RESUMEN
OBJECTIVES: Helicobacter pylori (H. pylori)-a gastric bacteria affecting almost 50% of the global population and leading to ulcers and cancer in severe cases-is a growing health concern among Indigenous populations who report a high burden of reported poor general health and gastrointestinal distress. We test hypothesized associations between H. pylori exposure patterns and environmental, social, and biological conditions among a sample of 212 Indigenous Awajún adults (112 males, 100 females, ages 18-65 years) living in the northern Peruvian Amazon. MATERIALS AND METHODS: Dried blood spots were analyzed for H. pylori-specific IgG using a recently developed enzyme-linked immunosorbent assay. Resulting seropositivity rates and antibody concentrations, proxying past exposures to H. pylori were analyzed in relation to relevant environmental (toilet type, floor material, reported water quality), social (household size and education level), and biological (age, sex, BMI, blood pressure, immune and metabolic biomarkers) factors using multivariable regression analyses. RESULTS: We found near ubiquitous seropositivity for H. pylori exposure in our sample (99.1% seropositive). In the regression analyses, elevations in H. pylori antibody concentrations were significantly higher among males compared to females (ß = 0.36, p = 0.01). No associations were found with any other factors. DISCUSSION: Anthropological research in the study communities suggests that the male bias in elevations of H. pylori antibody concentrations is related to cultural and biological factors. Future research is needed to further unravel these biocultural dynamics and determine whether elevations in H. pylori antibody concentrations have clinical relevance for gastrointestinal health outcomes in this population.
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Infecciones por Helicobacter , Helicobacter pylori , Indígenas Sudamericanos , Adolescente , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven , Anticuerpos Antibacterianos/sangre , Infecciones por Helicobacter/epidemiología , Infecciones por Helicobacter/sangre , Infecciones por Helicobacter/inmunología , Helicobacter pylori/inmunología , Helicobacter pylori/aislamiento & purificación , Inmunoglobulina G/sangre , Indígenas Sudamericanos/estadística & datos numéricos , Perú/epidemiología , PrevalenciaRESUMEN
Helicobacter pylori is a Gram-negative bacterium found on the luminal surface of the gastric mucosa in at least 50% of the world's human population. The protective effect of breastfeeding against H. pylori infection has been extensively reported; however, the mechanisms behind this protection remain poorly understood. Human IgA from colostrum has reactivity against H. pylori antigens. Despite that IgA1 and IgA2 display structural and functional differences, their reactivity against H. pylori had not been previously determined. We attested titers and reactivity of human colostrum-IgA subclasses by ELISA, immunoblot, and flow cytometry. Colostrum samples from healthy mothers had higher titers of IgA; and IgA1 mostly recognized H. pylori antigens. Moreover, we found a correlation between IgA1 reactivity and their neutralizing effect determined by inhibition of cytoskeletal changes in AGS cells infected with H. pylori. In conclusion, colostrum-IgA reduces H. pylori infection of epithelial gastric cells, suggesting an important role in preventing the bacteria establishment during the first months of life. As a whole, these results suggest that IgA1 from human colostrum provides protection that may help in the development of the mucosal immune system of newborn children.
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Anticuerpos Antibacterianos/inmunología , Antígenos Bacterianos/inmunología , Calostro/inmunología , Helicobacter pylori/inmunología , Inmunoglobulina A Secretora/inmunología , Citoesqueleto , Células Epiteliales , Femenino , Mucosa Gástrica/inmunología , Infecciones por Helicobacter/inmunología , Humanos , EmbarazoRESUMEN
Se determinó la respuesta inmunológica a proteínas recombinantes de Helicobacter pylori en pacientes dis-pépticos (adultos y niños), pacientes con cáncer gástrico y sus familiares asintomáticos adultos viviendo con ellos. Se utilizó la prueba recomLine® Helicobacter IgG e IgA, y con base en el reconocimiento de los factores de virulencia VacA y CagA se determinó si la cepa de H. pylori era de tipo I o II. El análisis de los datos fue descriptivo y analítico y se estimaron los intervalos de confianza de 95%, con un nivel de error de 0.05 y Odds ratio. El 58.7% (121/206) de los pacientes presentó la bacteria en tinción histológica de biopsia, positividad que disminuyó con la edad y daño histológico. La frecuencia de la respuesta a los anticuerpos IgG fue mayor que IgA, en ambos casos ésta fue menor en los niños. Las proteínas del H. pylori más reconocidas tanto por IgA como IgG fueron VacA y CagA, y la respuesta a las otras proteínas investigadas fue mayor al aumentar el daño histológi-co. La cepa tipo I fue la que predominó en la población en estudio con 66% (136/206). Se deben continuar con los estudios de prevalencia de la cepa tipo I del H. pylori y del reconocimiento de sus antígenos en la población guatemalteca a fin de determinar su utilidad en el diagnóstico y pronóstico de la infección.
