RESUMO
Field studies have suggested an immune-mediated mechanism associated with resistance to Schistosoma mansoni infection. Overall, levels of specific IgE have been correlated with resistance to infection, whereas levels of IgG4 have been associated with susceptibility. This study aimed to evaluate serum levels of soluble adult worm antigen preparation (SWAP)-specific IgE and IgG4 in relation to current infection in a large casuistic of individuals living in an endemic area of schistosomiasis in Bahia, Brazil. The prevalence of S. mansoni infection was 37·7% and the mean parasite burden was 55·4 (0-2100) epg/faeces. There was no significant difference in the levels of SWAP-specific IgE in individuals with different parasite burden, whereas high producers of parasite-specific IgG4 presented higher parasite burden when compared to low IgG4 producers. Additionally, S. mansoni parasite load was positively correlated with the levels of specific IgG4 or total IgE. No significant correlation was observed between parasite burden and SWAP-specific IgE. Nevertheless, SWAP-specific IgE/IgG4 ratio was higher in uninfected or lightly infected individuals (1-99 epg/faeces) than in heavily infected ones (≥400 epg/feces). These findings highlight the important role of IgE/IgG4 ratio in the resistance to infection, which could be useful for further studies in schistosomiasis vaccine candidates.
Assuntos
Anticorpos Anti-Helmínticos/sangue , Doenças Endêmicas , Imunoglobulina E/sangue , Imunoglobulina G/sangue , Schistosoma mansoni/imunologia , Esquistossomose mansoni/epidemiologia , Esquistossomose mansoni/imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Brasil/epidemiologia , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Carga Parasitária , Adulto JovemRESUMO
Interleukin (IL)-10 is a regulatory cytokine of the helper T cell type 2 (TH2) pathway, which underlies both the host defense to helminthic infection and atopic diseases, including asthma. Although IL10 promoter polymorphisms are associated with increased atopy risk, IL10 variation has not been thoroughly explored in schistosomiasis-endemic populations. Three atopy-related IL10 promoter polymorphisms (rs1800896, rs1800871 and rs1800872), complemented by six tagging single-nucleotide polymorphisms (SNPs), were genotyped in 812 individuals in 318 nuclear families from a schistosomiasis-endemic area in Brazil. Associations between markers and total serum Immunoglobulin E (tIgE) levels, indicating non-specific activation of the TH2 pathway, and Schistosoma mansoni fecal egg counts, indicating burden of infection reflecting effectiveness of schistosomiasis host immunity, were performed using family-based transmission disequilibrium tests for quantitative traits (QTDTs). Alleles A, T and A at the three promoter SNPs rs1800896, rs1800871 and rs1800872 were associated with high tIgE levels in the same direction as in atopy populations (P=0.0008, 0.026 and 0.045), but not with egg counts. IL10 promoter polymorphisms appear to influence non-specific tIgE levels, but not schistosomiasis-specific immunity. The tagging SNP rs3024495 was associated with high S. mansoni egg counts (P=0.005), suggesting a novel locus in IL10 may influence clinically relevant burden of infection.
Assuntos
Imunoglobulina E/sangue , Interleucina-10/genética , Polimorfismo de Nucleotídeo Único , Schistosoma mansoni/fisiologia , Esquistossomose mansoni/genética , Esquistossomose mansoni/imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Brasil , Criança , Feminino , Humanos , Imunoglobulina E/imunologia , Masculino , Pessoa de Meia-Idade , Regiões Promotoras Genéticas , Adulto JovemRESUMO
BACKGROUND: Single nucleotide polymorphisms (SNPs) in thymic stromal lymphopoietin (TSLP) have been associated with IgE (in girls) and asthma (in general). We sought to determine whether TSLP SNPs are associated with asthma in a sex-specific fashion. METHODS: We conducted regular and sex-stratified analyses of association between SNPs in TSLP and asthma in families of children with asthma in Costa Rica. Significant findings were replicated in whites and African-American participants in the Childhood Asthma Management Program, in African-Americans in the Genomic Research on Asthma in the African Diaspora study, in whites and Hispanics in the Children's Health Study, and in whites in the Framingham Heart Study (FHS). MAIN RESULTS: Two SNPs in TSLP (rs1837253 and rs2289276) were significantly associated with a reduced risk of asthma in combined analyses of all cohorts (P values of 2 × 10(-5) and 1 × 10(-5) , respectively). In a sex-stratified analysis, the T allele of rs1837253 was significantly associated with a reduced risk of asthma in males only (P = 3 × 10(-6) ). Alternately, the T allele of rs2289276 was significantly associated with a reduced risk of asthma in females only (P = 2 × 10(-4) ). Findings for rs2289276 were consistent in all cohorts except the FHS. CONCLUSIONS: TSLP variants are associated with asthma in a sex-specific fashion.
