Respuesta inmune Th1/Th2 en pacientes co-infectados con Helicobacter pylori y helmintos / Immune response Th1/Th2 to Helicobacter pylori and Helminths in co-infected patients

Resumen: Introducción: La inflamación asociada con la infección por Helicobacter pylori (H. pylori) se relaciona con la pro gresión de las lesiones precancerosas gástricas. Las infecciones por helmintos podrían modular la respuesta proinflamatoria a la infección por H. pylori desde un perfil tipo LTCD4+ Th1 hacia una respuesta menos perjudicial tipo LTCD4+ Th2. Objetivo: Caracterizar la polarización de la respuesta inmune tipo LTCD4+ Th1/Th2 de pacientes coinfectados por H. pylori y helmintiasis procedentes de áreas de bajo riego para el desarrollo de cáncer gástrico. Pacientes y Método: Se analizaron 63 pacientes, 40 adultos y 23 niños infectados con H. pylori. La determinación de los perfiles séricos de las interleucinas asociadas con la polarización de la respuesta inmune tipo LTCD4+ Th1 (IL-1Β, INF-γ y TNF-α) y tipo LTCD4+ Th2 (IL-4, IL-10 e IL-13) se realizó con Análisis Multiplex (xMAP). La relación entre el estado de coinfección por helmintos en pacientes infectados con H. pylori y la polarización de la respuesta inmune mediada por LTCD4+ Th1 y LTCD4+ Th2, se estudió con un modelo de regresión logístico de efectos mixtos. Resultados: La frecuencia de helmintos fue similar en adultos (15%) y niños (17%). La polarización de la respuesta inmune fue más prevalente hacia el tipo LTCD4+ Th1. Los valores séricos de las interleucinas asociadas con la polarización de la respuesta inmune tipo LTCD4+ Th1 (IL-1 Β, INF-γ y TNF-α) y tipo LTCD4+ Th2 (IL-4, IL-10 e IL-13) fueron independientes del estado de infestación por helmintos. Conclusión: La prevalencia de infección por parasitismo intestinal fue alta y la polarización de la respuesta inmune fue predominantemente hacia un perfil tipo LTCD4 + Th1.

Abstract: Introduction: Inflammation associated with Helicobacter pylori (H. pylori) infection is linked to the development of a gastric precancerous lesion. Helminth infections could influence the pro-inflam matory response to such infection from LTCD4+ Th1 to a less harmful LTCD4+ Th2 response. Ob jective: To characterize the polarization of the LTCD4+ Th2 immune response in co-infected pa tients with H. pylori and helminths from low-risk areas for developing gastric cancer. Patients and Method: We analyzed 63 patients infected by H. pylori (40 adults and 23 children). Through the Multiplex Analysis technology (xMAP), we determined the serum profiles of the interleukins asso ciated with the polarization of the immune response of LTCD4+ Th1 (IL-1Β, INF-γ, TNF-α) as well as the LTCD4+ Th2 (IL-4, IL-10, and IL-13). The ratio between helminths co-infection status in H. pylori-infected patients and the polarization of the immune response mediated by LTCD4+ Th1 and LTCD4+ Th2 was assessed using a Mixed Effects Logistic Regression Model. Results: The frequency of helminths was similar between adults (15%) and children (17%). The polarization of the immu ne response was more prevalent in LTCD4+ Th1. Serum values of interleukins associated with the immune response polarization of LTCD4+ Th1 (IL-1Β, INF-γ, and TNF-α) and LTCD4+ Th2 (IL-4, IL-10, and IL-13) were independent of helminths infection status. Conclusion: The prevalence of in testinal parasitic infection was high and the immune response polarization was mainly LTCD4 + Th1.

Intestinal parasites infection: protective effect in rheumatoid arthritis? / Parasitoses intestinais: efeito protetor na artrite reumatoide?