The immune response to recombinant Helicobacter pylori proteins was determined in dyspeptic patients (adults and children), patients with gastric cancer and their asymptomatic adults' relatives living with them. The recomLine® Helicobacter IgG and IgA test was used and based on the recognition of the virulence factors VacA and CagA, it was determined whether the H. pylori strain was type I or II. The data analysis was descriptive and analytic, and 95% confidence intervals were estimated, with an error level of 0.05, and Odds ratio. The patients that presented the bacterium in histological biopsy were 58.7% (121/206), positivity that decreased with age and histological damage. The frecuency of response to IgG antibodies was higher than IgA, in both cases it was lower in children. VacA and CagA were the H. pylori proteins most recognized by both IgA and IgG and it was observed that the number of recognized proteins was greater with increasing histological damage. The type I strain was the one that predominated in the study population 66% (136/206). Prevalence studies of the type I strain of H. pylori ant the recognition of its antigens in the Guatemalan population should continue in order to determine its usefulness in the diagnosis and prognosis of infection.
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Humanos , Niño , Adulto , Neoplasias Gástricas/inmunología , Inmunoglobulina A/inmunología , Inmunoglobulina G/inmunología , Helicobacter pylori/inmunología , Dispepsia/inmunología , Neoplasias Gástricas/microbiología , Neoplasias Gástricas/patología , Biopsia , Proteínas Recombinantes/análisis , Proteínas Recombinantes/inmunología , Inmunoglobulina A/análisis , Inmunoglobulina G/análisis , Helicobacter pylori/aislamiento & purificación , Helicobacter pylori/patogenicidad , Dispepsia/microbiología , Dispepsia/patología , GuatemalaRESUMEN
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.
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Linfocitos T CD4-Positivos/inmunología , Coinfección/inmunología , Infecciones por Helicobacter/inmunología , Helicobacter pylori/inmunología , Helmintiasis/inmunología , Balance Th1 - Th2 , Adolescente , Adulto , Anciano , Biomarcadores/sangre , Linfocitos T CD4-Positivos/metabolismo , Niño , Preescolar , Coinfección/sangre , Coinfección/diagnóstico , Coinfección/patología , Femenino , Infecciones por Helicobacter/sangre , Infecciones por Helicobacter/diagnóstico , Infecciones por Helicobacter/patología , Helmintiasis/sangre , Helmintiasis/diagnóstico , Helmintiasis/patología , Humanos , Modelos Logísticos , Masculino , Persona de Mediana EdadRESUMEN
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.
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Humanos , Masculino , Femenino , Preescolar , Niño , Adolescente , Adulto , Persona de Mediana Edad , Anciano , Linfocitos T CD4-Positivos/inmunología , Helicobacter pylori/inmunología , Infecciones por Helicobacter/inmunología , Balance Th1 - Th2 , Coinfección/inmunología , Helmintiasis/inmunología , Biomarcadores/sangre , Linfocitos T CD4-Positivos/metabolismo , Modelos Logísticos , Infecciones por Helicobacter/diagnóstico , Infecciones por Helicobacter/patología , Infecciones por Helicobacter/sangre , Coinfección/diagnóstico , Coinfección/patología , Coinfección/sangre , Helmintiasis/diagnóstico , Helmintiasis/patología , Helmintiasis/sangreRESUMEN
Infection by Helicobacter pylori is a major risk factor for gastric cancer (GC), the second leading cause of cancer-related death worldwide. Although biomarkers such as pepsinogens (PGs) and soluble urokinase plasminogen activator receptor (suPAR) may have diagnostic and/or prognostic value in patients with GC, their levels may be affected by H. pylori infection. The aim of this study was to investigate the association of the presence of antibodies to H. pylori and cytotoxin-associated gene A (CagA) with plasma levels of PGs and suPAR in a cohort of Guatemalan GC patients and controls. To this end, levels of suPAR, Pepsinogens I and II (PGI and PGII), and antibodies to H. pylori and CagA toxin were determined by ELISA in plasma samples from 67 GC patients and 136 matched healthy controls. Seropositivity for CagA was significantly higher in patients with GC than in controls. Pepsinogens II and suPAR levels were higher and PGI/PGII ratios were lower in GC patients than in controls. There was a significant association of H. pylori seropositivity status with increased levels of PGII and lower PGI/PGII ratios, particularly in the control (non-GC) population. The levels of suPAR were not significantly affected by H. pylori or CagA seropositivity status. These results suggest that the seropositivity status for H. pylori and CagA need to be taken into account during the GC diagnostic process.
