Validation of the Spanish Version of the Food Allergy Quality of Life Questionnaire-Parent Form (S-FAQLQ-PF).

BACKGROUND: Food allergy is an emerging health problem. Several questionnaires can be used to establish health-related quality of life (HRQOL) in food allergy patients. Current questionnaires should be translated in such a way that they take account of the culture of the country in which they are to be used. Objective: To translate and perform a cross-sectional validation of the Food Allergy Quality of Life Questionnaire-Parent Form (FAQLQ-PF). METHODS: The parents of 54 children diagnosed with food allergy were recruited to assess the Spanish version of the FAQLQ-PF (S-FQLQ-PF). RESULTS: The S-FQLQ-PF was translated into Spanish according to WHO guidelines (including a forward-backward translation). The statistical analysis showed that feasibility, reliability, and internal consistency were very good for the global S-FAQLQ-PF score and for the different domains. Assessment of construct validity indicated that S-FAQLQ-PF has reduced capacity for measurement of HRQOL in younger children. Cross-sectional validation of the S-FAQLQ-PF demonstrated that HRQOL of a Spanish pediatric population was affected by patient age, severity of symptoms, and number of reactions. HRQOL was not affected by sex, food implicated, number of foods implicated, ingestion of the implicated food, or presence of anaphylaxis. CONCLUSIONS: Translation into Spanish and cultural validation of the FAQLQ-PF demonstrated the influence of factors, such as patient age, severity of symptoms, and number of reactions on the HRQOL of a pediatric Spanish population.

Identification of novel peptide biomarkers to predict safety and efficacy of cow's milk oral immunotherapy by peptide microarray.

BACKGROUND: Cow's milk oral immunotherapy (CM-OIT) is still an experimental treatment. The development of novel biomarkers to predict the safety and efficacy of CM-OIT is crucial to translate this treatment to common clinical practice. OBJECTIVE: To analyse long-term changes in IgE and IgG4 epitope binding profile induced by CM-OIT to identify safety and efficacy biomarkers. METHODS: We studied 25 CM-allergic children who underwent CM-OIT and seven non-treated CM-allergic children as controls. CM-OIT patients were classified as low, moderate, and high risk according to the number of allergic reactions (safety), time required to achieve desensitization (efficacy) and need of premedication. IgE and IgG4 peptide microarray immunoassay was performed using a library of overlapping peptides of CM proteins at baseline, after oral desensitization, and 6, 12, and 24 months of follow-up. RESULTS: Cow's milk oral immunotherapy induced a rapid increase of IgG4-binding epitopes and a slow decrease in IgE-binding epitopes. High-risk patients recognized a statistically significant higher number of IgE peptides in caseins at all the times studied. Similar but less pronounced changes were observed for IgG4-positive peptides. Clustering analysis grouped together the high-risk patients, and we identified 13 regions of caseins significantly differed between groups of patients. Bioinformatics analysis selected two sets of 16 IgE-binding peptides at baseline that predicted safety (R(2)  = 0.858) and efficacy (R(2)  = 0.732), respectively, of CM-OIT. CONCLUSION AND CLINICAL RELEVANCE: We found two sets of IgE-binding peptides that can be used as novel biomarkers to predict the safety and efficacy of CM-OIT before starting treatment.

Predictors of health-related quality of life of European food-allergic patients.