Abstract Rheumatoid arthritis (RA) is a systemic autoimmune inflammatory disease, with a progressive course, characterized by chronic synovitis that may evolve with deformities and functional disability, and whose early treatment minimizes joint damage. Its etiopathogenesis is not fully elucidated but comprises immunologic responses mediated by T helper cells (Th1). An apparent minor severity of RA in patients from regions with lower income could be associated with a higher prevalence of gut parasites, especially helminths. Strictly, a shift in the immune response toward the predominance of T helper cells (Th2), due to the chronic exposure to helminths, could modulate negatively the inflammation in RA patients, resulting in lower severity/joint injury. The interaction between the immunological responses of parasitic helminths in rheumatoid arthritis patients is the purpose of this paper.

Resumo A artrite reumatoide (AR) é uma doença inflamatória autoimune, sistêmica, de curso progressivo, caracterizada por exuberante sinovite crônica, que pode gerar deformidades e incapacidade funcional, cujo tratamento precoce minimiza o dano às juntas. Sua etiopatogenia ainda não está completamente elucidada, mas compreende respostas imunológicas com a participação de células T auxiliares (Th1). Uma aparente menor gravidade da AR em pacientes de regiões com menor renda poderia estar associada a maior prevalência de parasitoses intestinais, especialmente as helmintíases. A rigor, um desvio na resposta imune para o predomínio de células T auxiliares (Th2), decorrente da exposição crônica a helmintos, modularia negativamente a inflamação em doentes com AR, e levaria a menor gravidade e dano articular. A revisão de aspectos da influência da reposta imunológica nas parasitoses intestinais, especialmente as helmintíases, em pacientes com artrite reumatoide é o objetivo desse trabalho.

Regulación por helmintos de las respuestas inmunitarias del hospedero / Helminth regulation of host immune responses

Introducción: durante las últimas dos décadas se ha producido una rápida acumulación de conocimientos sobre la inmunología de las helmintosis. La información ahora disponible permite un mejor entendimiento de los mecanismos defensivos del hombre contra la infección por helmintos. Otra área del saber sobre la inmunología de las helmintosis, la relacionada con la regulación de las respuestas inmunitarias del hospedero ejercida por el parásito, con sus muy disímiles implicaciones clínicas y epidemiológicas, también se ha beneficiado de la expansión cognoscitiva de los últimos años. Objetivos: revisar lo publicado sobre las evidencias, mecanismos y consecuencias de la regulación de las respuestas inmunitarias del hospedero ejercida por los helmintos. Métodos: con el auxilio de diferentes buscadores electrónicos, se realiza una revisión de los artículos sobre helmintos, helmintosis y regulación de las respuestas inmunitarias del hospedero publicados durante el período 1995-2015. Algunas monografías y artículos originales fechados con anterioridad al intervalo mencionado también fueron consultados. Resultados: se expone y analiza, y hasta donde es posible se sistematiza, la información colectada sobre los temas seleccionados. Conclusiones: datos epidemiológicos, clínicos y experimentales evidencian que los helmintos logran modular las respuestas inmunitarias de sus respectivos hospederos y con ello sobrevivir en aquellos. Adicionalmente, la modulación de las respuestas inmunitarias del hospedero tiene importantes consecuencias clínicas y epidemiológicas que, en aras de una práctica médica de mejor calidad, deben ser conocidas por los profesionales relacionados con el diagnóstico, tratamiento y control de estas parasitosis(AU)

Introduction: the last two decades have witnessed a swift accumulation of knowledge about the immunology of helminthiases. The information now available allows to better understand human defense mechanisms against helminth infection. Another area of knowledge about the immunology of helminthiases which has also benefited from such recent expansion of knowledge is the regulation of host immune responses by the parasite, with its great variety of clinical and epidemiological implications. Objectives: review publications about the evidence, mechanisms and consequences of the regulation of host immune responses by helminths. Methods: using various search engines, a review was conducted of papers about helminths, helminthiasis and regulation of host immune responses published from 1995 to 2015. Several monographs and original papers dated before that period were also consulted. Results: the information gathered about the topics selected is presented, analyzed and whenever possible systematized. Conclusions: epidemiological, clinical and experimental data show that helminths can modulate the immune responses of their hosts and thus survive within them. Additionally, modulation of host immune responses has important clinical and epidemiological consequences which should be known by professionals related to the diagnosis, treatment and control of these parasitic diseases in order to improve the quality of medical practice(AU)