Assuntos
Asma/genética , Citocinas/genética , Predisposição Genética para Doença/genética , Caracteres Sexuais , População Negra/genética , Criança , Estudos de Coortes , Costa Rica , Feminino , Predisposição Genética para Doença/etnologia , Estudo de Associação Genômica Ampla , Genótipo , Hispânico ou Latino/genética , Humanos , Masculino , Polimorfismo de Nucleotídeo Único , Fatores de Risco , População Branca/genética , Linfopoietina do Estroma do TimoRESUMO
BACKGROUND: G protein-coupled receptor 154 was described as an asthma susceptibility gene by positional cloning. It has been subsequently associated with asthma and other inflammatory diseases in several populations with different ethnic origin. Replication of associations adds reliability to these findings. OBJECTIVE: To analyze the association of G protein-coupled receptor 154 with asthma and total and mite-specific IgE levels in a population of the Caribbean Coast of Colombia. METHODS: We genotyped seven single nucleotide proteins (SNPs) in GPR154 in 475 asthmatics, 394 controls and 116 families from Cartagena, Colombia using either SnaPshot or TaqMan. Total and specific IgE against Blomia tropicalis and Dermatophagoides pteronyssinus were determined by ELISA. Hardy-Weinberg equilibrium was assessed and case-control and family-based analyses were performed to evaluate the association between the SNPs and their haplotypes and asthma and IgE. Association analyses in the case-control dataset were corrected by population stratification using 52 ancestry informative markers. RESULTS: Allelic distribution was similar to that described in other populations. Two SNPs were associated with the same direction of the effect in both datasets. Allele A of Hopo546333 was protective for asthma (case-control OR: 0.42; 95% CI: 0.17-0.99, P=0.042; P=0.043; families Z score=-2,236; P=0.025). Similarly, allele C of rs740347 conferred low risk for asthma (OR: 0.44; 95% CI: 0.28-0.70, P=0.00017; Pc=0.00037) and total IgE (OR: 0.29; 95% CI: 0.09-0.88, P=0.015; Pc=0.030) in the case-control study and families (Z score=-3.207, P=0.0013; Z score=-3.182, P=0.0014, respectively). Haplotype CCAGGT was associated with total IgE (OR: 1.76; 95% CI: 1.14-2.71, P=0.006, Pc=0.007) in the case-controls group and CGCGGT with both phenotypes (P=0.044 and P=0.032, respectively) in families. Neither SNPs nor haplotypes were associated with levels of mite-specific IgE. CONCLUSIONS: Our findings in a sample of asthmatics from Colombia suggest a relevant role of G protein-coupled receptor 154 in the pathogenesis of asthma and allergy.
