Can component-based microarray replace fluorescent enzimoimmunoassay in the diagnosis of grass and cypress pollen allergy?

BACKGROUND: Few data on the diagnostic accuracy in pollinosis of the microarray ISAC of allergens are available. OBJECTIVE: We aim to comparatively analyse ISAC CRD103 with the whole-extract ImmunoCAP in grass and cypress pollen allergy, evaluating the suitability of the manufacturer's recommended cut-off points for both techniques. METHODS: We studied 120 atopic patients grouped into grass and cypress pollen-allergic patients and controls based on clinical history and skin prick tests. Specific IgE against Phleum pratense and Cupressus arizonica by ImmunoCAP and ISAC CRD103 were performed on all subjects. RESULTS: In the grass pollen group (43 allergic/26 controls), both microarray and CAP showed high sensitivity (Se) and specificity (Sp) values (ISAC: Se 97.7, Sp 92.3; CAP: Se 95.3, Sp 96.1) for recommended cut-off points. Comparing the optimal (ISAC: 0.4 ISU; CAP: 0.33 kU/L) with the recommended cut-off points within the same technique, diagnostic agreement was observed in both techniques. Thus, CAP and ISAC showed similar diagnostic performance in grass pollen allergy when using recommended cut-off points. In cypress pollen group (12 allergic/92 controls), the microarray (Se: 91.7, Sp 91.3) showed similar Se but significantly higher Sp (P=0.034) than CAP (Se: 91.7, Sp: 80.4) using recommended cut-off points. However, although diagnostic performance of the microarray did not change when comparing the optimal (0.82 ISU) with the recommended cut-off point, CAP improved diagnosis of cypress pollen allergy, when applying the optimal (0.66 kU/L)(CAP Se: 91.7, Sp: 89.1) instead of the manufacturer's recommended cut-off point. Thus, when the most suitable cut-off point for both techniques (ISAC: 0.3 ISU; CAP: 0.66 kU/L) is selected, microarray and CAP provide equivalent diagnoses. CONCLUSIONS AND CLINICAL RELEVANCE: Component-based microarray ISAC CRD103 and whole-allergen CAP showed high Se and Sp diagnosing equally grass and cypress pollen allergy. The cut-off point for each allergen should be properly applied for both techniques.

A new rapid desensitization protocol for chemotherapy agents.

BACKGROUND: Desensitization has been used for some decades to treat patients with the allergenic drug when an alternative drug with similar efficacy and safety is not available. We present the results from a series of oncology patients desensitized at our hospital during the last 2 years. OBJECTIVE: To assess the efficacy of a new desensitization protocol in patients allergic to chemotherapy drugs. METHODS: We performed an observational retrospective study of 11 women (6 breast cancer and 5 ovarian cancer) who underwent our desensitization protocol. Four patients had immediate reactions to carboplatin, 3 to docetaxel, 3 to paclitaxel, and 1 to both docetaxel and paclitaxel. Premedication was administered in all cases. A 5-step protocol based on 5 different dilutions of the drugs was used. RESULTS: We performed 39 desensitization procedures: 14 to carboplatin, 3 to oxaliplatin, 16 to docetaxel, and 6 to paclitaxel. Eight patients tolerated the full dose in 36 procedures. One patient suffered an anaphylactic reaction to carboplatin that reverted with treatment. One patient had dyspnea after a paclitaxel cycle. One patient experienced dyspnea due to chronic pulmonary thromboembolism related to her disease. CONCLUSION: Desensitization is a useful procedure in patients who are allergic to their chemotherapy agents.

Delphi project in bronchial asthma. Two stages.

From the paediatric point of view, we have undertaken two Delphi studies into bronchial asthma. The first is related to the consensus known as the consensus document of the five associations. The second is more recent and has been undertaken with GEMA (the Spanish Guidelines on the Management of Asthma). The aim of this paper is to carry out a descriptive study comparing the 2 Delphi processes and to objectively assess if in some way behaviour over the past two years has changed as far as expert opinion is concerned. In the consensus document those points giving rise to most controversy were the treatment of children under three years of age and treatment with immunotherapy in allergic asthma. It is also necessary to highlight how important it was at that particular point in time to define the phenotypes of wheezing and the predictive index of asthma in children of less than 3 years of age. Of the 52 questions in the questionnaire, in 13.6% the panel of experts reached no consensus in their positions. Following GEMA the Delphi methodology, 56 questions were asked in the first round of the questionnaire, and consensus was reached in 87.5%. As regards the paediatric part relating to diagnosis and treatment in children, agreement was reached on all the questions in the first round. Agreement was reached in 8.92% questions in the second round. Clinical guidelines and consensus documents can modify behaviour towards an illness, both in the diagnosis and treatment.

