Egg yolk immunoglobulin Y as a promising tool to detect immune complexes in neurocysticercosis serum samples.

BACKGROUND: Neurocysticercosis (NCC) is a neglected tropical disease and its diagnosis is still a challenge due to non-specific manifestations. Neuroimaging techniques are used in the diagnosis of NCC, however, due to the high cost of these methods and the advantages presented in the use of immunological tests, such as ease of performance and satisfactory results, immunoassays are commonly used to detect antibodies against Taenia sp. antigens. The aim of the present study was to produce, characterize and apply specific polyclonal immunoglobulin Y (IgY) anti-Taenia crassiceps extracted from egg yolk of hens immunized with T. crassiceps metacestodes. METHODS: Indirect enzyme-linked immunosorbent assay (ELISA), avidity ELISA, immunoblotting and indirect immunofluorescence tests were performed for characterization of IgY antibodies. Diagnostic performance was verified by ELISA for immune complex detection testing 90 serum samples. RESULTS: Values of sensitivity, specificity, positive and negative likelihood ratios (LR+/LR-) and area under the curve (AUC) were calculated and presented the following results: sensitivity 83.3%, specificity 96.7%, AUC 0.966, LR+ 25.0 and LR- 0.17. CONCLUSIONS: Results of this pioneering and innovative study demonstrate that anti-T. crassiceps IgY antibodies present potential applicability and can be used as an efficient tool in human NCC serodiagnosis.

IgY antibody and human neurocysticercosis: a novel approach on immunodiagnosis using Taenia crassiceps hydrophobic antigens.

Human neurocysticercosis (NCC) is a worldwide neglected disease caused by Taenia solium metacestode and responsible for various complications and neurological disorders. This study aimed to evaluate the use of specific immunoglobulin Y (IgY) produced by laying hens immunized with a hydrophobic fraction of Taenia crassiceps metacestodes (hFTc) in NCC diagnosis. Egg yolk IgY antibodies were fractionated, purified and characterized. Enzyme-linked immunosorbent assay (ELISA) was carried out to evaluate the production kinetics and avidity maturation of anti-hFTc IgY antibodies throughout the IgY obtention process. Antigen recognition tests were carried out by Western blotting and immunofluorescence antibody test using purified and specific anti-hFTc IgY antibodies for detection of parasitic antigens of T. crassiceps and T. solium metacestodes. Sandwich ELISA was performed to detect circulating immune complexes formed by IgG and parasitic antigens in human sera. The results showed high diagnostic values (93.2% sensitivity and 94.3% specificity) for immune complexes detection in human sera with confirmed NCC. In conclusion, specific IgY antibodies produced from immunized hens with hFTc antigens were efficient to detect T. solium immune complexes in human sera, being an innovative and potential tool for NCC immunodiagnosis.

Antigenic fractions from Taenia crassiceps metacestodes obtained by hydrophobicity for the immunodiagnosis of active and inactive forms of neurocysticercosis in human cerebrospinal fluid samples.

This study aimed to evaluate the total extract of Taenia crassiceps metacestodes (TC) and its antigenic fractions obtained by Triton X-114 fractionation techniques, such as detergent (DC) and aqueous (AC), in the immunodiagnosis of human neurocysticercosis (NCC). Cerebrospinal fluid samples were divided into two groups: Group 1 (n=40), which was further divided into active (n=20) and inactive (n=20) NCC, and Group 2 (control group), which comprised 39 CSF samples from patients who had another neurological disorder, were suffering from other infectious diseases of the brain or had other parasitic infections. The total extracts and antigenic fractions were tested by enzyme-linked immunosorbent assay (ELISA) to detect human IgG anti-Taenia solium. T. crassiceps fractions (DC and AC) showed the same value of sensitivity (Se), 100%, for active and inactive NCC and a specificity (Sp) of 97.4%. The DS fraction obtained from T. solium showed 100% Se for active NCC, 95% Se for inactive NCC and a 92.3% Sp. The AS fraction obtained from T. solium showed 100% Se for both active and inactive NCC and a 94.9% Sp. There was a positive correlation between the total saline extract of T. crassiceps (TC) and T. solium (TS) and their fractions (DC, AC, DS and AS). Positive predictive value, negative predictive value, diagnostic efficiency and Youden index were calculated. In conclusion, these results demonstrated that detergent and aqueous fractions obtained from T. crassiceps metacestodes are important sources of specific antigens and are efficient for immunodiagnosis of active and inactive NCC.