Assuntos
Especificidade de Anticorpos , Asma/sangue , Asma/genética , Imunoglobulina E/sangue , Polimorfismo de Nucleotídeo Único , Receptores Acoplados a Proteínas G/genética , Adolescente , Adulto , Alelos , Animais , Antígenos de Dermatophagoides/efeitos adversos , Asma/epidemiologia , Estudos de Casos e Controles , Colômbia , Feminino , Haplótipos , Humanos , Masculino , Receptores Acoplados a Proteínas G/metabolismoRESUMO
Proinflammatory and immunoregulatory products from C3 play a major role in phagocytosis, respiratory burst, and airways inflammation. C3 is critical in adaptive immunity; studies in mice deficient in C3 demonstrate that features of asthma are significantly attenuated in the absence of C3. To test the hypothesis that the C3 gene on chromosome 19p13.3-p13.2 contains variants associated with asthma and related phenotypes, we genotyped 25 single nucleotide polymorphism (SNP) markers distributed at intervals of approximately 1.9 kb within the C3 gene in 852 African Caribbean subjects from 125 nuclear and extended pedigrees. We used the multiallelic test in the family-based association test program to examine sliding windows comprised of 2-6 SNPs. A five-SNP window between markers rs10402876 and rs366510 provided strongest evidence for linkage in the presence of linkage disequilibrium for asthma, high log[total IgE], and high log[IL-13]/[log[IFN-gamma] in terms of global P-values (P = 0.00027, 0.00013, and 0.003, respectively). A three-SNP haplotype GGC for the first three of these markers showed best overall significance for the three phenotypes (P = 0.003, 0.007, 0.018, respectively) considering haplotype-specific tests. Taken together, these results implicate the C3 gene as a priority candidate controlling risk for asthma and allergic disease in this population of African descent.
Assuntos
Asma/genética , População Negra , Complemento C3/genética , Predisposição Genética para Doença , Barbados/etnologia , População Negra/etnologia , Região do Caribe/etnologia , Variação Genética , Genótipo , Humanos , Fenótipo , Polimorfismo de Nucleotídeo ÚnicoRESUMO
BACKGROUND: The inflammatory functions of complement component 5 (C5) are mediated by its receptor, C5R1, which is expressed on bronchial, epithelial, vascular endothelial and smooth muscle cells. A susceptibility locus for murine allergen-induced airway hyper-responsiveness was identified in a region syntenic to human chromosome 19q13, where linkage to asthma has been demonstrated and where the gene encoding C5R1 is localized. OBJECTIVE: The aim of this study was to screen for novel polymorphisms in the C5R1 gene and to determine whether any identified polymorphisms are associated with asthma and/or atopy and whether they are functional. METHODS: Single-nucleotide polymorphism (SNP) detection in the gene encoding C5R1 was performed by direct sequencing. Genotyping was performed in three populations characterized for asthma and/or atopy: (1) 823 German children from The Multicenter Allergy Study; (2) 146 individuals from Tangier Island, Virginia, a Caucasian isolate; and (3) asthma case-parent trios selected from 134 families (N=783) in Barbados. Functional studies were performed to evaluate differences between the wild-type and the variant alleles. RESULTS: We identified a novel SNP in the promoter region of C5R1 at position -245 (T/C). Frequency of the -245C allele was similar in the German (31.5%) and Tangier Island (36.3%) populations, but higher in the Afro-Caribbean population (53.0%; P=0.0039 to <0.0001). We observed no significant associations between the -245 polymorphism and asthma or atopy phenotypes. Upon examination of the functional consequences of the -245T/C polymorphism, we did not observe any change in promoter activity. CONCLUSION: This new marker may provide a valuable tool to assess the risk for C5a-associated disorders, but it does not appear to be associated with asthma and/or atopy.
Assuntos
Asma/genética , Cromossomos Humanos Par 19 , Hipersensibilidade/genética , Proteínas de Membrana/genética , Mutação Puntual , Regiões Promotoras Genéticas/genética , Receptores de Complemento/genética , Asma/etnologia , Asma/imunologia , Barbados , Sequência de Bases , População Negra , Criança , Pré-Escolar , Estudos de Coortes , Feminino , Expressão Gênica , Frequência do Gene , Alemanha , Humanos , Hipersensibilidade/etnologia , Hipersensibilidade/imunologia , Lactente , Recém-Nascido , Masculino , Dados de Sequência Molecular , Receptor da Anafilatoxina C5a , Transfecção/métodos , Células U937 , Estados Unidos , População BrancaRESUMO
In the present study we propose a multipoint approach, for the mapping of genes, that is based on the case-parent trio design. We first derive an expression for the expected preferential-allele-transmission statistics for transmission, from either parent to an affected child, for an arbitrary location within a chromosomal region demarcated by several genetic markers. No assumption about genetic mechanism is needed in this derivation, beyond the assumption that no more than one disease gene lies in the region framed by the markers. When one builds on this representation, the way in which one may maximize the genetic information from multiple markers becomes obvious. This proposed method differs from the popular transmission/disequilibrium test (TDT) approach for fine mapping, in the following ways: First, in contrast with the TDT approach, all markers contribute information, regardless of whether the parents are heterozygous at any one marker, and incomplete trio data can be utilized in our approach. Second, rather than performing the TDT at each marker separately, we propose a single test statistic that follows a chi(2) distribution with 1 df, under the null hypothesis of no linkage or linkage disequilibrium to the region. Third, in the presence of linkage evidence, we offer a means to estimate the location of the disease locus along with its sampling uncertainty. We illustrate the proposed method with data from a family study of asthma, conducted in Barbados.
