Differences in molecular sensitization profiles between a Spanish and Latin American mite allergic patients.

BACKGROUND AND OBJECTIVE: To analyze the sensitization pattern to Dermatophagoides pteronyssinus and to associate the diagnostic findings and clinical severity in 218 allergic patients from two different continents. METHODS: Mite allergic patients were recruited by the Allergology departments from Latin America (n=88: Colombia, Costa Rica and Guatemala) and Spain (N=130). All patients had allergic rhinitis with or without asthma and positive skin prick test results to D. pteronyssinus. Specific IgE levels to D. pteronyssinus, D. farinae, Der p 1, Der p 2, and Der p 23 were quantified by ImmunoCAP system (ThermoFisher Scientific). Allergenic profile was also determined by western blot. Comparative Statistical analysis was performed by GraphPad software. RESULTS: Patients recognized most frequently Der p 2 (79%) followed by Der p 1 (73%), and Der p 23 (69%) allergens. The percentage of asthmatic patients increases with the number of sensitizations however none statistically significant differences were found. Interestingly, asthmatic patients presented the highest median levels of total IgE and specific IgE levels of D. pteronyssinus and molecular allergens, mainly Der p 2. Analysing the two different populations, Spanish patients were predominantly sensitized to Der p 2 (88.46%) and Der p 1 (83.84%), whereas Latin American population were more sensitized to Der p 23. CONCLUSION: Our data support the relevance of Der p 2 in mite allergy as the major allergen, with the high number of patients sensitized to it and its importance in the development of asthma. Sensitization to Der p 23 was more important in Latin America.

Prevalencia de dermatitis atópica en la población infantil en una consulta de alergología / Comparison of the prevalence of atopic among the children visiting an allergology department

Objetivo: Comparar las características de dos grupos de niños alérgicos que acudieron a una consulta de Alergología en 1997 y 2000.Métodos: 150 pacientes en 1997, 89 niños y 61 niñas (grupo A), y 267 pacientes en 2000, 162 niños y 105 niñas (grupo B). Se dividieron en: 0-5 años, 5-10 y >10 años. Se realizó anamnesis, examen físico, analítica y pruebas alergológicas. Resultados: En el grupo A, la prevalencia de dermatitis atópica fue del 13,1 por ciento y en el B del 19,5 por ciento (p >0,05). Como antecedentes familiares de atopia en niños con dermatitis atópica (DA), el 44 por ciento tenía padre o madre atópicos y el 25 por ciento tenía padre y madre atópicos. En el grupo A el 39 por ciento había recibido lactancia materna exclusiva, y el 38 por ciento en el grupo B. Otras enfermedades alérgicas concomitantes con DA: grupo B, el 51,9 por ciento padecía asma y el 34 por ciento rinitis alérgica. En el grupo A, el 22,8 por ciento padecía rinitis alérgica. Los alergenos más frecuentes para ambos grupos que presentaban DA fueron huevo, leche y ácaros. Los valores de IgE se encontraban en una media de 453,98 KU/L ñ 617,70 en la población general y de 628 KU/L ñ 875 en los pacientes con DA. Conclusiones: Los antecedentes familiares por sí solos no justifican el aumento en la prevalencia de DA, pero sí otros factores ambientales, como la sensibilización precoz a alergenos alimentarios y, posteriormente, a otros alergenos inhalantes. Las medidas de prevención precoces ayudan a evitar o disminuir estas sensibilizaciones, previniendo así el desarrollo de otras enfermedades alérgicas como el asma y la rinitis (AU)

Respiratory infection in asthma.

Ever since the first decades of the 20th century, some authors have given respiratory infection triggered by bacteria an etiologic role in bronchial asthma, focusing on infection and the asthmatic response. In 1995 our group already presented a study in this sense on nasal secretion cultures and the relationship between IgE and sensitization to allergens. There is a significant association between patients with sensitization to Dermatophagoides, high levels of total IgE, and positive culture to Staphylococcus aureus. Following studies by Norn, we performed a study with 40 children, aged 2-14 years, where we observed that children with sensitization to mites and a positive culture had higher levels of histamine release than did children with negative culture and controls, the differences being significant. We also found, like other authors, that the joint presence of Staphylococcus aureus and Derrmatophagoides pteronyssinus potentiates antigen-specific histamine release. In recent years, with the increasing prevalence of bronchial asthma being studied, the role that infection could play in this increase is being considered again among other factors. As participants of the ISAAC project and using the same methods as in this study, we performed a simultaneous questionnaire with questions related with triggering and contributing factors, etc., including respiratory infection. We found an association between having had more than three episodes of "bronchitis" with fever and lasting for longer than seven days in the last year and having ever had asthma (OR 29.09). This association is still greater with having had wheezing in the last 12 months (OR 43.26), a finding that it is also associated with requiring attention in an emergency room (OR 30.65). From these results, we concluded that respiratory infection is an aggravating factor of asthma, something we already knew. In order to have our own experience, we studied serum interleukin 4 (IL-4) and interferon gamma (IFNgamma) in a sample of 41 children aged 3 to 17 years. The most frequent values of IL-4 ranged between 0.25 and 0.40 ng, and very low dispersion was found in the sample, which did not allow correlation with other parameters. Regarding IFNgamma, we found values between < 5 pg/ml and 605 pg/ml. When we studied children under treatment with antigen-specific immunotherapy, we observed mean values of IFNgamma of 115.86 pg/ml, whereas the ones who did not follow this treatment or had followed it for less than one year had a mean of 66.06 pg/ml, these differences being significant (p = 0.035), and proving a Th1 response to immunotherapy. This significance is not found if children who have been under immunotherapy for less than one year are included. When we studied children with bacterial immunotherapy, we found that the mean IFNgamma value in children under immunotherapy for longer than one year was 56.4 pg/ml, whereas in children with no immunotherapy it was 101.75 pg/ml (p = 0.034). We conclude that bacterial immunotherapy modifies the Thl response, inhibiting it in those children with greater susceptibility to infections.

