The diagnostic importance of species specific and cross-reactive components of Taenia solium, Echinococcus granulosus, and Hymenolepis nana

Montenegro, T.; Gilman, Robert H.; Castillo, Rosa Menéndez; Tsang, Victor C. W.; Brandt, J; Guevara, Angela; Sanabria, Hernán; Verástegui, Manuela; Sterling, Charles R.; Miranda, Elba

doi:10.1590/s0036-46651994000400005

Cited by 12 publications

(8 citation statements)

References 18 publications

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“…and Hymenolepis sp. (Taeniidae family), as previously described (28,37). Cross-reactivity in S. stercoralis infections was also observed in the present study when the serum samples were tested by ELISA using a saline extract or jacalin-unbound fraction.…”

Section: Discussionsupporting

confidence: 85%

Taenia saginata Metacestode Antigenic Fractions without Affinity to Concanavalin A Are an Important Source of Specific Antigens for the Diagnosis of Human Neurocysticercosis

Oliveira

Machado

Mineo

et al. 2010

Clin Vaccine Immunol

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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.Taenia solium is a parasite whose larvae (metacestodes) may be located in the central nervous system of humans, causing neurocysticercosis (NC). Clinical manifestations are nonspecific and vary in severity, ranging from headaches, dizziness, and occasional seizures to a very severe neurological condition with intracranial hypertension or dementia (39,40,42).The diagnosis of NC is given by the combined analysis of clinical data and neuroimaging (computerized tomography and magnetic resonance imaging) as well as immunological and epidemiological data (10). From the neuroimaging findings of NC, only the presence of cystic lesions demonstrating the scolex should be considered pathognomonic (4). In many countries where T. solium is endemic, neuroimaging methods could be inaccessible and/or too expensive for the population at risk, often rural. Under these conditions, serology may provide a viable tool for diagnosis of the infection (6,16,18,35).As NC immunodiagnosis continues to be a challenge because of the increasing difficulty in obtaining parasites from naturally infected pigs for the preparation of T. solium homologous antigen (33), alternative antigens, including heterologous antigens from Taenia saginata, have also been used with satisfactory results to diagnose human NC (29,31,32). T. saginata cysticerci in the cysti...

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Section: Discussionsupporting

confidence: 85%

Taenia saginata Metacestode Antigenic Fractions without Affinity to Concanavalin A Are an Important Source of Specific Antigens for the Diagnosis of Human Neurocysticercosis

Oliveira

Machado

Mineo

et al. 2010

Clin Vaccine Immunol

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“…It should be stated, however, that E. granulosus and T. saginata are closely related to T. solium and have always shown high cross-reaction with immunodiagnostic tests for cysticercosis [20], and the cross-reaction with H. nana, the highest rate of cross-reaction in our study, has been previously shown in another study [21]. Although the endemic prevalence of H. nana is high [22], the impact of the diagnostic cross-reaction would not likely be significant since clinical symptoms can differentiate the two infections [23].…”

supporting

confidence: 69%

TsAg5, a Taenia solium cysticercus protein with a marginal trypsin-like activity in the diagnosis of human neurocysticercosis

Rueda

Sifuentes

Gilman

et al. 2011

Molecular and Biochemical Parasitology

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Neurocysticercosis is an endemic parasitic disease caused by Taenia solium larva. Although the mechanism of infection is not completely understood, it is likely driven by proteolytic activity that degrades the intestinal wall to facilitate oncosphere penetration and further infection. We analyzed the publicly available Taenia solium EST/DNA library and identified two contigs comprising a full-length cDNA fragment very similar to E. granulosus Ag5 protein. The Taenia solium cDNA sequence included a proteolytic trypsin-like-domain in the C-terminal region, and a thrombospondin type-1 adherence-domain in the N-terminal region. Both the trypsin-like and adherence domains were expressed independently as recombinant proteins in bacterial systems. TsAg5 showed marginal trypsin-like activity and high sequence similarity to Ag5. The purified antigens were tested in a Western immunoblot assay to diagnose human neurocysticercosis. The sensitivity of the trypsin-like-domain was 96.36% in patients infected with extraparenchymal cysts, 75.44% in patients infected with multiple cysts, and 39.62% in patients with a single cyst. Specificity was 76.70%. The thrombospondin type-1 adherence-domain was not specific for neurocysticercosis.

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“…and Hymenolepis sp. (Taeniidae family) and to the presence of common antigenic components between these species (Montenegro et al 1994). Cross-reactivity in S. stercoralis infections can be related to the infection of these individuals with both species (T. solium and S. stercoralis), as the city of Uberlândia and the "Triângulo Mineiro" region is considered endemic in terms of human cysticercosis, according to Silveira-Lacerda et al (2002) and Oliveira et al (2006), and hyperendemic for S. stercoralis according to Machado and Costa-Cruz (1998).…”

Section: Discussionmentioning

confidence: 99%

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

et al. 2007

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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.

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The diagnostic importance of species specific and cross-reactive components of Taenia solium, Echinococcus granulosus, and Hymenolepis nana

Cited by 12 publications

References 18 publications

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 Antigenic Fractions without Affinity to Concanavalin A Are an Important Source of Specific Antigens for the Diagnosis of Human Neurocysticercosis

TsAg5, a Taenia solium cysticercus protein with a marginal trypsin-like activity in the diagnosis of human neurocysticercosis

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

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