RESUMO
PROBLEM: The structure and protective activity of antibodies against tetanus (anti-T) and diphtheria (anti-D), produced during human pregnancy and transferred to new-born, was studied. METHOD: Antibody levels were measured by ELISA in non-pregnant women (control group), primiparae, and multiparae, and in their children. The proportion of symmetric and asymmetric IgG molecules was determined and their respective protective capacity evaluated. RESULTS: The quantity of asymmetric anti-T and anti-D antibodies in mothers at the time of delivery was roughly four- and three-fold that of the control group, respectively, dropping significantly 1 month later. A similar proportion of these antibodies was observed in the new-born. The lower neutralizing capacity of asymmetric molecules was demonstrated in vivo. CONCLUSION: Results show that during pregnancy there is a modulation of the immune response with an increase in the production of asymmetric molecules of lower protective capacity.
Assuntos
Anticorpos Antibacterianos/biossíntese , Anticorpos Antibacterianos/química , Difteria/prevenção & controle , Imunidade Materno-Adquirida/imunologia , Recém-Nascido/imunologia , Tétano/prevenção & controle , Adolescente , Adulto , Animais , Anticorpos Antibacterianos/uso terapêutico , Difteria/imunologia , Vacina contra Difteria, Tétano e Coqueluche/imunologia , Feminino , Cobaias , Humanos , Fragmentos Fab das Imunoglobulinas/biossíntese , Fragmentos Fab das Imunoglobulinas/química , Fragmentos Fab das Imunoglobulinas/uso terapêutico , Imunoglobulina G/biossíntese , Imunoglobulina G/química , Imunoglobulina G/uso terapêutico , Camundongos , Gravidez , Relação Estrutura-Atividade , Tétano/imunologia , Toxoide Tetânico/imunologiaRESUMO
The immunogenicity of the diphtheria component of 73 commercial vaccines from five different manufacturers was tested by the toxin neutralization test (TNT) and the enzyme-linked immunosorbent assay (ELISA) developed in our laboratory. A comparison of the antibody levels measured by both assays showed a very good correlation (r = 0.95, p < 0.001). The results suggest that the proposed ELISA is a reliable, simple and economical alternative to the TNT in guinea pigs. Also, the ELISA was found to measure IgG antibody levels as low as 5.5 x 10(-5) IU ml-1. To evaluate the possibility of accelerating the active immunization during the activity test of vaccines, an alternative schedule using one single human dose was assayed. A very good correlation was observed between the IgG antibody response obtained with this schedule and with the traditional programme. Therefore, the cost and the time required to perform the activity test may be considerably reduced when both the rapid immunization schedule and the ELISA are used.
Assuntos
Anticorpos Antibacterianos/sangue , Toxoide Diftérico/imunologia , Animais , Toxoide Diftérico/farmacologia , Ensaio de Imunoadsorção Enzimática , Feminino , Cobaias , Esquemas de Imunização , Imunoglobulina G/sangue , Masculino , Testes de Neutralização , Reprodutibilidade dos TestesRESUMO
An enzyme-linked immunosorbent assay (ELISA) has been developed to measure anti-tetanus toxoid antibody levels in immunized guinea-pig sera as a useful alternative to the currently used toxin neutralization test (TNT) in determining the activity of the tetanus toxoid in vaccines. The ELISA was found to measure antibody levels as low as 5.8 x 10(-5) IU/ml. Furthermore, a comparison of the results from ELISA and TNT involving 132 different commercial vaccines showed a very good correlation (r = 0.94, p < 0.001) between antibody levels measured by both methods. The results suggest that the proposed ELISA is a reliable, simple and economical alternative to the TNT in mice for assessing the activity of tetanus toxoids in vaccines.