M.C.R. Barbosa

Measurement of IgE antibodies to shrimp tropomyosin is superior to skin prick testing with commercial extract and measurement of IgE to shrimp for predicting clinically relevant allergic reactions after shrimp ingestion

BACKGROUND Shrimp is a frequent cause of food allergy. Tropomyosin is the major allergen in shrimp, and it shares homology to tropomyosins from other crustaceans, dust mites, cockroach, and parasites. OBJECTIVE The aim of this study was to determine the value of detection of IgE to shrimp tropomyosin in the diagnosis of shrimp allergy. METHODS We have studied 35 patients with asthma, rhinitis, or both who were sensitized to Dermatophagoides pteronyssinus. All subjects underwent skin prick testing in addition to double-blind, placebo-controlled food challenges (DBPCFC); oral open challenges; or both with shrimp. Measurements of IgE to shrimp and shrimp tropomyosin were carried out by means of CAP and chimeric ELISA, respectively. RESULTS Oral challenges confirmed the diagnosis of shrimp allergy in 7 patients. IgE measurement to shrimp tropomyosin was positive in 71.4% of the patients with shrimp allergy. Of the 28 patients without shrimp allergy, only 7.1% (2/28) had IgE to shrimp tropomyosin compared with 25% (7/28) who had IgE to shrimp and 35.7% (10/28) who had positive skin prick test responses to shrimp. Sensitivity was similar for all 3 methods (71.4%); in contrast, specificity of IgE to shrimp tropomyosin (92.8%) was greater than that of IgE to shrimp (75%) and skin prick testing (64.2%). With regard to diagnostic efficiency, measurement of IgE to shrimp tropomyosin was superior to measurement of IgE to shrimp and skin prick testing (88.5%, 74.2%, and 65.7%, respectively). CONCLUSION Use of measurements of IgE to shrimp tropomyosin provided added value to the diagnosis of shrimp allergy.

Efficacy of Recombinant Allergens for Diagnosis of Cockroach Allergy in Patients with Asthma and/or Rhinitis

Background: Immunoglobulin E (IgE) reactivity to individual allergens among cockroach-allergic patients has revealed wide variability. The aim of this study was to assess the effectiveness of recombinant cockroach allergens for skin testing, and to determine sensitization profiles among cockroach-allergic patients living in Brazil. Methods: Fifty-seven cockroach-allergic patients with asthma and/or rhinitis were recruited. Skin testing with recombinant (r) allergens from Periplaneta americana (rPer a 1 and rPer a 7) and Blattella germanica (rBla g 2, rBla g 4 and rBla g 5) were performed at 10 μg/ml and 5 μg/ml (rPer a 1). IgE antibodies to rPer a 7 and rPer a 1 were quantitated by ELISA. Results: Of 57 patients tested, 3 (5.3%), 24 (42.1%), 4 (7%), 3 (5.3%) and 4 (7%) showed positive reactions to rPer a 1, rPer a 7, rBla g 2, rBla g 4 and rBla g 5, respectively. Twenty-eight patients (49.1%) had positive tests to at least one allergen. In keeping with skin test results, 31/57 patients (54.4%) and 5/55 patients (9%) had detectable IgE to rPer a 7 and rPer a 1, respectively. Levels of IgE to rPer a 7 were higher in patients with positive tests to rPer a 7 than those with negative tests (geometric mean 13.2 and 1.8 IU/ml, p < 0.05). There was good concordance of results of skin tests and measurements of serum IgE to rPer a 7. Conclusion: IgE reactivity to rPer a 7 (P. americana tropomyosin) was dominant among patients in Brazil. However, 50% of the patients did not present reactivity to any of the recombinant allergens tested.

Study of risk factors for atopic sensitization, asthma, and bronchial hyperresponsiveness in animal laboratory workers

Study of risk factors for atopic sensitization, asthma, and bronchial hyperresponsiveness in animal laboratory workers: Christian Silva Simoneti, et al. Department of Medicine, Medical School of Ribeirão Preto, University of São Paulo, Brazil

High prevalence of enteroparasites in children from Ribeirão Preto, São Paulo, Brazil

