypersensitivity to an immunosuppressive agent.
abstract: A 6-yr-old white boy, Patient L. B., who was receiving cyclophosphamide (CY) for chemotherapy of a localized undifferentiated small cell sarcoma of the chest wall, developed generalized urticaria on three separate occasions immediately after CY administration. Serum samples were obtained 2 and 5 wk after the patient's last reaction and were examined for reaginic activity to the drug. Homocytotropic antibody activity to CY was found in the 2-wk postreaction sample by Prausnitz-Küstner type passive transfer skin testing to chimpanzees. This homocytotropic antibody was found to be of the IgE type, by means of an in vitro double-antibody coprecipitation assay measuring binding of free 14C-CY by specific immunoglobulin E and G fractions. Sera from 3 CY-treated patients who did not have adverse reactions to the drug and 6 normal, age-matched volunteers were used as control samples for the coprecipitation assay. None of the 3 CY-treated control patients had significant binding of 14C-CY by IgE when compared to normal individuals. However, it was found that all CY-treated patients had significant binding of 14C-CY by their IgG fraction when compared to normal subjects.
mesh_terms: D001666:Binding Sites, Antibody; D002648:Child; D003520:Cyclophosphamide / Q000627:therapeutic use; D004342:Drug Hypersensitivity / Q000276:immunology*; D006801:Humans; D007116:Immunization, Passive; D007070:Immunoglobulin A / Q000032:analysis; D007073:Immunoglobulin E / Q000032:analysis / Q000378:metabolism; D007074:Immunoglobulin G / Q000032:analysis / Q000378:metabolism; D007075:Immunoglobulin M / Q000032:analysis; D008297:Male; D012509:Sarcoma / Q000188:drug therapy; D012882:Skin Tests; D013899:Thoracic Neoplasms / Q000188:drug therapy; D014581:Urticaria / Q000139:chemically induced*
chemical_list: D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D007073:Immunoglobulin E; D003520:Cyclophosphamide