Snake antivenoms from hyperimmunized horses: comparison of the antivenom activity and biological properties of their whole IgG and F(ab’)2 fragments.

The research investigates the comparative anti-venom activity and biological factors of immunoglobulin G (IgG) and F(ab’)2 fragments, which were produced using horse plasma containing specific antibodies against Brazilian Bothrops or Crotalus venoms.

Methodology

• The researchers utilized horse plasma that was rich in specific antibodies against either Brazilian Bothrops or Crotalus venoms. From this plasma, they prepared both IgG and F(ab’)2 fragments.
• These preparations were free of high levels of contamination from non-immunoglobulin proteins.
• In vitro tests were conducted to evaluate if these preparations could combine with their corresponding antigens. They examined whether immune complexes were formed at antigen excess, antibody excess, or at equivalence, and whether either the classic or alternative pathways activated the complement (C) system.

Results

• The results indicated that the IgG preparation was more successful in neutralizing lethal factors present in Bothrops or Crotalus venom compared to the F(ab’)2 fragments.
• However, when dealing with the Bothrops venom’s haemorrhagic and defibrinating activities, IgG and F(ab’)2 were almost equally efficient at neutralizing these elements.
• The caprylic acid precipitation method, used to purify IgG, was found to yield richer anti-venoms regarding the specific antibodies’ presence compared to the method usually employed to prepare antivenoms containing F(ab’)2. This method led to a higher specific activity, recovery, and yield.

Conclusion

• The research provides valuable insights into the efficiency and biological properties of antivenoms derived from IgG and F(ab’)2, that can potentially inform the development of more effective and potent antivenom treatments.