The importance of in vitro component-resolved diagnosis in paediatric patients.

In recent years, thanks to advances in molecular biology, allergological diagnosis has improved and specific IgE (sIgE) against an allergenic source has been transformed into sIgE against an allergenic protein or glycoprotein. This change, which has resulted in a more precise diagnosis of sensitisation, could explain the different dangers of certain molecular sensitisations and in many cases cross-reactivity phenomena, and could change indications for immunotherapy or clinical management. Here, we present two cases of children where the indication for immunotherapy and management of the disorder changed due to component-resolved diagnosis. However, the clinical history and skin prick tests should complement molecular in vitro diagnosis to improve routine clinical practice.

Risk factors associated to the prevalence of asthma in adolescence.

The ISAAC project (International Study of Asthma and Allergies in Childhood) was developed with the purpose of determining the prevalence of asthma in schoool children, with the definition of two age groups: infancy, when asthma is more frequent, and adolescence, when mortality associated to asthma is greater. However, the study does not address the risk factors associated with this pathology. Our aim is to comparatively analyze the prevalence of respiratory symptoms and the asthma epidemiological factors in the two age groups and in both sexes. Since the results of ISAAC Phase I are available, we can study the variations in risk factors, relating them to the current prevalence of asthma. The prevalence of bronchial asthma in our adolescents is 10 % - this implying a significant increase with respect to the data corresponding to ISAAC Phase I. Likewise, the prevalence of wheezing in the last 12 months has also increased significantly with respect to the data corresponding to ISAAC Phase I. It can be affirmed that familial antecedents of asthma are significantly correlated to the fact of having experienced asthma at some point in time, or to wheezing in the previous 12 months. In the same way as for bronchial asthma, the increase in rhinitis has been significant. The presence of animals in the home is significantly associated to the fact of having experienced asthma at some point in time, though the presence of animals in the home has decreased significantly. An encouraging finding in our study is the fact that smoking has decreased significantly among adolescents in comparison with the previous data. However, the same does not apply to smoking among parents, which shows results similar to those recorded in the previous study - with an influence upon the same habit in the offspring. As in other studies, active smoker status is seen to be associated with the fact of having experienced asthma at some point in time. Although a common observation, the importance of hyper-responsiveness with exercise among adolescents is still not acknowledged, despite its significant correlation to the fact of having experienced asthma at some point in time, or wheezing in the previous 12 months.

Seasons and other factors affecting the quality of life of asthmatic children.

OBJECTIVE: To study the effect of seasons on the health-related quality of life (HRQL) of asthmatic children. METHODS: Four groups of asthmatic children 7 to 14 years old were recruited by pediatricians during each season of the year. Their HRQL was assessed by means of the Paediatric Asthma Quality of Life Questionnaire (PAQLQ). Other factors surveyed were asthma severity, atopy, medical treatment, immunotherapy, obesity, parental smoking, and anti-allergic measures. RESULTS: The mean (SD) overall PAQLQ score was highest in summer at 6.2 (1.0) and lowest in autumn at 5.5 (1.2). The same trend was found for domains in summer and autumn, respectively: symptoms, 6.2 (1.0) vs 5.4 (1.4); emotions, 6.5 (0.8) vs 6.0 (1.0); and activities, 5.9 (1.4) vs. 5.0 (1.5). Factors such as male gender (odds ratio [OR], 0.60; 95% confidence interval [CI], 0.41-0.87), being on immunotherapy (OR, 0.59; 95% CI, 0.38-0.92), living in an urban environment (OR, 0.56; 0.33-0.93), and residing on the northern coast of Spain along the Bay of Biscay (OR, 0.56; 0.36-0.89) were independent protective factors against having a total PAQLQ score in the lower tertile. Conversely, being recruited in a primary care setting (OR, 1.55; 1.01-2.38) and having more severe asthma were risks for being in the lower tertile. CONCLUSIONS: Irrespective of the severity of the disease, season has a significant influence on the HRQL of asthmatic children.

