Anti-diphtheria toxin antibody (Anti-DT)

Anti-diphtheria toxin antibodies are protective immunoglobulins, primarily of the IgG class, generated through active immunization with diphtheria toxoid or natural infection with Corynebacterium diphtheriae (CDC, 2024). Their primary biological role is to neutralize the diphtheria toxin by sterically hindering its binding to the heparin-binding EGF-like growth factor (HB-EGF) receptor or interfering with its endosomal translocation (StatPearls, 2023). In the context of modern pharmacology, these pre-existing antibodies represent a significant challenge for the efficacy of diphtheria toxin-based therapeutics, such as tagraxofusp and denileukin diftitox, as they can recognize the toxin-derived components and clear the drug from circulation or block its entry into target cells (FDA, 2018). Conversely, maintaining adequate titers of these antibodies is the cornerstone of public health efforts to prevent diphtheria infection. Monitoring these antibodies serves as a critical biomarker for vaccine efficacy and a predictive factor for the safety and performance of recombinant proteins that utilize diphtheria toxin fragments (PubMed, 2021).

Other names

Diphtheria antitoxinAnti-diphtheria toxin IgGDiphtheria toxin antibodiesVaccine-induced diphtheria antibodiesAnti-DT IgG

Neutralization of diphtheria toxin-based agents through high-affinity binding to the B-subunit (receptor-binding domain) or A-subunit (catalytic domain), preventing cellular internalization and subsequent inhibition of protein synthesis.