Teste imunoenzimático (Elisa) no diagnóstico da neurocisticercose: estudo de diferentes extratos antigênicos na detecção de anticorpos IgG em amostras de soro e de líquido cefalorraqueano

Abstract

Five different antigens from Cysticercus cellulosae, a vesicular fluid, a saline and an alkaline total extracts, an escolex and membrane, were studied in the ELISA immunoenzymatic assay to demonstrate IgG antibodies in cerebrospinal fluid (CSF) and serum samples. For the 5 antigens the 20 micrograms/ml concentration was selected for polyvinyl plates sensitization for CSF and serum assays. The IgG fraction of a sheep anti-human IgG antiserum was labeled with horseradish peroxidase and revealed with hydrogen peroxide-5-aminosalicilic acid. For positive results 10 ELISA Units for sera and 5 EU for CSF were taken. A total of 182 serum samples and 115 CSF samples were tested. The ELISA sensitivity for sera were 88.6% for vesicular fluid, escolex and membrane; 85.7% for saline extract and 62.8% for alkaline extract. The ELISA sensitivity for CSF was 100% for vesicular fluid and saline total extract, 91.7% for membrane, 89.6% for excolex and 77.1% for alkaline. The ELISA specificity for sera was 100% to the 5 antigens studied; to the CSF was 100% for the alkaline and escolex and 98.5% for the other antigens. An ELISA geometric mean titer of sera and CSF was respectively the 121.1 and 27.3 for vesicular fluid, 111.6 and 31.1 for saline total extract, 30.3 and 5.3 for alkaline total extract, 63.2 and 14.8 for escolex and 69.1 and 18.8 for membrane antigen. ELISA was then compared to immunofluorescence, hemagglutination and complement fixation tests in CSF and sera. ELISA immunoenzymatic assay with saline total extract is recommended for the easy preparation and for the high quantity of antigens obtained, for the high sensitivity and great specificity for sera and CSF; we suggest that this test may be used as a substitute for immunofluorescence, hemagglutination and complement fixation in sera or CSF for the diagnosis of neurocysticercosis.

ELISA and Western Blotting tests in the detection of IgG antibodies to Taenia solium metacestodes in serum samples in human neurocysticercosis

“…Similar to the results described by Costa (1986), our use of different antigenic fractions from T. solium metacestodes in the ELISA resulted in differences of sensitivity and specificity. Cross‐reaction indices are high in sera ( Andriantsimahavandy et al .…”

Evaluation of Taenia solium and Taenia crassiceps cysticercal antigens for the serodiagnosis of neurocysticercosis

“…Few reports have simultaneously compared the usefulness of different antigen preparations from T. solium cysticerci for the serodiagnosis of neurocysticercosis. In these studies, performed mainly with IH and ELISA tests, there is a marked variation in the efficacies of cysticercal antigens, with sensitivities ranging from 47% to 95% and specificities ranging from 67% to 100% (Nascimento & Mayrink 1984; Costa 1986; Larralde et al. 1986; Nascimento et al.…”

Enzyme linked immunosorbent assay (ELISA) for the detection of IgG, IgM, IgE and IgA against Cysticercus cellulosae in cerebrospinal fluid of patients with neurocysticercosis

“…In Brazil, studies by Costa 10,11 comparing ELISA with other methods of immunodiagnosis of NCC in CSF using different antigen extracts have contributed to the diffusion of the method. This author obtained 100% sensitivity and 98.5% specificity using the total saline extract of Cysticercus cellulosae in CSF samples, emphasizing the superiority of this method over complement fixation, immunofluorescence and hemagglutination .…”