Quantitation by enzyme-immunoassay of antibodies against Bothrops myotoxins in four commercially-available antivenoms

Abstract

An enzyme-immunoassay (EIA) for the quantitation of antibodies against myotoxins present in the venoms of Bothrops asper (Costa Rica), B. atrox (Colombia) and B. moojeni (Brazil), was developed. This EIA was utilized for the evaluation of four antivenoms produced in Mexico (Laboratorios Myn; MYN), Costa Rica (Instituto Clodomiro Picado; ICP), Colombia (Instituto Nacional de Salud; INS) and Brazil (Instituto Butantan; IB). Antivenoms ICP, IB and INS showed a higher titer of antibodies against the three myotoxins tested, with only slight differences between them, depending on the antigen utilized. In contrast, MYN antivenom had very low levels of antibodies to the three myotoxins. Seventeen batches of ICP antivenom were analyzed by EIA, using B. asper myotoxin II as antigen. Although all batches had high anti-myotoxin titers, these varied significantly. Batches produced after 1988 had, in general, higher titers than older (1986-1987) ones. Antivenom stored for one year at 37 degrees C had a slight, but significant (P less than 0.002) decrease of anti-myotoxin activity, compared to antivenom stored at 4 degrees C or 23 degrees C. No correlation was found between anti-myotoxin concentration and lethality-neutralizing ability of the ICP antivenom.