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Introduction: The hygiene hypothesis identified a relationship between living in rural areas and acquiring protective environmental factors against the development of asthma and atopy. In our previous study, we found a correlation between particular bacterial species and early-onset wheezing in infants from the rural tropics of Ecuador who were corticosteroid-naïve and had limited antibiotic exposure. We now describe a longitudinal study of infants conducted to determine the age-related changes of the microbiome and its relationship with wheezing. Methods: We performed an amplicon sequencing of the 16S rRNA bacterial gene from the oropharyngeal samples obtained from 110 infants who had a history of recurrent episodic wheezing sampled at different ages (7, 12, and 24 months) and compared it to the sequencing of the oropharyngeal samples from 150 healthy infants sampled at the same time points. Bioinformatic analyses were conducted using QIIME and R. Results: As expected, the microbiota diversity consistently increased as the infants grew older. Considering age-based microbiota changes, we found that infants with wheeze had significantly lower species richness than the healthy infants at 7 months, but not at 12 or 24 months. Most of the core and accessory organisms increased in abundance and prevalence with age, except for a few which decreased. At 7 months of age, infants with wheeze had notably higher levels of a single Streptococcus operational taxonomic unit and core microbiota member than controls. Conclusions: In a cohort with limited antibiotic and corticosteroid use, a progressively more complex and diverse respiratory microbial community develops with age. The respiratory microbiota in early life is altered in infants with wheeze, but this does not hold true in older infants.
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A COVID-19 resultou em milhares de óbitos e até o presente momento assola diversos pacientes com as suas implicações. Uma das consequências da doença foi o isolamento social, realizado por quase todos os países, o que configurou a alteração de diversos padrões de convivência e principalmente de exposição a outros agentes não patogênicos e patogênicos essenciais para o desenvolvimento da microbiota. Com isso, o seguinte projeto tem como objetivo a descrição dos impactos da pandemia da COVID-19 na microbiota intestinal de lactentes do período pandêmico e as consequências geradas no sistema imunológico imaturo, prejudicando seu desenvolvimento e maturação. A metodologia consiste na análise e seleção de artigos científicos publicados nos últimos 10 anos com auxílio de Descritores em Ciências da Saúde (DeCS) específicos nas línguas inglesa e portuguesa para o tema da pesquisa, sendo a combinação dos descritores feita por meio de operadores booleanos. Conclui-se que a composição da microbiota intestinal é iniciada intraútero e influenciada pela via de parto, contato pele a pele após o nascimento e pela presença da amamentação materna. A modificação das práticas durante a pandemia da COVID-19, pode alterar a microbiologia neonatal, assim como impactar na maturação do sistema imunológico do lactente, predispondo futuramente à doenças gastrointestinais, metabólicas e atópicas, como asma.
COVID-19 has resulted in thousands of deaths and until now is affecting many patients with its implications. One of the consequences of the disease was social isolation, carried out by almost all countries, which resulted in changes in different patterns of coexistence and mainly exposure to other non-pathogenic and pathogenic agents essential for the development of the microbiota. Therefore, the following project aims to describe the impacts of the COVID-19 pandemic on the microbiota of infants during the pandemic period and the consequences generated on the immature immune system, damaging its development and maturation and relating microbiology, essentially intestinal, throughout the project. The methodology consists of the analysis and selection of scientific articles published in the last 10 years with the help of specific Health Sciences Descriptors in English and Portuguese for the research topic, with the combination of descriptors made using Boolean operators. It is concluded that the composition of the intestinal microbiota begins in utero and is influenced by the mode of delivery, skin-to- skin contact after birth, and the presence of maternal breastfeeding. Modifying practices during the COVID-19 pandemic may alter neonatal microbiology and impact the maturation of the infant's immune system, potentially predisposing them to future gastrointestinal, metabolic, and atopic diseases such as asthma.
