Abbas: Cellular and Molecular Immunology, 9th Edition

Abbas: Cellular and Molecular Immunology, 9th Edition Antibodies and Antigens Test Bank Matching Questions 1-5 Match each of the descriptions in questions 1-5 with the correct lettered antibody isotype (A-E). (Answers may be used more than once.) A. IgA B. IgD C. IgE D. IgG E. IgM 1. The secreted form of this isotype forms pentamers around a J chain ANS: E. IgM is secreted as a J chain–linked pentamer. 2. The most abundant Ig isotype in the blood ANS: D. The blood IgG concentration is about 3.5mg/ml and includes four subtypes (IgG1 to IgG4). 3. The isotype only found in membrane-bound form on naive B cells ANS: B. Very little IgD is secreted, and in membrane form is only on the surface of naive B cells. Its function is not well understood. 4. The isotype found predominantly in mucosal secretions ANS: A. IgA accounts for almost two thirds of the 3 g of antibody produced each day by an adult, most of which is produced in the gastrointestinal associated lymphoid tissues and secreted into the gut lumen. 5. The isotype most closely associated with immediate hypersensitivity (allergic) disease