Beta lactam hypersensitivities

Background Allergic reactions to drugs are often unpredictable and can lead to serious side effects such as anaphylactic shock. According to the hapten hypothesis, any drug with a molecular weight lower than 1000 daltons cannot induce an immune response by itself and must be bound to a protein. Antigen presenting cells, such as dendritic cells (DC), internalize hapten-protein conjugates and digest them into peptides bound with the drug. The latter are then presented on HLA molecules to drug-specific T cells inducing specific-drug immune response. Knowing that drugs provoke IgE mediated hypersensitivity reactions in treated patients, the CD4+ T-cell response to benzylpenicillin (BP) was investigated. The objectives of this study were to evaluate the frequency of naïve CD4+ T cells specific to BP and to identify BP-haptenized peptides responsible for T lymphocyte activation.