El COVID-19 ha provocado miles de muertes y todavía afecta a muchos pacientes con sus implicaciones. Una de las consecuencias de la enfermedad fue el aislamiento social, llevado a cabo por casi todos los países, que resultó en cambios en diferentes patrones de convivencia y principalmente exposición a otros agentes patógenos y no patógenos esenciales para el desarrollo de la microbiota. Com eso, el siguiente proyecto tiene como objetivo describir los impactos de la pandemia de COVID-19 en la microbiota de los lactantes durante el periodo pandémico y las consecuencias generadas sobre el sistema inmunológico inmaduro, perjudicando su desarrollo y maduración y relacionando la microbiología, fundamentalmente intestinal, a lo largo del proyecto. La metodología consiste en el análisis y selección de artículos científicos publicados en los últimos 10 años con la ayuda de Descriptores en Ciencias de la Salud específicos en inglés y portugués para el tema de investigación, con la combinación de descriptores realizada mediante operadores booleanos. Se concluye que la composición de la microbiota intestinal comienza intraútero y está influenciada por la vía de parto, el contacto piel a piel después del nacimiento y la presencia de la lactancia materna. La modificación de las prácticas durante la pandemia de COVID-19 puede alterar la microbiología neonatal y afectar la maduración del sistema inmunológico del lactante, predisponiéndolo potencialmente a enfermedades gastrointestinales, metabólicas y atópicas en el futuro, como la asma.
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BACKGROUND: Studies have shown an association between cesarean section (CS) and increased prevalence of childhood allergic diseases. While these observations have been consistent in industrialized countries, evidence from developing countries is limited. OBJECTIVE: To assess the association between the mode of delivery and allergic diseases in children aged 3-12 years in Quito, Ecuador. METHODS: In this cross-sectional study, parents were surveyed using an anonymous, standardized questionnaire from the International Study of Asthma and Allergies in Childhood project to assess the presence of asthma, allergic rhinitis, atopic dermatitis, and food allergies in their children. The children's age, sex, birthplace, delivery mode (CS/vaginal), socioeconomic status, and ethnicity were recorded. Other parameters included gestational age, breastfeeding, smoking status during pregnancy, and parental allergic diseases. RESULTS: After adjusting for confounding factors, children delivered via CS were found to have a higher risk of wheezing (odds ratio [OR] = 4.12, 95% confidence interval [CI]: 1.43-11.89), physician-diagnosed asthma (OR = 24.06; 95% CI: 1.98-292.3), and pimples, or eczema with the itching for 6 months (OR = 2.65; 95% CI: 1.06-6.61) than children delivered vaginally. No association was found between the delivery mode and rhinitis or food allergies. After stratifying by socioeconomic status, CS was only associated with allergic disorders in children of medium/high socioeconomic backgrounds. CONCLUSIONS: As seen in industrialized settings, children born by CS in nonindustrialized countries have an increased risk of developing allergic disorders including asthma and dermatitis, compared to those delivered vaginally.
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Asma , Rinite Alérgica , Cesárea , Criança , Pré-Escolar , Estudos Transversais , Equador , Feminino , Humanos , MasculinoRESUMO
This study aimed to evaluate the effects of early-life exposure to different extracts of Angiostrongylus cantonensis (A. cantonensis) on airway inflammation in an allergic asthma model. The total soluble extract (TE) and the soluble extracts of the digestive (AcD), reproductive (AcR), and cuticle (AcC) systems of A. cantonensis were used for immunisation before ovalbumin (OVA)-sensitisation/challenge in an OVA-induced allergic asthma model. The initial hypothesis of the study was that some soluble extract of the systems (AcD, AcR, or AcC) could be more potent to the modulation of inflammation than the TE. Our data, however, shows that immunisation with the TE is more promising because it decreased the high influx of inflammatory cells on airways and promoted an increase of interferon-γ (IFN-ɣ) and interleukin-10 (IL-10) levels. Besides this, the immunisation with the TE also led to a reduction of goblet cells and mucus overproduction in the lung tissue of asthmatic mice. We believe that the extracts have a distinct capacity to modulate the immune system, due to the TE possessing a greater variability of molecules, which together leads to control of airway inflammation. In conclusion, this is the first study to reveal that the TE of A. cantonensis adult worms has a greater potential for developing a novel therapeutic for allergic asthma.
