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Helminths possibly down-modulate immune responses to airborne allergens through the induction of a regulatory network. The identification of helminths bioactive molecules is highly desirable, given their immunomodulatory potential which could be used in immunotherapies for allergy and autoimmune diseases. To investigate the immunoregulatory potential of the adult Toxocara canis crude extract and ten protein fractions of its extract, human peripheral blood mononuclear cells (PBMC) from 10 allergic and 9 non-allergic individuals were cultivated, in vitro, in the presence or absence of these antigens, and their supernatants were evaluated for cytokine production (TGF-β, IL-10, IL-12, TNF-α, IL-6, IL-5, IL13, and IL-17). To determine the cell viability, the PBMC were cultivated for 24 h in the presence of the antigens and, following, they were subjected to a cytotoxicity assay. The viability of the PBMC was not affected by incubation with the T. canis antigens. As some fractions stimulated the production of immunoregulatory (TGF-β and/or IL-10), IL-12 and Th1 (TNF-α) cytokines, without stimulating Th2 cytokines (IL-5 and IL13) and IL-17, it was proposed that they would be potential candidates for further studies, especially involving the purification and characterization of specific proteins, which could be tested separately to evaluate their specific role as adjuvants in immunotherapy for inflammatory diseases., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Atopic asthma is a chronic lung disease of lower airways caused mainly due to action of T-helper (Th) 2 type cytokines, eosinophilic inflammation, mucus hypersecretion and airway remodelling. Interleukin (IL)-33 increases type 2 immunity polarization in airway playing critical role in eosinophilic asthma. On the other hand, NLRP3 inflammasome activation results in the release of caspase-1 (Casp-1) which, in its turn, promotes IL-33 inactivation. Recent studies have shown associations between NLRP3 variants and inflammatory diseases. However, no study with genes in NLRP3 inflammassome route has been conducted so far with asthma and atopy in any population to date. Blood samples were collected from 1246 asthmatic and non-asthmatic children. Associations were tested for single nucleotide polymorphism (SNP)s in NLRP3 and CASP1 with asthma and markers of atopy and in cultures stimulated with Blomia tropicalis (Bt) mite crude extract. The T allele of rs4925648 ( NLRP3) was associated with increased asthma risk (OR 1.50, P = 0.005). In addition, the T allele of rs12130711 polymorphism, whithin the same gene, acted as a protector factor for asthma (OR 0.78, P = 0.038). On the other hand, the C allele of rs4378247 NLRP3 variant was associated with lower levels of IL-13 production when peripheral blood cells were stimulated with Bt (OR 0.39, P = 4E-04). In addition, the greater the number of risk alleles in IL33 / NLRP3 / CASP1 route the greater was the risk for asthma. The T allele of rs7925706 CASP1 variant was also associated with increased risk for asthma (OR 1.47, P = 0.008). In addition, this same allele increased the eosinophil counts in blood (mm3) in asthmatic individuals compared with non-asthmatic (P = 0.0004). These results suggest that NLRP3 and CASP1 polymorphisms may be associated with susceptibility for asthma and markers of atopy in our population., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2020 The Authors.)

Introduction: Allergen-specific immunotherapy (AIT) represents a curative approach for treating allergies. In the tropical and subtropical regions of the world, Blomia tropicalis (Blo t 5 and Blo t 21) is the likely dominant source of indoor allergens., Aim: To generate a hypoallergenic Blo t 5/Blo t 21 hybrid molecule that can treat allergies caused by B tropicalis., Methods: Using in silico design of B tropicalis hybrid proteins, we chose two hybrid proteins for heterologous expression. Wild-type Blo t 5/Blo t 21 hybrid molecule and a hypoallergenic version, termed BTH1 and BTH2, respectively, were purified by ion exchange and size exclusion chromatography and characterized by physicochemical, as well as in vitro and in vivo immunological, experiments., Results: BTH1, BTH2 and the parental allergens were purified to homogeneity and characterized in detail. BTH2 displayed the lowest IgE reactivity that induced basophil degranulation using sera from allergic rhinitis and asthmatic patients. BTH2 essentially presented the same endolysosomal degradation pattern as the shortened rBlo t 5 and showed a higher resistance towards degradation than the full-length Blo t 5. In vivo immunization of mice with BTH2 led to the production of IgG antibodies that competed with human IgE for allergen binding. Stimulation of splenocytes from BTH2-immunized mice produced higher levels of IL-10 and decreased secretion of IL-4 and IL-5. In addition, BTH2 stimulated T-cell proliferation in PBMCs isolated from allergic patients, with secretion of higher levels of IL-10 and lower levels of IL-5 and IL-13, when compared to parental allergens., Conclusions and Clinical Relevance: BTH2 is a promising hybrid vaccine candidate for immunotherapy of Blomia allergy. However, further pre-clinical studies addressing its efficacy and safety are needed., (© 2020 The Authors. Clinical & Experimental Allergy published by John Wiley & Sons Ltd.)

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., (© 2019 John Wiley & Sons Ltd.)

Background: Asthma is a chronic disease of the airways and its most common phenotype is characterized by a T2 type response with IgE production and inflammatory mediators in response to common allergens. Cysteinyl leukotrienes (CysLTs), LTC4, LTD4 and LTE4, are mediators known to possess important proinflammatory action. CysLTs can bind to the Cysteinyl leukotriene receptor type 2 (CysLTR2) and activate an inflammatory. Polymorphisms in CysLTR2 have been associated with asthma and atopy, although the mechanism is not clear., Objective: To evaluate the association between genetic polymorphisms in CYSLTR2 with asthma phenotypes, atopy markers and helminth infection., Methods: Genotyping was performed using a panel Illumina and carried out in 1245 participants of SCAALA program (Social Change, Asthma, Allergy in Latin American). Logistic regressions for asthma, helminth infections (Trichuris trichiura and Ascaris lumbricoides) and allergy markers (skin tests and IgE production) were performed using PLINK 1.9 software adjusted for sex, age, helminth infection and ancestry markers., Results: The G allele of rs1323556 was negatively associated with asthma in the additive model (OR 0.74, 95% CI 0.59-0.93) and in the dominant model (OR 0.71, 95% CI 0.53-0.74). The G allele of rs1575464 was also negatively associated with asthma in two genetic models, additive (OR 0.77, 95% CI 0.62-0.96) and dominant (OR 0.73, 95% CI 0.55-0.97). The G allele of rs61735175 was positively associated with asthma severity in the additive model (OR 1.72, 95% CI 1.07-2.77) and in the dominant model (OR 1.77, 95% CI 1.09-2.85). Five SNVs were associated with atopy markers and four SNVs were associated with helminth infections., Conclusion: Polymorphisms in the CYSLTR2 gene are associated with asthma, atopy markers and helminth infection in Brazilian individuals, which may lead to protection or risk for such conditions, however, more studies are needed to evaluate the functional of this variants here in described., (Copyright © 2019. Published by Elsevier Ltd.)

Medicinal plants have long been used as an alternative to traditional drugs for the treatment of inflammatory conditions due to the classical side effects and restricted access of various commercially available drugs, such as steroids (GCs) and nonsteroidal anti-inflammatory drugs (NSAIDs). Sambucus australis is a Brazilian herb that is commonly used to treat inflammatory diseases; however, few studies have examined the use of this species in the treatment of inflammatory conditions. The present study aims to evaluate the potential anti-inflammatory activity of S. australis in vitro. We established spleen cell cultures stimulated with pokeweed mitogen (PWM) to evaluate the production of proinflammatory cytokines, such as IL-4, IL-5, IFN-y, and IL-10 (by ELISA), and the expression of the transcription factor NF-kB (by RT-PCR). In addition, we evaluated the levels of nitric oxide in macrophage cultures and the membrane-stabilizing activity of S. australis methanolic extract (EMSA). Treatment with EMSA at concentrations of 100, 50, 25 and 12.5 µg/ml significantly decreased IL-4 (p<0.001) and IL-5 (p<0.001) levels. Treatment with 100 µg/ml EMSA reduced IFN-у (p<0.001) levels. Moreover, at 100 mg/ml, EMSA also increased IL-10 production and reduced NF-kB expression (p<0.01). In macrophage cultures stimulated with LPS, EMSA decreased nitric oxide levels (p<0.001) at all concentrations tested (100, 50, 25 and 12.5 µg/ml). Additionally, EMSA had a protective effect in the erythrocyte membrane stabilization assay. Taken together, these results suggest that S. australis has anti-inflammatory potential in vitro, characterized by the reduction of both inflammatory cytokines and the expression of NF-kB along with the up-regulation of IL-10.

