NEUTRALIZING POTENCY OF HORSE ANTIBOTHROPIC ANTIVENOM - CORRELATION BETWEEN IN-VIVO AND IN-VITRO METHODS

The correlation coefficients between in vivo neutralization of lethal toxicity (ED50), neutralization of the hemolytic activity (PLA(2)) and levels of antibodies measured by ELISA, was investigated to test the potency of horse anti-bothropic antivenom. Twenty six horses were hype rimmunized with Bothrops venoms (B. alternatus, B, jararaca, B, jarara cussu, B. neuwiedii and B, moojeni). To set up an indirect ELISA, for neutralization of PLA(2) activity and for determination of ED50 in Swi ss mice, the whole Bothrops jararaca venom (reference venom for assess ing the bothropic antivenom potency in Brazil) was used. The toxic fra ction (purified from B, jararaca venom by Sephadex G-100 chromatograph y) was also used as antigen for ELISA, All antivenoms analyzed effecti vely neutralized the lethal activity in the range of 1.6 to 9.6 mg/ml of antivenom. The correlation coefficient between ED50 and ELISA antib ody titers against the crude venom and toxic fraction was r = 0.65 (P < 0.001) and r = 0.85 (P < 0.0001), respectively. Correlation between ED50 and neutralization of PLA(2) activity was r = 0.52 (P < 0.01), an d the correlation between ELISA antibody titers and neutralization of PLA(2) activity was r = 0.58 (P < 0.002), Thus, the ELISA which measur es only the antibody against the major toxic fraction of the B, jarara ca venom should be most suitable for use as an in vitro assay of bothr opic antivenom potency, (C) 1998 Elsevier Science Ltd, All rights rese rved.