Botulinum Antitoxin Quiz

The correct answer is Equine Botulism Antitoxin, which is a heptavalent antitoxin with heterogenous antibodies that cover botulism types A,B,C,D,E, F and G. Although the vast majority of infant botulism is caused by types A and B, rare cases of type C and E have been reported for infant botulism (PMC4261338). Baby big only covers types A and B. The other answers actually tell you what they cover in the name. Toxoid vaccines for botulinum toxin are no longer used.

Measured in median intraperitoneal mouse LD50, H-BAT is by far the most potent. A single vial ranges from 10^6-10^7 MIPLD50’s per IU contained within the vial. BabyBig falls in second with 10^5 for A and B, and the others are 10^3-10^4 per IU. Of note, BabyBIG seems to be preferred by pediatric intensivists because the majority of cases are due to serotypes A and B and there is decreased risk of hypersensitivity reaction or serum sickness.

The first answer is obviously BS, but might not be a bad idea for the future. The second answer must be incorrect because bacteria cannot fold antibodies unless, theoretically, someone where to install a gene network which allowed for a modified a protein folding pathway. PBT is no longer used for creation of BT antitoxins. Currently BabyBIG is manufactured from pooled serum sample of donors who have been innoculated with toxoid from types A and B.

Formaldehyde is highly reactive leading to amino acid cross-linking within the toxic enzyme. This inactivates the toxic function of the protein, but still preserving overall protein structure. After formaldehyde cross-linking, there should still be enough topology that is homologous to the wild-type protein, allowing for an effective immunogenic response. All of the other answers could theoretically work, but not are what has been proven in practice.

PEG-Linked Human IG (investigational) > Human IG > Animal IG > FAb(2) > FAb; note that you get FAb with papain digestion and FAb(2) with pepsin digestion. BabyBIG’s half life is about 28 days, and a single infusion most likely will bind to and neutralize all subsequent toxin for that time.

The next move that will most likely benefit the patient is to re-dose the H-BAT. The heptavalent equine immunoglubulin covers A-G, however there is an H type and H-BAT may have decreased MIPLD50 for the “untypeable toxins”.

Antitoxin will likely not cross the cellular membrane. But it likely can cross through to the ECF as well.

Early administration of Botulinum antitoxin is associated with decreased mortality and decreased days of ventilatory dependence. Delayed neuropsychiatric effects are more associated with Carbon Monoxide (CO) poisoning.