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Angiostrongylus cantonensis/metabolismo , Asma/imunologia , Imunomodulação , Angiostrongylus cantonensis/anatomia & histologia , Animais , Asma/induzido quimicamente , Asma/prevenção & controle , Citocinas/metabolismo , Modelos Animais de Doenças , Feminino , Imunização , Inflamação , Pulmão/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Ovalbumina/efeitos adversos , Mucosa Respiratória/metabolismoRESUMO
BACKGROUND: The etiology of inflammatory bowel disease (IBD) is unknown, but it is believed to be multifactorial. The hygiene hypothesis proposes that better hygiene conditions would lead to less infectious disease during childhood and favor the development of immune-mediated diseases. AIM: To test the hygiene hypothesis in IBD by assessing the environmental risk factors associated with IBD development in different regions of Brazil with diverse socioeconomic development indices. METHODS: A multicenter case-control study was carried out with 548 Crohn's disease (CD) and 492 ulcerative colitis (UC) outpatients and 416 healthy controls, from six IBD centers within different Brazilian states at diverse socioeconomic development stages. A semi-structured questionnaire with 87 socioeconomic and environmental questions was applied. Logistic regression model was created to assess the odds ratio (OR) with P value and 95% confidence intervals (CI). RESULTS: Predictive variables for both diseases (CD and UC) were women [odd ratios (OR) = 1.31; OR = 1.69], low monthly family income (OR = 1.78; OR = 1.57), lower number of cohabitants (OR = 1.70; OR = 1.60), absence of vaccination (OR = 3.11; OR = 2.51), previous history of bowel infections (OR = 1.78; OR = 1.49), and family history of IBD (OR = 5.26; OR = 3.33). Associated risk factors for CD were age (18-39 years) (OR = 1.73), higher educational level (OR = 2.22), absence of infectious childhood diseases (OR = 1.99). The UC predictive variables were living in an urban area (OR = 1.62), inadequate living conditions (OR = 1.48) and former smokers (OR = 3.36). Appendectomy was a risk factor for CD (OR = 1.58) with inverse association with UC (OR = 4.79). Consumption of treated and untreated water was associated with risk of CD (OR = 1.38) and UC (OR = 1.53), respectively. CONCLUSION: This is the first examining environmental exposures as risk factors for inflammatory bowel disease in Brazil. Most of the variables associated with disease risk support the role of the hygiene hypothesis in IBD development.
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Colite Ulcerativa , Doenças Inflamatórias Intestinais , Adolescente , Adulto , Brasil/epidemiologia , Estudos de Casos e Controles , Colite Ulcerativa/diagnóstico , Colite Ulcerativa/epidemiologia , Feminino , Humanos , Masculino , Fatores de Risco , Adulto JovemRESUMO
OBJECTIVES: Little research exists documenting levels of intestinal inflammation among indigenous populations where exposure to macroparasites, like soil-transmitted helminths (STHs), is common. Reduced STH exposure is hypothesized to contribute to increased prevalence of elevated intestinal inflammation in wealthy nations, likely due to coevolutionary histories between STHs and human immune systems that favored anti-inflammatory pathways. Here, we document levels of intestinal inflammation and test associations with STH infection among the Shuar of Ecuador, an indigenous population undergoing socioeconomic/lifestyle changes that influence their hygienic environment. We predict that fecal calprotectin (FC; a measure of intestinal inflammation) will be lower in STH infected individuals and that FC will be negatively associated with infection intensity. METHODS: Stool samples to analyze FC levels and STH infection were collected from 69 Shuar participants (ages 5-75 years). Children (<15 years) and adults (15+ years) were analyzed separately to understand the role of exposure in immune system development and the intestinal inflammatory response. RESULTS: Two species of STH were present: Ascaris lumbricoides and Trichuris trichiura. The relationships between infection and intestinal inflammation were age- and species-specific. While no significant relationships were found among adults, children who were singly infected with T. trichiura had lower FC levels than uninfected children. Infection intensity was not significantly associated with FC in children or adults. CONCLUSIONS: These preliminary results provide limited support for our hypotheses, documenting tentative age- and species-specific associations between FC and infection status. Findings may point to the importance of species-specific STH exposure during immune system development.