Geohelmintiasis, asma y enfermedad alérgica / Geohelminthiasis, asthma and allergic disease

Las infecciones producidas por enteroparásitos están presentes en todas las zonas tropicales y subtropicales del planeta y, dentro de este grupo, las parasitosis transmitidas por el contacto con el suelo, o también conocidas como geohelmintiasis, constituyen una de las infecciones más comunes. A pesar de la exitosa generación de respuesta Th2, a menudo los helmintos poseen la capacidad de vivir en el interior de sus hospederos y les causan infecciones crónicas durante largos períodos de tiempo, como consecuencia de mecanismos de adaptación evolutiva que les permiten evadir las respuestas inmunitarias de estos. Las observaciones epidemiológicas muestran que la prevalencia de geohelmintiasis ha disminuido en países desarrollados, en oposición a lo que ha ocurrido con la prevalencia de enfermedades causadas por alteraciones inmunológicas e inflamatorias como la alergia y el asma. En este trabajo de revisión nos propusimos exponer las principales evidencias epidemiológicas publicadas a nivel internacional y en Cuba acerca de dicha relación. Se discuten además los principales mecanismos inmunológicos que se invocan

Enteroparasite infections occur in tropical and subtropical regions of the planet. Among them are parasitoses transmitted by contact with the ground, also known as geohelminthiases, which are among the most common. Despite the successful generation of Th2 response, helminths are often capable of living inside their hosts, causing them chronic infections for long periods of time, as a result of evolutionary adaptation mechanisms allowing them to evade immunological responses. Epidemiological observations show that the prevalence of geohelminthiases has decreased in developed countries, in contrast to the rising prevalence of diseases caused by immunological and inflammatory alterations, such as allergy and asthma. The present review paper is aimed at presenting the main epidemiological evidence published both internationally and in Cuba about such a relationship. A discussion is also provided of the main immunological mechanisms invoked

Consideraciones sobre la evolución de la respuesta inmunitaria Th2 y sus posibles relaciones con parasitosis y alergia / The evolution of the Th2 immune responses and its relationships with parasitic diseases and allergy

Hay diversos vínculos entre las parasitosis, especialmente las helmintiasis, y las enfermedades alérgicas, ambas condiciones de importancia epidemiológica en las regiones tropicales. Mientras que se ha especulado con frecuencia los efectos de las enfermedades parasitarias sobre la evolución del sistema inmunitario, no se conocen las fuerzas selectivas que han moldeado la respuesta alérgica y pensamos que incluyen mecanismos evolutivos distintos a los tradicionalmente divulgados. Los helmintos, fuente infecciosa y antigénica inductora de una respuesta parecida a la alérgica, se establecieron como parásitos en huéspedes que ya tenían grupos celulares de inmunidad de tipo 2. Hoy sabemos que un componente esencial en la relación de parasitismo entre los helmintos y sus huéspedes es la inmunosupresión que los primeros inducen, al crear una especie de equilibrio que permite la supervivencia de ambos. El desarrollo de este equilibrio debió incluir adaptaciones de ambos organismos y la supervivencia del parásito podría ser el resultado de la adquisición de mecanismos supresores de la respuesta defensiva, la selección de los huéspedes con menor intensidad de la respuesta de tipo 2, o ambas. Esto, a su vez, sugiere que aunque las infecciones helmínticas hayan influido en la conformación de la inmunidad de tipo 2, no han sido una fuerza selectiva importante en el caso particular de la respuesta alérgica que, a su vez, está más ligada a una exagerada respuesta Th2/IgE.