Diethylaminoethyl (DEAE) binding fraction from Taenia solium metacestode improves the neurocysticercosis serodiagnosis.

Neurocysticercosis (NC) is one of the most important diseases caused by parasites affecting the central nervous system. We fractionated by ion-exchange chromatography using diethylaminoethyl (DEAE)-sepharose resin the total saline extract (S) from Taenia solium metacestodes and evaluated obtained fractions (DEAE S1 and DEAE S2) by enzyme-linked immunosorbent assay (ELISA, n = 123) and immunoblotting (IB, n = 22) to detect human NC in serum. Diagnostic parameters were established by ROC and TG ROC curves for ELISA tests. IB was qualitatively analyzed. S and DEAE S1 presented sensitivity of 87. 5% and DEAE S2 90%. The best specificity was observed for DEAE S2 (90.4%). In IB, using DEAE S2 samples from NC patients presented bands of 20-25, 43-45, 55-50, 60-66, 82, 89, and 140 kDa. The great diagnostic parameters reached by DEAE S2 suggest the potential applicability of this fraction in NC immunodiagnosis.

Dexamethasone effects in the Strongyloides venezuelensis infection in a murine model.

The aim of this study was to investigate the immunomodulatory effects of glucocorticoids on the immune response to Strongyloides venezuelensis in mice. Balb/c mice were infected with S. venezuelensis and treated with Dexamethasone (Dexa) or vehicle. Dexa treatment increased circulating blood neutrophil numbers and inhibited eosinophil and mononuclear cell accumulation in the blood, bronchoalveolar, and peritoneal fluid compared with control animals. Moreover, Dexa decreased tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), interleukin-3 (IL-3), IL-4, IL-5, IL-10, and IL-12 production in the lungs and circulating immunoglobulin G1 (IgG1), IgG2a, and IgE antibody levels while increasing the overall parasite burden in the feces and intestine. Dexa treatment enhanced the fertility of female nematodes relative to untreated and infected mice. In summary, the alterations in the immune response induced by Dexa resulted in a blunted, aberrant immune response associated with increased parasite burden. This phenomenon is similar to that observed in S. stercoralis-infected humans who are taking immunosuppressive or antiinflammatory drugs, including corticosteroids.

A glance at Taenia saginata infection, diagnosis, vaccine, biological control and treatment.

The Taenia saginata taeniasis-cysticercosis complex is a cosmopolitan zoonosis of great medical, veterinary and economic importance where humans play an important role as the carrier of adult stage and cattle as carrier of the larval stage of the parasite. Here we reviewed aspects concerning diagnosis, vaccine development, biological control and treatment of the disease.

Strongyloides stercoralis and other enteroparasites in individuals of rural area of Uberlandia, Minas Gerais State, Brazi

O objetivo deste estudo foi verificar a ocorrência de Strongyloides stercoralis e outros enteroparasitos em habitantes da área rural de Uberlândia, Minas Gerais, entre setembro de 1996 e maio de 1997, utilizando os métodos de Baermann-Moraes e de Lutz. Dos 180 indivíduos estudados, 92 (51,1por cento) estavam infectados. Doze indivíduos (6,7por cento) estavam infectados por S. stercoralis, sendo cinco em crianças com idade de entre zero e 12 anos e sete em indivíduos acima de 12 anos. Outros enteroparasitos diagnosticados foram Entamoeba coli (27,2por cento), Giardia lamblia (10,6por cento), Ancilostomatídeos (7,2por cento), Endolimax nana (3,9por cento), Ascaris lumbricoides (3,3por cento), Entamoeba hartmanni (3,3por cento), Enterobius vermicularis (2,2por cento), Hymenolepis nana (1,1por cento), Iodamoeba butschlii (1,1por cento), Entamoeba histolytica/dispar (0,6por cento) e Schistosoma mansoni (0,6por cento). Dos 92 casos positivos houve 71,0por cento de monoparasitismo, 25,0por cento biparasitismo e 4,0por cento poliparasitismo. Concluiu-se que a estrongiloidíase é hiperendêmica na área rural de Uberlândia. Destacamos a importância do uso de múltiplos métodos parasitológicos realizados em três diferentes amostras fecais de cada indivíduo que possibilitou a detecção de elevada taxa de enteroparasitas (51,1por cento) demonstrando um sério problema de Saúde Pública.