Role of the home environment in rhinoconjunctivitis and eczema in schoolchildren in Pamplona, Spain.

BACKGROUND AND OBJECTIVE: Indoor air quality has become an important factor for sensitization and development of allergic diseases because of increased time spent in homes. We aimed to analyze the possible home-condition risk factors for allergic rhinoconjunctivitis, atopic eczema, and severe disease in schoolchildren aged 5 through 8 years. MATERIAL AND METHODS: The parents of 3360 school children in Pamplona, Spain in the 5-8-year-old age bracket answered questions about rhinitis and eczema symptoms from the protocol of the International Study of Asthma and Allergies in Childhood (ISAAC). The instrument contained additional questions about current home conditions related to mold and dust exposure and about conditions in the first year of life. Associations between the allergic diseases and early and current exposure were studied with chi(2) tests and bivariate and multivariate logistic regression. RESULTS: Exposure to certain home conditions related to molds and dust in the first year of life increased the risk of allergic disease, but having good isolating windows in the first year of life protected against allergic rhinoconjunctivitis and severe atopic eczema. Some current home conditions were also related to an increased risk of current allergic disease; severe atopic eczema was more common among children with single glazing over the bedroom window. CONCLUSION: Current and first-year-of-life home conditions related to dust and mold exposure should be controlled because they influence the prevalence of allergic rhinoconjunctivitis and atopic eczema diseases. Moreover, having a double-glazed window currently and in the first year of life seems to protect against these diseases.

Validation of the Spanish version of the Phase III ISAAC questionnaire on asthma.

The prevalence of allergic diseases in childhood has increased significantly over the last decades. This increase seems to be closely associated with the way of life of western societies. The high prevalence differences on different regions may be due to linguistic and cultural reasons and not to real variations in prevalence. This is the reason why several authors felt the need to perform an objective validation of their versions. Our working group has published the results of the Phase I validation and now is publishing the Phase III validation in order to guarantee the reliability of this phase results. The study sample is formed by 366 children aged 3 to 17 years. The following steps were followed in this study: I. Assessment of the "Criterion validity" of the Spanish ISAAC-Bronchial Asthma questionnaire, evaluating the sensitivity, specificity, relative value, and positive and negative predictive values. 2. Determine the questionnaire reliability, analysing its "Inner consistency". 3. Statistical comparison between our ISAAC-Bronchial Asthma results and the ones obtained by other groups (external concordance and consistency), in order to prove the previously evaluated reliability. 4. Comparison between the ISAAC-Bronchial asthma questionnaire diagnostic ability and the standard diagnostic criteria universally used in clinical praxis. We could confirm that there is a high and very significant concordance between the questions aimed to detect children with asthma. In this sense, it is especially useful the question about "ever had wheezing" because of its high sensitivity (93.3%) and specificity (89.9%), that make it able to be used as initial screening test in a general population, and that has shown a high concordance percentage with the questions "ever had asthma" (98%), "wheezing with exercise" (75%), and "cough at night"(80%). The questions that give more information about the evolution and control of the asthmatic disease are "wheezing in the last 12 months", "number of attacks in the last 12 months", "wakening at night", "wheezing with exercise" and "dry cough at night in the last 12 months". The questions more related to asthma severity were "number of attacks in the last 12 months", "wakening at night", "stop speaking in order to breath", and "wheezing with exercise". We conclude that ISAAC-Asthma questionnaire Phase III is a useful tool for the assessment of childhood asthma due to its criterion validity, inner consistency and external concordance.

Allergy to dexchlorpheniramine. Study of a case.

INTRODUCTION: Dexchlorpheniramine (DH) is a classical or first generation antihistamine belonging to the ethanolamine group. Adverse effects related to these antihistamines are frequent, but the hypersensitivity reactions described in the literature since 1940 are exceptional. We report the case of a 32-year-old woman who experienced two episodes of akathisia secondary to intravenous (i.v.) dexchlorpheniramine administration for a possible hypersensitivity reaction to local anesthetics. MATERIAL AND METHODS: Allergological study consisted of the following tests: skin prick tests with routine allergens, with a negative result; skin prick and intradermal tests with local anesthetics and DH, with a positive result to DH in the intradermal skin test (+ +); serum specific IgE, which was within normal levels; histamine release test with DH with a negative result, and the basophil activation test (BAT) with local anesthetics and DH, which was positive for DH and weakly positive to Lidocaine. CONCLUSION: BAT is proving to be a highly useful tool in the field of drug allergy, with a higher sensitivity and specificity than other in vitro tests. Because it avoids the need for provocation tests, this is especially important in drug-induced allergic reactions in which in vivo tests are repeatedly negative despite a clear clinical history.

