ABSTRACT
Isolated circulating immune complexes (CICs) from sera of patients with amoebiasis were characterized to determine Entamoeba histolytica antigens that participate in the disease process. In total, 116 serum samples were collected before starting anti-amoebic therapy, and their CICs were isolated by differential polyethylene glycol precipitation. The presence of amoeba-specific antigens in CICs was detected by antigen capture enzyme-linked immunosorbent assay (ELISA) and by immunoblot assay. Antigen capture ELISA showed significantly higher optical density (p < 0.001) in all patients with amoebiasis than in the normal healthy controls and patients of non-amoebic hepatic disorder. Immunoblot assay detected amoeba-specific CICs in all 18 patients (100%) with confirmed amoebic liver abscess, 28 (80%) of 35 patients with clinically-suspected amoebic liver abscess, and 18 (78.26%) of 23 patients with amoebic colitis. No patients with non-amoebic hepatic disorders and healthy control subjects had any detectable level of amoebic antigens in CICs. Immunoblot assay revealed E. histolytica antigens of relative molecular masses of 35, 56, 70, and 90 kDa present in CICs of 64 of 76 patients with amoebiasis. The 35-kDa polypeptide was observed in 52 patients (81.25%). The results of the study suggest that the 35-kDa polypeptide antigen can be a diagnostic marker in active amoebiasis.
Subject(s)
Adult , Amebiasis/blood , Animals , Antigen-Antibody Complex/blood , Antigens, Protozoan/blood , Dysentery, Amebic/diagnosis , Electrophoresis, Polyacrylamide Gel , Entamoeba histolytica/immunology , Enzyme-Linked Immunosorbent Assay , Female , Humans , Immunoblotting , Liver Abscess, Amebic/diagnosis , Liver Diseases/diagnosis , Male , Chemical Precipitation , Propylene Glycol/immunologyABSTRACT
Foi desenvolvido um teste de ELISA de Captura usando anticorpos policlonais purificados obtidos em coelhos contra tres diferentes cepas axenicas de Entamoeba Histolystica(ICB-CSP and ICB-462 do Brasil e HM1 do Mexico)para deteccao de coproantigenos em amostras de fezes de individuos: a) sintomaticos, b)assintomaticos, c)com outros parasitos intestinais, e d)sadios. Imunoglobina G (IgG) contra E. histolystica foi isolada de imune soro de coelho, em duas etapas: cromatografia de afinidade em uma coluna contendo antigenos de E. histolystica unidos a Sepharose 4B, seguido por outra cromatogradia em Sepharose 4B Proteina A. O teste de ELISA usando anticorpos purificados, foi capaz de detectar ate um so trofozoito por lamina ou 70 ng de proteina de ameba por orificio, apresentando uma sensibilidade de 93 por cento e uma especificidade de 94 por cento. A combinacao do exame microscopico com o metodo ELISA de Captura teve uma concordancia e discordancia de 93,25 por cento e 6,75 por cento, respectivamente. Pode-se concluir que o teste de ELISA de Captura utilizando anticorpo purificado e altamente especifico para a deteccao de coproantigenos de E. histolystica em fezes de pacientes infectados, rapido, facil e mais sensivel que o exame microscopico.
Subject(s)
Humans , Animals , Amebiasis/diagnosis , Enzyme-Linked Immunosorbent Assay , Feces/parasitology , Amebiasis/immunology , Amebiasis/blood , Antigens, Protozoan/isolation & purification , Culture Media , Entamoeba histolytica/immunologyABSTRACT
Con el fin de determinar si existe elevación de la IgE sérica en niños con amibiasis invasora en comparación con un grupo control, se realizó un estudio prospectivo, observacional y descriptivo, con 20 pacientes del grupo problema y 21 del grupo control, en los que, descartando otro tipo de causas de elevación de la IgE, se determinó este anticuerpo en suero y se comparó con los niveles medios normales reportados para población mexicana y extranjera. Se encontró una notable elevación de la IgE sérica en ambos grupos estudiados, sin diferencias significativas entre los dos, no demostrándose que la IgE se encuentra elevada en el grupo problema como parte de la respuesta inmunológica en contra de E. histolytica
Subject(s)
Humans , Infant , Child, Preschool , Child , Male , Female , Amebiasis/blood , Immunoglobulin E/analysis , Case-Control StudiesABSTRACT
Serological studies were done on 127 cases using three different techniques namely indirect haemagglutination (IHA), indirect fluorescent antibody test (IFT) and counter immunoelectrophoresis (CIEP) to detect antiamoebic antibodies. All amoebic liver abscess cases showed significant titre of antibodies by all the three tests used. In the group of patients suffering from amoebic pathology of liver, 90.47 per cent were positive by IHA, 100 per cent by IFT and 85.71 per cent by CIEP respectively. Among amoebic dysentry and amoebic colitis cases 81.81 per cent and 80.64 per cent respectively were positive by IHA. The corresponding figures for IFT were 100 per cent and 74.19 per cent and for CIEP 90.90 per cent and 64.51 per cent respectively. Follow up study showed no significant fall in antibody titre in nine cases studied upto 10 weeks after treatment. Amoebic antigen could be detected in pus from all the nine cases with amoebic liver abscess by CIEP test.