A variety of links occur between parasites, particularly helminths, and allergic diseases--both common conditions of epidemiological importance in tropical regions. Although speculations are often made about the effects of parasitic diseases on the evolution of the immune system, the selective forces that have shaped the allergic response are unknown and probably include evolutionary mechanisms different to those traditionally reported. Helminths, infectious and antigenic sources that induce allergic-like responses, established themselves as parasites in organisms that already had cell groups related to the type 2 immunity. An essential component in the relationship between helminths and their hosts is that the former induce immunosuppression, creating a kind of balance that allows the survival of both. The development of this equilibrium undoubtedly includes adaptations in both organisms, and the survival of the parasite is the result of (a) acquiring immune suppressor mechanisms and (b) finding hosts with lower intensity of the type 2 response. This in turn suggests that although helminth infections have influenced the formation of type 2 immunity, they have not been an important selective force in the particular case of allergic response. The latter is more related to an exaggerated Th2/IgE response.

Involvement of nitric oxide and its up/down stream molecules in the immunity against parasitic infections

Nitric oxide (NO) is a potent mediator with diverse roles in regulating cellular functions and signaling pathways. The NO synthase (NOS) enzyme family consists of three major isoforms, which convey variety of messages between cells, including signals for vasorelaxation, neurotransmission and cytotoxicity. This family of enzymes are generally classified as neuronal NOS (nNOS), endothelial NOS (eNOS) and inducible NOS (iNOS). Increased levels of NO are induced from iNOS during infection; while eNOS and nNOS may be produced at the baseline in normal conditions. An association of some key cytokines appears to be essential for NOS gene regulation in the immunity of infections. Accumulating evidence indicates that parasitic diseases are commonly associated with elevated production of NO. NO plays a role in the immunoregulation and it is implicated in the host non-specific defence in a variety of infections. Nevertheless, the functional role of NO and NOS isoforms in the immune responses of host against the majority of parasites is still highly controversial. In the present review, the role of parasitic infections will be discussed in the controversy related to the NO production and iNOS gene expression in different parasites and a variety of experimental models.

Eosinophil-Mediated Tissue Inflammatory Responses in Helminth Infection

Eosinophilic leukocytes function in host protection against parasitic worms. In turn, helminthic parasites harbor specific molecules to evade or paralyze eosinophil-associated host immune responses; these molecules facilitate the migration and survival of parasitic helminths in vivo. This competition between eosinophil and worm leads to stable equilibria between them. An understanding of such dynamic host-eosinophil interactions will help us to uncover mechanisms of cross talk between host and parasite in helminth infection. In this review, we examine recent findings regarding the innate immune responses of eosinophils to helminthic parasites, and discuss the implications of these findings in terms of eosinophil-mediated tissue inflammation in helminth infection.

Controvérsias na associação entre diabetes mellitus tipo 1 e asma / Controversies in the association between type 1 diabetes and asthma

OBJETIVO: Revisão crítica da literatura sobre a associação entre asma e diabetes mellitus tipo 1 (DM1). FONTE DOS DADOS: Pesquisa bibliográfica na base de dados MEDLINE e LILACS nos últimos vinte anos. SíNTESE DOS DADOS: Muitos estudos mostram associação inversa entre asma, atopia e o risco de desenvolver DM1. De acordo com a "Hipótese da Higiene", o risco de doenças alérgicas diminui com infecções precoces na infância no sentido de afastar-se do perfil Th2, predominante ao nascimento, em direção ao fenótipo Th1. No entanto, outros trabalhos demonstram associação positiva ou ausência de associação entre DM1 e alergias. Existe a possibilidade de fatores ambientais contribuírem para ocorrência de doenças mediadas por células Th1 e Th2 no mesmo indivíduo, por provável deficiência de mecanismos imunomodulatórios mediados pela interleucina-10 e células regulatórias. CONCLUSÃO: As informações sobre a associação inversa entre doenças mediadas por resposta Th1 (por exemplo, DM1), e aquelas mediadas por resposta Th2 (por exemplo, alergias) são conflitantes, requerendo mais estudos para esclarecer esta questão.