BACKGROUND: Although food allergy has universally been found to impair HRQL, studies have found significant differences in HRQL between countries, even when corrected for differences in perceived disease severity. However, little is known about factors other than disease severity which may contribute to HRQL in food-allergic patients. Therefore, the aim of this study was to identify factors which may predict HRQL of food-allergic patients and also to investigate the specific impact of having experienced anaphylaxis and being prescribed an EAI on HRQL. METHODS: A total of 648 European food-allergic patients (404 adults, 244 children) completed an age-specific questionnaire package including descriptive questions. Multivariable regression analyses were performed to develop models for predicting HRQL of these patients. RESULTS: For adults, the prediction model accounted for 62% of the variance in HRQL and included perceived disease severity, type of symptoms, having a fish or milk allergy, and gender. For children, the prediction model accounted for 28% of the variance in HRQL and included perceived disease severity, having a peanut or soy allergy, and country of origin. For both adults and children, neither experiencing anaphylaxis nor being prescribed an epinephrine auto-injector (EAI) contributed to impairment of HRQL. CONCLUSIONS: In this study, food allergy-related HRQL may be predicted to a greater extent in adults than in children. Allergy to certain foods may cause greater HRQL impairment than others. Country of origin may affect HRQL, at least in children. Experiencing anaphylaxis or being prescribed an EAI has no impact on HRQL in either adults or children.

The impact of double-blind placebo- controlled food challenge (DBPCFC) on the socioeconomic cost of food allergy in Europe.

BACKGROUND: Double-blind placebo controlled food challenge (DBPCFC) is the gold standard diagnostic test in food allergy because it minimizes diagnostic bias. OBJECTIVE: To investigate the potential effect of diagnosis on the socioeconomic costs of food allergy. METHODS: A prospective longitudinal cost analysis study was conducted in Spain and Poland within the EuroPrevall project. Food-allergic patients were enrolled into the study and in all cases diagnosis was confirmed through a standardized DBPCFC. Data were collected through a self-administered survey on all aspects of health and social care resource use, costs of living, and costs of leisure activities. Costs were measured before and 6 months after the DBPCFC and reported in international dollars with 2007 as the benchmark year. RESULTS: Forty-two patients were enrolled. Twenty-one patients had a negative DBPCFC and the suspected food was reintroduced into their diet. Comparing total direct costs before and after the DBPCFC, the reactive group spent a significantly higher amount (median increase of $813.1 over baseline), while the tolerant group's spending decreased by a median of $87.3 (P = .031). The amount of money spent on food 6 months after diagnosis was also significantly higher in the reactive group (P = .040). Finally, a larger, but not statistically significant, decrease in total indirect costs was observed in the tolerant group compared with the reactive group ($538.3 vs $32.3). CONCLUSION: DBPCFC has an impact on indirect and direct costs of living. The main contribution to this increase was money spent on food.

Adaptation and validation of the Spanish version of the Quality Of Life in Latex Allergy questionnaire (QOLLA).

OBJECTIVE: The aim of the present study was to translate into Spanish and transculturally adapt the Quality of Life in Latex Allergy questionnaire (QOLLA) in order to provide a validated instrument for use in research and daily practice. METHODS: Patients diagnosed with latex allergy were invited to participate in an observational prospective multicenter study to validate the Spanish version of the QOLLA following the recommendations of the World Health Organization. The study included 3 phases--feasibility, reliability, and cross-sectional validation-and was approved by the Ethics Committee of Hospital Ramón y Cajal. RESULTS: Mean time to complete the questionnaire was 4.7 minutes. The maximum score was 28 (mean, 7.7; median, 4).The SF-12 score ranged from 25.8 to 51.6 in the physical domain and from 20.8 to 61.5 in the mental domain. Internal consistency was excellent (Cronbach alpha, 0.9348). The kappa index fluctuated between 0.40 and 0.93. A kappa of 0.84 was obtained for the global score in 5 categories. Sixty patients were included to evaluate construct validity. Mean age was 39 years and 49 patients were women (80%). The global score ranged between 0 and 30 (mean, 11.69; median, 11). Spearman correlation coefficients between the QOLLA and a visual analog scale and the SF-12 physical, mental, and severity scales according to the researcher were--0.47, 0.37, 0.29, and 0.54, respectively. CONCLUSION: The QOLLA is a feasible, valid, and reliable instrument for the measurement of disease-specific quality of life in adult patients diagnosed with latex allergy. It could play an important role in determining suitable treatment for latex-allergy.