This corrects the article on p. 406 in vol. 10, PMID: 29949837., (Copyright © 2018 The Korean Academy of Asthma, Allergy and Clinical Immunology · The Korean Academy of Pediatric Allergy and Respiratory Disease.)

Atopic asthma, which is characterized by the chronic inflammation and morbidity of airways, is a disease of great complexity, and multiple genetic and environmental factors are involved in its etiology. In the first genome-wide association study (GWAS) conducted in Brazil for asthma, a positive association was found between atopic asthma and a variant (rs1999071), which is located between the DAD1 and OXA1L genes, although neither gene has previously been reported to be associated with asthma or allergies. The DAD1 gene is involved in the regulation of programmed cell death, and OXA1L is involved in biogenesis and mitochondrial oxidative phosphorylation. This study aimed to evaluate how polymorphisms in DAD1 and OXA1L are associated with asthma and markers of atopy in individuals from the Salvador cohort of the SCAALA (Social Change Asthma and Allergy in Latin America) program. The DNA of 1220 individuals was genotyped using the Illumina 2.5 Human Omni Bead chip. Logistic regression analyses were performed with PLINK 1.9 software to verify the association between DAD1 and OXA1L polymorphisms and asthma and atopic markers, adjusted for sex, age, helminth infections and ancestry markers, using an additive model. The DAD1 and OXA1L genes were associated with some of the evaluated phenotypes, such as asthma, skin prick test (SPT), specific IgE for aeroallergens, and Th1/Th2-type cytokine production. Using qPCR, as well as in silico gene expression analysis, we have demonstrated that some of the polymorphisms in both genes are able to affect their respective gene expression levels. In addition, DAD1 was over-expressed in asthmatic patients when compared with controls. Thus, our findings demonstrate that variants in both the DAD1 and OXA1L genes may affect atopy and asthma in a Latin American population with a high prevalence of asthma., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Purpose: The use of tolerogenic dendritic cells (TolDCs) to control exacerbated immune responses may be a prophylactic and therapeutic option for application in autoimmune and allergic conditions. The objective of this work was to evaluate the effects of TolDC administration in a mouse model of allergic airway inflammation caused by mite extract., Methods: Mouse bone marrow-derived TolDCs were induced by incubation with granulocyte-macrophage colony-stimulating factor (GM-CSF) and dexamethasone, and then characterized by flow cytometry and cytokine production by enzyme-linked immunosorbent assay (ELISA). For the in vivo model of Blomia tropicalis-induced allergy, mice transplanted with antigen-pulsed TolDCs were sensitized intraperitoneally with B. tropicalis mite extract (BtE) adsorbed to aluminium hydroxide. After challenge by nasal administration of BtE, bronchoalveolar lavage fluid (BALF), lungs, spleen and serum were collected for analysis., Results: Induction of TolDCs was efficiently achieved as shown by low expression of major histocompatibility complex (MHC) II, programmed death-ligand (PD-L) 2 and pro-inflammatory cytokine production, and up-regulation of interleukin (IL)-10, upon LPS stimulation in vitro. Transplantation of 1 or 2 doses of BtE-pulsed TolDCs reduced the number of inflammatory cells in BALF and lungs as well as mucus deposition. Moreover, compared to saline-injected controls, TolDC-treated mice showed lower serum levels of anti-BtE immunoglobulin E (IgE) antibodies as well as reduced Gata3 and IL-4 gene expression in the lungs and decreased IFN-γ levels in the supernatant of splenocyte cultures Transplantation of TolDCs increased the percentage of the regulatory T cells in the spleen and the lungs., Conclusions: Preventive treatment with TolDCs protects against dust mite-induced allergy in a mouse model, reinforcing the use of tolerogenic dendritic cells for the management of allergic conditions., Competing Interests: There are no financial or other issues that might lead to conflict of interest., (Copyright © 2018 The Korean Academy of Asthma, Allergy and Clinical Immunology · The Korean Academy of Pediatric Allergy and Respiratory Disease.)

Background: Asthma and allergies prevalence increased in recent decades, being a serious global health problem. They are complex diseases with strong contextual influence, so that the use of advanced machine learning tools such as genetic programming could be important for the understanding the causal mechanisms explaining those conditions. Here, we applied a multiobjective grammar-based genetic programming (MGGP) to a dataset composed by 1047 subjects. The dataset contains information on the environmental, psychosocial, socioeconomics, nutritional and infectious factors collected from participating children. The objective of this work is to generate models that explain the occurrence of asthma, and two markers of allergy: presence of IgE antibody against common allergens, and skin prick test positivity for common allergens (SPT)., Results: The average of the accuracies of the models for asthma higher in MGGP than C4.5. IgE were higher in MGGP than in both, logistic regression and C4.5. MGGP had levels of accuracy similar to RF, but unlike RF, MGGP was able to generate models that were easy to interpret., Conclusions: MGGP has shown that infections, psychosocial, nutritional, hygiene, and socioeconomic factors may be related in such an intricate way, that could be hardly detected using traditional regression based epidemiological techniques. The algorithm MGGP was implemented in c ++ and is available on repository: http://bitbucket.org/ciml-ufjf/ciml-lib .

Introduction: Bacille Calmette-Guérin (BCG) downmodulates allergen-specific IgE levels and prevents other atopic responses in experimental models but fails to protect against respiratory allergies. Human responsiveness to BCG is variable and may interfere with protection., Methods: Multivariate models were evaluated to test the possible effect of responsiveness (assessed by IFN-γ production) to BCG revaccination on the modulation of total and allergen-specific serum IgE levels in healthy volunteers participating in a randomized controlled trial., Results: Serum total or Derp-specific IgE levels did not change regardless of the increase in IFN-γ levels., Conclusions: BCG responsiveness does not affect protection against atopy.