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Antígenos Bacterianos/inmunología , Proteínas Bacterianas/inmunología , Infecciones por Helicobacter/epidemiología , Helicobacter pylori/inmunología , Pepsinógeno A/sangre , Receptores del Activador de Plasminógeno Tipo Uroquinasa/sangre , Neoplasias Gástricas/microbiología , Anticuerpos Antibacterianos/sangre , Anticuerpos Antibacterianos/inmunología , Estudios de Casos y Controles , Ensayo de Inmunoadsorción Enzimática , Femenino , Guatemala/epidemiología , Infecciones por Helicobacter/complicaciones , Humanos , Masculino , Persona de Mediana Edad , Estudios Seroepidemiológicos , Neoplasias Gástricas/sangreRESUMEN
BACKGROUND AND AIM: The relationship between race/ethnicity and H pylori infection has been extensively reported, with a higher prevalence of infection observed in black individuals. Whether such differences are due to genetic factors underlying African ancestry remains to be clarified. In the present study, we evaluated the association between the proportion of individual African ancestry and H pylori infection in a sample of 1046 children living in a large Latin American urban center. MATERIALS AND METHODS: Estimation of individual biogeographical ancestry was based on 370,539 SNPs and performed using the ADMIXTURE software. Multivariate logistic regression models and mediation analysis considering the influence of previously recognized socioenvironmental risk factors to H pylori infection were performed. All analyses were conducted using the statistical package STATA v.14.0. RESULTS: Each 10% increase in the proportion of individual African ancestry was positively and independently associated with H pylori infection in our population (adjusted OR = 1.22, 95% CI = 1.10-1.36, P < .001). Mediation analysis demonstrated that only 9.23% of the effect of the individual African ancestry on H pylori infection was explained by factors such as household income, the absence of street paving and crowding. CONCLUSIONS: The results suggest that genetic variants that covariate with African ancestry may explain an important part of the racial differences observed for the prevalence of H pylori infection.
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Negro o Afroamericano/genética , Infecciones por Helicobacter/etnología , Infecciones por Helicobacter/genética , Negro o Afroamericano/estadística & datos numéricos , Anticuerpos Antibacterianos/sangre , Niño , Preescolar , Estudios de Cohortes , Femenino , Predisposición Genética a la Enfermedad , Infecciones por Helicobacter/epidemiología , Infecciones por Helicobacter/microbiología , Helicobacter pylori/inmunología , Helicobacter pylori/aislamiento & purificación , Helicobacter pylori/fisiología , Humanos , América Latina/epidemiología , América Latina/etnología , Masculino , Polimorfismo de Nucleótido Simple , Población Urbana/estadística & datos numéricosRESUMEN
Helicobacter pylori (H. pylori) is a gram-negative bacterium that infects approximately 4.4 billion individuals worldwide. However, its prevalence varies among different geographic areas, and is influenced by several factors. The infection can be acquired by means of oral-oral or fecal-oral transmission, and the pathogen possesses various mechanisms that improve its capacity of mobility, adherence and manipulation of the gastric microenvironment, making possible the colonization of an organ with a highly acidic lumen. In addition, H. pylori presents a large variety of virulence factors that improve its pathogenicity, of which we highlight cytotoxin associated antigen A, vacuolating cytotoxin, duodenal ulcer promoting gene A protein, outer inflammatory protein and gamma-glutamyl transpeptidase. The host immune system, mainly by means of a Th1-polarized response, also plays a crucial role in the infection course. Although most H. pylori-positive individuals remain asymptomatic, the infection predisposes the development of various clinical conditions as peptic ulcers, gastric adenocarcinomas and mucosa-associated lymphoid tissue lymphomas. Invasive and non-invasive diagnostic methods, each of them with their related advantages and limitations, have been applied in H. pylori detection. Moreover, bacterial resistance to antimicrobial therapy is a major challenge in the treatment of this infection, and new therapy alternatives are being tested to improve H. pylori eradication. Last but not least, the development of effective vaccines against H. pylori infection have been the aim of several research studies.
