RESUMEN
An enzyme-linked immunosorbent assay was developed for measuring immunoglobulin G anti-diphtheric toxin antibodies in human serum. The assay was done in plastic plates coated with purified diphtheric toxoid. Since a straight-line relationship was found between logs of extinction values and of antibody concentrations, with a very constant slope, serum titers could be expressed as log10 of the serum dilution corresponding to a definite optical density, such as 0.5. The assay furnished highly reproducible titers on a continuous range, with coefficients of variation less than 10%. Only one or two serum dilutions were usually sufficient for serum titration. To establish correspondence of the enzyme-linked immunosorbent assay titers with biologically determined antitoxin international units, a regression equation was fitted between the respective values for 112 serum samples titrated in both tests. The enzyme-linked immunosorbent assay titer of 2.38 corresponded to an antitoxin titer of 0.01 U, which is considered as the minimal protective level. Simple to perform, economical, and precise, the immunoenzymatic assay seems to be a very practical procedure for seroepidemiological purposes.
Asunto(s)
Anticuerpos Antibacterianos/análisis , Toxina Diftérica/inmunología , Ensayo de Inmunoadsorción Enzimática , Técnicas para Inmunoenzimas , Niño , Pruebas de Hemaglutinación , HumanosRESUMEN
Foi estudado o comportamento da cinetica de anticorpogenese em cobaias inoculadas com uma dose de toxoide difterico precipitado pelo alumen. Paralelamente, foi estudada a dinamica da imunidade passiva naturalmente transmitida aos filhotes. Em cobaias vacinadas com uma dose de antigeno, foi verificado que a sintese de antitoxina difterica persiste, em titulos detectaveis, ate 36 meses apos. Os anticorpos transferidos, passivamente, da mae vacinada para os filhotes atingiram nestes,concentracoes plasmaticas superiores, sendo que a imunidade perdurou em titulos detectaveis ate cerca de tres meses de idade dos mesmos