Asthma is a heterogeneous disease associated with a complex basis involving environmental factors and individual variabilities. The DENN Domain Containing 1B (DENND1B) gene has an important role on T cell receptor (TCR) down-regulation on Th2 cells and studies have shown that mutations or loss of this factor can be associated with increased Th2 responses and asthma. The aim of this work is to evaluate the association of polymorphisms in the DENND1B with asthma and allergy markers phenotypes in Brazilian children. Genotyping was performed using a commercial panel from Illumina (2.5 Human Omni bead chip) in 1309 participants of SCAALA (Social Change, Asthma, Allergy in Latin American) program. Logistic regressions for asthma and atopy markers were performed using PLINK software 1.9. The analyzes were adjusted for sex, age, helminth infections and ancestry markers. The DENND1B gene was associated with different phenotypes such as severe asthma and atopic markers (specific IgE production, skin prick test and IL-13 production). Among the 166 SNPs analyzed, 72 were associated with asthma and/or allergy markers. In conclusion, polymorphisms in the DENND1B are significantly associated with development of asthma and atopy and these polymorphisms can influence DENND1B expression and consequently, asthma., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Toxocara canis, Toxocara cati, are roundworms that live in the intestines of dogs and cats, respectively, and are predominantly agents of human toxocariasis. Studies have suggested that Toxocara spp. seroprevalence increases levels of total and aeroallergen-specific IgE (sIgE), asthma prevalence and asthma morbidity. Nevertheless, other work reported a negative association between Toxocara spp. seropositivity with skin hypersensititity and a positive association with sIgE. The objective of the present study was to evaluate risk factors for acquiring Toxocara spp. infection and to investigate possible significant association between its seroprevalence with atopy and asthma. Students from elementary schools, residents in a small town and its surroundings of Northeast Brazil, underwent blood sampling to measure levels of anti-Toxocara spp. IgG, peripheral blood eosinophils, and specific IgE to aeroallergens. We used univariable and multivariable logistic regression analyses to assess possible risk factors for Toxocara spp. seropositivity and its association with atopy, wheeze/asthma with asthma phenotypes, in a sample of 791 elementary school children aged 6-13 years. Toxocara spp. seroprevalence reached 63.6%; 49.9% had sIgE; 7.2% and 3.3% had atopic wheeze/asthma and non-atopic wheeze/asthma respectively. Risk factors associated with Toxocara spp. seropositivity were: contact with dogs (adj. OR 2.33; 95% CI=1.70-3.19) and cats (adj. OR 3.09; 95% CI=2.10-4.55), and male sex (adj. OR 2.21; 95% CI=1.62-3.02). The presence of anti-Toxocara IgG was statistically associated with blood eosinophils >4% and >10% (adj. OR 1.84; 95% CI=1.33-2.55 and adj. OR 2.07; 95% CI=1.45-2.97, respectively), and atopy (adj. OR 2.00; 95% CI=1.49-2.68), but it was not associated with wheeze/asthma. Concluding, the results obtained in this study showing the association of Toxocara spp. seroprevalence with sIgE may suggest a possible immunological cross-reactivity between IgE epitopes from Toxocara spp. and aeroallergens., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Ethnopharmacological Relevance: Solanum paniculatum L., popularly known as jurubeba, is a common subtropical plant from Brazil, Paraguay, Bolivia and Argentina, that is used in folk medicine for the treatment of anemia, gastrointestinal disorders and inflammatory conditions in general. In addition to that, an ethnobotanical survey in "Todos os Santos" Bay have pointed out S. paniculatum as an herb to treat asthma. Previous publications have shown that S. paniculatum possesses antibiotic, antioxidant and modulatory effects on gastric acid secretion; however, its anti-inflammatory potential remains unexplored., Aim of the Study: Herein, we analyzed the S. paniculatum fruits hexane extract (SpE) for the presence of stigmasterol and β-sitosterol and investigated the anti-inflammatory effect of SpE in vitro., Materials and Methods: SpE was subjected to high-performance liquid chromatography (HPLC) for standardization and quantification of stigmasterol and β-sitosterol. Spleen cells from BALB/c mice were cultivated and stimulated with pokeweed mitogen and also exposed to 15, 30 and 60µg/mL of SpE. Following treatment, levels of IFN-γ, IL-4 and IL-10 in the culture supernatants were assessed by ELISA. We also evaluated nitric oxide (NO) production by murine LPS-stimulated peritoneal macrophages using the Griess technique. In addition, the ability of SpE to stabilize membranes was assessed using a model of hemolysis induced by heat on murine erythrocytes. Gene expression of Th1-cell-specific Tbx21 transcription factor (TBET), zinc-finger transcription factor-3 (GATA3), and nuclear factor-κB (NFKB) in murine spleen cells were assessed by quantitative Polymerase Chain Reaction (qRT-PCR)., Results: SpE at 15, 30 and 60µg/mL significantly attenuated cell proliferation, decreased IL-4 release, reduced NO production and improved erythrocyte membrane stabilization in a concentration-dependent manner. SpE was also able to decrease the release of IFN-γ without altering IL-10 levels. The mechanism whereby SpE decreased inflammatory markers may be related to the reduction of NFKB, TBET and GATA3 gene expression., Conclusions: This study is the first to test the anti-inflammatory action of S. paniculatum. Herein, we provided evidence for the popular use of S. paniculatum in inflammatory conditions. Additional studies must be conducted to further explore the anti-inflammatory potential of SpE and to elucidate possible clinical applications., (Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.)

Allergic diseases are considered a major problem for healthcare systems in both developed and developing countries. House dust mites are well-known triggers of allergic manifestations. While the Dermatophagoides genus is widely distributed globally, Blomia tropicalis is the most prominent mite species in the tropical and subtropical regions of the world. Over the last decades, an increase in sensitization rates to B. tropicalis has been reported, leading to increased research efforts on Blomia allergens. In fact, 8 new allergens have been identified and characterized to different degrees. Here, we provide an overview of recent developments concerning the identification and production of recombinant Blomia allergens, as well as their structural and immunological characterization. Although considerable progress has been achieved, detailed molecule-based studies are still needed to better define the clinical relevance of Blomia allergens. Thus, the establishment of a well-standardized and fully characterized panel of allergens remains a challenge for the development of better diagnosis and therapy of allergic diseases induced by B. tropicalis., (© 2017 The Author(s) Published by S. Karger AG, Basel.)

In the present article, we provide shortly, data on risk factors for acquiring Toxocara spp. infection and investigate possible associations between this infection with atopy and asthma in school children of a small town and its semi-rural areas of Northeast Brazil. The data set are composed by demographic, social and home environment variables. The detection of anti- Toxocara spp. IgG and specific IgE to aeroallergens was determined by ELISA and ImmunocAP/Phadiatrope systems, respectively. The data presented in this article are related to the article entitled "Risk factors for Toxocara spp. seroprevalence and its association with atopy and asthma phenotypes in school-age children in a small town and semi-rural areas of Northeast Brazil" (M.B. Silva, A.L. Amor, L.N. Santos, A.A. Galvão, A.V. Oviedo Vera, E.S. Silva et al., 2016) [1].

Introduction: Allergies are among the most prevalent chronic diseases worldwide. Allergen-specific immunotherapy is used as an alternative treatment to pharmacotherapy. These immunotherapies are performed with crude extracts, which have disadvantages when compared to the new approaches, among them are recombinant proteins and hypoallergens. This review aims to assess immunotherapy for allergies through patent application analysis spanning recent decades., Areas Covered: Patents referring to allergen immunotherapies used in allergy treatment. Data were obtained from the Espacenet® website, using the Cooperative Patent Classification (CPC) system. Two-hundred-and-one patent applications were analyzed, taking into consideration their classification by the type of technology and applicant., Expert Opinion: Allergen-specific immunotherapy represents the only potentially curative therapeutic intervention for the treatment of allergic diseases. The extract-based immunotherapy is being replaced by the use of recombinant allergens, highlighting the hypoallergenic forms, which have low IgE-binding while retaining T-cell reactivity. It is expected that the development of hypoallergens will expand the scope of allergen-specific immunotherapy, especially if associated with alternative systems for expression and delivery systems with future potential. Furthermore, these new developments will likely address the problem of long-term protocols in allergen-specific immunotherapy, thus allowing better patient adherence and compliance.

Background: The prevalence of allergic diseases such as asthma has significantly increased worldwide, making it a public health concern. There is an urgent need for new anti-inflammatory agents with selective pharmacology and lower toxicity. Plant extracts have been used for centuries in traditional medicine to alleviate inflammatory diseases. In this work, we evaluated the anti-allergic activity of Cymbopogon citratus (Cy), a medicinal herb used by folk medicine to treat asthma., Methods: We used a murine model of respiratory allergy to the mite Blomia tropicalis (Bt) and evaluated certain parameters known to be altered in this model. A/J mice were sensitized (100 μg/animal s.c.) and challenged (10 μg/animal i.n.) with Bt mite extract and treated with 60, 120 or 180 mg/kg of Cy standardized hexane extract. The parameters evaluated included: cellular infiltrate in bronchoalveolar lavage (BAL); eosinophil peroxidase activity (EPO); histopathological examination of the lung; serum levels of specific IgE, IgG1 and IgG2a; Th2 cytokine concentrations in BAL and expression of NF-κB., Results: Our results showed that oral administration of a Cy hexane extract (especially 180 mg/Kg) reduced the numbers of leukocytes/eosinophils in BAL; the eosinophil peroxidase activity in BAL; the infiltration of leukocytes in lung tissue; the production of mucus in the respiratory tract; the level of IL-4 in BAL and the nuclear expression of NF-κB., Conclusions: The results presented demonstrate the potential of the Cy hexane extract to modulate allergic asthma; this extract may be an alternative future approach to treat this pathology.