Objective: To determine the prevalence of intestinal parasites and possible associated factors. Method: Cross-sectional epidemiological study of 962 children (3-12-years) from an area within the scope of a basic health unit in Ribeirão Preto, São Paulo, Brazil. Data were collected by home interviews and three-sample stool analysis and evaluated with the chi-square and Fishers exact tests (p<0.05). Results: The prevalence of intestinal parasites was significantly high (57.5%). Giardia lamblia was the most prevalent (50.8%), followed by Ascaris lumbricoides (17.8%), Entamoeba histolytica, Hymenolepis nana, Entamoeba coli and Enterobius vermiculares (5.6-7.3%) and other parasites of lower prevalence, such as Schistosoma japonicum (1%) and Schistosoma mansoni (0.5%). No statistically significant associations were detected between prevalence and the risk factors analyzed. Conclusion: Since the area presents good conditions of environmental sanitation, health education programs should be implemented that emphasize hygiene procedures for the hands and for food and water to be consumed by the population.

Evaluation of the concentration of the coat of dogs aeroallergens (Canis lupus familiaris) and the dust from families of children with asthma and or allergic rhinitis

Background Allergens from house dust mites are perennial and also have enzymatic nature. They are commonly found in bedding, mattresses, pillows, bedroom floor and living room. In addition, they are often associated with sensitization and intensification in the symptoms of allergic rhinitis and asthma for susceptible individuals. The aim of this study was to evaluate the concentrations of Der p 1, Der f 1, Blo t 5, Can f 1 and Fel d 1 in the coat of dogs and spread throughout the environment to check if dogs can serve as a reservoir of allergens for the space as well as being able to trigger allergic reactions in their owners and other individuals.

Evaluation of the concentration of allergens from mites in fur of household dogs (Canis lupus familiaris) in Curitiba - PR - Brazil

Background Allergens from house dust mites are perennial and also have enzymatic nature. They are commonly found in bedding, mattresses, pillows, bedroom floor and living room. In addition, they are often associated with sensitization and intensification in the symptoms of allergic rhinitis and asthma for susceptible individuals. Household dogs are continuously in contact with the ecological niches of house dust mites, and it has been observed that the microclimate between their skin and coat may favor its proliferation. Therefore, the present study aims to evaluate the concentrations of Der p 1, Der f 1 and Blo t 5, in the fur of household dogs, in order to check if they can serve as a reservoir of such allergens in the environment.

Alérgenos recombinantes: papel no diagnóstico e na imunoterapia alérgeno-específica

RESUMO Nos ultimos 30 anos tem havido um avanco notavel na identificacao, purificacao e expressao recombinante de alergenos relevantes das mais variadas fontes, incluindo acaros, insetos, ma‑ miferos, polens, alimentos, fungos, latex e outras fontes. Estes avancos resultaram na utilizacao crescente de alergenos purificados, naturais ou recombinantes, para melhorar o diagnostico de alergia pelos metodos que dispomos, incluindo os testes cutâneos de hipersensibilidade imediata, e os metodos in vitro para medida de anticorpos IgE especificos, como ImmunoCAP, ImmunoCAP- ISAC, ELISA e MARIA. Mais recentemente, o uso de alergenos recombinantes de polen de betula (rBet v 1) e de gramas (coquetel de 5 alergenos) em imunoterapia foi relatado como seguro e eficaz, com resultados comparaveis aos obtidos usando extratos naturais, em pacientes com rinoconjuntivite alergicos a polens. No presente artigo, apresentamos revisao atualizada do uso de alergenos recombinantes em diagnostico de alergia e em imunoterapia alergeno-especifica, incluindo novas estrategias de imunoterapia. Focalizamos na avaliacao critica de estudos que investigaram sensibilidade, especificidade, reatividade cruzada e valor prognostico de metodos diagnosticos com uso de alergenos recombinantes versus extratos naturais; nas recomendacoes atuais para o uso destes novos metodos na pratica clinica; e na revisao de estudos clinicos com imunoterapia usando alergenos recombinantes realizados ate o momento.

Influence of gender and sexual reproductive state in concentration of CAN f 1 in the fur of dogs (Canis lupus familiaris).

Background The allergens from cats and dogs have been implicated as extrinsic factors involved in sensitization, precipitation and exacerbation of allergic rhinitis and asthma in susceptible children and adults, at rates ranging from 10 to 25%. The major allergen from the epithelium of dogs is the Can f 1, responsible for the majority of sensitivity reactions to these. The Can f 1 is a lipocalin, which confers adhesive properties, derived from the sebaceous glands and found in fur, scales and saliva of dogs. The aim of this study is to assess the influence of gender and sexual reproductive state on concentrations of Can f 1 in the fur of dogs.