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Helmintíase/complicações , Helmintíase/epidemiologia , Doenças Inflamatórias Intestinais/complicações , Doenças Inflamatórias Intestinais/epidemiologia , Adolescente , Adulto , Idoso , Ascaríase/complicações , Ascaríase/epidemiologia , Criança , Pré-Escolar , Estudos Transversais , Equador , Fezes/química , Fezes/parasitologia , Feminino , Humanos , Complexo Antígeno L1 Leucocitário/análise , Masculino , Pessoa de Meia-Idade , Tricuríase/complicações , Tricuríase/epidemiologia , Adulto JovemRESUMO
The hygiene hypothesis was proposed almost three decades ago. Nevertheless, its mechanism still remains with relevant controversies. Some studies defend that early exposures during childhood to microbes and parasites are key determinants to prevent allergies and autoimmune diseases; however, other studies demonstrated that these early exposures can even potentiate the clinical scenario of the diseases. Based on several studies covering the influences of microbiome, parasites, related theories and others, this review focuses on recent advances in the hygiene hypothesis field. In addition, the main immunological mechanisms underlying the hygiene hypothesis are also discussed. We also strongly encourage that researchers do not consider the hygiene hypothesis as a theory based strictly on hygiene habits, but a theory combining diverse influences, as illustrated in this review as the hygiene hypothesis net.
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Doenças Autoimunes/prevenção & controle , Microbioma Gastrointestinal/fisiologia , Hipótese da Higiene , Hipersensibilidade/prevenção & controle , Infecções/imunologia , Animais , Criança , Humanos , ParasitosRESUMO
The Tropics is very appropriate to test the hypotheses raised to explain the increasing trends of allergy and other inflammatory diseases worldwide. The absence of parasite infection as a possible cause of the increase of allergic diseases was proposed by J. Gerrard a long time ago; however, the idea that helminth infections, which induce a strong Th2 could reduce allergy symptoms seems counterintuitive; but the fact is that they have a dual effect: they increase the Th2 responses but also exert immunosuppression and both effects influence the symptoms of allergy. Basic experimentation has provided valuable information about the mechanisms of allergic inflammation and more recently, about its control by helminth induced immunomodulation, discovering helminth molecules with anti-inflammatory properties that are meant to replace the live helminth therapeutic approaches. The immunosuppressive power of helminths makes them excellent candidates to be considered in the hygiene hypotheses. Future comprehensive studies evaluating simultaneously the role of microbial infections, helminth infections, microbiota, pollution and biodiversity will help to elucidate the causes of the increasing trends of allergic disorders. Doing this in the tropics, where all these variables are still present could be difficult but no doubt that will be more informative.
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Helmintíase/imunologia , Hipersensibilidade/imunologia , Células Th2/imunologia , Animais , Colômbia , Helmintos/imunologia , Humanos , Hipótese da Higiene , Imunomodulação , Clima TropicalRESUMO
AIM: To identify environmental risk factors associated with the development of Crohn's disease (CD) in order to re-assess the hygiene hypothesis. METHODS: A hospital-based, case-control study was carried out with CD patients (n = 145) and controls (n = 163) representing a socioeconomically diverse statewide catchment area in Brazil. Controls were recruited from caregivers of patients seen in different outpatient clinics at the same hospital. A multi-item survey with 94 questions regarding family history of CD, perinatal and childhood circumstances, living conditions, tobacco use and familial socioeconomic status was carried out by interviewers. RESULTS: On the univariate analysis, predictive variables for CD included being male, under age of 40, a high education level, urban dweller, smaller family size, exposure to enteric pathogens and user of treated water (P < 0.005). On the multivariate analysis, variables significantly associated with CD were male gender (OR = 2.09), under age 40 (OR = 3.10), white (OR = 2.32), from a small family in childhood (OR = 2.34) and adulthood (OR = 3.02), absence of viral infections in childhood (OR = 2.23), exposure to enteric pathogens (OR = 2.41), having had an appendectomy (OR = 2.47) and prior or current smoker (OR = 2.83/1.12). CONCLUSION: Most variables supporting the "hygiene hypothesis" are associated with the development of CD but are not independent predictors of the diagnosis.
