Increase in the prevalence of allergen skin sensitization in successive birth cohorts

Clinical Findings among Patients with Respiratory Symptoms Related to Moisture Damage Exposure at the Workplace-The SAMDAW Study

BACKGROUND

Respiratory tract symptoms are associated with workplace moisture damage (MD). The focus of this observational clinical study was patients with workplace MD-associated symptoms, to evaluate the usefulness of different clinical tests in diagnostics in secondary healthcare with a special interest in improving the differential diagnostics between asthma and laryngeal dysfunction.

METHODS

In patients referred because of workplace MD-associated respiratory tract symptoms, we sought to systematically assess a wide variety of clinical findings.

RESULTS

New-onset asthma was diagnosed in 30% of the study patients. Laryngeal dysfunction was found in 28% and organic laryngeal changes in 22% of the patients, and these were common among patients both with and without asthma. Most of the patients (85%) reported a runny or stuffy nose, and 11% of them had chronic rhinosinusitis. Atopy was equally as common as in the general population.

CONCLUSIONS

As laryngeal changes were rather common, we recommend proper differential diagnostics with lung function testing and investigations of the larynx and its functioning, when necessary, in cases of prolonged workplace MD-associated symptoms. Chronic rhinosinusitis among these patients was not uncommon. Based on this study, allergy testing should not play a major role in the examination of these patients.

Mining of Ebola virus genome for the construction of multi-epitope vaccine to combat its infection

Ebola virus is the primary causative agent of viral hemorrhagic fever that is an epidemic disease and responsible for the massive premature deaths in humans. Despite knowing the molecular mechanism of its pathogenesis, to date, no commercial or FDA approved multiepitope vaccine is available against Ebola infection. The current study focuses on designing a multi-epitope subunit vaccine for Ebola using a novel immunoinformatic approach. The best predicted antigenic epitopes of Cytotoxic-T cell (CTL), Helper-T cells (HTL), and B-cell epitopes (BCL) joined by various linkers were selected for the multi-epitope vaccine designing. For the enhanced immune response, two adjuvants were also added to the construct. Further analysis showed the vaccine to be immunogenic and non-allergenic, forming a stable and energetically favorable structure. The stability of the unbound vaccine construct and vaccine/TLR4 was elucidated via atomistic molecular dynamics simulations. The binding free energy analysis (ΔG_Bind = -194.2 ± 0.5 kcal/mol) via the molecular mechanics Poisson-Boltzmann docking scheme revealed a strong association and thus can initiate the maximal immune response. Next, for the optimal expression of the vaccine construct, its gene construct was cloned in the pET28a + vector system. In summary, the Ebola viral proteome was screened to identify the most potential HTLs, CTLs, and BCL epitopes. Along with various linkers and adjuvants, a multi-epitope vaccine is constructed that showed a high binding affinity with the immune receptor, TLR4. Thus, the current study provides a highly immunogenic multi-epitope subunit vaccine construct that may induce humoral and cellular immune responses against the Ebola infection.Communicated by Ramaswamy H. Sarma.

AlgPred 2.0: an improved method for predicting allergenic proteins and mapping of IgE epitopes

AlgPred 2.0 is a web server developed for predicting allergenic proteins and allergenic regions in a protein. It is an updated version of AlgPred developed in 2006. The dataset used for training, testing and validation consists of 10 075 allergens and 10 075 non-allergens. In addition, 10 451 experimentally validated immunoglobulin E (IgE) epitopes were used to identify antigenic regions in a protein. All models were trained on 80% of data called training dataset, and the performance of models was evaluated using 5-fold cross-validation technique. The performance of the final model trained on the training dataset was evaluated on 20% of data called validation dataset; no two proteins in any two sets have more than 40% similarity. First, a Basic Local Alignment Search Tool (BLAST) search has been performed against the dataset, and allergens were predicted based on the level of similarity with known allergens. Second, IgE epitopes obtained from the IEDB database were searched in the dataset to predict allergens based on their presence in a protein. Third, motif-based approaches like multiple EM for motif elicitation/motif alignment and search tool have been used to predict allergens. Fourth, allergen prediction models have been developed using a wide range of machine learning techniques. Finally, the ensemble approach has been used for predicting allergenic protein by combining prediction scores of different approaches. Our best model achieved maximum performance in terms of area under receiver operating characteristic curve 0.98 with Matthew's correlation coefficient 0.85 on the validation dataset. A web server AlgPred 2.0 has been developed that allows the prediction of allergens, mapping of IgE epitope, motif search and BLAST search (https://webs.iiitd.edu.in/raghava/algpred2/).

Trends in aeroallergen sensitization in Germany - An analysis of 2919 serological data sets of a university ENT department

Background: Recently, population-based birth-cohort studies provided an insight into the allergic march during childhood.Aims: Our study aimed to investigate sensitization pattern until advanced age.Patients and methods: Demographic, clinical and serological characteristics of 2919 patients with positive allergen-specific IgE between 1999 and 2019 were analyzed. We performed subgroup analysis of various age-groups and different years of birth to distinguish between age-dependent changes and birth-cohort-effects.Results: Since 1999, the proportion of sensitized children has significantly increased. The prevalence of sIgE towards most allergens reached its peak in adolescence or young adulthood. Only to mites, the highest rate of sensitization was found in childhood. With further aging, the prevalence of sIgE significantly decreased in most sensitizations. Only to Fagales, the highest rate of sensitization was observed among patients >65 years. The year-of-birth analysis proved the above-mentioned changes to be age-dependent. Further, it revealed various sensitization trends from older to younger generations.Conclusions and significance: The increased proportion of children with sensitization during the last 20 years outlines the allergy epidemic. Probably due to immunosenescence, the aeroallergen sensitization rates decreased with aging, except for Fagales. Over time, different aeroallergens gained or lost relevance, potentially due to environmental and life-style changes.

Exploring sand fly salivary proteins to design multiepitope subunit vaccine to fight against visceral leishmaniasis

Visceral leishmaniasis (VL) is caused by the parasites of Leishmania donovani complex, leads to the death of 20 000 to 40 000 people from 56 affected countries, worldwide. Till date, there is not a single available vaccine candidate to prevent the VL infection, and treatment only relies upon expensive and toxic chemotherapeutic options. Consequently, immunoinformatics approach was applied to design a multiepitope-based subunit vaccine to enhance the humoral as well as cell-mediated immunity. Constructed vaccine candidate was further subjected to evaluation on allergenicity and antigenicity and physiochemical parameters. Later on, disulfide engineering was performed to increase the stability of vaccine construct. Also, molecular docking and molecular dynamics simulation study were performed to check the binding affinity and stability of toll-like receptor-4 to vaccine construct complex. Finally, codon optimization and in silico cloning were performed to ensure the expression of proposed vaccine construct in a microbial expression system.

Fungal Allergy: Pattern of sensitization over the past 11 years

INTRODUCTION AND OBJECTIVES

Although the prevalence of sensitization to fungi is not precisely known, it can reach 50% in inner cities and has been identified as a risk factor in the development of asthma. Whereas the prevalence of allergic diseases is increasing, it is unclear whether the same occurs with sensitization to fungi.

PATIENTS AND METHODS

A retrospective study was performed at the "Hospital Infantil de México Federico Gómez". From skin tests taken between 2004 and 2015, information was gathered about Alternaria alternata, Aspergillus fumigatus, Candida albicans, Cladosporium herbarum, