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1.
Allergy ; 59(7): 753-7, 2004 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15180763

RESUMO

BACKGROUND: Blomia tropicalis is a common mite found in the house dust of many tropical countries including Venezuela. The prevalence of skin test and specific serum immunoglobulin (Ig)E reactivity to B. tropicalis in Venezuela has not been previously evaluated. METHODS: In the present study we evaluated the skin reactivity by skin prick test and specific IgE by a multiple antigen blot assay, against B. tropicalis and Dermatophagoides pteronyssinus, in a group of 115 subjects who attended the Allergy Clinic of the Institute of Biomedicine, Caracas, Venezuela, and we studied possible cross reactions between similar proteins of these two mites. RESULTS: One hundred and six patients with persistent allergic respiratory symptoms showed a positive skin prick test to at least one of the mite extracts, with the frequency of positive reactions to B. tropicalis being as high as to D. pteronyssinus. Twelve patients reacted only to D. pteronyssinus and 13 different patients only to B. tropicalis. Specific IgE to each of the mite extracts was found with similar frequency, and the results coincided with the skin test reactivity. CONCLUSIONS: The study indicated the importance of including B. tropicalis in routine diagnostic testing in tropical and sub-tropical situations.


Assuntos
Ácaros/imunologia , Hipersensibilidade Respiratória/diagnóstico , Adulto , Alérgenos/efeitos adversos , Alérgenos/imunologia , Animais , Antígenos de Dermatophagoides/imunologia , Asma/etiologia , Asma/imunologia , Reações Cruzadas/imunologia , Reações Cruzadas/fisiologia , Ensaio de Imunoadsorção Enzimática/métodos , Feminino , Humanos , Imunoglobulina E/sangue , Imunoglobulina E/imunologia , Masculino , Pyroglyphidae/imunologia , Hipersensibilidade Respiratória/imunologia , Rinite Alérgica Perene/imunologia , Testes Cutâneos/métodos , Venezuela
2.
J Trop Pediatr ; 49(3): 136-42, 2003 06.
Artigo em Inglês | MEDLINE | ID: mdl-12848201

RESUMO

It is well established that malnutrition affects the immune response and increases the susceptibility to parasitic infection. In the present study we evaluated some aspects of the cellular and cytokine network that regulate the IgE responses, which are important components of host defence mechanisms against helminthic parasites in children infected with the intestinal helminth Ascaris lumbricoides, and with differing degrees of malnutrition. We found a defective T cell response in malnourished children, as indicated by diminished levels of circulating total (CD3+), helper (CD4+), IL-2-receptor-bearing (CD4+CD25+) and memory helper T cell responses (CD4+CD45RO+) in keeping with the decreased specific IgE levels against Ascaris lumbricoides. In contrast, the proportions of total B cells (CD20+), and those bearing the low-affinity IgE receptor (CD23+) were increased in the moderated malnourished children. Moreover, serum IL-4 levels and total IgE were also increased in these children. We suggest that malnutrition can cause an imbalance in T cell subpopulations that may lead to a defective T cell maturation and a decreased specific anti-Ascaris IgE response thus increasing the susceptibility to such infections. The high levels of total IgE observed may be related to a non-specific stimulation of the proliferation of activated B cells, probably caused by helminthic parasites and other infectious agents that are frequent in malnourished children.


Assuntos
Anticorpos Anti-Helmínticos/biossíntese , Antígenos de Diferenciação de Linfócitos T/sangue , Ascaríase/imunologia , Ascaris lumbricoides/imunologia , Imunoglobulina E/biossíntese , Distúrbios Nutricionais/imunologia , Análise de Variância , Animais , Antígenos CD/metabolismo , Criança , Fezes/parasitologia , Citometria de Fluxo , Humanos , Imunoglobulina E/sangue , Interleucina-4/sangue , Contagem de Linfócitos , Distúrbios Nutricionais/epidemiologia , Distúrbios Nutricionais/parasitologia , Contagem de Ovos de Parasitas , Teste de Radioimunoadsorção , Venezuela/epidemiologia
3.
Rev Panam Salud Publica ; 8(3): 156-63, 2000 Sep.
Artigo em Espanhol | MEDLINE | ID: mdl-11036425

RESUMO

We investigated the influence of nutritional status, as determined from anthropometric measurement, and of helminthic infections on the immune response of children of low socioeconomic status in two rural communities in Venezuela: El Cardón in the state of Nueva Esparta and San Daniel in the state of Miranda. A total of 125 boys and girls between 2 and 15 years old participated in the study. Their socioeconomic stratum was determined by a modified Graffar method. A physical examination was performed, as was also an anthropometric evaluation that took into account three indicators--weight-for-height, weight-for-age, and height-for-age--according to parameters established by the World Health Organization. Other examinations included feces, secretory IgA in saliva, total serum IgE, and anti-Ascaris-specific immunoglobulins. The children in both of the communities were in strata IV and V of the of Graffar scale, with a significantly greater number of stratum V inhabitants in San Daniel (P < 0.001). The results suggest that exposure level and individual susceptibility to the parasites are determining factors in parasitic infection and immune system behavior. The intensity of the parasitic burden plays an important role in stimulating polyclonal IgE, which diminishes the effectiveness of the specific response to those infections. On the other hand, nutritional deficiencies could change the immune mechanisms of the mucous membranes, negatively influence the synthesis of secretory IgA, and stimulate the production of polyclonal IgE. Poor sanitary and socioeconomic conditions promote more exposure to gastrointestinal parasites and a deficient nutritional status, which modulates the immune response and affects serum IgE and secretory IgA production mechanisms.


Assuntos
Ascaríase/imunologia , Estado Nutricional , Tricuríase/imunologia , Adolescente , Formação de Anticorpos , Antígenos de Helmintos/imunologia , Criança , Pré-Escolar , Feminino , Humanos , Imunoglobulina A/imunologia , Imunoglobulina E/imunologia , Lactente , Masculino , População Rural , Fatores Socioeconômicos , Venezuela
4.
Lancet ; 356(9225): 242-4, 2000 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-10963213

RESUMO

Modern man's ancestors lived in an environment where infectious, tropical diseases would have been endemic. We postulate that this relatively hostile environment would have caused genetic selection for increased proinflammatory immune responses. On migrating to temperate regions, pronounced proinflammatory responses would have been less important and selected against due to increased mortality from overly vigorous responses to harmless environmental agents. This hypothesis is supported by the observation that proinflammatory alleles in several genes involved in inflammation are more prevalent in populations with long-term tropical ancestry than those with long-term residence in temperate regions. In addition, when the former populations relocate from a tropical to a temperate region, they have a higher incidence of allergic inflammatory diseases than the latter populations. These observations suggest that there may be general patterns of recent evolutionary adaptation of the human immune system to particular regions and that these adaptations can produce differences in disease susceptibility.


Assuntos
Evolução Biológica , Mediadores da Inflamação/imunologia , Inflamação/imunologia , Adaptação Fisiológica/imunologia , Alelos , Clima , Suscetibilidade a Doenças/imunologia , Meio Ambiente , Evolução Molecular , Humanos , Hipersensibilidade/imunologia , Infecções/imunologia , Seleção Genética , Clima Tropical
5.
J Parasitol ; 86(4): 859-62, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10958474

RESUMO

This report examines the presence of proteolytic activity detected in media collected from in vitro cultures of Giardia intestinalis, and the partial characterization by gelatin-substrate polyacrylamide gel electrophoresis and inhibition studies. Gelatin-substrate polyacrylamide gel electrophoresis revealed 6 bands with proteolytic activity, with estimated molecular weights of 36, 59, 63, 72, 103, and 175 kDa. These bands were not present in the control medium. On the other hand, G. intestinalis trophozoite lysates showed proteolytic bands at 16, 20, 66, 82, 108, and 120 kDa, thus indicating that intracellular proteases could be different from the excretory/secretory (E/S) products. Based on inhibition studies, 2 bands of 59 and 63 kDa were inhibited by iodoacetic acid, indicating the presence of cysteine proteases. Partial inhibition of a band of 36 kDa was found with EDTA, a metal-chelating agent, suggesting the possible presence of metalloproteases. The presence of aspartic and serine proteases were not detected under the assay conditions used. As G. intestinalis E/S may be involved in differentiation mechanisms of the parasite and also be responsible for the mucosal alterations that occur in giardiasis, the characterization of these proteases may facilitate their evaluation as targets in the therapy of the disease.


Assuntos
Giardia lamblia/enzimologia , Peptídeo Hidrolases/isolamento & purificação , Animais , Meios de Cultura , Ácido Edético/farmacologia , Eletroforese em Gel de Poliacrilamida , Ácido Iodoacético/farmacologia , Peso Molecular , Pepstatinas/farmacologia , Peptídeo Hidrolases/química , Peptídeo Hidrolases/metabolismo , Fluoreto de Fenilmetilsulfonil/farmacologia , Inibidores de Proteases/farmacologia
6.
Int Arch Allergy Immunol ; 120(2): 100-7, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10545763

RESUMO

BACKGROUND: Of the ten recognised groups of Dermatophagoides pteronyssinus allergens, the group 4 is the only group that has not been characterised at the molecular level. METHODS: Primers were designed to PCR amplify Der p 4 (D. pteronyssinus) and Eur m 4 (Euroglyphus maynei) cDNA. These fragments were used to screen the corresponding cDNA libraries and the cDNA clones obtained were subsequently sequenced. The coding regions of Der p 4 and Eur m 4 were cloned into the pET expression vector and recombinant histidine-tagged proteins expressed in Escherichia coli. RESULTS: cDNA clones which included the mature protein coding sequence for Der p 4 and Eur m 4 were sequenced. The Der p 4 and Eur m 4 genes were found to code for 496 amino acid mature proteins with residues important for the function of alpha-amylase highly conserved. Der p 4 and Eur m 4 were calculated to be 90% identical and a BLAST search of the GenBank database found these sequences to be approximately 50% identical to insect and mammalian alpha-amylases. The calculated molecular weights of Der p 4 and Eur m 4 were approximately 57,000, although recombinant Der p 4 and Eur m 4 migrate on SDS-PAGE at about 60,000. Der p 4 recombinant protein was found to bind specific IgE in 3 of the 10 house dust mite allergic patients tested. CONCLUSIONS: This paper describes the first cDNA sequence of Der p 4 and Eur m 4 confirming that this allergen is house dust mite alpha-amylase.


Assuntos
Glicoproteínas/química , Glicoproteínas/genética , Alérgenos/imunologia , Sequência de Aminoácidos , Amilases/genética , Animais , Antígenos de Dermatophagoides , Proteínas de Artrópodes , Sequência de Bases , Poeira/análise , Biblioteca Gênica , Proteínas de Insetos , Ácaros/imunologia , Dados de Sequência Molecular , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Homologia de Sequência de Aminoácidos
7.
J Trop Pediatr ; 45(4): 215-20, 1999 08.
Artigo em Inglês | MEDLINE | ID: mdl-10467832

RESUMO

We evaluated helminthic infection and anthropometric indicators of nutritional status in a group of school-age children from a slum area of Caracas, Venezuela. The proportions of children at or below the 10th percentiles for height/age and weight/age were significantly higher in those presenting helminthiasis than in those uninfected. Although this could partially reflect a codependence of both helminthic infection and undernutrition or poverty, when the children were administered regular anthelmintic treatment for a year their anthropometric values improved significantly. When they were re-evaluated 8 months after the end of anthelmintic administration, the degree of reinfection by the most common helminth, Ascaris lumbricoides, was significantly higher in the growth-retarded children. These results confirm the relationship between helminthic infection and decreased growth rates in underprivileged populations, and indicate that children at nutritional risk are more susceptible to such infections, even after a prolonged parasite-free period.


Assuntos
Anti-Helmínticos/uso terapêutico , Helmintíase/tratamento farmacológico , Distúrbios Nutricionais/prevenção & controle , Áreas de Pobreza , Antropometria , Criança , Seguimentos , Helmintíase/complicações , Helmintíase/epidemiologia , Humanos , Distúrbios Nutricionais/epidemiologia , Distúrbios Nutricionais/etiologia , Recidiva , Venezuela/epidemiologia
9.
Brain Behav Immun ; 13(1): 1-13, 1999 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10371674

RESUMO

In the present study we evaluated the impact of a program of psychosocial intervention (PSI) on the immunological status and the clinical management of a group of asthmatic children of an island population in Venezuela. We studied a total of 35 asthmatic children who belonged to either a PSI group (19 patients) or a control group (16 patients), both of which received conventional antiasthmatic treatment. The PSI group received, in addition, a 6-month psychosocial intervention program which included relaxation, guided imagery, and self-esteem workshops. During the PSI period, the number of asthmatic episodes and the use of bronchodilator medication were significantly reduced, and pulmonary function was significantly improved, compared to the 6 months before intervention. There was also a significant reduction in the specific IgE responses against the most important allergen in these children, the intestinal parasite Ascaris lumbricoides. PSI resulted in a significant increase of NK cells, an augmented expression of the T-cell receptor for IL-2, and a significant decrease of leukocytes with low affinity receptors for IgE. In fact, these surface markers became similar to those of nonasthmatic children from both Coche Island and the mainland. None of these clinical or immunological changes were seen in the control group of asthmatics who did not undergo PSI. These results are consistent with the possibility that PSI induces immunological alterations that are responsible for the clinical and physiological improvements observed in the study group.


Assuntos
Asma/imunologia , Asma/terapia , Adolescente , Animais , Ascaris lumbricoides/imunologia , Asma/tratamento farmacológico , Broncodilatadores/administração & dosagem , Broncodilatadores/uso terapêutico , Criança , Terapia Combinada , Feminino , Humanos , Imagens, Psicoterapia , Imunoglobulina E/análise , Células Matadoras Naturais/imunologia , Contagem de Leucócitos , Masculino , Receptores de Interleucina-2/metabolismo , Terapia de Relaxamento , Testes de Função Respiratória , Autoimagem , Linfócitos T/imunologia , Linfócitos T/metabolismo , Venezuela
10.
Hum Genet ; 104(3): 269-74, 1999 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10323253

RESUMO

The diminishing incidence of parasitic infection in westernised societies has been suggested to result in an increased prevalance of asthma. Asthma is a polygenic disease and genome screens have shown that genes on chromosome 5q31-33 are strongly linked to the disease. The gene for the beta2-adrenoreceptor is located in this region and two polymorphisms have been identified that result in amino acid changes at positions 16 (ArgGly) and 27 (GlnGlu). To determine whether these polymorphisms influence asthma and parasitic infection, a genotype/phenotype study has been performed on a cohort of 126 children from Coche Island in Venezuela. There is a high incidence of asthma on the island and intestinal helminthiasis is endemic. Genotyping for both polymorphisms was carried out by using the polymerase chain reaction and allele-specific oligonucleotide hybridisation. Genotype frequencies in this cohort were consistent with other studies and both polymorphisms were in significant linkage disequilibrium. Individuals who were homozygous for Arg16 had significantly higher levels of specific IgE to Ascaris lumbricoides (P=0.002), significantly higher A. lumbricoides egg counts (P<0.001) and significantly larger wheal sizes following skin-prick testing with A. lumbricoides allergen (P=0.008). There was no association between either polymorphism and total serum IgE or asthma in this population. A combination of mast cell degranulation and the lung migratory phase of A. lumbricoides larvae may result in bronchoconstriction in infected individuals. These results suggest that the Gly 16 allele confers resistance to high levels of parasitic infection in this population. An alternative explanation for the association is that it may be the result of linkage disequilibrium with other genes in the chromosome 5q31-33 region.


Assuntos
Helmintíase/epidemiologia , Receptores Adrenérgicos beta 2/genética , Adolescente , Substituição de Aminoácidos , Animais , Arginina/genética , Ascaris lumbricoides/imunologia , Asma/epidemiologia , Asma/genética , Criança , Pré-Escolar , Interpretação Estatística de Dados , Eosinófilos/citologia , Feminino , Genótipo , Glutamina/genética , Helmintíase/genética , Humanos , Imunoglobulina E/sangue , Imunoglobulina E/imunologia , Contagem de Leucócitos , Masculino , Contagem de Ovos de Parasitas , Polimorfismo Genético , Prevalência , Pele/imunologia , Venezuela/epidemiologia
11.
Ann Trop Med Parasitol ; 93(8): 823-7, 1999 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10715676

RESUMO

The blood concentrations of haemoglobin were investigated in 82 children aged 2-9 years. Fifty-seven (31 boys and 26 girls) were stool-positive for Giardia intestinalis but the other 25, used as controls, were negative. The mean (S.D.) haemoglobin concentration among the infected children was significantly lower pre-treatment than that for the control group [11.6 (1.2) v. 12.6 (1.5) g/dl; P < 0.05]. Treatment of the infected children with a single oral dose of secnidazole (30 mg/kg) led to a significant increase in their mean haemoglobin level 15 days later, from 11.6 (1.2) g/dl pre-treatment to 12.4 (1.2) g/dl post-treatment (P < 0.05). The results indicate that the therapeutic control of giardiasis could be important in programmes to combat anaemia in children living in endemic areas.


Assuntos
Antiprotozoários/uso terapêutico , Giardíase/tratamento farmacológico , Hemoglobinas/análise , Metronidazol/análogos & derivados , Anemia/sangue , Anemia/etiologia , Anemia/prevenção & controle , Estudos de Casos e Controles , Criança , Pré-Escolar , Feminino , Giardíase/sangue , Giardíase/complicações , Humanos , Masculino , Metronidazol/uso terapêutico , Resultado do Tratamento
12.
Clin Exp Allergy ; 29 Suppl 4: 31-4, 1999 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10641563

RESUMO

The immunoglobulin E (IgE) antibody system is important in the genesis of asthma, but it appears to have originally evolved for defence against parasite infection. In order to study how IgE contributes to asthma, there are advantages in studying parasitized populations. Firstly, the IgE system can be studied when it is operating in a more natural state, and this could allow new insight into basic immune function. Secondly, the genetic susceptibility to produce high levels of IgE is more likely to be expressed, as the most intense IgE responses in nature are those found in the presence of parasitic infection. These more intense IgE responses should facilitate finding new 'asthma genes', assist in investigating how the DNA variations in candidate genes affect gene function and provide the possibility of developing new approaches to the treatment of asthma.


Assuntos
Genoma Humano , Imunoglobulina E/biossíntese , Doenças Parasitárias/genética , Doenças Parasitárias/imunologia , Asma/genética , Asma/imunologia , Humanos
13.
Ann Allergy Asthma Immunol ; 81(3): 261-5, 1998 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9759805

RESUMO

BACKGROUND: Previous studies have indicated that there may be an association between infection by the intestinal protozoan Giardia lamblia and the expression of allergic disease. OBJECT: We evaluated a group of children who attended the Outpatient Clinic of the Children's Hospital in Caracas, Venezuela, a group in which both allergic disease and giardiasis were common. METHODS: We performed feces examination and measured total and specific serum IgE (immunoglobulin E) in these children. RESULTS: We found that 70% of the children infected with G. lamblia presented symptoms of allergy, in contrast to 43% of the non-Giardia parasitized group (P <.05). In addition, the G. lamblia parasitized children showed significantly higher levels of total serum IgE (1194 IU/mL) than the non-Giardia group (822 IU/mL) (P <.005). Children infected with G. lamblia showed higher levels of specific serum IgE antibody against food allergens compared both with the non-parasitized group (P <.0001) and children infected with parasites other than Giardia (P <.05). In contrast, IgE responses against the house dust mite Dermatophagoides pteronyssinus were similar in all the groups studied. CONCLUSIONS: These results reveal a clear relationship between giardiasis and allergy, possibly because infection by this protozoon enhances sensitization towards food antigens, due to increased antigen penetration through damaged intestinal mucosa.


Assuntos
Giardíase/epidemiologia , Giardíase/imunologia , Hipersensibilidade/epidemiologia , Anticorpos Antiprotozoários/sangue , Criança , Pré-Escolar , Feminino , Hipersensibilidade Alimentar/parasitologia , Giardíase/sangue , Humanos , Hipersensibilidade/parasitologia , Imunoglobulina E/sangue , Masculino , Hipersensibilidade Respiratória/parasitologia , Venezuela/epidemiologia
14.
Allergy ; 53(8): 808-11, 1998 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9722232

RESUMO

BACKGROUND: House-dust mites contain components that are allergenic in mite-sensitive patients, and a number of these have been produced in recombinant form. METHODS: In the present study, we evaluated by skin prick testing the positivity to native Der p 2 and recombinant Der p 2, Der p 5, and Der p 7 allergens of Dermatophagoides pteronyssinus in patients with rhinitis, asthma, or a combination of these diseases, who were positive to whole-mite extract. RESULTS: In all patients, the positivity to both native and recombinant Der p 2 was high. In patients with either rhinitis or asthma, the reactivity to Der p 5 and 7 was significantly lower than to Der p 2. However, in patients with combined disease, the positivity to the minor allergens was almost as high as that to Der p 2. CONCLUSIONS: These results raise the question of whether patients with combined allergic rhinitis and asthma, when compared to those with either of these diseases alone, are predisposed to react to a wider range of mite allergens, or, inversely, whether patients who respond to the minor allergens are more susceptible to suffering the combined disease.


Assuntos
Asma/imunologia , Glicoproteínas/imunologia , Ácaros/imunologia , Rinite Alérgica Perene/imunologia , Clima Tropical , Administração por Inalação , Adolescente , Adulto , Alérgenos/imunologia , Animais , Antígenos de Dermatophagoides , Criança , Poeira/efeitos adversos , Escherichia coli/genética , Feminino , Glutationa Transferase/genética , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas Recombinantes de Fusão/imunologia , Testes Cutâneos , Venezuela
16.
J Allergy Clin Immunol ; 101(2 Pt 1): 217-21, 1998 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9500755

RESUMO

BACKGROUND: Although IgE antibody is clearly involved in allergic reactions to environmental allergens, this immunoglobulin is an important component of host-protective immune responses against the helminthic parasites that are endemic in the majority of the world population. However, these infections not only stimulate the production of antiparasite IgE antibody but can nonspecifically induce polyclonal IgE synthesis that results in highly elevated total serum IgE levels. Such polyclonal stimulation can diminish specific IgE antibody responses and cause saturation of mast cell Fc epsilon receptors, thus inhibiting allergic reactivity. This may represent a mechanism of immune evasion by the parasite. OBJECTIVE: Because an atopic disposition is generally recognized to be associated with elevated IgE synthesis against environmental allergens, the aim of this study was to evaluate the influence of atopy on the antiparasite response. To this end, we examined two groups of Venezuelan children in whom the intestinal helminth Ascaris lumbricoides is endemic but that differ greatly in their level of atopy. One group was from an island population (Coche Island) that has a very strong atopic background and in which the prevalence of allergic disease is extremely high. The other was a group of nonatopic children belonging to a mainland population (Barrio Los Erasos) that is of comparable socioeconomic level and has an exposure to helminthic infection similar to that of the island group but a relatively low expression of allergic diseases. RESULTS: Although the living conditions and the prevalence of Ascaris infection of the two groups were comparable, the intensity of the parasitic infection was considerably higher in the nonatopic mainland children (geometric mean values of eggs per gram of feces: Barrio Los Erasos, 7621; Coche Island, 1435; p < 0.001). In addition, their total serum IgE levels were significantly more elevated than in the atopic island group (geometric mean: Barrio Los Erasos, 2172; Coche Island, 941 IU/ml; p < 0.001). In contrast, the specific anti-Ascaris response was much stronger in the atopic children (geometric mean: Barrio Los Erasos, 0.30; Coche Island, 0.91 PRU/ml; p < 0.001), which resulted in the ratio of specific to total IgE being nine times higher than in the nonatopic mainland subjects. These differences were maintained even when the children were matched on the basis of infection intensity, thus indicating that the atopic children have an intrinsic propensity to favor specific over polyclonal IgE responses to the parasite. CONCLUSIONS: The children with a strong atopic background demonstrated IgE responses concordant with an enhanced protective response against helminthic parasites and had significantly lower intensities of infection than their nonatopic counterparts. These observations support the concept that the atopic state has conferred a selective evolutionary advantage that could compensate for its involvement in allergic disease.


Assuntos
Anticorpos Anti-Helmínticos/biossíntese , Ascaríase/imunologia , Ascaris lumbricoides/imunologia , Hipersensibilidade Imediata/imunologia , Imunoglobulina E/biossíntese , Animais , Criança , Pré-Escolar , Feminino , Humanos , Hipersensibilidade/sangue , Hipersensibilidade/imunologia , Hipersensibilidade Imediata/sangue , Masculino , Clima Tropical
17.
Int Arch Allergy Immunol ; 114(1): 59-67, 1997 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9303332

RESUMO

Der p 2, Der p 5 and Der p 7 are three allergens of the house-dust mite Dermatophagoides pteronyssinus that have been cloned and expressed in Escherichia coli as fusion proteins with glutathione-S-transferase (GST). We showed that these recombinant allergens produced immediate hypersensitivity skin-test reactions in 70, 60 and 52% respectively of a group of mite-sensitive allergic patients who were strongly positive to whole mite extract (WME). Comparable positivities were found for serum levels of specific IgE antibody against these allergens, as measured by the radioallergosorbant test (RAST). Overall, for the group of allergic patients that we evaluated, the serum IgE antibody concentrations against Der p 2, 5 and 7 were calculated to represent about one third, one quarter and one fifth respectively of the levels measured against the WME. However, for some patients the activity determined against the separate allergens was far higher than that detected against the WME, thus indicating that the concentration of these can be limiting in the WME. We found no significant correlations between the RAST levels against Derp 2 and either Derp 5 or 7, and RAST-inhibition tests indicated a lack of cross-reactivity between Der p 2 and the other two allergens. In contrast, the RAST results revealed the existence of a significant immunological relationship between Der p 5 and 7. Although a certain degree of reactivity against the GST fusion partner was found in the allergic patients studied, this was not a significant influence in determining the positivity against the recombinant allergens. These results confirm the in vivo biological activity of recombinant Der p 2, 5 and 7, and indicate that whilst Der p 2 is undoubtedly a major mite allergen, both Der p 5 and 7 make important contributions toward the overall allergenic activity of house-dust mites.


Assuntos
Alérgenos/imunologia , Glicoproteínas/imunologia , Ácaros/imunologia , Adulto , Alérgenos/genética , Animais , Especificidade de Anticorpos , Antígenos de Dermatophagoides , Estudos de Casos e Controles , Reações Cruzadas , Escherichia coli/genética , Feminino , Glutationa Transferase/genética , Glicoproteínas/genética , Humanos , Hipersensibilidade Imediata , Imunoglobulina E/sangue , Masculino , Ácaros/genética , Teste de Radioalergoadsorção , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/imunologia , Testes Cutâneos
18.
Am J Respir Crit Care Med ; 156(1): 50-4, 1997 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9230725

RESUMO

Intestinal helminths are among the most common infectious organisms of humans, particularly in tropical regions, and can induce the production of large quantities of IgE antibody. Part of this response is directed against the helminths own antigens, but a polyclonal stimulation also occurs that may increase the allergic reactivity toward environmental allergens. The importance of this in the symptomatology of asthma in these regions is, however, uncertain. In the present study we evaluated the effect of regular anthelminthic treatment with albendazol for 1 yr on a group of asthmatic patients in a zone in which these parasites are endemic. The number of asthmatic crises, need for maintenance therapy with inhaled steroids, and use of inhaled beta 2-agonists were compared both with those in the year prior to the study for the treated patients, and with those in a group of asthmatic subjects evaluated in parallel, but in whom the parasitic infections were not controlled. Significant improvement in all of these indicators of clinical status occurred in the treated group, not only for the period of anthelminth administration, but also for the year following. However, after 2 yr without treatment, the severity of asthma reverted to the initial state. No significant changes were observed in the control group over the entire period of evaluation. At the beginning of the study, the patients' pulmonary function was below the levels predicted for normal individuals, but this was not changed by the anthelminthic treatment. The patients' total serum IgE levels, which were elevated at the beginning of the study, were significantly diminished by the anthelminth administration, as were the specific IgE antibody levels and positivity in skin tests for immediate hypersensitivity to the common environmental allergen Dermatophagoides sp. However, the specific response to Ascaris lumbricoides, a common helminth in the area, was maintained despite treatment. These results indicate that intestinal helminthic infections can contribute to the clinical symptoms of asthma in an endemic situation. This may occur via a direct response to the parasite and/or a nonspecific potentiation of allergic reactivity to environmental allergens.


Assuntos
Albendazol/uso terapêutico , Anti-Helmínticos/uso terapêutico , Asma/etiologia , Helmintíase/complicações , Adolescente , Alérgenos , Animais , Antígenos de Dermatophagoides , Antígenos de Helmintos/imunologia , Ascaris lumbricoides/imunologia , Asma/imunologia , Doenças Endêmicas , Feminino , Glicoproteínas , Helmintíase/tratamento farmacológico , Helmintíase/imunologia , Humanos , Imunoglobulina E/sangue , Masculino , Ácaros/imunologia , Testes de Função Respiratória
19.
Acta Cient Venez ; 47(2): 103-9, 1996.
Artigo em Espanhol | MEDLINE | ID: mdl-9433826

RESUMO

House dust mites are the most important source of allergens in the tropical environment, and aqueous whole body extracts of these organisms have wide use in the diagnosis and treatment of allergic diseases. However, it has been reported that mite excretions have a high allergenic activity. Because of this, we have evaluated spent house-dust mite culture medium as an alternative source of allergens from these organisms. We demonstrated that the extraction of allergens from this material is more efficient in alkaline solutions such as ammonium bicarbonate, and when the extraction process is extended to 48 hours. When the purification process is complemented with dialysis and ammonium sulphate precipitation, the toxicity of the extract decreases and its allergenic activity increases. The electrophoretic pattern of proteins of the spent culture medium extract showed bands that bound specific IgE antibodies, but this extract may be deficient in one of the principle allergens of mites, Der pII. The extract stimulates immediate hypersensitivity skin reactions in house-dust allergic patients, and produces RAST inhibitions with their sera. The allergenic activity of this extract is comparable to that of the 1st. International Standard for house-dust mite extracts. These results demonstrate that spent house-dust mite culture medium is an appropriate source of allergens from these organisms, and because of its low commercial value, may be an economical alternative for the production of allergenic extracts.


Assuntos
Alérgenos , Meios de Cultivo Condicionados , Ácaros/imunologia , Animais , Humanos , Hipersensibilidade Imediata/imunologia , Camundongos , Proteínas/análise , Testes Cutâneos
20.
Trans R Soc Trop Med Hyg ; 89(5): 562-5, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-8560541

RESUMO

Helminthic infection can stimulate the interleukin-4 (IL-4)-dependent polyclonal synthesis of immunoglobulin E (IgE) in children endemically exposed to these parasites. As such children are also frequently at nutritional risk, in this study we considered the possible influence of malnutrition on serum IL-4 levels and the IgE response in helminthic infection. We evaluated 85 Ascaris-infected children living in an urban slum area of Caracas, Venezuela, and found that the serum levels of IL-4 and total IgE were significantly higher in malnourished children than in their well nourished counterparts. In contrast, the specific anti-Ascaris IgE antibody response was significantly lower in the malnourished group. After anthelmintic treatment of the children, the total serum IgE and IL-4 levels decreased significantly in the well nourished group, while the specific anti-Ascaris IgE antibody response increased. No significant change was detected, however, in the malnourished group. Our results suggested that malnutrition potentiates the polyclonal stimulation of IgE synthesis induced by helminths. As specific IgE antibody has been implicated in the resistance to helminthic infection, and the polyclonal stimulus diminishes this response, these factors may increase the susceptibility of malnourished children to such parasites.


Assuntos
Anticorpos Anti-Helmínticos/biossíntese , Ascaríase/imunologia , Ascaris lumbricoides/imunologia , Imunoglobulina E/biossíntese , Distúrbios Nutricionais/imunologia , Animais , Anti-Helmínticos/uso terapêutico , Especificidade de Anticorpos , Ascaríase/sangue , Ascaríase/tratamento farmacológico , Criança , Fezes/parasitologia , Humanos , Interleucina-4/sangue , Distúrbios Nutricionais/parasitologia , Estado Nutricional , Contagem de Ovos de Parasitas , Áreas de Pobreza
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