Background: Asthma is an inflammatory condition characterized by airway hyperresponsiveness and chronic inflammation. The resolution of inflammation is an essential process to treat this condition. In this study we investigated the effect of Allium cepa L. extract (AcE) and quercetin (Qt) on cytokine and on smooth muscle contraction in vitro and its therapeutic potential in a murine model of asthma., Methods: AcE was obtained by maceration of Allium cepa L. and it was standardized in terms of quercetin concentration using high performance liquid chromatography (HPLC). In vitro, using AcE 10, 100 or 1000 μg/ml or Qt 3.5, 7.5, 15 μg/ml, we measured the concentration of cytokines in spleen cell culture supernatants, and the ability to relax tracheal smooth muscle from A/J mice. In vivo, Blomia tropicalis (BT)-sensitized A/J mice were treated with AcE 100, 1000 mg/kg or 30 mg/kg Qt. We measured cell influx in bronchoalveolar lavage (BAL), eosinophil peroxidase (EPO) in lungs, serum levels of Bt-specific IgE, cytokines levels in BAL, and lung histology., Results: We observed a reduction in the production of inflammatory cytokines, a relaxation of tracheal rings, and a reduction in total number of cells in BAL and EPO in lungs by treatment with AcE or Qt., Conclusion: AcE and Qt have potential as antiasthmatic drugs, as they possess both immunomodulatory and bronchodilatory properties.

Background: Helminths are modulators of the host immune system, and infections with these parasites have been associated with protection against allergies and autoimmune diseases. The human host is often infected with multiple helminth parasites and most studies to date have investigated the effects of helminths in the context of infections with single parasite or types of parasites (e.g. geohelminths). In this study, we investigated how co-infections with three nematodes affect markers of allergic inflammation and asthma in children. We selected Ascaris lumbricoides and Trichuris trichiura, two parasites that inhabit the human intestine and Toxocara spp (Toxocara canis and/or T. cati), intestinal roundworms of dogs and cats that cause systemic larval infection in humans. These parasites were selected as the most prevalent helminth parasites in our study population., Results: 36.4% of children were infected with one parasite; 12.7% with 2 and 5.2% with 3. Eosinophilia>4% and >10% was present in 74.3% and 25.5% of the children, respectively. Total IgE>200 IU/mL, sIgE≥0.70 kU/L and SPT positivity were present in 59.7%, 37.1% and 30% of the children, respectively. 22.7% had recent asthma (12.0% non-atopic and 10.7% atopic). Helminth infections were associated in a dose-dependent way to decrease in the prevalence of SPT and increase in eosinophilia, total IgE, and the production of the regulatory cytokine IL-10 by unstimulated peripheral blood leukocytes. No association with asthma was observed., Conclusions: Helminth co-infections in this population were associated with increased markers of the Th2 immune response, and with a host immune regulatory phenotype that may suppress allergic effector responses such as immediate hypersensitivity reactions in the skin.

Diseases such as leishmaniases are important causes of morbidity and mortality in Brazil, and their diagnoses need to be improved. The use of monoclonal antibodies has ensured high specificity to immunodiagnosis. The development of an immunosensor, coupling a monoclonal antibody to a bioelectronic device capable of quickly detecting Leishmania sp. antigens both qualitatively and quantitatively, is a promising alternative for the diagnosis of leishmaniasis due to its high specificity, low cost, and portability, compared with conventional methods. The present work was aimed at developing an immunosensor-based assay for detecting Leishmania infantum antigens in tissues of infected hosts. Four hybridomas producing monoclonal antibodies against L. infantum had their specificity confirmed by enzyme-linked immunosorbent assay. These antibodies were immobilized on a gold surface, covered with a thin film of 2-aminoethanethiol (cysteamine) and glutaraldehyde, blocked with glycine, and placed into contact with extracts of L. infantum -infected and noninfected control hamster spleens. The assay was able to detect 1.8 × 10(4) amastigotes/g of infected tissue. These results demonstrated that this assay may be useful for quantifying L. infantum amastigotes in organs of experimental animals for studies on pathogenesis and immunity and that it is a promising tool for the development of a diagnostic method, based on antigen detection, of human and dog visceral leishmaniasis.

Aim: This study's objective was to investigate whether candidin or trichophytin elicit recall immune responses that could potentially inhibit a Th2 response., Materials & Methods: Peripheral blood mononuclear cells from nine allergic and seven nonallergic individuals were cultivated in vitro in the presence or absence of these fungal extracts., Results: Trichophytin or candidin, or both, stimulated the production of regulatory cytokines (TGF-β and/or IL-10), accompanied or not by stimulation of production of cytokines associated with the Th1 response (TNF-α, IL-12 and IFN-γ), but without stimulation of Th2 cytokines (IL-5 and IL-13) and IL-17, by peripheral blood mononuclear cells of most allergic and nonallergic individuals., Conclusion: These results indicate that these fungal extracts could be used as adjuvants in personalized therapeutic vaccines in a fair proportion of individuals. In addition, they justify the carrying out of investigations aimed at identifying molecules in these extracts that might exclusively induce Treg and/or Th1 immune responses.

Despite the availability of many parasitological methods for detection of Cryptosporidium and Isospora (Cystoisospora) belli in fecal samples, there are uncertainties about the accuracy of these techniques in laboratory practice. In this study, 27 formalin-fixed positive stool samples for Cryptosporidium and 15 for I. belli were analyzed by 2 concentration methods, sedimentation by centrifugation (SC) and formalin-ethyl acetate (FE), and by 3 tintorial techniques, modified Ziehl-Neelsen (ZN), safranin (SF), and auramine (AR). No significant differences were observed on Cryptosporidium identification between concentration methods, while a significantly higher number of I. belli oocysts (P < 0.0001) was detected in fecal smears concentrated by the SC than by the FE method. Fecal samples processed by FE produced a median oocyst loss to the fatty ring of 34.8% for Cryptosporidium and 45.4% for I. belli. However, FE concentration provided 63% of Cryptosporidium and 100% of I. belli slides classified as superior for microscopic examination. Regarding the efficiency of staining methods, a more significant detection of Cryptosporidium oocysts was observed in fecal smears stained by ZN (P < 0.01) or AR (P < 0.05) than by the SF method. Regular to high-quality slides for microscopic examination were mostly observed in fecal smears stained with AR or ZN for Cryptosporidium and with SF or ZN for I. belli. This study suggests a great variability in oocyst power detection by routine parasitological methods, and that the most frequent intestinal coccidians in humans have specific requirements for concentration and staining.

Experimental evidence and epidemiological studies indicate that exposure to endotoxin lipopolysaccharide (eLPS) or other TLR agonists prevent asthma. We have previously shown in the OVA-model of asthma that eLPS administration during alum-based allergen sensitization blocked the development of lung TH2 immune responses via MyD88 pathway and IL-12/IFN-γ axis. In the present work we determined the effect of eLPS exposure during sensitization to a natural airborne allergen extract derived from the house dust mite Blomia tropicalis (Bt). Mice were subcutaneously sensitized with Bt allergens co-adsorbed onto alum with or without eLPS and challenged twice intranasally with Bt. Cellular and molecular parameters of allergic lung inflammation were evaluated 24 h after the last Bt challenge. Exposure to eLPS but not to ultrapure LPS (upLPS) preparation during sensitization to Bt allergens decreased the influx of eosinophils and increased the influx of neutrophils to the airways. Inhibition of airway eosinophilia was not observed in IFN-γdeficient mice while airway neutrophilia was not observed in IL-17RA-deficient mice as well in mice lacking MyD88, CD14, TLR4 and, surprisingly, TLR2 molecules. Notably, exposure to a synthetic TLR2 agonist (PamCSK4) also induced airway neutrophilia that was dependent on TLR2 and TLR4 molecules. In the OVA model, exposure to eLPS or PamCSK4 suppressed OVA-induced airway inflammation. Our results suggest that B. tropicalis allergens engage TLR4 that potentiates TLR2 signaling. This dual TLR activation during sensitization results in airway neutrophilic inflammation associated with increased frequency of lung TH17 cells. Our work highlight the complex interplay between bacterial products, house dust mite allergens and TLR signaling in the induction of different phenotypes of airway inflammation.

Allergic asthma has emerged as an important public health problem of urban populations in developed countries. Very often herbal medicine is used to treat this widespread disease, due to the lack of efficacy and the important side effects related to the classical drugs in use. Along this line, Ocimum gratissimum (Og) is a plant widely used in Brazilian folk medicine to treat inflammatory disorders, such as asthma. In the present study we evaluated the immunomodulatory effects of Og and rosmarinic acid (RA, a polyphenolic compound) in a murine model of respiratory allergy induced by the Blomia tropicalis (Bt) mite. The respiratory allergy was induced in A/J mice by administration of Bt extract and the treatment was done using 25, 50 or 100mg/kg of an Og methanolic extract or using 2, 20 or 200mg/kg of RA. We then evaluated the changes induced by these drugs on immunological parameters related to the allergic process, which are up-regulated in this allergic model. The treatment of animals with 100mg/Kg Og and 200mg/Kg RA led to a significant reduction in the numbers of leukocytes/eosinophils in bronchoalveolar lavage (BAL); eosinophil peroxidase activity in BAL; presence of mucus in respiratory tract, histopathological changes in the lung, and IL-4 in BAL. These results suggest that the methanolic extract of Og and the polyphenol RA have therapeutic potential in this murine model of respiratory allergy to a clinically relevant human sensitizer allergen., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Background: Asthma constitutes a serious public health problem in many regions of the world, including the city of Salvador, State of Bahia-Brazil. The purpose of this study was to analyse the factors associated with poor asthma control., Methodology/principal Findings: Two definitions were used for asthma: 1) wheezing in the last 12 months; 2) wheezing in the last 12 months plus other asthma symptoms or asthma diagnosis ever. The definition of poorly controlled asthma was: at least one reported hospitalisation due to asthma and/or high frequency of symptoms, in the last year. Children with poorly controlled asthma (N = 187/374) were compared with wheezing children with controlled asthma regarding age, gender, atopy, parental asthma, rhinitis, eczema, exposure to second hand tobacco smoke, presence of moulds, pets and pests in the house, helminth infections and body mass index. Crude and logistic regression adjusted odds ratios were used as measures of association. There was a higher proportion of poorly controlled asthma among children with eczema (OR = 1.55; 95% CI 1.02; 2.37). The strength of the association was greater among children with eczema and rhinitis (42.6%, 53.4% and 57.7%, respectively, in children who had no rhinitis nor eczema, had only one of those, and had both (p = 0.02 for trend test). The presence of mould in the houses was inversely associated with poorly controlled asthma (OR = 0.54; 95% CI 0.34; 0.87)., Conclusions/significance: Our results indicate an association between eczema and poor asthma control in this environment, but emphasize the role of various other individual and environmental factors as determinants of poor control.

Toxocara canis is a highly prevalent worldwide canine nematode responsible for enzootic and zoonotic infections. It is considered to be one of the main agents of human visceral and ocular larva migrans. False negative diagnosis may occur because adult infected dogs with "dormant" larvae may have negative fecal test results since they usually do not shed parasite eggs in their stools. During pregnancy, the larvae become active and infect the offspring through the placenta. A serological test can distinguish infected animals, thus increasing the accuracy of the diagnosis for epidemiological studies and prophylactic purposes. In the present work a serological investigation was carried out to study the risk factors for the acquisition of this infection in 301 dogs inhabiting the city of Salvador, northeast Brazil. A validated questionnaire was applied to the donors and caretakers to assess animal management practices. All dogs were submitted to clinical evaluation and blood collection. Serum samples were analyzed for IgG antibodies against excretory-secretory products of T. canis larvae, used as antigens, by indirect ELISA. The overall seroprevalence of anti-T. canis IgG antibodies was 82.7%. Risk factors for T. canis infection included sex, area of origin within the city, homemade leftover food intake, failure to receive regular vaccination against infectious diseases and lack of preventive anti-helminthic treatment. Most of these risk factors suggest a lack of veterinary care and poverty. The high frequency of seropositivity found for toxocariasis in dogs suggests that results based on parasitological fecal examination could underestimate the actual prevalence of the infection., (Copyright © 2011 Elsevier B.V. All rights reserved.)

The American visceral leishmaniasis is an important cause of morbidity and mortality in Brazil for both humans and dogs. Attempts to make a diagnosis of this disease need to be improved, especially in endemic areas, and in the tracking and screening of asymptomatic dogs, which are their main host in urban areas. A quartz crystal microbalance immunosensor for the diagnosis of the canine visceral leishmaniasis using a recombinant antigen of Leishmania chagasi (rLci2B-NH6) was developed. The rLci2B-NH6 was tightly immobilized on a quartz crystal gold electrode by self-assembled monolayer based on short-chain length thiol. The strategy was the use of the antigen-histidine tail covalently linked to glutaraldehyde performing a Schift base which permits a major exposure of epitopes and a reduced steric hindrance. The immunosensor showed good results regarding sensitivity and reproducibility, being able to distinguish positive and negative canine serum for L. chagasi. Furthermore, the immunosensor can be reused through exposure to sodium dodecyl sulfate solution, which promotes the dissociation of antigen-antibody binding, restoring the sensor surface with immobilized biologically active antigens for further analysis.

Background: Two conditions are used as markers of atopy: the presence of circulating anti-allergen IgE antibodies and the presence of positive skin prick test (SPT) reactions to allergenic extracts. The correlation between these conditions is not absolute. This study aimed at investigating immunological parameters that may mediate this lack of correlation. Individuals whose sera contained anti-B. tropicalis extract IgE antibodies (α-BtE IgE) were divided into two groups, according to the presence or absence of skin reactivity to B. tropicalis extract (BtE). The following parameters were investigated: total IgE levels; α-BtE IgE levels; an arbitrary α-BtE IgE/total IgE ratio; the proportion of carbohydrate-reactive α-BtE IgE; the proportion of α-BtE IgE that reacted with Ascaris lumbricoides extract (AlE); the production of IL-10 by BtE- and AlE-stimulated peripheral blood cells (PBMC)., Results: Total IgE levels were similar in the two groups, but α-BtE IgE was significantly higher in the SPT-positive group (SPT+). A large overlap of α-BtE IgE levels was found in individuals of both groups, indicating that these levels alone cannot account for the differences in SPT outcome. Individuals of the two groups did not differ, statistically, in the proportion of α-BtE IgE that reacted with carbohydrate and in the production of IL-10 by BtE- and AlE-stimulated PBMC. Both groups had part of α-BtE IgE activity absorbed out by AlE, indicating the existence of cross-reactive IgE antibodies. However, the α-BtE IgE from the SPT-negative individuals (SPT-) was more absorbed with AlE than the α-BtE IgE from the SPT+ individuals. This finding may be ascribed to avidity differences of the α-BtE IgE that is present in the two groups of individuals, and could occur if at least part of the α-BtE IgE from the SPT- individuals were elicited by A. lumbricoides infection., Conclusion: The present results suggest that a low ratio of specific IgE to total IgE levels (in a minority of individuals), and differences in α-BtE IgE avidities (which would have high affinities for A. lumbricoides antigens in SPT- than in SPT+ individuals) may play a role in the down-modulation of type-I hypersensitivity reaction against aeroallergens described in helminth-infected individuals.

