ABSTRACT
OBJECTIVE: To evaluate the performance of two antigenic preparations (vesicular fluid - VF and a glycoprotein fraction, LLa-Gp fraction, purified from a whole parasite extract by lentil lectin affinity chromatography) from Taenia solium cysticerci for the immunodiagnosis of neurocysticercosis. METHOD: Fifty-six cerebrospinal fluid (CSF) samples (22 from patients with neurocysticercosis and 34 from patients with other neurological disorders) and 57 serum samples (22 from patients with neurocysticercosis, 18 from patients with other infections and 17 from presumably healthy persons) were assayed for anticysticercal IgG antibodies with an enzyme-linked immunosorbent assay (ELISA). RESULTS: The VF ELISA showed 100 percent sensitivity and specificity in CSF and serum samples, whereas the sensitivity and specificity of the LLa-Gp ELISA were, respectively, 90.9 percent and 97.1 percent, with the CSF samples and 95.5 percent and 100 percent with serum samples. There was no significant difference in the sensitivity and specificity of the two antigenic preparations used to screen CSF and serum samples. CONCLUSION: Considering the complexity and high cost of obtaining the LLa-Gp fraction, VF could be more suitable for screening specific antibodies by ELISA in CSF and serum samples from patients with neurocysticercosis.
OBJETIVO: Avaliar o desempenho de duas preparações antigênicas (líquido vesicular - LV e uma fração glicoprotéica, fração LL a-Gp, purificada do extrato total dos parasitas por cromatografia de afinidade com lentil lectina) de cisticercos de Taenia solium para o imunodiagnóstico da neurocisticercose. MÉTODO: Cinquenta e seis amostras de líquido cefalorraquidiano (LCR) (22 de pacientes com neurocisticercose e 34 de pacientes com outras doenças neurológicas) e 57 amostras de soro (22 de pacientes com neurocisticercose, 18 de pacientes com outras infecções e 17 de pessoas presumivelmente sadias) foram analisadas quanto à presença de anticorpos IgG anti-cisticercos com uma reação imunoenzimática (ELISA). RESULTADOS: A reação ELISA LV apresentou 100 por cento de sensibilidade e especificidade em amostras de LCR e soro, enquanto a sensibilidade e a especificidade da reação ELISA LLa-Gp em amostras de LCR e soro foram de 90,9 por cento e 97,1 por cento e 95,5 por cento e 100 por cento, respectivamente. Não foram encontradas diferenças significativas na sensibilidade e especificidade das duas preparações antigênicas utilizadas, tanto para amostras de LCR como para amostras de soro. CONCLUSÃO: Considerando a complexidade e o alto custo de obtenção da fração LLa-Gp, o LV pode ser mais adequado para a pesquisa de anticorpos específicos por ELISA em amostras de LCR e soro de pacientes com neurocisticercose.
Subject(s)
Animals , Humans , Antibodies, Helminth/cerebrospinal fluid , Antigens, Helminth , Immunoglobulin G/cerebrospinal fluid , Neurocysticercosis/diagnosis , Taenia solium/immunology , Antibodies, Helminth/blood , Antigens, Helminth/immunology , Case-Control Studies , Chromatography, Affinity , Cyst Fluid/immunology , Cysticercus/immunology , Enzyme-Linked Immunosorbent Assay/methods , Glycoproteins/immunology , Immunoglobulin G/blood , Neurocysticercosis/immunology , Plant Lectins/immunology , Sensitivity and SpecificityABSTRACT
Cystic hydatid disease [Hydatidosis] is the most serious tape-worm infection prevalent in the cattle and sheep raising area of the world. Hydatidosis in man [as an accidental host] is caused by infection with the ova containing larval stage of Echinococcus granulosus. In the last decade, different techniques have been employed for sero-diagnosis of hydatidosis; as IHA, IFA, ELISA, CCLE [Counter Current Immuno-electrophoresis]. This paper evaluated the validity of ELISA and IHA. Since whole hydatid cyst fluid was used as a source of antigen for serodiagnosis. Thirty surgical and pathological hydatidosis proven patients were examined. The sensitivity and specificity of ELISA were 96.7% and 97.5% respectively, and that of IRA were 86.7%, and 95% respectively
Subject(s)
Humans , Male , Female , Enzyme-Linked Immunosorbent Assay/methods , Hemagglutination Tests/methods , Cross Reactions , Cyst Fluid/immunologyABSTRACT