IgA detection in human neurocysticercosis using different preparations of heterologous antigen.

Neurocysticercosis (NC) is the most important neurological disease of parasitic origin in humans. IgA and IgG detection in serum from neurocysticercosis patients was tested using some antigenic preparations of total saline extract from Taenia saginata: detergent (D) and aqueous (A) phases extracted with Triton X-114 and the jacalin bound (JBF) and unbound fractions (JUF) obtained by affinity chromatography using jacalin column. Samples were obtained from 45 patients with definitive NC, who were subdivided into active-NC group and inactive-NC group; 35 patients with other parasitoses; and 30 apparently healthy individuals. Sensitivity and specificity were calculated. Specificity to detect IgA and IgG for D phase, respectively, were 89.8% and 86.9% and for IgG detection 91.3% and 76.8% when using D phase and JUF, respectively. D phase and JBF proved to be specific and efficient and could be efficiently utilized as an alternative antigen for IgA detection in NC, with comparable results with IgG.

Taenia saginata metacestode antigenic fractions without affinity to concanavalin A are an important source of specific antigens for the diagnosis of human neurocysticercosis.

Taenia saginata metacestode antigens have been constituted a useful alternative antigen for neurocysticercosis (NC) serodiagnosis, particularly due to an increasing difficulty to obtain Taenia solium homologous antigen. Cross-reactivity with Echinococcus granulosus infection occurs in homologous and heterologous antigens and could be avoided by using different purified methods. The present study evaluated antigen fractions obtained from saline extracts of T. saginata metacestodes purified by affinity chromatography with jacalin or concanavalin A (ConA) lectins to detect IgG antibodies by enzyme-linked immunosorbent assay (ELISA) and immunoblot analysis to diagnose human NC. Serum samples were collected from 142 individuals: 40 of them were diagnosed with NC, 62 presented Taenia sp. and other parasites, and 40 were apparently healthy individuals. The jacalin- and ConA-unbound fractions demonstrated sensitivity and specificity higher than those of bound fractions. Among unbound fractions, ConA demonstrated statistically higher sensitivity and specificity by ELISA (90% and 93.1%, respectively). By immunoblot assay, the 64- to 68-kDa component from the ConA-unbound fraction showed 100% sensitivity and specificity, making this component suitable for use as a specific antigen for diagnosis of NC. To our knowledge, this is the first report showing the relevance of using the unbound ConA fraction of T. saginata metacestodes to diagnose NC. In conclusion, the results obtained herein clearly demonstrate that antigenic fractions without affinity to ConA, obtained from T. saginata metacestodes, are an important source of specific peptides and are efficient in the diagnosis of NC when tested by immunoblot assay.

Intestinal parasites inside public restrooms and buses from the city of Uberlândia, Minas Gerais, Brazil / Parasitas intestinais no interior de sanitários públicos e ônibus na cidade de Uberlândia, Minas Gerais, Brasil

The objective of this study was to describe the occurrence of intestinal parasites inside public restrooms and buses from a Brazilian city. Sample material was obtained using a transparent adhesive tape. Thirty two public restrooms were investigated and two (6.25%) were contaminated with helminth eggs (Ascaris lumbricoides and Enterobius vermicularis). Of the sixteen different bus lines, three (18.7%) were found to harbor eggs of E. vermicularis. Public restrooms and buses can be an important source of parasite transmission and sanitary education could be improved by using these points.

O objetivo do presente estudo foi descrever a ocorrência de parasitas intestinais em sanitários públicos e ônibus de uma cidade do Brasil. As amostras foram obtidas utilizando-se fita adesiva transparente. Trinta e dois sanitários públicos foram investigados e dois (6,25%) estavam contaminados com ovos de helmintos (Ascaris lumbricoides e Enterobius vermicularis). Das 16 diferentes linhas de ônibus, três (18,7%) foram positivas para ovos de E. vermicularis. Sanitários públicos e ônibus podem ser uma importante via de transmissão de parasitas e a educação sanitária pode ser aperfeiçoada por meio do uso destes pontos.