Allergy to heparin: a new in vitro diagnostic technique.

INTRODUCTION: Few descriptions of allergic reactions to heparin have been published, because these reactions are not well known, their prevalence is low and they are difficult to diagnose due to the lack of an in vitro test until now. We propose a new technique, the basophil activation test (BAT) for the diagnosis of these reactions. METHODS AND RESULTS: We performed in vivo and in vitro studies with heparin and its derivatives in two patients with heparin-induced acute urticaria. In both patients the results of prick tests with sodium and calcium heparin, enoxaparin and nadroparin with immediate reading were negative. Intradermal skin tests with immediate reading and reading at 48 and at 96 hours with calcium heparin, enoxaparin and nadroparin were positive in the immediate reading and after 48 hours in the first patient. The second patient showed positivity to nadroparin in the immediate reading. The same drugs were also tested using patch tests, with reading after 48 and 72 hours. The second patient showed positivity to nadroparin after 48 hours. The BAT was positive to enoxaparin in the first patient and revealed showed slight positivity to sodium heparin in the second patient. CONCLUSIONS: We consider the BAT to be a useful, safe and reliable test for the in vitro diagnosis of heparin allergy. This test avoids the use of provocation tests, which present a risk to the patient.

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.

[Etiologic implication of foods in atopic dermatitis: evidence in favor]. / Implicación etiológica de los alimentos en la dermatitis atópica: datos a favor.

Some of the immunopathologic mechanisms involved in IgE responses are currently being identified; Th2 lymphocytes are known to be activated in patients with atopic dermatitis with subsequent production of the cytokines interleukin (IL)-4 and IL-5, which are responsible for IgE production and eosinophil recruitment. Nevertheless, T cell activation in this disease takes place in two phases. In the first phase, Th2 cells are activated and IL-4, IL-5 and IL-13 are produced; this first stage is produced with the initial activation induced by the antigen. In the second phase there are chronic lesions, Th1 lymphocytes are activated and IFg is produced. This chronic phase is associated with the presence of eosinophils and macrophages that produce IL-12.Numerous articles have demonstrated food sensitization to be an etiopathogenic factor in atopic dermatitis. The prevalence of sensitization varies, depending on the patient's age and the severity of the disease. Children with moderate-to-severe atopic dermatitis have been observed to have a positive skin test and high IgE concentrations to various foods. Nevertheless, a positive skin test to foods in such children does not always implicate these foods as the cause of the clinical manifestations; moreover, in children showing subsequent tolerance to these foods, skin tests can sometimes remain positive and high levels of specific IgE can persist. It is now known that IgE not only participate in the degranulation of mastocyte cells but also in reactions mediated by T cells and other antigen-presenting cells (dendritic cells) which have high-affinity receptors for IgE.The immediate IgE response is well known but it is also known that in addition to the immediate response, a delayed response is also involved, evidenced by the presence of antigen-specific T cells to foods or other allergens such as inhalant allergens. After a strict exclusion diet, children with atopic dermatitis and sensitivity to foods such as milk, egg, flour and soya can develop tolerance; for this reason provocation tests with the food in question should be repeated every 2-3 years. In children with sensitivity to other foods such as dried fruits, fish, and shellfish, sensitivity can sometimes persist into adulthood without tolerance being achieved. In conclusion, there are two groups of children with atopic dermatitis. One group consists of those with atopic dermatitis (allergic disease), which is characterized by early development, high IgE titers, the presence of antigen-specific IgE to allergens and a family history of atopy and which is clinically moderate or severe. Early diagnosis and treatment are important in these children, as is the prevention of progression of the disease to bronchial asthma. The other group consists of children whose dermatitis is clinically atopic in terms of its localization and morphology, who have no demonstrable allergic disease and whose management differs from that in children presenting allergic disease.