Avaliação e correlação de ensaios in vitro e in vivo de antivenenos botrópicos

Abstract

The correlation coefficients between in vivo neutralization of lethal toxicity (ED50), neutralization of the hemolytic activity (PLA²) and levels of antibodies measured by ELISA, was investigated to test the potency of horse anti-bothropic antivenom. Thirty horses were hyperimmunized with Bothrops venoms (B. alternatus, B. jararaca, B. jararacussu, B. neuwiedii and B. moojeni). To set up an indirect ELISA, for neutralization of PLA² activity and for determination of ED50 in . Swiss mice, the whole Bothrops jararaca venom (reference venom for assessing the bothropic antivenom potency in Brazil) was used. The toxic fraction (purihed from B. jararaca venom by Sephadex G-100 chromatography) was also used as antigen for ELISA. All antivenoms analyzed effectively neutralized the lethal activity in the range of 1.6 to 9.6 mg/ml of antivenom. The correlation coefticient between ED50 and ELISA antibody titers against the crude venom and toxic fraction was r=0.45 (P<0.05) and r=0.60 (P<0.0005), respectively. Correlation between ED50 and neutralization of PLA; activity was r=0.46 (P<0.02), and the correlation between ELISA antibody titers and neutralization of PLA² activity was r=0.59 (P<0.001). Thus, the ELISA which · measures only the antibody against the major toxic fraction of the B. jararaca venom should be most suitable for use as an in vitro assay of bothropic antivenom potency.