OBJECTIVE: Critical review of the literature to investigate the relationship between asthma and type 1 diabetes mellitus (DM1). SOURCE OF DATA: Bibliography search in MEDLINE and LILACS databases in the last twenty years. SUMMARY OF DATA: Several studies demonstrate an inverse relationship between asthma, atopic diseases and the risk to develop DM1. According to the "Hygiene Hypothesis", the risk of allergic diseases decreases with infections early in childhood, towards distance of Th2 profile, common at birth, to the Th1 phenotype. Other articles described lack of association or positive association between DM1 and allergies. There is a possibility of environmental factors interfering in the development of disorders mediated by Th1 and Th2 cells, in the same individual, due to the absence of immunomodulatory mechanisms mediated by interleukin-10 and regulatory cells. CONCLUSION: The existing information about the inverse association between Th1-mediated diseases (e.g., DM1), and those that are Th2-mediated (e.g., allergies) are conflicting requiring more investigation to explain this question.

Inter-relação entre asma, atopia e infecções helmínticas / Interrelationship among asthma, atopy, and helminth infections

Este estudo teve como objetivo descrever as principais evidências encontradas na literatura acerca da inter-relação entre infecções helmínticas, atopia e asma. Foi feita uma revisão não sistemática da literatura. Encontramos numerosas publicações sobre o tema nas quais se verifica controvérsia quanto à capacidade das infecções por geohelmintos de inibir a reatividade ao teste alérgico cutâneo e os sintomas das doenças alérgicas. Por outro lado, estudos em pacientes infectados por Schistosoma spp., apesar de escassos, sugerem que estes helmintos são capazes de inibir a reatividade ao teste alérgico cutâneo e os sintomas de asma. Nos estudos in vitro, as evidências sugerem que as helmintíases inibem as respostas imunes mediadas por linfócitos T auxiliares do tipo 1 e 2, o que abre novas possibilidades terapêuticas para o tratamento de doenças do sistema imunológico.

To describe the principal evidence in the literature regarding the interrelationship among helminth infections, atopy, and asthma, a nonsystematic review of the literature was conducted. Among the publications on the subject, we found a number in which there was controversy regarding the capacity of geohelminth infections to inhibit responsiveness to skin allergy tests and to minimize the symptoms of allergic diseases. However, although small in number, studies of patients infected with Schistosoma spp. suggest that these helminths can inhibit the responsiveness to skin allergy testing and minimize asthma symptoms. Evidence provided by in vitro studies suggests that helminthiases inhibit T helper 1- and T helper 2-type immune responses. This opens new therapeutic possibilities for the treatment of immune system diseases.

Total IgE level in respiratory allergy: study of patients at high risk for helminthic infection

OBJETIVO: Eosinofilia e elevação de IgE sérica são expressões de atopia, contudo há fatores intervenientes como, por exemplo, as parasitoses intestinais. Esta pesquisa verifica a relação entre IgE sérica total, eosinófilos e IgE específica anti-áscaris em indivíduos portadores de asma e/ou rinite alérgica. MÉTODOS: Estudo do tipo transversal em adolescentes portadores de asma e/ou rinite alérgica que foram examinados quanto ao nível sérico de IgE total, de IgE anti-áscaris e de contagem dos eosinófilos sangüíneos. RESULTADOS: Foram analisados 101 pacientes com idade entre 12 e 21 anos. A mediana da IgE foi 660 UI/mL (P25-75 243,5-1500), e a dos eosinófilos foi 510 células/mm³ (P25-75 284-811). A IgE anti-áscaris foi positiva em 73 por cento (74/101) da amostra, mas houve apenas 33,7 por cento (34/101) de positividade ao parasitológico de fezes. Os coeficientes de correlação encontrados foram: 0,34 (p = 0,001) entre IgE total e eosinófilos, 0,52 (p < 0,001) entre IgE total e IgE anti-áscaris e 0,26 (p = 0,01) entre eosinófilos e IgE anti-áscaris. O modelo de regressão linear múltipla final encontrou que IgE anti-áscaris foi fator contribuinte para IgE sérica total com coeficiente de determinação (r2 ajustado) de 0,25 (F = 12,35; p < 0,001), e esse efeito foi independente de contagem de eosinófilos séricos e de parasitose intestinal por helmintos. CONCLUSÃO: Em pacientes com alergia respiratória e IgE sérica total bastante elevada, oriundos de áreas com alto risco de infecção por helmintos, a pesquisa de IgE anti-áscaris como possível fator explicativo pode ser de maior ajuda que a realização do parasitológico de fezes.