Utility of diagnostic tests in the follow-up of egg-allergic children.

BACKGROUND: Better knowledge of the accuracy of a skin prick test (SPT) and specific IgE (sIgE) levels to egg allergens would help to identify persistent egg-allergic children, avoiding unnecessary risky challenges. This study was designed to assess the accuracy of a SPT and sIgE levels to egg allergens in order to determine persistent egg allergy in IgE-mediated allergic children after an egg-free diet. METHODS: Children below 16 years were prospectively and consecutively recruited. Inclusion criteria were: allergy to egg proteins (children with a positive clinical case of IgE-mediated egg allergy and a positive SPT to egg allergens and/or positive sIgE levels), and strict egg avoidance diet followed for at least 6 months. Clinical histories were recorded and all patients underwent SPTs, sIgE levels to egg allergens and the gold standard -a double-blind placebo-controlled egg challenge (DBPCFG). DBPCFG was interpreted without knowledge of the results of the other tests and vice-versa. A SPT and sIgE levels' ROC curves analysis was performed to compare the diagnostic performance of the different tests. RESULTS: Finally, 157 children were included in the study. One hundred out of these 157 children (63.7%) had a positive oral challenge. Ninety-six were male (61%), and the median age was 2.5 years. One hundred and three (66.9%) had atopic dermatitis. A 7 mm egg white prick test had a positive likelihood ratio (+LR) of 6.7, and a level of 1.3 KU/L egg white-sIgE had a +LR of 5.1. A 7 mm egg white SPT had a positive predictive value of 92.3% (95% CI 85.1-99.5), and for a 9 mm egg white SPT this value was 95.6% (95% CI 87.3-100.0). For egg white-sIgE, 1.5 KU/L had a positive predictive value of 90.4% (95% CI 82.4-98.4) and for 25 KU/L it was 100.0% (95% CI 100.0-100.0). SPTs with ovotransferrin and lysozyme showed the lowest accuracy, followed by yolk and ovalbumin SPTs. CONCLUSION: This study is the first to evaluate both tests (SPT and sIgE levels) and all egg allergens to determine the persistence of egg allergy in IgE-mediated allergic children. Measuring the SPT and sIgE levels is useful to predict persistent allergy in these children, especially with the egg white complete extract. An oral challenge should not be performed in egg allergic paediatric patients with either an egg white prick test above 7 mm or a white egg-sIgE determination above 1.3 KU/L, because there is a 90% probability of remaining allergic.

Skin prick test predictive value on the outcome of a first known egg exposure in milk-allergic children.

Children with milk allergy have higher incidence of other food allergies, especially egg allergy. The objective of this study was to ascertain the accuracy of the prick test in children with IgE-mediated milk allergy for diagnosing egg allergy. Children under the age of 1 yr who came consecutively to Allergy Department 2003-05, and were diagnosed with IgE-mediated milk allergy were selected for this study. Egg introduction was completely avoided until the age of 14 months when clinical history, skin prick tests (SPT), specific-IgE antibodies determination and egg challenge test were performed. One hundred and four milk-allergic children were included. At least one positive prick test to any egg allergen was found in 65 out of the 104 (62.5%). Thirty-eight (36.5%) were allergic to egg proteins as well. Prick tests with egg white and ovomucoid (OVM) had the best diagnostic performances showing the largest areas under the receiver operating characteristic curve. The optimal diagnosis cut-off point was 6 mm for egg white and 5 mm for OVM. The positive likelihood ratios for these cut-off points were: 2.95 (95% CI: 1.74-4.99) for egg white prick test, and 20 (95% CI: 2.9-143.7) for OVM prick test. Children with specific IgE-mediated cow's milk allergy must be closely followed as a risk group for egg allergy. Early diagnosis is necessary and the SPT has shown itself to be a very useful tool for diagnosing immediate IgE reactions to egg on first known exposure.