ANTIGEN COMPONENTS FOR CORAL ANTIVENOM PREPARATION

Mourão, M.M., Maria, W.S., Velarde, D.T

Divisão de Imunobiológicos, Fundação Ezequiel Dias, FUNED, Belo Horizonte, MG, Brazil.

Objectives: By government regulation the preparation of antivenom against coral snakes has to use for equine hyperimmunization a mixture of Micrurus frontalis and M. corallinus venoms. The aim of this work was to evaluate the most adequate antigen proportion of each venom component to get a most effective antivenom.

Methods: Five group of four equines each were selected and immunized with as follows antigens : Group 1 (G1), 100 % of M. frontalis venom, G2, 75/ 25 % M. frontalis / M. corallinus, G3, 50/ 50 % M. frontalis / M. corallinus, G4, 25/ 75 % M. frontalis / M. corallinus, G5, 100 % M. corallinus. During the first cycle immunization a total 18 mg of venom was used during three weeks : 6 mg in each week using CFA in first, IFA in second and saline in third week. Following cycles of immunization were as conducted the two last weeks above. The horses were bled after ten and twelve days and rested for two weeks prior to re-immunization. The study was done for four cycles. The individual and combined samples were analysed by indirect haemolysis, Elisa and ED-50 in mice.

Results: The M. corallinus venom showed a very low phospholipase activity. The G2 showed the best results in neutralizing  M. frontalis and M. corallinus venoms by Elisa. G2 and G3 demonstrated the highest and similar lethality protection in mice against both M. frontalis and M. corallinus venoms.

Conclusions: For the preparations coral antivenom, antigen proportions of 75/25 or 50/50 % from M. frontalis/ M. corallinus venoms could be used.

Supported by: FAPEMIG, FUNED

CORRESPONDENCE TO:

Velarde, D.T., Divisão de Imunobiológicos, Fundação Ezequiel Dias, Conde Pereira Carneiro 80, 03550-010, Belo Horizonte, MG, Brazil, Email: davtovel@funed.mg.gov.br