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Mucosa Gástrica/microbiología , Infecciones por Helicobacter/terapia , Helicobacter pylori/patogenicidad , Gastropatías/terapia , Antiácidos/uso terapéutico , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Vacunas Bacterianas/uso terapéutico , Farmacorresistencia Bacteriana , Quimioterapia Combinada , Mucosa Gástrica/efectos de los fármacos , Mucosa Gástrica/patología , Infecciones por Helicobacter/diagnóstico , Infecciones por Helicobacter/microbiología , Infecciones por Helicobacter/transmisión , Helicobacter pylori/efectos de los fármacos , Helicobacter pylori/inmunología , Humanos , Concentración de Iones de Hidrógeno/efectos de los fármacos , Probióticos/administración & dosificación , Inhibidores de la Bomba de Protones/uso terapéutico , Gastropatías/diagnóstico , Gastropatías/microbiología , Resultado del Tratamiento , Factores de Virulencia/metabolismoRESUMEN
H. pylori infection shows an inverse relationship with allergies. Dendritic cells regulate mucosal immune responses including the induction of T regulatory cells which are fundamental in Helicobacter pylori-induced dampening of allergies. In this respect expression of high-affinity IgE receptor (FcεRI) has been associated with a regulatory dendritic cell profile. Therefore we aimed to evaluate possible mechanisms by which H. pylori infection might modify atopy in pediatric patients. Here we show that H. pylori-infected children exhibited both increased expression of FcεRI on peripheral myeloid and plasmacytoid dendritic cells and higher levels of Foxp3 and Latency Associated Peptide on T regulatory cells. Moreover, exposure to H. pylori drove increased FcεRI expression and IL-10 secretion by both pediatric H. pylori-exposed monocyte derived dendritic cells and T cells. Finally, we show a positive correlation between expression of FcεRI in circulating myeloid DCs and total Treg cells, suggesting that in children, H. pylori infection may have a modulating role in atopy, mediated by both altered surface expression of FcεRI on children's DC and an increased T regulatory cell profile.
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Células Dendríticas/metabolismo , Regulación de la Expresión Génica , Infecciones por Helicobacter/inmunología , Helicobacter pylori/inmunología , Receptores de IgE/metabolismo , Linfocitos T Reguladores/patología , Adolescente , Niño , Femenino , Factores de Transcripción Forkhead/metabolismo , Infecciones por Helicobacter/sangre , Infecciones por Helicobacter/patología , Humanos , Tolerancia Inmunológica , Inmunoglobulina E/sangre , Interleucina-10/metabolismo , Recuento de Linfocitos , Masculino , Linfocitos T Reguladores/metabolismoRESUMEN
Helicobacter pylori is an infectious agent that colonizes the gastric mucosa of half of the population worldwide. This bacterium has been recognized as belonging to group 1 carcinogen by the World Health Organization for the role in development of gastritis, peptic ulcers, and cancer. Due to the increase in resistance to antibiotics used in the anti-H. pylori therapy, the development of an effective vaccine is an alternative of great interest, which remains a challenge. Therefore, a rational, strategic, and efficient vaccine design against H. pylori is necessary where the use of the most current bioinformatics tools could help achieve it. In this study, immunoinformatics approach was used to design a novel multiepitope oral vaccine against H. pylori. Our multiepitope vaccine is composed of cholera toxin subunit B (CTB) that is used as a mucosal adjuvant to enhance vaccine immunogenicity for oral immunization. CTB fused to 11 epitopes predicted of pathogenic (UreB170-189, VacA459-478, CagA1103-1122, GGT106-126, NapA30-44, and OipA211-230) and colonization (HpaA33-52, FlaA487-506, FecA437-456, BabA129-149, and SabA540-559) proteins from H. pylori. CKS9 peptide (CKSTHPLSC) targets epithelial microfold cells to enhance vaccine uptake from the gut barrier. All sequences were joined to each other by proper linkers. The vaccine was modeled and validated to achieve a high-quality three-dimensional structure. The vaccine design was evaluated as nonallergenic, antigenic, soluble, and with an appropriate molecular weight and isoelectric point. Our results suggest that our newly designed vaccine could serve as a promising anti-H. pylori vaccine candidate.