Assuntos
Mapeamento Cromossômico/métodos , Desequilíbrio de Ligação/genética , Núcleo Familiar , Alelos , Asma/genética , Barbados , Distribuição de Qui-Quadrado , Mapeamento Cromossômico/estatística & dados numéricos , Cromossomos Humanos Par 12/genética , Feminino , Marcadores Genéticos/genética , Predisposição Genética para Doença/genética , Heterozigoto , Humanos , Masculino , Modelos GenéticosRESUMO
Genetic heterogeneity has been proposed as a hallmark feature of allergic disease. To test the hypothesis that total IgE levels are jointly influenced by a locus on chromosome 12q21.1-q21.31 and a locus on 17q11.2-q21.2, we conducted multipoint allele-sharing analyses using nonparametric linkage (NPL) methods on Afro-Caribbean families from Barbados to test for evidence of gene-gene interactions. Significant correlations were observed between NPL scores at D12S1052 and both D17S1293 and D17S1299 for a dichotomized phenotype of total IgE. An analysis of family-specific NPL scores revealed that evidence for interaction was being driven largely by one multiplex pedigree (NPL = 12.01, 12.23, and 12.16 at D12S1052, D17S1293, and D17S1299, respectively). Using the programs SIMWALK (v2.0) and GOLD, a different set of haplotypes in this influential family was observed around D12S1052 and the 17q loci compared to the other Barbados pedigrees. Our findings are a classic example of founder effect, provide evidence for sensitivity of this type of linkage analysis to unusual pedigrees, and highlight an element of genetic heterogeneity that has been given little attention in the study of complex traits.
Assuntos
Heterogeneidade Genética , Ligação Genética/genética , Imunoglobulina E/genética , Asma/epidemiologia , Barbados/epidemiologia , Cromossomos Humanos Par 12/genética , Cromossomos Humanos Par 17/genética , Saúde da Família , Feminino , Regulação da Expressão Gênica/genética , Marcadores Genéticos , Predisposição Genética para Doença , Haplótipos , Humanos , Hipersensibilidade/genética , Imunoglobulina E/metabolismo , Masculino , Linhagem , FenótipoRESUMO
As many as 80 percent of asthmatics have atopy and between 60 and 80 percent of allergic asthmatic have coexisting rhinitis. It has been proposed that asthma and allergic rhinitis are essentially the same inflammatory disease of human airways. Previously, we provided the first evidence for linkage of asthma and "high" total serum IgE concentration to chromosome 12q markers among families from Barbados and the US. To identify loci in this chromosome 12q region contributing to the distinct clinical phenotypes of asthma and allergic rhinitis, we conducted linkage analyses among 33 multiplex Barbadian families using densely-spaced microsatellite markers in the 12q14.3-q24.1 region. Maximal evidence for linkage to asthma and allergic rhinitis occurred at markers separated by 4.5 cM. D12S326 and D12S1052 = (NPL = 3.52, p = 0.001 and 1.72, p = 0.039, respectively), these two markers lie 9.13 cM downstream from IFNG. There was no evidence of linkage to either phenotype at markers flanking STAT6. These results suggest that a common gene on the long arm of chromosome 12 is important for both asthma and allergic rhinitis.(AU)
Assuntos
Humanos , Asma/genética , Rinite Alérgica Perene/genética , Cromossomos Humanos Par 12RESUMO
Findings from numerous studies have demonstrated that there is a strong heritable component to asthma and atrophy, although the genetic pathophysiology of these traits is poorly understood. To identify loci in chromosome 12q1s-q24.1 contributing to asthma and asthma-associated traits, we conducted linkage analyses among 29 multiples Barbadian families. Sib-pair analysis of 10 polymorphic micro satellite markers in 345 full and 219 half-sib pairs from Barbados revealed evidence for linkage of certain markers with a gene(s) controlling asthma (D12S379,p=0.001; D12S311,p=0.010; D12S95,p=0.010; D12S360,p=0.018), allergic rhinitis (D12S1052,p=0.040; D12S311,p=0.005; D12S95,p0.021), total serum IgE concentration (D12S1052,p=0.016; D12S311,p=0.007; D12S360,p=0.013; D12S78,p=0.002), and specific IgE antibodies (Alec) to the storage mite Blomia tropicalis (Blot M; D12S311,p=0.006; D12S360,p=0.007; D12S78,p=0.003). Significant evidence of transmission disequilibrium was observe for certain alleles at these loci in addition to high multi allergen IgE Ab. These findings suggest that a gene(s) in the 12q 15-q24.1 region, which contains several candidate genes, including interferon-y (IFNG), is important for asthma and the associated traits of allergic rhinitis, "high" total IgE, and "high" specific IgE (AU).
