Immunology of the monobactam aztreonam.
To assess the immunological cross-reactivity of the monobactam antibiotic aztreonam (AZ), rabbits were immunized with protein conjugates of benzylpenicillin, cephalothin (CEPH), and AZ. The resulting antibenzylpenicilloyl (BPO) and anti-CEPH rabbit antibodies showed negligible cross-reactivity with AZ conjugated to human serum albumin (AZ-HSA), whereas anti-AZ showed negligible cross-reactivity with BPO-HSA and CEPH-HSA. Unlike benzylpenicillin and CEPH, unconjugated AZ was as effective as AZ conjugated to epsilon aminocaproic acid (AZ-EACA) in inhibiting the binding of homologous antibody. Studies with various analogs of AZ confirmed that immunoglobulin G (IgG) anti-AZ was entirely side-chain specific. The inhibition of the binding of human IgE anti-penicilloyl to BPO-HSA was studied in the presence of AZ-EACA, BPO-formyl lysine, and CEPH-EACA. Whereas CEPH-EACA displayed 3% cross-reactivity with BPO-lysine, AZ-EACA showed little or no cross-reactivity (much less than 0.9%). To assess the immunogenicity of AZ in humans, IgE and IgG antibodies were measured in sera from 36 healthy male volunteers receiving 0.5 or 1 g intravenously or intramuscularly every 8 h for 7 days. None of the subjects had detectable preexisting IgE reactive with AZ or demonstrated an IgE response to antibiotic administration. Four subjects gave evidence for naturally occurring IgG cross-reactive with AZ, but only one subject demonstrated a rise in IgG levels after exposure to AZ. This anti-AZ IgG did not cross-react with BPO or CEPH conjugates of bovine thyroglobulin and was completely side-chain specific. These studies suggest that AZ displays very low immunological cross-reactivity with other beta-lactam antibiotics and may be only weakly immunogenic in humans.
D000818:Animals; D000900:Anti-Bacterial Agents / Q000276:immunology*; D001398:Aztreonam; D002512:Cephalothin / Q000276:immunology; D003429:Cross Reactions; D006801:Humans; D007106:Immune Sera / Q000276:immunology; D007073:Immunoglobulin E / Q000276:immunology; D007074:Immunoglobulin G / Q000276:immunology; D010400:Penicillin G / Q000276:immunology; D011817:Rabbits
D000900:Anti-Bacterial Agents; D007106:Immune Sera; D007074:Immunoglobulin G; D007073:Immunoglobulin E; D001398:Aztreonam; D010400:Penicillin G; D002512:Cephalothin