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Proteínas Bacterianas/inmunología , Vacunas Bacterianas/inmunología , Epítopos/inmunología , Infecciones por Helicobacter/prevención & control , Helicobacter pylori/inmunología , Adyuvantes Inmunológicos/administración & dosificación , Adyuvantes Inmunológicos/farmacología , Administración Oral , Secuencia de Aminoácidos , Animales , Proteínas Bacterianas/administración & dosificación , Proteínas Bacterianas/química , Vacunas Bacterianas/administración & dosificación , Vacunas Bacterianas/química , Toxina del Cólera/administración & dosificación , Toxina del Cólera/inmunología , Biología Computacional , Epítopos/administración & dosificación , Infecciones por Helicobacter/inmunología , Helicobacter pylori/química , Humanos , Ratones , Modelos Moleculares , Estructura Secundaria de ProteínaRESUMEN
BACKGROUND: Helicobacter pylori urease (HPU) is a key virulence factor that enables bacteria to colonize and survive in the stomach. We early demonstrated that HPU, independent of its catalytic activity, induced inflammatory and angiogenic responses in vivo and directly activated human neutrophils to produce reactive oxygen species (ROS). We have investigated the effects of HPU on endothelial cells, focusing on the signaling mechanism involved. METHODS: Monolayers of human microvascular endothelial cells (HMEC-1) were stimulated with HPU (up to 10 nmol/L): Paracellular permeability was accessed through dextran-FITC passage. NO and ROS production was evaluated using intracellular probes. Proteins or mRNA expressions were detected by Western blotting and fluorescence microscopy or qPCR assays, respectively. RESULTS: Treatment with HPU enhanced paracellular permeability of HMEC-1, preceded by VE-cadherin phosphorylation and its dissociation from cell-cell junctions. This caused profound alterations in actin cytoskeleton dynamics and focal adhesion kinase (FAK) phosphorylation. HPU triggered ROS and nitric oxide (NO) production by endothelial cells. Increased intracellular ROS resulted in nuclear factor kappa B (NF-κB) activation and upregulated expression of cyclooxygenase-2 (COX-2), hemeoxygenase-1 (HO-1), interleukin-1ß (IL-1ß), and intercellular adhesion molecule-1 (ICAM-1). Higher ICAM-1 and E-selectin expression was associated with increased neutrophil adhesion on HPU-stimulated HMEC monolayers. The effects of HPU on endothelial cells were dependent on ROS production and lipoxygenase pathway activation, being inhibited by esculetin. Additionally, HPU improved vascular endothelial growth factor receptor 2 (VEGFR-2) expression. CONCLUSION: The data suggest that the pro-inflammatory properties of HPU drive endothelial cell to a ROS-dependent program of differentiation that contributes to the progression of H pylori infection.
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Diferenciación Celular/efectos de los fármacos , Infecciones por Helicobacter/inmunología , Helicobacter pylori/enzimología , Transducción de Señal/efectos de los fármacos , Ureasa/farmacología , Células Endoteliales/efectos de los fármacos , Células Endoteliales/inmunología , Infecciones por Helicobacter/microbiología , Helicobacter pylori/inmunología , Humanos , Inflamación , Fosforilación , Especies Reactivas de Oxígeno/metabolismo , Factores de Virulencia/farmacologíaRESUMEN
BACKGROUND: Serological tests are practical, with low cost, but no noninvasive tests are available for diagnosing Helicobacter pylori (H. pylori) infection in Brazil. The aim here was to develop and validate enzyme-linked immunosorbent assay (ELISA) serological tests to detect anti-H. pylori immunoglobulin G antibodies, based on cultured strains from Brazilian patients. DESIGN AND SETTING: Cross-sectional, diagnostic accuracy study comparing a locally developed and validated ELISA and invasive tests among dyspeptic patients at two public hospitals in São Paulo, Brazil. METHODS: An ELISA test was prepared using whole-cell antigen from 56 strains. After genotypic characterization, it was standardized and optical density (OD) cutoffs were determined based on the serum antibody response of 100 H. pylori-negative samples, compared with 82 H. pylori-positive samples. Validation was performed on 174 symptomatic patients. RESULTS: The optimal OD cutoffs established (for monoclonal and polyclonal tests, respectively) were 0.167 and 0.164; overall ELISA sensitivity: 84.3%, 78.9%; specificity: 88.6%, 90.6%; positive predictive value (PPV): 75.4%, 80%; negative predictive value (NPV): 93.1%, 81.8%; accuracy: 87.3%, 86.2%; child and adolescent ELISA sensitivity: 74.2%, 81.8%; specificity: 90.8%, 86.7%; PPV: 66.6%, 84.3%; NPV: 95.8%, 84.8%; accuracy: 88.5%, 84.6; adult ELISA sensitivity: 84.4%, 75%; specificity: 86.9%, 93%; PPV: 81.8%, 78.3%; NPV: 88.9%, 91.8%; accuracy: 85.9%, 88.5%. CONCLUSION: The polyclonal serological test developed using local strains presented better diagnostic performance among children and adolescents, while the monoclonal test was better among adults. The results from both tests suggest that these in-house serological tests could be used to detect anti-H. pylori antibodies in our population, for screening purposes.