The first trial to detect G1 genotype in Egyptian human isolates of hydatid cysts [HC] and serum samples to approach diagnosis of cystic echinococcosis [CE] using human sera by PCR. Using strain specific primers, 27/36 confirmed CE patients [75%] showed G1 specific band in their sera at 254 bp. Specificity was 100% without detecting bands for either other parasitosis, or mass occupying lesions. Using PCR, G1 genotype was detected in 83.3% of HC samples, without significant difference between types of human isolates [pulmonary, hepatic, or multi-organ]. G1 genotype detection in human sera was in 75% of CE patients compared to 83.3% in HC samples of the same group of patients proved satisfactory, simple and safer than HCF sampling. IHAT gave sensitivity of 58.3% compared to histopathological examination of surgically removed cysts or examination of hydatid cyst fluid [HCF] for pro-toscolices [gold standards]. The specificity was 70% with false positive reactions with other parasitic infections and mass occupying lesions. PCR detection of G1 genotype in Egyptian animal hydatid cysts showed 90% in camel isolates and 80%; in sheep isolates, but pig isolates were negative. The presence of this genotype in a high percentage in camel isolates incriminated sheep strain as the source of CE camel infection. The results may give an explanation to the contradicting results of other studies that did not relay upon molecular aspects
Subject(s)
Humans , Male , Female , Genotype , Polymerase Chain Reaction/methods , Cyst Fluid/immunology , Hemagglutination/methodsABSTRACT
Hydatid cyst fluid (HCF), somatic antigens (S-Ag) and excretory-secretory products (ES-Ag) of Echinococcus granulosus protoscoleces are used as the main antigenic sources for immunodiagnosis of human and dog echinococcosis. In order to determine their non-shared as well as their shared antigenic components, these extracts were studied by ELISA-inhibition and immunoblot-inhibition. Assays were carried out using homologous rabbit polyclonal antisera, human sera from individuals with surgically confirmed hydatidosis, and sera from dogs naturally infected with E. granulosus. High levels of cross-reactivity were observed for all antigenic extracts, but especially for ES-Ag and S-Ag. Canine antibodies evidenced lesser avidity for their specific antigens than antibodies from human origin. The major antigenic components shared by HCF, S-Ag, and ES-Ag have apparent molecular masses of 4-6, 20-24, 52, 80, and 100-104 kDa, including doublets of 41/45, 54/57, and 65/68 kDa. Non-shared polypeptides of each antigenic extract of E. granulosus were identified, having apparent masses of 108 and 78 kDa for HCF, of 124, 94, 83, and 75 kDa for S-Ag, and of 89, 66, 42, 39, 37, and 35 kDa for ES-Ag.
Subject(s)
Animals , Dogs , Humans , Rabbits , Antigens, Helminth/immunology , Echinococcosis, Hepatic/immunology , Echinococcus granulosus/immunology , Helminth Proteins/immunology , Antigens, Helminth , Cross Reactions , Cyst Fluid/chemistry , Cyst Fluid/immunology , Dog Diseases/immunology , Enzyme-Linked Immunosorbent Assay , Echinococcosis/immunology , Echinococcosis/veterinary , Immunoblotting , SheepABSTRACT
The aim of this work was to assess the influence in the diagnostic value for human hydatid disease of the composition of bovine hydatid cyst fluid (BHCF) obtained from fertile (FC) and non-fertile cysts (NFC). Eight batches from FC and 5 from NFC were prepared and analysed with respect to chemical composition: total protein, host-derived protein, carbohydrate and lipid contents. No differences were observed in the first two parameters but carbohydrate and lipid contents were shown to be higher in batches from FC than in those from NFC. Bands of 38 and 116 kD in SDS-PAGE profiles were observed to be present in BHCF from FC only. Two pools were prepared from BHCF batches obtained from FC (PFC) and NFC (PNFC), respectively. Antigen recognition patterns were analysed by immunoblot. Physicochemical conditions for adsorption of antigens to the polystyrene surface (ELISA plates) were optimized. The diagnostic value of both types of BHCF as well as the diagnostic relevance of oxidation of their carbohydrate moieties with periodate were assessed by ELISA using 42 serum samples from hydatid patients, 41 from patients with other disorders, and 15 from healthy donors. Reactivity of all sera against native antigen were tested with and without free phosphorylcholine. The best diagnostic efficiency was observed using BHCF from periodate-treated PFC using glycine buffer with strong ionic strength to coat ELISA plates