Asthma is one of the most prevalent chronic diseases worldwide. Medicinal plants are historically used in its treatment. The plant Cissampelos sympodialis, known in Northeastern Brazil as "Jarrinha" or "Milona", is used to treat some inflammatory conditions, including asthma. The objective of this study was to evaluate the potential of Cissampelos sympodialis EICHL. extract (CsE) and its isolated alkaloids, especially warifteine (Wa) on a Blomia tropicalis extract (BtE)-induced experimental model of allergy. The respiratory allergy was induced in AJ mice by the administration of BtE. Mice were orally treated with the 400 mg/kg of CsE or 8 mg/kg of total alkaloids fraction (TAF) or 4 mg/kg of Wa and the following parameters were analyzed: (a) total cell numbers in bronchoalveolar fluid (BAF); (b) differential cell numbers in BAF; (c) eosinophil peroxidase (EPO) activity in BAF; (d) IgE serum levels by passive cutaneous anaphylaxis; (e) IL-5, IL-13, IL-10, and IFN-γ levels in BAF; (f) histopathological alterations in the lung. The treatment of the animals with CsE, Wa or TAF led to a reduction in the numbers of total cells and eosinophils in BAF. The same reduction was observed in EPO levels in the BAF. The levels of IL-5 and IL-13 were also reduced in animals treated with Cissampelos sympodialis, while IL-10 levels were significantly increased in the BAF of CsE-treated animals. The treatment also decreased the density of inflammatory cells in the lung by histopathological examination demonstrating the potential of this medicinal plant as new agent for asthma treatment.

Background: Sanitation affects health, especially that of young children. Residents of Salvador, in Northeast Brazil, have had a high prevalence of intestinal parasites. A citywide sanitation intervention started in 1996 aimed to raise the level of sewer coverage from 26% to 80% of households., Objectives: We evaluated the impact of this intervention on the prevalence of Ascaris lumbricoides, Trichuris trichuria, and Giardia duodenalis infections in preschool children., Methods: The evaluation was composed of two cross-sectional studies (1998 and 2003-2004), each of a sample of 681 and 976 children 1-4 years of age, respectively. Children were sampled from 24 sentinel areas chosen to represent the range of environmental conditions in the study site. Data were collected using an individual/household questionnaire, and an environmental survey was conducted in each area before and after the intervention to assess basic household and neighborhood sanitation conditions. Stool samples were examined for the presence of intestinal parasites. The effect of the intervention was estimated by hierarchical modeling, fitting a sequence of multivariate regression models., Findings: The prevalence ofA. lumbricoides infection was reduced from 24.4% to 12.0%, T. trichuria from 18.0% to 5.0%, and G. duodenalis from 14.1% to 5.3%. Most of this reduction appeared to be explained by the increased coverage in each neighborhood by the sewage system constructed during the intervention. The key explanatory variable was thus an ecological measure of exposure and not household-based, suggesting that the parasite transmission prevented by the program was mainly in the public (vs. the domestic) domain., Conclusion: This study, using advanced statistical modeling to control for individual and ecological potential confounders, demonstrates the impact on intestinal parasites of sanitation improvements implemented at the scale of a large population.

Background: The elucidation of factors that trigger the development of transient wheezing in early childhood may be an important step toward understanding the pathogenesis of asthma and other allergic diseases later in life. Transient wheezing has been mainly attributed to viral infections, although sensitisation to aeroallergens and food allergens may occur at an early age. In developing countries, intestinal helminthic infections have also been associated with allergy or atopy-related disorders., Objective: The aim of this study was to explore the association of Trichuris trichiura and Ascaris lumbricoides infections with wheezing and atopy in early childhood., Study Design: A cross-sectional study using a Portuguese-language ISAAC phase I questionnaire, adapted for preschool-aged children, nested in a cohort study of childhood diarrhoea, was conducted on 682 children. Two faecal samples per child were examined for the presence of intestinal helminthic infection. IgE antibodies against three allergenic preparations (Dermatophagoides pteronyssinus, Blomia tropicalis and common child food), as well as against A. lumbricoides antigens, were measured in a sub-sample of these children, whose parents allowed the procedure. Atopy was defined by the presence of levels of serum IgE antibodies ≥0.35 kU/L against at least one of the three tested allergenic preparations., Results: Active T. trichiura infection but not A. lumbricoides infection was positively associated with wheezing in the total studied children population [adjusted OR = 2.60; CI = 1.54;4.38] and in the atopic children sub-population [adjusted OR = 3.07; CI = 1.00;9.43]. The association with atopy was also positive and statistically significant only in the brute analysis [OR = 2.13; CI = 1.03;4.40]. Anti-A. lumbricoides IgE antibodies, but not current A. lumbricoides infection, were positively associated with wheezing in atopic children [adjusted OR = 2.01; CI = 1.00;4.50] and in non-atopic children [adjusted OR = 3.07; CI = 1.13;8.35] and it was also associated with atopy [adjusted OR = 7.29; CI = 3.90; 13.4]. On the other hands, reports of wheezing were not significantly associated with atopy., Conclusions: These data corroborate previous studies showing that wheezing is predominantly associated with infection in early childhood and shows that anti-A. lumbricoides IgE antibodies, but not active Ascaris infections, are associated with wheezing and atopy. Additionally, the data demonstrate that T. trichiura infection may play a role in the pathogenesis of atopic wheezing in early childhood.

Background: Helicobacter pylori infection has been proved to be of great relevance to public health in unindustrialized countries, especially in low socioeconomic groups. Poor hygiene, deficient sanitation, and crowded conditions have been reported as risk factors for this infection. In this work, we investigated whether social and demographic characteristics were associated with anti-H. pylori IgG antibodies in 1104 children aged 4-11 years old from Salvador, a large city located in northeastern Brazil., Methods: Standardized questionnaires were used to obtain social, demographic, and environmental data for the studied population in two periods of time (from 1997 to 2003 and in 2005). Anti-H. pylori IgG antibodies were assessed by indirect enzyme-linked immunosorbent assay in 2005., Results: Anti-H. pylori IgG antibody was present in 28.7% of the children. Among the studied variables, the following were positively associated with the presence of anti-H. pylori antibodies in multivariable analyses: age above 8 years old (OR = 1.72, 95% CI = 1.23-2.40), a larger sibling number (OR = 1.66, 95% CI = 1.26-2.18), nursery attendance (OR = 1.49, 95% CI = 1.04-2.12), location of the house at an unpaved street (OR = 2.03, 95% CI = 1.44-2.87) and absence of a flush toilet (OR = 1.32, 95% CI = 1.00-1.74)., Conclusion: Our data show that H. pylori infection in children from a major Brazilian city is associated with variables indicative of a crowded environment and deficient sanitation/habitation conditions, leading to the conclusion that improvements in hygiene and social conditions may protect children against this infection.

Background: The dust mite Blomia tropicalis is an important source of aeroallergens in tropical areas. Although a mouse model for B. tropicalis extract (BtE)-induced asthma has been described, no study comparing different mouse strains in this asthma model has been reported. The relevance and reproducibility of experimental animal models of allergy depends on the genetic background of the animal, the molecular composition of the allergen and the experimental protocol., Objectives: This work had two objectives. The first was to study the anti-B. tropicalis allergic responses in different mouse strains using a short-term model of respiratory allergy to BtE. This study included the comparison of the allergic responses elicited by BtE with those elicited by ovalbumin in mice of the strain that responded better to BtE sensitization. The second objective was to investigate whether the best responder mouse strain could be used in an experimental model of allergy employing relatively low BtE doses., Methods: Groups of mice of four different syngeneic strains were sensitized subcutaneously with 100 microg of BtE on days 0 and 7 and challenged four times intranasally, at days 8, 10, 12, and 14, with 10 microg of BtE. A/J mice, that were the best responders to BtE sensitization, were used to compare the B. tropicalis-specific asthma experimental model with the conventional experimental model of ovalbumin (OVA)-specific asthma. A/J mice were also sensitized with a lower dose of BtE., Results: Mice of all strains had lung inflammatory-cell infiltration and increased levels of anti-BtE IgE antibodies, but these responses were significantly more intense in A/J mice than in CBA/J, BALB/c or C57BL/6J mice. Immunization of A/J mice with BtE induced a more intense airway eosinophil influx, higher levels of total IgE, similar airway hyperreactivity to methacholine but less intense mucous production, and lower levels of specific IgE, IgG1 and IgG2 antibodies than sensitization with OVA. Finally, immunization with a relatively low BtE dose (10 microg per subcutaneous injection per mouse) was able to sensitize A/J mice, which were the best responders to high-dose BtE immunization, for the development of allergy-associated immune and lung inflammatory responses., Conclusions: The described short-term model of BtE-induced allergic lung disease is reproducible in different syngeneic mouse strains, and mice of the A/J strain was the most responsive to it. In addition, it was shown that OVA and BtE induce quantitatively different immune responses in A/J mice and that the experimental model can be set up with low amounts of BtE.

Background: Environmental factors are likely to have profound effects on the development of host immune responses, with serious implications for infectious diseases and inflammatory disorders such as asthma., Objective: This study was designed to investigate the effects of environmental exposures on the cytokine profile of children., Methods: The study involved measurement of T helper (Th) 1 (interferon-gamma), 2 [interleukin (IL)-5 and IL-13], and the regulatory cytokine IL-10 in unstimulated peripheral blood leukocytes from 1,376 children 4-11 years of age living in a poor urban area of the tropics. We also assessed the impact of environmental exposures in addition to biological characteristics recorded at the time of blood collection and earlier in childhood (0-3 years before blood collection)., Results: The proportion of children producing IL-10 was greater among those without access to drinking water [p < 0.05, chi-square test, odds ratio (OR) = 1.67]. The proportion of children producing IL-5 and IL-10 (OR = 10.76) was significantly greater in households that had never had a sewage system (p < 0.05, trend test)., Conclusions: These data provide evidence for the profound effects of environmental exposures in early life as well as immune homeostasis in later childhood. Decreased hygiene (lack of access to clean drinking water and sanitation) in the first 3 years of life is associated with higher spontaneous IL-10 production up to 8 years later in life.

Toxocara canis is a dog helminth which causes visceral larva migrans (VLM) when infecting humans as a larva. The infection is demonstrated by detecting IgG antibodies against excretory-secretory larval antigens (ESLA) in serum by ELISA. The production of ESLA involves the collection of adult worms from dog puppy stools, the separation of eggs from dissected uteri, and the in vitro growing of egg-derived larvae, following the time-consuming and laborious protocol described by De Savigny [De Savigny, D.H., 1975. In vitro maintenance of T. canis larvae and a simple method for the production of Toxocara ES antigen for the uses in serodiagnostic tests for visceral larva migrans. Journal of Parasitology 61, 781-782]. In this work, an improved protocol for obtaining T. canis larvae is described. The modifications proposed improved the efficiency of the original De Savigny method in three ways: (i) increasing the parasite yield up to five fold, (ii) improving the larval purity, and (iii) markedly reducing the execution time of the protocol.

Objectives: To study the prevalence of Cryptosporidium infection by measuring the levels of anti-Cryptosporidium IgG antibodies among people inhabiting three neighbourhoods of a periurban area of Salvador, Northeast of Brazil; and to investigate the effects of environmental sanitation measures, hygienic habits and household water supply, storage and handling on the frequency of these antibodies in sera of the studied population., Methods: Cryptosporidium inter-household transmission was studied by comparing the frequency of anti-Cryptosporidium IgG antibodies among people inhabiting areas with or without different environmental sanitation measures and intra-household transmission by comparing the presence of these antibodies in families with or without cases of diarrhoea, associated with the presence of Cryptosporidium oocysts in their stools. Children or family members with diarrhoeal episodes were evaluated parasitologically for Cryptosporidium infection by testing stool specimens with the Ritchie-modified formol-ether concentration and the acid-fast staining methods. All groups were serologically evaluated for parasite exposure by an indirect enzyme-linked immunosorbent assay., Results: A statistically significant difference was detected in the prevalence of Cryptosporidium infection between area 1 which had no environmental sanitation measures and area 3 which had improved environmental sanitation measures (P = 0.044). Most of the hygienic habits investigated did not correlate with the presence of anti-Cryptosporidium antibody in sera of the population studied. However, positive associations were found between both poor household water supply (OD = 0.17; 90% CI = 0.09-0.32; P = 0.0001) and drinking unboiled/unfiltered water (OD = 0.40; 90% CI = 0.24-0.67; P = 0.0002) with high levels of anti-Cryptosporidium antibodies in sera., Conclusions: These data suggest that although uncorrected household water supply, storage and handling play an important role on Cryptosporidium transmission in periurban areas of developing country cities, like Salvador, Brazil, inadequate environmental conditions may also contribute to the spread of this parasite.

Allergy is considered to be caused by complex interactions between genetic and environmental factors. Socioeconomic status (SES) may be the most important environmental determinant of allergy because it determines the living environment, but few studies have addressed the causal role of SES in allergy. The aim of this study was to compare the prevalence of asthma and rhinitis symptoms in two SES groups in a Brazilian city. History of asthma and rhinitis symptoms was collected using the International Study of Asthma and Allergies in Childhood questionnaire. SES was determined by the Gallup method. Sera from subgroups of the individuals were used to determine total, anti-Dermatophagoides pteronyssinus and anti-Blomia tropicalis IgE. The prevalence of asthma and rhinitis symptoms was higher in the A and B (A&B) SES group than in the C, D, and E (C, D&E) SES group. Individuals with asthma and/or rhinitis were more frequently positive for anti-B. tropicalis and anti-D. pteronyssinus IgE than individuals without these symptoms. A positive association between total IgE levels and asthma and rhinitis symptoms was observed in the A&B SES group but not in the C, D&E SES group. Women reported more respiratory symptoms than men. These results revealed higher prevalence rates ofasthma and rhinitis symptoms in individuals with higher SES and may provide support for the hygiene hypothesis, which attributes the high prevalence of respiratory allergies observed in individuals from developed countries to a low exposure to pathogens. The observed higher prevalence of asthma and rhinitis symptoms in women than in men could be attributed to differences in the perception of these symptoms or in exposures to allergens and protective pathogens.

Different individuals, when infected with the same parasite, rarely produce antibodies against the same set of antigens. Indeed, unless a particular antigen happens to be recognized by antibodies in all individuals, the use of a single antigen in the serodiagnosis of parasitic diseases leads, invariably, to false-negative results. A straightforward method for pin-pointing, in genetic libraries, the precise antigens that would increase serodiagnostic assay sensitivities is presented. The method is based on the utilization of sera that produced false-negative results against previously available antigens. Employing this false-negative serum-selection methodology for the identification of new Leishmania infantum recombinant antigens (rAgs), the sensitivity of a dipstick assay for anti-Leishmania antibodies in a panel of sera from patients with visceral leishmaniasis was increased from 83.3% to 98.1%, without affecting its specificity, by the inclusion of a fifth and a sixth L. infantum rAg.

Background: Asthma and allergic diseases are becoming increasingly frequent in children in urban centres of Latin America although the prevalence of allergic disease is still low in rural areas. Understanding better why the prevalence of asthma is greater in urban migrant populations and the role of risk factors such as life style and environmental exposures, may be key to understand what is behind this trend., Methods/design: The Esmeraldas-SCAALA (Social Changes, Asthma and Allergy in Latin America) study consists of cross-sectional and nested case-control studies of school children in rural and urban areas of Esmeraldas Province in Ecuador. The cross-sectional study will investigate risk factors for atopy and allergic disease in rural and migrant urban Afro-Ecuadorian school children and the nested case-control study will examine environmental, biologic and social risk factors for asthma among asthma cases and non-asthmatic controls from the cross-sectional study. Data will be collected through standardised questionnaires, skin prick testing to relevant aeroallergen extracts, stool examinations for parasites, blood sampling (for measurement of IgE, interleukins and other immunological parameters), anthropometric measurements for assessment of nutritional status, exercise testing for assessment of exercise-induced bronchospasm and dust sampling for measurement of household endotoxin and allergen levels., Discussion: The information will be used to identify the factors associated with an increased risk of asthma and allergies in migrant and urbanizing populations, to improve the understanding of the causes of the increase in asthma prevalence and to identify potentially modifiable factors to inform the design of prevention programmes to reduce the risk of allergy in urban populations in Latin America.