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Ensayo de Inmunoadsorción Enzimática/métodos , Infecciones por Helicobacter/diagnóstico , Helicobacter pylori/aislamiento & purificación , Determinación de Anticuerpos Séricos Bactericidas/normas , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Anticuerpos Antibacterianos/sangre , Niño , Preescolar , Estudios Transversales , Ensayo de Inmunoadsorción Enzimática/normas , Femenino , Infecciones por Helicobacter/microbiología , Helicobacter pylori/inmunología , Humanos , Masculino , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa , Estándares de Referencia , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Estómago/microbiología , Estómago/patología , Adulto JovenRESUMEN
ABSTRACT BACKGROUND: Serological tests are practical, with low cost, but no noninvasive tests are available for diagnosing Helicobacter pylori (H. pylori) infection in Brazil. The aim here was to develop and validate enzyme-linked immunosorbent assay (ELISA) serological tests to detect anti-H. pylori immunoglobulin G antibodies, based on cultured strains from Brazilian patients. DESIGN AND SETTING: Cross-sectional, diagnostic accuracy study comparing a locally developed and validated ELISA and invasive tests among dyspeptic patients at two public hospitals in São Paulo, Brazil. METHODS: An ELISA test was prepared using whole-cell antigen from 56 strains. After genotypic characterization, it was standardized and optical density (OD) cutoffs were determined based on the serum antibody response of 100 H. pylori-negative samples, compared with 82 H. pylori-positive samples. Validation was performed on 174 symptomatic patients. RESULTS: The optimal OD cutoffs established (for monoclonal and polyclonal tests, respectively) were 0.167 and 0.164; overall ELISA sensitivity: 84.3%, 78.9%; specificity: 88.6%, 90.6%; positive predictive value (PPV): 75.4%, 80%; negative predictive value (NPV): 93.1%, 81.8%; accuracy: 87.3%, 86.2%; child and adolescent ELISA sensitivity: 74.2%, 81.8%; specificity: 90.8%, 86.7%; PPV: 66.6%, 84.3%; NPV: 95.8%, 84.8%; accuracy: 88.5%, 84.6; adult ELISA sensitivity: 84.4%, 75%; specificity: 86.9%, 93%; PPV: 81.8%, 78.3%; NPV: 88.9%, 91.8%; accuracy: 85.9%, 88.5%. CONCLUSION: The polyclonal serological test developed using local strains presented better diagnostic performance among children and adolescents, while the monoclonal test was better among adults. The results from both tests suggest that these in-house serological tests could be used to detect anti-H. pylori antibodies in our population, for screening purposes.
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Humanos , Masculino , Femenino , Preescolar , Niño , Adolescente , Adulto , Persona de Mediana Edad , Anciano , Anciano de 80 o más Años , Adulto Joven , Ensayo de Inmunoadsorción Enzimática/métodos , Helicobacter pylori/aislamiento & purificación , Infecciones por Helicobacter/diagnóstico , Determinación de Anticuerpos Séricos Bactericidas/normas , Estándares de Referencia , Estómago/microbiología , Estómago/patología , Ensayo de Inmunoadsorción Enzimática/normas , Reacción en Cadena de la Polimerasa , Estudios Transversales , Reproducibilidad de los Resultados , Helicobacter pylori/inmunología , Infecciones por Helicobacter/microbiología , Sensibilidad y Especificidad , Anticuerpos Antibacterianos/sangreRESUMEN
BACKGROUND: Primary Helicobacter pylori (H. pylori) infection is acquired predominantly in childhood in the family setting. We aimed to investigate the presence of intrafamilial concurrent H. pylori infection. DESIGN AND SETTING: Cross-sectional analytical study with a control group, conducted in a tertiary care hospital. METHODS: Fifty adult patients with gastroduodenal symptoms who underwent gastroscopy (index parents), their spouses and their children were enrolled in the study. Blood samples were collected from all of the study subjects to test for immunoglobulin G (IgG) antibody response. H. pylori antigen was investigated in the stool specimens of children only. RESULTS: The participants were divided into two groups: Group 1 consisted of the 40 patients in whom H. pylori infection was demonstrated via endoscopy, their spouses and their children. Group 2 included the remaining 10 patients who underwent endoscopy revealing negative results for H. pylori, their spouses and their children. IgG antibodies were present in all of the index parents, 95% of their spouses and 93% of their children in group 1; 13 of the children (9%) were also positive for H. pylori stool antigen (HpSA). However, IgG antibodies were present in only 2 of the 10 index parents in group 2. One of their spouses and one of their children had a positive antibody response. All of their children had negative stool antigen test results. CONCLUSION: H. pylori infections exhibit intrafamilial clustering. Parental infection, age ≥ years and having three or more siblings are the major risk factors for H. pylori infection in children.