Allergy to pine nut.

BACKGROUND: food allergy is highly prevalent in our environment, especially among atopic patients. Pinus pinea is common in our region and its fruit, the pine nut, is allergologically important. Several cases have been reported in the literature that demonstrate the existence of common antigenic bands between pine nut and almond. In this study we try to assess this finding and the possible existence of common allergens by in vitro techniques. METHODS AND RESULTS: we present a 10-year-old boy, previously diagnosed of seasonal rhinoconjunctivitis with sensitisation to grass and olive pollen, who had an anaphylactic reaction after eating pine nut. We performed in vivo (prick test, prick-by-prick) and in vitro tests (total and specific IgE determinations [CAP-FEIA]), histamine release test, and immunoblotting (SDS-PAGE). We also reviewed the literature through the MEDLINE database in PubMed. CONCLUSIONS: because pine nut is commonly consumed in our environment, the prevalence of allergic reactions is probably considerable and these reactions take place at an early age. We demonstrate the existence of common antigenic proteins between pine nut and peanuts.

Flow cytometric basophil activation test: a review.

Flow cytometry is a technique enabling the analysis of physical and biological characteristics of cells or other biological particles when labeled with antibodies coupled to fluorochromes or other dyes. The basophil activation test (BAT), also called flow-cytometric allergen stimulation test (FAST) [commercially available under the name of Flow CAST (Bühlmann Laboratories) or BASOTEST (Beckton-Dickinson)] is based on the in vitro allergen-induced specific activation of basophils. This assay rests on the demonstration of some membrane protein markers that appear after exposure to the allergen. This paper reviews some of the literature about the use of this technique in the investigation of immediate-type allergies to inhalant allergens, drugs, and foods, as well as our own experience with this diagnostic technique. Flow cytometry is a reliable method for the quantification of basophil activation after allergenic stimulus in vitro and in vivo. It also enables us to detect allergic and pseudoallergic reactions because of other mechanisms than allergen-specific IgE antibodies. Further clinical evaluation of this technique will allow validation and better establishment of its diagnostic value in allergy.

Distal splenorenal shunt vs. portal-systemic shunt: current status of a controlled trial.

A prospective controlled comparison of portal-systemic (PSS) and distal splenorenal shunts (DSRS) in cirrhotic patients who had survived hemorrhage from esophagogastric varices was undertaken 5 yr ago at five hospitals by the Boston-New Haven Collaborative Liver Group. The clinical and endoscopic criteria for massive hemorrhage were satisfied in 155 patients. Thirty-four patients were excluded, primarily because of uncontrolled hemorrhage. Thirty-four were rejected because the were poor operative risks and 21 because they did not satisfy criteria. Thirteen patients refused to participate; the remaining 53 were randomized; 29 to receive PSS and 24, DSRS. The two groups were similar in clinical, laboratory, and manometric characteristics. The DSRS group was older and tended to have had more previous hemorrhages. Followup ranged from 1 to 56 months (mean 21). After PSS, which was performed by 10 different surgeons, 6 patients died during the hospital admission (21%) compared to 2 after DSRS (12%). There were 6 late deaths in the PSS group and 4 in the DSRS group. Portal-systemic encephalopathy occurred in 5 of the 23 survivors of PSS (23%), and in 6 of the 19 who survived DSRS (32%. Two patients in the PSS group bled (9%), 1 after thrombosis and 1 after stenosis of the shunt. Three patients in the DSRS group bled (16%) and all had thrombosis of the shunt. PSS was associated with an unexplained but inordinately high operative mortality. Although the DSRS was accomplished with an acceptably low operative mortality, it was associated with frequent portal-systemic encephalopathy, shunt occlusion, and recurrent hemorrhage. Similar incidences of portal-systemic encephalopathy, shunt occlusion, and recurrent hemorrhage were observed in the PSS group. More patients and longer followup are necessary to determine which of these portal decompressive procedures is superior.