Community-based monitoring was conducted in order to investigate the occurrence of diarrhea in 'sentinel areas' of Salvador, Brazil, and to establish a preliminary profile of the most common pathogens present in children's diarrhea by screening stool samples. This report describes the results obtained from twice weekly home visits to identify and follow diarrhea episodes and testing of carer-requested stool sample collection over a 6-month period. Participants were selected from a large longitudinal study in 21 areas representing the city's poorer socioeconomic and sanitary conditions. Fecal samples were examined for the presence of pathogenic bacteria, viruses and protozoa. The mean incidence of diarrhea was 4.97 episodes per child-year, and longitudinal prevalence was 13.6 days per child-year (3.7%). Pathogens were found in 44% of the fecal samples examined. Bacteria were the most frequently encountered pathogens (isolated in 22% of samples), followed by protozoa (19.5%) and viruses (16%). Viral and bacterial pathogens were associated with episodes of severe diarrhea, while viral and protozoan pathogens were associated with longer episodes. The study demonstrated the importance of a public health monitoring system based on 'sentinel areas'.

Background: Dermatophagoides pteronyssinus, Dermatophagoides farinae and Blomia tropicalis dust mites are among the most important agents of hypersensitivity reactions in human beings. However, a role of other mites in the etiology of these reactions has not yet been excluded., Objectives: To investigate the nature of the dust mite fauna and the presence of Der p 1 (allergen 1 of Dermatophagoides pteronyssinus) and Blo t 5 (allergen 5 of Blomia tropicalis) on beds used by individuals with different socioeconomic backgrounds in Salvador, a major Brazilian city and to investigate possible associations of mite frequencies and allergen levels with (a) season of the year, (b) housing characteristics, (c) bed cleaning behaviors that could affect mite densities, and (d) allergy history., Methods: Dust samples were collected from 459 beds of 101 residences from two groups with different socioeconomic levels (hereafter called wealthy and poor groups) in the city of Salvador, Brazil, for the identification of mite species and determination of Der p 1 and Blo t 5 levels. History of allergy was collected using the ISAAC phase I questionnaire., Results: Eighty nine percent of the beds analyzed harbored at least one mite species. B. tropicalis was found in 71.8%, D. pteronyssinus in 39.9%, Cheyletus sp. in 33.9%, and Gohieria fusca in 21.1% of the beds. B. tropicalis was found with a similar frequency in beds of the two socioeconomic groups; D. pteronyssinus was found more frequently in the beds of the wealthy than of the poor group, whereas the reverse was observed with G. fusca. The concentrations of Der p 1 and Blo t 5 allergens exceeded the cut-off for sensitization of 2 microg/g of dust in 94.0% and 69.3% of the wealthy and poor group beds, respectively. No associations were found between history of allergy and mite species or between history of allergy and the concentrations of mite allergens., Conclusions: The observation of B. tropicalis and D. pteronyssinus as the most frequently found mites is consistent with previous reports from tropical regions. The higher frequency of G. fusca in beds of individuals from the poor group than those from the wealthy group could be a consequence of different bed cleaning behaviors between the two groups.

Trypanosoma cruzi is an obligate intracellular protozoan parasite that actively penetrates into non-phagocytic mammalian cells. To accomplish this, the parasite relies on the binding of cell surface ligands. It is reported herein that the T. cruzi trans-sialidase (TS), which is exposed on the parasite surface, binds to mouse heart cells, and should therefore be further studied as a possible cell penetration-related ligand. In addition, as has been proposed elsewhere, the binding of T. cruzi to tissues may turn them into targets for parasite-specific immune reactions. Washed heart sections from T. cruzi-infected mice were subjected to immunoenzymatic staining with antisera against whole T. cruzi and with polyclonal or monoclonal antibodies against TS. The anti-TS antibodies stained both parasites and uninfected heart cells in the vicinity of T. cruzi nest remains/trypomastigotes. On the other hand, an anti-T. cruzi serum, which did not recognize TS, only stained the parasites. In addition, normal heart sections from uninfected nude mice were shown to react with both enzymatically active and inactive recombinant TS molecules, probably through their amino-terminal region, since a recombinant TS lacking this region failed to bind.

This work aims at identifying an effective protocol to raise anti-Leishmania chagasi amastigote antibodies in different animal species. Protocols of immunization by subcutaneous injections of L. chagasi promastigote and amastigote lysates or by either intravenous or subcutaneous inoculation of live metacyclic promastigotes were assessed in mice, rabbits, and dogs. The immunization with live promastigotes produced a strong humoral immune response against L. chagasi amastigotes in all three animal species. The sera from animals immunized with the promastigote lysate did not react with amastigotes and, conversely, the sera from mice immunized with the amastigote lysate did not react with promastigotes. Taken all data together, the immunization through infection with metacyclic promastigotes was considered the most satisfactory way to immunize animals for obtaining anti-amastigote and anti-promastigote antibodies, since it did not only allowed the obtention of antibody against the two forms of the parasite, but it is also cheap, less laborious than carrying out the purification of amastigotes from infected tissues and avoid the use of a large number of hamsters for obtention the amastigotes, necessary to produce the immunogenic lysates. Furthermore, this immunization protocol was comparable to the amastigote lysate immunization protocol for the obtaining of mouse monoclonal antibodies (mAbs)., (Copyright 2004 Elsevier B.V.)

The humoral antibody response to Cryptosporidium was investigated in mice genetically selected for high (H) and low (L) antibody responsiveness. Groups of 4-5 mice from two different selections, general primary (GP) and general secondary (GS), were studied. Following immunization with Cryptosporidium parvum antigens, the maximum levels of IgG in the HGP (X +/- SD = 1.13 +/- 0.35, N = 5) in the HGS (0.42 +/- 0.15, N = 4) lines, and of IgM in the HGP line (0.86 +/- 0.53, N = 5) were significantly higher than those in their L counterparts (0.04 +/- 0.02, N = 5; 0.05 +/- 0.02, N = 4 and 0.24 +/- 0.07, N = 5, respectively). These findings were similar to those reported for other immunogens. However, the IgG (0.22 +/- 0.05, N = 4) and the IgM (0.33 +/- 0.08, N = 4) responses to immunization of F1 (LGP x HGP) hybrids indicated an incomplete dominance of the low response, in contrast to the incomplete dominance of the high response described for many other antigens and representing an important exception. In addition, the H, L and F1 mice did not develop detectable infections when inoculated with live Cryptosporidium oocysts, supporting the view that a reduced or zero antibody production itself is not enough to permit the establishment of Cryptosporidium infection in adult mice.

Parasite-derived trans-sialidase (TS) activity was demonstrated in the serum and blood of Trypanosoma cruzi-infected mice. Serum TS activity levels correlated well with parasitemia in BALB/c and Swiss mice during the initial stages of the infection. However, in later stages the TS activity levels decreased despite increasing parasitemia. This coincided with the appearance of circulating TS antibodies. On the other hand, there was always a good correlation between TS activity and parasitemia in athymic nude mice. Sera from mice with high parasitemia and low TS activity inhibited TS activity in vitro. The inhibition was also observed with purified serum IgG, and it was absorbed by staphylococcal protein A, indicating that it was caused by anti-TS IgG antibodies. These antibodies inhibited the enzymatic activity of insolubilized TS, indicating that they act by interfering with the catalytic site rather than by aggregating the enzyme. The presence of inhibitory antibodies, however, did not prevent the progression of parasitemia in BALB/c mice.

The intradermal inoculation in naive or in previously sensitized individuals of small amounts of Leishmania extract (Montenegro's skin test) induced or modulated, respectively, the immune response to Leishmania, as assessed by subsequent Montenegro's skin tests. These phenomena could hinder the interpretation of Montenegro's skin tests in a population already subjected to the test in the past and, in addition, could affect in an unknown way the development of mucosal lesions in people infected with L. braziliensis or L. amazonensis, since those lesions have been associated with hypersensitivity to Leishmania antigens. Anti-Leishmania antibody responses, assessed by enzyme-linked immunosorbent assay, were not induced in naive individuals by Montenegro's skin tests, but tended to become more intense following these tests in previously sensitized individuals.