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Enfermedades Duodenales/diagnóstico , Salud de la Familia , Infecciones por Helicobacter/diagnóstico , Helicobacter pylori , Adolescente , Adulto , Factores de Edad , Anticuerpos Antibacterianos/sangre , Niño , Preescolar , Estudios Transversales , Femenino , Infecciones por Helicobacter/sangre , Infecciones por Helicobacter/inmunología , Infecciones por Helicobacter/transmisión , Helicobacter pylori/inmunología , Humanos , Inmunoglobulina G/sangre , Lactante , Masculino , Persona de Mediana Edad , Hermanos , EspososRESUMEN
Helicobacter pylori infection is associated with important gastric pathologies. An aggressive proinflammatory immune response is generated in the gastric tissue infected with H. pylori, resulting in gastritis and a series of morphological changes that increase the susceptibility to cancer development. Probiotics could present an alternative solution to prevent or decrease H. pylori infection. Among them, the use of immunomodulatory lactic acid bacteria represents a promising option to reduce the severity of chronic inflammatory-mediated tissue damage and to improve protective immunity against H. pylori. We previously isolated Lactobacillus fermentum UCO-979C from human gastric tissue and demonstrated its capacity to reduce adhesion of H. pylori to human gastric epithelial cells (AGS cells). In this work, the ability of L. fermentum UCO-979C to modulate immune response in AGS cells and PMA phorbol 12-myristate 13-acetate (PMA)-differentiated THP-1 (human monocytic leukaemia) macrophages in response to H. pylori infection was evaluated. We demonstrated that the UCO-979C strain is able to differentially modulate the cytokine response of gastric epithelial cells and macrophages after H. pylori infection. Of note, L. fermentum UCO-979C was able to significantly reduce the production of inflammatory cytokines and chemokines in AGS and THP-1 cells as well as increase the levels of immunoregulatory cytokines, indicating a remarkable anti-inflammatory effect. These findings strongly support the probiotic potential of L. fermentum UCO-979C and provide evidence of its beneficial effects against the inflammatory damage induced by H. pylori infection. Although our findings should be proven in appropriate experiments in vivo, in both H. pylori infection animal models and human trials, the results of the present work provide a scientific rationale for the use of L. fermentum UCO-979C to prevent or reduce H. pylori-induced gastric inflammation in humans.
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Infecciones por Helicobacter/tratamiento farmacológico , Infecciones por Helicobacter/inmunología , Helicobacter pylori/fisiología , Inmunidad Innata/efectos de los fármacos , Limosilactobacillus fermentum/fisiología , Probióticos/farmacología , Animales , Citocinas/genética , Citocinas/inmunología , Células Epiteliales/efectos de los fármacos , Células Epiteliales/inmunología , Células Epiteliales/microbiología , Infecciones por Helicobacter/microbiología , Helicobacter pylori/inmunología , Humanos , RatonesRESUMEN
ABSTRACT BACKGROUND: Primary Helicobacter pylori (H. pylori) infection is acquired predominantly in childhood in the family setting. We aimed to investigate the presence of intrafamilial concurrent H. pylori infection. DESIGN AND SETTING: Cross-sectional analytical study with a control group, conducted in a tertiary care hospital. METHODS: Fifty adult patients with gastroduodenal symptoms who underwent gastroscopy (index parents), their spouses and their children were enrolled in the study. Blood samples were collected from all of the study subjects to test for immunoglobulin G (IgG) antibody response. H. pylori antigen was investigated in the stool specimens of children only. RESULTS: The participants were divided into two groups: Group 1 consisted of the 40 patients in whom H. pylori infection was demonstrated via endoscopy, their spouses and their children. Group 2 included the remaining 10 patients who underwent endoscopy revealing negative results for H. pylori, their spouses and their children. IgG antibodies were present in all of the index parents, 95% of their spouses and 93% of their children in group 1; 13 of the children (9%) were also positive for H. pylori stool antigen (HpSA). However, IgG antibodies were present in only 2 of the 10 index parents in group 2. One of their spouses and one of their children had a positive antibody response. All of their children had negative stool antigen test results. CONCLUSION: H. pylori infections exhibit intrafamilial clustering. Parental infection, age ≥ years and having three or more siblings are the major risk factors for H. pylori infection in children.