Assuntos
Humanos , Asma/genética , Ligação Genética , Rinite Alérgica Perene/genética , BarbadosRESUMO
Houses features contribute to house dust mite abundance and, therefore, exposure to mite allergens. Our study assessed the hypothesis that modernization of the domestic environment in a tropical setting may lead to a level of allergen from the house dust mites Dermatophagoides pteronyssinus (Trouessart) and D. farinae Hughes that previously has been defined clinically as at risk for people who suffer from allergic disease. Allergen (Der p 1 and Der f 1) levels were measured at 4 sites (mattress, bedroom floor, living room floor, and furniture) in 17 houses in Barbados during dry and rainy seasons. Der p 1 (17 of 17 homes) at all 4 sites did not vary significantly from the dry to rainy season. Allergen levels varied according to site, and were highest in living room furniture in both seasons (geometric mena 40.37 and 64.17 micrograms/g, respectively). Concentration of Der p 1 allergens were higher in concrete than in wood or mixed concrete and wood houses. Der f 1 (9 of 17 homes) levels were lower than Der p 1 by 1/1,000 (both seasons). Results indicated that season is less important in regard to levels of Der p 1 than house construction and confirm other studies that implicate D. pteronyssinus as a more abundant source of allergen than D. farinae in this tropical setting.(AU)
Assuntos
21003 , Humanos , Alérgenos/análise , Glicoproteínas/análise , ÁcarosRESUMO
To identify genes potentially relevant in atopic asthma, we analyzed markers in chromosome 12q15-q24.1 for linkage to asthma and total serum IgE concentration. Sib-pair analyses of 10 markers in 345 full- and 219 half-sib pairs from 29 multiplex Afro-Caribbean families provided evidence for linkage to this region for both asthma and total serum IgE. Certain alleles at these loci showed significant evidence of transmission disequilibrium with both asthma and high IgE. Using 6 of these markers and 11 additional markers, evidence for linkage of total IgE to 12q was also found in 12 Caucasian Amish kindreds (24 nuclear families) by both sib-pair and transmission disequilibrium analyses. These findings suggest that the 12q15-q24.1 region may contain a gene(s) controlling asthma and the associated "high total IgE" trait.