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Doença de Crohn/epidemiologia , Doença de Crohn/imunologia , Exposição Ambiental/efeitos adversos , Hipótese da Higiene , Fumar/efeitos adversos , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Apendicectomia/efeitos adversos , Brasil/epidemiologia , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Fatores de Risco , Fatores Sexuais , Classe Social , Inquéritos e Questionários , Adulto JovemRESUMO
It is generally accepted that autoimmune diseases like multiple sclerosis (MS) arise from complex interactions between genetic susceptibility and environmental factors. Genetic variants confer predisposition to develop MS, but cannot be therapeutically modified. On the other hand, several studies have shown that different lifestyle and environmental factors influence disease development, as well as activity levels and progression. Unlike genetic risk factors, these can be modified, with potential for prevention, particularly in high-risk populations. Most studies identifying particular lifestyle and environmental factors have been carried out in Caucasian patients with MS. Little or no data is available on the behavior of these factors in Latin American populations. Ethnic and geographic differences between Latin America and other world regions suggest potential regional variations in MS, at least with respect to some of these factors. Furthermore, particular environmental characteristics observed more frequently in Latin America could explain regional differences in MS prevalence. Site-specific studies exploring influences of local environmental factors are warranted.
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La búsqueda de la comprensión del individuo en su totalidad sintomática ha sido uno de los propósitos de la Homeopatía desde sus comienzos. A todo lo largo de su historia, los homeópatas se han interesado por la cuestión de que el tratamiento inadecuado de las enfermedades agudas en la infancia pudiera conducir a enfermedadescrónicas futuras. Hahnemann advirtió que tratar las enfermedades agudas con medicina alopática, con fuertes dosis de fármacos, o bien suprimir los síntomas locales detales enfermedades, incrementaría el riesgo de sufrir enfermedades crónicas futuras. Burnett propuso la teoría de la vacunosis y advirtió de las manifestaciones crónicas subsiguientes a la vacunación contra la viruela. Buscando el origen fisiopatológico de las enfermedades crónicas, homeópatas franceses las correlacionaron con la reacción anormal del sistema reticuloendotelial (RES, por sus siglas en inglés). Estudiando la patología experimental, Maffei atribuyó las manifestaciones sintomáticas al desequilibrio entre los fenómenos inmunológicos de la alergia y la inmunidad. Denominó meta-alergia y para-alergia a los efectos sensibilizantes y patogénicos de los medicamentos y vacunas, respectivamente. La hipótesis de la higiene se basa en evidencia de que el desequilibrio de la respuesta inmunológica en la niñez, específicamente entre las subpoblaciones de linfocitos Th1 y Th2, es responsable del desarrollo de ciertas enfermedades alérgicas y crónicas en el futuro.El factor perturbador para la predisposición a presentar una respuesta alérgica en el futuro (Th2) es la obstrucción de las manifestaciones naturales de las enfermedadesinfecciosas (respuesta de Th1) en los niños pequeños. El tratamiento homeopático busca equilibrar la reacción vital, correspondiente a una respuesta fisiológica integrativa, con la posibilidad de regular el desequilibrio de Th1/Th2. Sin embargo, se carece de estudios clínicos que sustenten tal hipótesis. (AU)
Seeking to understand the individual in his symptomatic totality has been an aim of homeopathy since its beginning. Throughout its history, homeopaths have beenconcerned that inadequate treatment of acute diseases in childhood may lead to future chronic diseases. Hahnemann cautioned that by treating acute diseases withallopathic medicine, with strong doses of drugs, or suppressing local symptoms of those diseases, would increase the risk of future chronic diseases. Burnett proposedthe theory of vaccinosis and warned of chronic manifestations subsequent to smallpox vaccination. French homeopaths, seeking the physiopathological origin of chronic diseases, correlated it to the abnormal reaction of the reticuloendothelial system (RES). Through the study of experimental pathology, Maffei attributed symptomaticmanifestations to the imbalance between the immunological phenomena of allergy and immunity. He termed the sensitizing and pathogenic effects of medications and vaccines, metallergy and parallergy, respectively. The hygiene hypothesis is based on evidence that the imbalance of immunological response in childhood, specifically among the Th1 and Th2 lymphocyte subpopulations, is responsible for the development of some allergic and chronic diseases in the future. The deranging factor for the predisposition to future allergic response (Th2) is the obstruction of natural manifestations of infectious diseases (Th1 response) in young children. Homeopathic treatment aims to equilibrate vital reaction, corresponding to an integrative physiological response, it may regulate Th1/Th2 imbalance. However, clinical trials to support this hypothesis are lacking. Homeopathy (2002) 91, 207216. (AU)