Asunto(s)
Humanos , Masculino , Femenino , Lactante , Preescolar , Niño , Adolescente , Adulto , Persona de Mediana Edad , Salud de la Familia , Helicobacter pylori/inmunología , Infecciones por Helicobacter/diagnóstico , Enfermedades Duodenales/diagnóstico , Inmunoglobulina G/sangre , Estudios Transversales , Infecciones por Helicobacter/inmunología , Infecciones por Helicobacter/sangre , Infecciones por Helicobacter/transmisión , Factores de Edad , Esposos , Hermanos , Anticuerpos Antibacterianos/sangreRESUMEN
In the Bolivian Chaco, south-east of Bolivia, studies conducted over the past three decades reported hepatitis A virus (HAV) and Helicobacter pylori seroprevalences above 90% and 60%, respectively. Hepatitis E virus (HEV) prevalence was previously found to be 6-7% but is probably an underestimate because of the poor sensitivity of the assays used. In November 2013, we conducted a cross-sectional study of 263 healthy volunteers from two rural communities of the Bolivian Chaco, aiming to reassess HAV, HEV, and H. pylori seroprevalence 10-20 years following the previous surveys. Hepatitis A virus seroprevalence was 95%, with universal exposure after the first decade of life; HEV seroprevalence was considerably higher (31-35%) than that previously reported; H. pylori seroprevalence was 59%, with an age-dependent distribution. The high prevalence of these infections suggests that major efforts are still needed to reduce fecal-oral transmission and to improve human health in the Bolivian Chaco.
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Anticuerpos Antibacterianos/sangre , Anticuerpos Antivirales/sangre , Helicobacter pylori/inmunología , Virus de la Hepatitis A/inmunología , Virus de la Hepatitis E/inmunología , Estudios Seroepidemiológicos , Adolescente , Adulto , Bolivia , Niño , Preescolar , Femenino , Humanos , Inmunoglobulina G/sangre , Lactante , Masculino , Persona de Mediana Edad , Población Rural , Adulto JovenRESUMEN
Helicobacter pylori es una bacteria gram negativa que posee numerosos antígenos que juegan un importante papel en la patogénesis de las enfermedades gastroduodenales. Debido a la necesidad de métodos de diagnóstico estandarizados con antígenos locales u autóctonos nos propusimos el diseño de una estrategia para la obtención de extractos de antígenos con reactividad frente a sueros de pacientes infectados por H. pylori. Dos cepas de H. pylori, una autóctona (IPK196A) y una de referencia ATCC 43504, se cultivaron en un medio líquido modificado. Se sometieron a los protocolos de ruptura por ultrasonido aplicándose tres variantes de precipitación y al fraccionamiento celular mediante ultracentrifugación diferencial. Los extractos proteínicos se visualizaron mediante electroforesis en gel de poliacrilamida y se transfirieron para la detección de antígenos inmunorreactivos a sueros de pacientes con infección por H. pylori e individuos sanos. La variante de ultrasonido y precipitación con Coomasie fue la más efectiva para concentrar las muestras. El método de ultracentrifugación mejoró la resolución de las proteínas reactivas y permitió separarlas según su localización subcelular. El sistema de transferencia húmedo fue ideal para la inmunodetección de los antígenos obtenidos por ultrasonido mientras que el sistema semiseco permitió detectar las proteínas de membrana obtenidas por ultracentrifugación diferencial. La introducción de una metodología en el laboratorio para la obtención y evaluación de extractos proteínicos antigénicos a partir de cepas autóctonas de H. pylori, constituye la antesala para el diseño de futuros diagnosticadores y candidatos vacunales(AU)
Helicobacter pylori is a gram-negative spiral-shaped bacterium, which has many antigens that play an important role in the pathogenesis of gastroduodenal diseases. Due to the lack of standardized methods from native or autochthonous antigens, we proposed in this study, the design of a strategy for extracting and obtaining immunoreactive antigens against H. pylori infected-patient sera. Two H. pylori strains, one autochthonous (IPK196A) and one reference ATCC 43504, were cultured in a modified liquid medium. Both strains were subjected to the ultrasound rupture protocols applying three precipitation variants and cell fractionation by differential ultracentrifugation. Protein extracts were visualized by polyacrylamide gel electrophoresis and transferred for the detection of immunoreactive antigens to sera from patients with H. pylori infection and healthy individuals. The precipitation with Coomasie was the most effective variant. The ultracentrifugation extraction method optimized the resolution of the proteins, which could be separated according to their subcellular location. The wet transfer system was ideal for the immunodetection of the antigens obtained by ultrasound, while the semi-dry system allowed detecting the membrane proteins by differential ultracentrifugation. The introduction of a methodology in the laboratory for obtaining and evaluating antigenic antibodies from autochthonous strains of H. pylori, is the prelude to the design for future diagnostics and vaccine candidates(AU)