Saline extract of Taenia saginata metacestodes as an alternative antigen for the immunodiagnosis of neurocysticercosis in human cerebrospinal fluid.

The aim of the present research was to test the application of Taenia saginata metacestodes as an alternative antigen for use in enzyme-linked immunosorbent assay (ELISA) and Western Blotting (WB) tests compared with the use of metacestodes antigen of Taenia solium in cerebrospinal fluid (CSF) samples. The samples were obtained from 35 patients with definitive neurocysticercosis (NCC)-group 1-and 44 patients with other neurological disorders (control)-group 2. The sensitivity and specificity of ELISA, using antigen obtained from T. solium, applied to the patients of group 1 yielded results of 100%. When the tests were conducted using T. saginata metacestodes, results were 100% and 93.2%, respectively. The 47-52-, 64-68-, and 70-kDa antigens showed high frequencies in CSF samples from patients with NCC when WB was conducted with both antigens. The results indicate that T. saginata metacestodes can be used as an alternative antigen for the diagnosis of human NCC in CSF samples.

Enteroparasites and commensals among individuals living in rural and urban areas in Abadia dos Dourados, Minas Gerais state, Brazil

The aim of this study was to evaluate the enteroparasite and commensal occurrence in inhabitants living in the city of Abadia dos Dourados, Minas Gerais, Brazil. Three hundred and seventy six people were selected at random, 188 living in the rural area and 188 living in the urban area, from January through December of 1996. Using the Lutz method 177 (47.1 percent) individuals infected: 102 (57.6 percent) in the rural population and 75 (39.9 percent) in the urban population (P < 0.05). Of the total 177 enteroparasite and commensal occurrences diagnosed were: Entamoeba coli (18.3 percent), hookworm (17.8 percent), Endolimax nana (6.1 percent>), Giardia lamblia (5.8 percent), Ascaris lumbricoides (2.6 percent>), Entamoeba hartmanni (2.1 percent), Iodamoeba biltschlii (1.6 percent), Strongyloides ster cor alls (1.3 percent), Enterobius vermicularis (0.5 percent), and Trichostrongylus sp (0.5 percent). Geohelminths were predominant in the rural area, with an occurrence ofhookworm infections at 28.2 percent in these individuals and 7.4 percent in the urban people (OR: 14.33 CI: 6.230 to 32.970). The infection rate of enteroparasites was high in the population studied. In conclusion, it is necessary to implement regular parasitological exams and education about the forms and consequences of transmitting parasites, primarily among people living in the rural area.

El objetivo de este estudio fue evaluar la presencia de enteroparasitas y comensales en habitantes de la ciudad de Abadia dos Dourados, Minas Gerais, Brasil. 376 personas fueron seleccionadas aleatoriamente, 188 viviendo en el área rural y 188 viviendo en el área urbana, enero a diciembre de 1996. Usando el método de Lutz, 177 (47,1 por ciento) individuos estaban infectados, siendo 102 (57,6 por ciento) del área rural y 75 (39,9 por ciento) del área urbana (P < 0,05). Del total de 177 positivos, la ocurrencia de entoparasitas y comenzáis diagnosticadas fueron: Entamoeba coli (18,3 por ciento), hookworm (17,8 por ciento), Endolimax nana (6,1 por ciento), Giardia lamblia (5,8 por ciento), Ascaris lumbricoides (2,6 por ciento), Entamoeba hartmanni (2,1 por ciento), Iodamoeba butschlii (1,6" por ciento), Stron-gyloides stercolaris (1,3 por ciento), Enterobius vermicularis (0,5 por ciento), y Trichostrongylus sp (0,5 por ciento), Geohelmintos fueron predominantes en el ßrea rural, con 28,2 por ciento de infección para hookworm en esta populación y 7,4 por ciento en la populación urbana (OR: 14,33 CI: 6.230 para 32.970). La tasa de infección para enteroparasitas fue alta en los individuos estudiados, siendo necesario hacer exámenes parasitológicos regulares en estas personas y adoptar medidas profilácticas sobre las formas y consecuencias de transmisión de parásitas, principalmente entre personas que viven en el área rural.