Assuntos
Asma/genética , População Negra/genética , Cromossomos Humanos Par 12 , Ligação Genética , Imunoglobulina E/sangue , População Branca/genética , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Feminino , Marcadores Genéticos , Humanos , Masculino , Pessoa de Meia-Idade , Núcleo Familiar , Índias OcidentaisRESUMO
To identify genes potentially relevant in atopic asthma, we analyzed markers in chromosome 12q15-q24.1 for linkage to asthma and total serum Ige concentration. Sib-pair analyses of 10 markers in 345 full- and 219 half-sib pairs from 29 multiplex Afro-Caribbean families provided evidence for linkage to his region for both asthma and total serum IgE. Certain alleles at these loci showed significant evidence of transmission disequilibrium with both asthma and high IgE. Using 6 of these markers and 11 additional markers, evidence for linkage of total IgE to 12q was also found in 12 Caucasian Amish kindreds (24 nuclear families) by both sib-pair and transmission disequilibrium analyses. These findings suggest that the 12q15-q24.1 region may contain a gene(s) contolling asthma and the associated high total IgE. trait.(AU)
Assuntos
Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Asma/genética , /genética , Cromossomos Humanos Par 12 , Imunoglobulina E/sangue , Ligação Genética , /genética , Núcleo Familiar , Índias Ocidentais , Marcadores GenéticosRESUMO
Fifty-one atopic asthmatic and/or allergic rhinitic children and 23 nonatopic control from Santo Domingo, the Dominican Republic, were skin tested with an extract mix of three cockroach species (Blattella germanica, Blatta orientalis, and Periplaneta americana). Sixteen percent of the atopics and none of the nonatopics demonstrated positive immediate skin reactions to the cockroach mix (chi 2 = 4.05, p = 0.04). Hypersensitivity was correlated with the quality of the homes; 22% (8/36) of the atopics who lived in a concrete home were skin test positive to the cockroach mix, while none (0/15) of the atopics who lived in a wood home were skin test positive (chi 2 = 4.86, p = 0.03). Although the incidence of cockroach allergy in this study is lower than that found elsewhere, these data support the notion that, in this tropical environment, sensitization to cockroaches is associated with housing quality.
Assuntos
Asma/epidemiologia , Baratas , Habitação , Rinite Alérgica Perene/epidemiologia , Adolescente , Alérgenos/efeitos adversos , Animais , Asma/etiologia , Hiper-Reatividade Brônquica/etiologia , Criança , Pré-Escolar , República Dominicana/epidemiologia , Feminino , Habitação/normas , Humanos , Incidência , Masculino , Rinite Alérgica Perene/etiologia , Testes Cutâneos , Fatores SocioeconômicosRESUMO
Assessment of the epidemiology of asthma requires that the asthma phenotype be characterized. A study was conducted in Barbados among 24 families (n = 175 persons). The geometric mean serum total IgE (tIgE) was 559.8 ng/ml, and was significantly higher in asthmatic subjects (n = 88; means = 1352.1) than in non-asthmatic subjects (n = 87; means = 229.6; t-test, p < 0.001). Asthma subjects reported shortness of breath (80.7 percent), cough (77.3 percent), wheezing (72.7 percent). An index of asthma severity was created based on questionnaire data. Shortness of breath, cough and wheeze were similarly correlated with the index of severity; however, none of the symptoms were significantly correlated with tIgE. Similarly, tIgE was not correlated with the severity score of any of the individual variables that comprised the severity score. The findings in this study of Afro-Caribbean subjects living in a tropical setting concur with those of Caucasian subjects living in developed, temperate locales, whereby tIgE is a good means of classifying the presence or absence of asthma. The poor association between tIgE and severity of asthma and asthma symptoms warrants further investigation into the validation of the severity scale, but raises the question regarding the absence of a relationship between tIgE and asthma severity (AU)
Assuntos
Humanos , Masculino , Feminino , Asma/diagnóstico , Asma/epidemiologia , Imunoglobulina E/diagnóstico , Barbados/epidemiologiaRESUMO
The prevalence of specific IgE (RAST) to Blomia tropicalis (Bt) was evaluated for 64 individuals from four families residing in Barbados, with self-reported atopic asthma (AA) and/or self-reported allergic rhinitis (AR) or individuals with no reported atopic disease (NA). The presence of specific IgE antibodies that reacted with components of Chortoglyphus arcuatus (Ca), Dermatophagoides pteronyssinus (Dp) and Euroglyphus maynei (Em) was also evaluated; components from Ca, Dp and Em were separated by SDS-PAGE, transferred to nitrocellulose membranes and screened with sera from the 22 AAs, 17 ARs and 25 NAs. Total serum IgE was significantly higher in individuals with self-reported AA (logIgE = 977 ng/ml) than in individuals reporting no AA (logIgE = 323 ng/ml). There was a significant difference between the number of AAs who were Bt-positive according to RAST (68 percent) and the number of individuals without AA(p=0.002). IgE antibodies to Ch and Em were significantly higher in individuals with AA than in those without AA (p = 0.001 and p = 0.005, respectively), and there was a weak correlation between IgE antibodies to Dp and self-reported AA (p=0.05). A significant pattern of conversion of response to certain bands within families was observed (AU)
Assuntos
Ácaros , Asma , Anticorpos Anti-IdiotípicosRESUMO
The prevalence of specific IgE (RAST) to tropical house dust mite Blomia tropicalis (Bt) was studied in 126 related individuals with self-reported atopic asthma (AA) and/or self-reported allergic rhinitis (AR) and individuals with no reported atopic disease. RAST results were considered positive when a serum bound > 5 percent of the total counts (percent TCB) added; 17 (65.4 percent) AA were positive to Bt, 7 (29.2 percent) AR without AA were positive to Bt, and 16 (21.9 percent) individuals reporting no AA or AR were positive to Bt. Total serum IgE was significantly higher in individuals with self-reported AA (750 ng/ml) than in individuals reporting no AA (282 ng/ml; Student's t test, p = 0.02). There was no association between total serum IgE and self-reported AR. Additionally, total IgE was weakly correlated with RAST (Bt) for all individuals (r=0.349, p=0.001). Subjects with self-reported AA had a significantly higher mean percentage TCB (19 + 17) than individuals without self-reported AA (10 + 14; Student's test, p<0.05). This study suggests that sensitivity to Bt is common in individuals with atopic asthma living in Barbados (AU)
Assuntos
Humanos , Ácaros , Asma , Rinite Alérgica Perene , Hipersensibilidade Imediata , Barbados/epidemiologiaRESUMO
Knowledge, beliefs, and practices related to the management of asthma were assessed among 143 parents of asthmatic children in Barbados. Nearly 54 per cent of the informants verbalized that the child could die during an asthmatic attack, and informants ranked asthma as the fourth most serious disease compared to 13 other illnesses. Preferred modes of treatment were compared for a sample of parents without asthmatic children (N = 34); parents of asthmatics were more likely to believe that asthma could be managed in the physician's office and at home with prescribed medications than parents without asthmatic children (t = 1.78; df = 67.0, equal variance; p = 0.08). Wealthy parents of asthmatics were more likely to use a private physician than poorer parents of asthmatics (F = 8.50; df = 3; p < 0.0001). Fewer than 10 per cent of the sample used traditional home remedies for asthma. Less than 76 per cent of the children with prescribed inhalers possessed them at all times. Minimal reliance on traditional home remedies, preference for treatment by professional physicians, and preference for a private physician when socio-economics allow, suggest that asthma is viewed as a contemporary illness best treated by professional health care deliverers. Findings from the disease ranking suggest that multi-media campaigns are effective in increasing community awareness and concern for managing specific illness (e.g. leptospirosis, cholera). Possession of a prescribed inhaler at all times by less than three-quarters of the sample population, in the face of a steady increase in asthma-related morbidity, emphasises the need for more aggressive patient and community education for the management of asthma (AU)
Assuntos
Humanos , Criança , Asma , Conhecimentos, Atitudes e Prática em Saúde , BarbadosRESUMO
The incidence of allergy to 14 different household pests, including 2 house dust mite species (D. farinae and D. pteronyssinus), was investigated among 156 asthmatic children in Barbados. Independent variables, including urban/rural residence, building material of the home, and presence of carpeting, were found to be significant factors related to the house dust mite allergy. The continuing trend of modernization of the domestic environment, which provides an optimal microhabitat for several household pests, is implicated as a probable contributing factor in the increasing overall prevalence of asthma reported in Barbados. Children between the ages of 5 and 18 years with a diagnosis of bronchial asthma were selected from attendees at six polyclinics distributed throughout the island, an urban private general practice, and the accident and emergency department of the only acute general hospital on the island. Skin tests were done by scratching, and by intradermal injection, if the scratch test proved negative. Allergy to the house dust mite was the most common of the reactions to the household pests tested, and was found in 81 percent of the asthmatic children (AU)