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Humanos , Masculino , Feminino , Pré-Escolar , Criança , Doença Crônica , Hipótese da Higiene , Homeopatia , SupressãoRESUMO
AIM: To assess the relationship between oral health and asthma. METHODS: Data from 1315 overweight or obese individuals, aged 40-65 years were used. Asthma was self-reported, whereas periodontitis, bleeding on probing (BOP) and plaque index were determined by clinical examinations. RESULTS: Using logistic regression adjusting for gender, smoking status, age, body mass index, family history of asthma and income level, revealed that the odds ratio (OR) of asthma for a participant with severe periodontitis was 0.44 (95% confidence interval: 0.27, 0.70) that of a participant with none/mild periodontitis. On the other hand, proportion of BOP sites and plaque index were not statistically significant. For a participant with severe periodontitis, the OR of taking asthma medication was 0.20 (95% confidence interval: 0.09, 0.43) that of a participant with none/mild periodontitis. Moreover, proportion of BOP sites was statistically associated with use of asthma medication, whereas plaque index still remained non-significant. CONCLUSION: Participants with severe periodontitis were less likely to have asthma. Stronger evidence of an inverse association was found when using asthma medication as outcome.
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Asma , Idoso , Índice de Placa Dentária , Humanos , Pessoa de Meia-Idade , Obesidade , Sobrepeso , Perda da Inserção Periodontal , Índice PeriodontalRESUMO
INTRODUCTION: The hygiene hypothesis, formulated to explain the increased incidence of allergic and autoimmune diseases observed in industrialized countries, remains controversial. We reflected upon this hypothesis during a medical mission to rural and impoverished villages of central Peru. MATERIALS AND METHODS: The mission was carried out in July 2015 to aid three Andean villages located near Cusco, and comprised 10 American physicians, 4 nurses, and 24 students. After recording the vital signs, patients were triaged by nurses based on the major complaint, visited by physicians, and prescribed medications. Physicians wrote their notes on a one-page form and established diagnoses purely on clinical grounds, without laboratory or imaging testing. Physician notes were then analyzed retrospectively in a de-identified and double-blinded fashion. RESULTS: A total of 1075 patients (357 men and 718 women) were visited during 5 consecutive clinic days, 840 being adults and 235 <18 years of age. The most common complaints were back pain, stomach pain, headache, and vision loss. Osteoarthritis, gastritis, visual disturbances, and parasitic infections dominated the diagnostic categories. Thirty-seven patients (3 %) were diagnosed with an allergic or autoimmune disease, mainly represented by asthma, rheumatoid arthritis, and Hashimoto's thyroiditis, a prevalence that was not significantly lower than that reported in industrialized countries. CONCLUSIONS: Although a study of this nature cannot definitively support or refute the hygiene hypothesis, it does provide a novel snapshot of disease prevalence in rural Andean villages of central Peru. The study could serve as a basis to implement basic public health interventions and prepare for future missions to the same or comparable regions.
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BACKGROUND: Bronchial asthma is one of the most common chronic diseases in childhood, with a current prevalence of 6% to 9%, but a prevalence that is increasing at an alarming rate. Asthma is a complex genetic disorder with strong environmental influence. It imposes a growing burden on our society in terms of morbidity, quality of life, and healthcare costs. Despite large-scale efforts, only a few asthma genes have been confirmed, suggesting that the genetic underpinning of asthma is highly complex. METHODS: A review of the literature was performed regarding atopic and nonatopic asthma risk factors, including environmental risk factors and genetic studies in adults and children. RESULTS: Several environmental risk factors have been identified to increase the risk of developing asthma such as exposure to air pollution and tobaccos smoke as well as occupational risk factors. In addition atopy, stress, and obesity all can increases the risk for asthma in genetically susceptible persons. CONCLUSION: Asthma represents a dysfunctional interaction with our genes and the environment to which they are exposed, especially in fetal and early infant life. The increasing prevalence of asthma in all age groups indicate that our living environment and immunity are in imbalance with each other reacting with airway inflammation to the environmental exposures and often non-harmful proteins, such as allergens causing the current "asthma and allergy epidemic." Because of the close relationship between asthma and chronic rhinosinusitis, it is important that otolaryngologists have a good understanding of asthma, the etiologic factors associated with disease, and its evaluation and management.