OBJECTIVE: Eosinophilia and increased serum IgE levels are indicators of atopy; however, other factors can also play a key role, such as intestinal parasitic infections. This study assesses the relationship between total serum IgE, eosinophil count, and anti-Ascaris IgE in individuals with asthma and/or allergic rhinitis. METHODS: A cross-sectional study was carried out in adolescents with asthma and/or allergic rhinitis. The patients had their total serum IgE, anti-Ascaris IgE and eosinophil count measured. RESULTS: A total of 101 patients aged 12 to 21 years were assessed. Median IgE level was 660 IU/mL (P25-75 243.5-1500), and the eosinophil count corresponded to 510 cells/mm³ (P25-75 284-811). Anti-Ascaris IgE was positive in 73 percent (74/101) of the individuals, but parasitological stool examination yielded positive results in only 33.7 percent (34/101). The correlation coefficients were the following: 0.34 (p = 0.001) between total IgE level and eosinophil count, 0.52 (p < 0.001) between total IgE level and anti-Ascaris IgE, and 0.26 (p = 0.01) between eosinophil count and anti-Ascaris IgE. The final multiple linear regression model pointed out that anti-Ascaris IgE contributed to a total serum IgE level with a coefficient of determination (adjusted R²) of 0.25 (F = 12.35; p < 0.001). This effect occurred regardless of eosinophil count and of the presence of intestinal helminthic infection. CONCLUSION: In patients with respiratory allergy and increased total serum IgE levels living in areas where there is a high risk for helminthic infections, the quantification of anti-Ascaris IgE can be more useful and more insightful than the parasitological stool examination.

Inmunodiagnóstico de las infecciones por Strongloides stercoralis en Chile utilizando la prueba de ELISA / Immunodiagnosis of Strongyloides stercoralis infections in Chile using ELISA test

BACKGROUND: Strongyloides stercoralis is a world wide distributed small intestinal nematode parasite. In immunocompetent individuals S stercoralis can produce asymptomatic infections or a moderate clinical picture of diarrhea, some cases become chronic. In immunocompromised patients, a disseminated disease may appear, sometimes fatal. In Chile, there is little epidemiological information about S stercoralis infections and appropriate diagnostic techniques are usually not used. AIM: To evaluate the yield of an ELISA test for the diagnosis of strongyloidiasis in Chilean patients. MATERIAL AND METHODS: Ten serum samples from patients with S stercoralis infections confirmed by a positive stool examination, 66 samples from individuals with other infections by tissue helminthes (24 toxocariasis, 15 trichinellosis, 11 hydatidosis, 12 fascioliasis and 4 cysticercosis), 13 samples from subjects with autoimmune diseases and 49 samples from apparently healthy individuals with a normal eosinophil count, were studied. ELISA antigen was prepared using a filariform larval extract obtained from a murine species of Strongyloides, maintained in laboratory animals. RESULTS: Using 0.33 optical density units as a cut off value, 9 of 10 sera of S stercoralis infected individuals, had a positive ELISA test. No cross reactions were observed with sera of patients with other helminthic infections, autoimmune diseases or in healthy individuals. Thus, specificity, positive and negative predictive values were 100 per cent. CONCLUSIONS: The results obtained are similar with those found by other investigators. ELISA test for strongyloidiasis is a useful tool for the diagnosis of clinical cases and for seroepidemiological studies of this nematode infection in Chile.

O papel protetor das infecçöes por helmintos / The protector role of helminths

O autor faz revisäo de trabalhos a respeito do papel das helmintoses nas alergopatias e indaga sobre as causas do aumento da incidência dos processos alérgicos na populaçäo urbana.