Parasitological and immunological diagnosis of Strongyloides stercoralis in patients with gastrointestinal cancer.

This study examined the frequency of Strongyloides stercoralis infection in patients with gastrointestinal cancer through parasitological and immunological tests. A total of 77 patients were evaluated, 33 with gastrointestinal cancer and 44 controls with other types of cancers. All the patients were undergoing chemotherapy and 14 (18.2%) were receiving concomitant radiotherapy. For a parasitological diagnosis, we applied the Baermann and Lutz methods. The immunological diagnosis involved the indirect fluorescence antibody test (IFAT) and enzyme linked immunosorbent assay (ELISA) to detect IgG antibodies using Strongyloides ratti antigens. The frequency of positive S. stercoralis in gastrointestinal cancer diagnosed by parasitological methods was 3 cases (9.1%), by serology it was 8 cases (24.2%). In the control group 1 case (2.3%) of S. stercoralis was diagnosed by parasitological methods and 2 cases (4.5%) by immunological tests (p<0.05). Patients with gastrointestinal cancer had a 6.7-fold greater chance of testing positive for S. stercoralis infection. Our data highlight the importance of parasitological and immunological diagnosis for S. stercoralis in patients with gastrointestinal cancer living in endemic areas of strongyloidiasis, since they have a higher risk of becoming infected with S. stercoralis than patients with other types of cancer.

Immunoparasitological diagnosis of Strongyloides stercoralis in garbage collectors in Uberlândia, MQ Brazil

The objective of this study was to determine the presence of Strongyloides stercoralis in urban garbage collectors through the use of immunological and parasitological methods. A total of 92 individuals were evaluated from August, 1997, to June, 1998. For the parasitological diagnosis Baermann and Lutz' methods were applied. The immunological diagnosis involved the indirect fluorescence antibody test (IFAT) and the enzyme-linked immunosorbent assay (ELISA) to detect specific IgG antibodies. Of the 92 workers examined, six (6.5 percent) were infected with larvae of S. stercoralis. The IFAT detected 19 (16.3 percent) and the ELISA 17 (18.5 percent) positive serum samples. The differences between the results of parasitological and immunological methods were statistically significant (p<0.05). These results demonstrate that there is a need to improve the health conditions of this category of city employees.

Seroepidemiological aspects of human Strongyloides stercoralis infections in Chile

To determine the frequency of Strongyloides stercoralis antibodies by means of the enzyme linked immunosorbent assay (ELISA) in Chile, in 2001-2003, 675 blood samples of patients of two psychiatric hospitals and 172 of healthy individuals (doctors, nurses and paramedicals) of these institutions, and 1,200 serum samples of blood donors of Northern region (Arica and Antofagasta), Central region (Valparaiso and Santiago) and Southern region (La Union) were collected. ELISA showed positivity of 12.1 percent in psychiatric hospitalized patients, none (0 percent) in the health personnel and 0.25 percent in blood donors (p < 0.05). Only in blood donors of Arica (1 percent) and La Union (0.5 percent) the ELISA test was positive suggesting that strongyloidiasis is focalized in determinate zones of the country. In Chile, human infections by S. stercoralis are endemic with very low frequency in apparently healthy individuals and high prevalence in risk groups such as the mentally ill hospitalized patients.

Entre os anos de 2001-2003 foram coletadas amostras de sangue de 675 pacientes de dois hospitais psiquiátricos da região central do Chile, 172 de indivíduos sadios (médicos, enfermeiros e paramédicos) destas instituições e 1200 de doadores de sangue de cidades das regiões norte (Arica e Antofagasta), central (Valparaiso e Santiago) e sul (La Union) para determinar a frequência de anticorpos anti Strongyloides stercoralis mediante a reação de enzyme linked immunosorbent assay (ELISA). Foram observadas soropositividade de 12.1 por cento em pacientes de hospitais psiquiátricos e de 0,25 por cento em doadores de sangue (p < 0.05). Todas as amostras dos indivíduos sadios foram não reagentes. Entre os doadores de sangue a soropositividade ocorreu somente nos indivíduos de Arica (1,0 por cento) e La Union (0,5 por cento) sugerindo que a estrongiloidíase poderia estar localizada em determinadas áreas geográficas do país. Conclui-se que no Chile as infecções por S. stercoralis seriam endêmicas, de baixa freqüência e afetando especialmente grupos de risco como os pacientes psiquiátricos.