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Asma , Asma/etiologia , Asma/genética , Meio Ambiente , Predisposição Genética para Doença , Humanos , Fatores de RiscoRESUMO
The Central American countries: Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica, and Panama are in transition from a dietary culture based mainly on maize to a wheat-containing diet. Several other changes are occurring, such as a decrease of parasitic and infectious diseases. The environmental changes permit a prediction of an increase of celiac disease and other autoimmune diseases such as type I diabetes and thyroid disease in these genetically heterogeneous countries. At present, celiac disease and gluten-related disorders are considered to be of no relevance at the level of public health in these nations. This review documents the presence of celiac disease in Central America. It draws attention to some of the challenges in planning systematic studies in the region since up until recently celiac disease was unknown. The aim of this review is to disseminate knowledge obtained with preliminary data, to stimulate clinical and basic scientists to study these diseases in Central America and to alert authorities responsible for the planning of education and health, to find possibilities to avoid a rise in these disorders before the epidemics start, as has occurred in the Mediterranean countries.
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Doença Celíaca/etnologia , Dieta/efeitos adversos , Triticum/efeitos adversos , Zea mays , Animais , Autoanticorpos/sangue , Autoimunidade , Biomarcadores/sangue , Doença Celíaca/diagnóstico , Doença Celíaca/dietoterapia , Doença Celíaca/genética , Doença Celíaca/imunologia , América Central/epidemiologia , Características Culturais , Dieta/etnologia , Dieta Livre de Glúten , Predisposição Genética para Doença , Humanos , Indígenas Centro-Americanos/genética , Valor Preditivo dos Testes , Fatores de Risco , Fatores de Tempo , Triticum/imunologiaRESUMO
Pathogenic mechanisms underlying multiple sclerosis development have yet to be clearly identified, but considerable evidence indicates that autoimmunity plays an important role in the etiology of the disease. It is generally accepted that autoimmune diseases like MS arise from complex interactions between genetic susceptibility and environmental factors. Although environmental factors unequivocally influencing MS development have yet to be established, accumulating evidence singles out several candidates, including sunlight-UV exposure or vitamin D deficiency, viral infections, hygiene, and cigarette smoking. Vitamin D deficiency has been associated with different autoimmune diseases. Several investigations indicate 125 (OH)2 vitamin D plays a critical role in shaping T-cell response and inducing T cells with immunosuppressive properties. Likewise, helminth infections represent another potential environmental factor exerting immunomodulatory properties. Both epidemiological and experimental data provide evidence to support autoimmune down-regulation secondary to parasite infections in patients with MS, through regulatory T- and B-cell action, with effects extending beyond simple response to an infectious agent. Finally, different epidemiological studies have demonstrated that Epstein-Barr virus infection confers added risk of developing MS. Proposed mechanisms responsible for this association include activation and expansion of self-reactive T and B cells, lower threshold for self-tolerance breakdown, and enhanced autoreactive B-cell survival, all to be discussed in this review. Understanding environmental factors influencing propensity to MS will lead to new and more effective approaches to prevent and treat the disease.