Alergia a Anisakis simplex: estudios clínicos e inmunológicos y reactividad cruzada con otros parásitos / Allergy by Anisakis simplex: clinical and immunological study and cross-reactivity with other parasites

El Anisakis simplex es un parásito perteneciente a la familia Anisakidae, de la clase nematodos, que vive en el tubo digestivo de grandes mamíferos marinos y parasita accidentalmente al hombre al ingerir pescado crudo o poco cocinado. Recientemente se ha implicado como posible factor etiológico de reacciones alérgicas inducidas tras la ingesta de pescado parasitado. En el presente estudio investigamos la posible sensibilización a antígenos de A. simplex en 11 pacientes que presentaron reacciones alérgicas tras la ingesta de pescado. También se estudió la existencia de reactividad cruzada con otros parásitos. En todos los pacientes se demostró, mediante pruebas inmunológicas "in vivo" e "in vitro", la existencia de un mecanismo de hipersensibilidad inmediata a antígenos de A. simplex. Las pruebas cutáneas con el extracto comercial, así como la determinación de IgE específica por técnica CAP y la liberación de histamina frente a este parásito fueron positivos, confirmando la sensibilización mediada por anticuerpos IgE a antígenos de Anisakis. Al estudiar la posible reactividad cruzada con otros parásitos (Ascaris lumbricoides, Echinococcus granulosus) por medio del inhibición del CAP, ésta resultó muy escasa para Ascaris lumbricoides, por lo que en estos pacientes dicha reactividad cruzada parece poco relevante. En cambio la inhibición del CAP a Eschinococcus granulosus con A. simplex llegó hasta el 30-60 por ciento, sugiriendo la existencia de cierto grado de reactividad cruzada entre ambos parásitos, aunque estén más alejados taxonómicamente. Debido a que el Anisakis simplex es un parásito ubicuo, ya que infecta a pescados y mariscos en mares de todo el mundo, sugerimos que ante la historia de manifestaciones alérgicas tras la ingesta de esta clase de alimentos, se investigue la sensibilidad a este parásito, además de los antígenos propios de los frutos de mar. Por otra parte, se debería estudiar la posible sensibilización a A. simplex en los pacientes a los cuales se les detecta IgE específica a E. granulosus, descartándose con anterioridad la enfermedad hidatídica.

Evaluación de la ELISA IgG, usando un antígeno purificado en el diagnóstico de la hidatidosis humana / Evaluation of ELISA IgG test using a purified antigen in the human hydatidosis diagnosis

An enzyme-linked immunosorbent assay (ELISA) was developed for the detection of IgG antibodies to purified sheep hydatic cyst fluid antigen in 56 sera of confirmed cases of hydatidosis. The cut-off value was determined using serum samples from 80 healthy persons, employing two serum dilutions (1:100 and 1:500) with two and three standard desviations (SD). This assay was compared with the indirect hemaglutination test (IHAT). The sensitivity of ELISA-IgG was 94,3 for percent, for hepatic cysts and 92,9 for percent, for pulmonary cysts, whereas the values for IHAT were 77,1 and 64,3 for percent, respcetively. According to Mac Nemar test, both thod presented statistical significance (p < 0,05). In order to find out the specificity, additional 70 serum samples from individuals with other parasitoses, such as cysticercosis (30), trichinosis (26) and fascioliasis (14) were also tested, IHAT presented a specificity of 92,7 for percent and for ELISA-IgG the specificity using a cut-off of average + 3 SD was 99,3 and 100,0 por percent with sera dilution of 1:100 and 1:500 respectively when a cut-off of average +2 SD was considered, we found a specificity of 91,3 and 97,3 por percent, for 1:100 and 1:500 dilutions. The use of ELISA-IgG and purified antigen in the diagnosis of human hydatidosis is discussed

Total serum IgE level in patients with amoebic liver abscess and other parasitic infections.

Total serum IgE level was determined by the radioactive single radial diffusion technique in blood donors, nurse-aid students with the stool positive and negative for parasites, and in patients with helminthic infections. A geometric mean of 445.1 IU/ml in the sera from blood donors was found. Patients with helminthic infections had significantly higher levels than the blood donors and the nurse-aid students with the stool negative for parasites. Intestinal protozoal infections did not cause an increase in IgE level.