Application of Taenia saginata metacestodes as an alternative antigen for the serological diagnosis of human neurocysticercosis.

Serological tests are an important tool for the diagnosis of neurocysticercosis (NCC), the disease caused by Taenia solium metacestodes. The aim of the present research was to test the application of Taenia saginata metacestodes as an alternative antigen for use in the immunofluorescence antibody test (IFAT), enzyme-linked immunosorbent assay (ELISA), and Western blotting (WB) tests compared with the metacestodes antigen of T. solium in serum samples. The samples were obtained from 130 individuals: 20 from patients with definitive NCC, Group 1; 18 from individuals infected by Taenia sp., Group 2; 40 from individuals infected by various parasites, Group 3; and 40 from healthy individuals, Group 4. The sensitivity of IFAT, ELISA, and WB using antigen obtained from T. solium applied to the patients of Group 1 yielded results of 85, 95, and 95%, respectively, for the three tests. When the tests were conducted using T. saginata metacestodes, results were 75, 80, and 85%, respectively. The specificity of IFAT, ELISA, and WB using antigen obtained from T. solium yielded results of 94.9, 88.8, and 93.9%. When the tests were conducted using T. saginata metacestodes, results were 95.9, 88.8, and 93.6%, respectively. No statistical differences for sensitivity or specificity among the antigens were found. In conclusion, the results indicated that T. saginata metacestodes can be used as an alternative antigen for NCC diagnosis.

Anti-Taenia solium metacestode IgG antibodies in serum samples from inhabitants of a central-western region of Brazil.

A total of 354 serum samples from inhabitants who frequent the Clinical Laboratory in Catalão, Goiás, in the central-western region of Brazil, were collected from June to August, 2002. The samples were evaluated by indirect immunofluorescence antibody tests and an enzyme linked immunosorbent assay in order to detect anti-Taenia solium metacestode IgG antibodies. Reactive and inconclusive samples were tested by Western blotting (WB). Considering WB as a confirmation, the frequency of antibodies in the serum samples of the above population was 11.3% (CI 5.09-17.51). The immunodominant bands most frequently recognized in WB were 64-68 kDa (97.5%) and 47-52 kDa (80%). The percentage of seropositivity to cysticercosis was significantly higher for individuals residing in areas without sewage systems (p < 0.0001). In conclusion, the results indicate a probable endemic situation of cysticercosis in this population. These results reinforce the urgent need for control and prevention measures to be taken by the local public health services.

Anti-Taenia solium metacestode IgG antibodies in serum samples from inhabitants of a central-western region of Brazil

Um total de 354 amostras de soro de habitantes que freqüentaram o Laboratório Clínico em Catalão, Goiás, na região centro-oeste do Brasil, foram colhidas no período de junho a agosto de 2002. As amostras foram avaliadas pelo teste de imunofluorescência indireta e enzyme-linked immunosorbent assay (ELISA) com o objetivo de detectar anticorpos IgG anti-metacestódeo de Taenia solium. As amostras reativas e inconclusivas foram testadas pelo Western blotting (WB). Considerando WB como reação confirmatória, a freqüência de anticorpos nas amostras de soro da população estudada foi 11,3% (IC: 5,09 - 17,51). As bandas imunodominantes mais frequentemente reconhecidas no WB foram 64-68 kDa (97,5%) e 47-52 kDa (80%). A porcentagem de soropositividade para cisticercose foi significativamente maior nos indivíduos que residiam em áreas sem sistema de esgoto (p < 0,0001). Concluiu-se que os resultados indicam uma provável situação de endemicidade para cisticercose nesta população, reforçando a urgente necessidade de medidas de controle e prevenção que devem ser implantadas pelo serviço de saúde pública local.