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Meio Ambiente , Infecções por Vírus Epstein-Barr/epidemiologia , Esclerose Múltipla/epidemiologia , Doenças Parasitárias/epidemiologia , Vitamina D/fisiologia , Infecções por Vírus Epstein-Barr/complicações , Helmintíase/complicações , Helmintíase/epidemiologia , Humanos , Sistema Imunitário , Estado Nutricional , Doenças Parasitárias/complicaçõesRESUMO
The "hygiene hypothesis" postulates an inverse relationship between the prevalence of parasitic infections and the frequency of multiple sclerosis (MS). Objective: It was to study whether antibodies against parasites could be demonstrated more frequently in blood serum from MS patients with oligoclonal bands (OCB) than from MS patients without OCB. Methods: We studied serum samples from 164 patients who had previously been analyzed to investigate OCB. Parasitic antibodies were studied through unidimensional electrophoresis of proteins on polyacrylamide gel against Taenia antigens, searching for antiparasitic specific low molecular weight antibodies and also for antiparasitic nonspecific high molecular weight antibodies. Results: Two of the 103 patients with no evidence of OCB had antibodies of low molecular weight and 59 of them had antibodies of high molecular weight. Of the 61 patients with evidence of OCB, one showed antibodies of low molecular weight and 16 showed antibodies of high molecular weight. Conclusion: Antiparasitic antibodies are detected with similar frequency in MS patients with OCB and in MS patients without OCB.
A "hipótese da higiene" postula haver relação inversamente proporcional entre a prevalência de infecções por parasitas e a frequência da esclerose múltipla (EM). Objetivo: Foi verificar se em pacientes com EM aparecem anticorpos antiparasitários mais frequentemente no grupo com bandas oligoclonais (BOC) do que no grupo sem BOC. Métodos: Foram estudadas amostras de sangue de 164 pacientes previamente analisadas para investigar BOC. Foi feita eletroforese unidimensional de proteínas em gel de poliacrilamida contra antígenos de Taenia para pesquisa de anticorpos específicos de baixo peso molecular e também de anticorpos inespecíficos de alto peso molecular. Resultados: Dois dos 103 pacientes em que não havia BOC apresentaram anticorpos de baixo peso molecular, e 59 apresentaram anticorpos de alto peso molecular. Dos 61 pacientes em que não havia BOC, um apresentou anticorpos de baixo peso molecular e 16, anticorpos de alto peso molecular. Conclusão: Anticorpos antiparasitários foram detectados com frequência semelhante em doentes com EM independentemente da presença ou não de BOC.
Assuntos
Animais , Humanos , Anticorpos Anti-Helmínticos/sangue , Antígenos de Helmintos/sangue , Esclerose Múltipla/líquido cefalorraquidiano , Bandas Oligoclonais/líquido cefalorraquidiano , Taenia solium/imunologia , Anticorpos Anti-Helmínticos/química , Eletroforese em Gel de Poliacrilamida , Peso MolecularRESUMO
A esclerose múltipla (EM) é uma doença inflamatória, crônica e desmielinizante do sistema nervoso central (SNC). A caracterização de uma estratégia profilática e/ou terapêutica na EM é necessária, já que não há cura para essa doença. No contexto da hipótese da higiene, a exposição diminuída a certos agentes infecciosos como os helmintos, os lactobacilos e as micobactérias saprófitas estaria relacionada com o aumento na incidência de doenças alérgicas e autoimunes. Assim, o objetivo deste trabalho foi caracterizar a infecção por Strongyloides venezuelensis em ratos Lewis e avaliar se a mesma modula as características clínicas, imunológicas e histopatológicas da encefalite autoimune experimental (EAE) nestes animais. Na primeira etapa, caracterizamos as fases aguda e de recuperação da infecção e avaliamos os padrões de resposta imune nestas duas fases. Na segunda etapa, avaliamos o efeito de uma ou várias infecções com S. venezuelensis na evolução da EAE. Os animais foram avaliados diariamente quanto ao peso e escore clínico da doença e a eutanásia foi realizada na fase de recuperação da EAE para avaliação da resposta imune (produção de citocinas e anticorpos) e do processo inflamatório no SNC. A frequência de células T CD4+CD25+Foxp3+ no baço e nos linfonodos (inguinais e poplíteos) também foi determinada após infecção única (fase aguda e de recuperação) ou múltipla com este helminto. De acordo com os diversos parâmetros avaliados, os resultados demonstraram que a infecção com S. venezuelensis não modificou a progressão da EAE em ratos Lewis e também não alterou a frequência de células T CD4+CD25+Foxp3+ nos órgãos linfóides secundários...