Horse IgG isotypes and cross-neutralization of two snake antivenoms produced in Brazil and Costa Rica.

The research study compares the efficacy and specifics of two snake antivenoms from Brazil and Costa Rica, investigating their capability to neutralize certain venom toxins. The results show both antivenoms have the same IgG profile, with the IgG(T) isotype contributing significantly to their neutralizing properties.

Specificity, ELISA titers and IgG subclass content of Antivenoms

• The study geared towards comparing the characteristic features of the polyvalent antivenom produced by the Instituto Clodomiro Picado in Costa Rica and the bothropic antivenom from the Instituto Butantan in Brazil.
• The polyvalent antivenom targets venom from Bothrops asper, Crotalus durissus durissus, and Lachesis muta stenophrys snakes, while the bothropic antivenom targets venom from a different range of Bothrops species: B. jararaca, B. jararacussu, B. moojeni, B. neuwiedi, and B. alternatus.
• Both antivenoms displayed the capability to recognize venom from B. asper and B. jararaca through an immunoblotting technique, and similar antibody titers were recorded when they were assayed through ELISA.
• The research also revealed the distribution order of IgG subclasses in both antivenoms, with IgG(T) being the highest, followed by IgGa, IgGb, and finally IgGc.

Role of IgG(T) and IgGa in neutralizing venom toxic activities

• The study focused on the specific role of IgG(T) and IgGa subclasses in neutralizing venom039s toxic activities.
• The IgG subclasses isolated from both antivenoms using affinity chromatography were tested for their ability to neutralize lethal, hemorrhagic, coagulant, and phospholipase A2 activities of the homologous venom.
• The results point to IgG(T) as the major isotype responsible for neutralizing all the tested venom activities, followed by IgGa.

Cross neutralization and effectiveness of Antivenoms

• The research also explored the cross neutralization capabilities of these antivenoms, assessing their ability to neutralize the lethal effects induced by both homologous (same species) and heterologous (different species) venoms in mice.
• It found that both the antivenoms from Instituto Butantan and Instituto Clodomiro Picado share the same profile of IgG isotypes contributing to their neutralizing capacity. Their efficacy is primarily due to the presence of the IgG(T) isotype.
• However, the bothropic antivenom from Instituto Butantan was found to be more effective in neutralizing lethality in mice induced by both homologous and heterologous venoms.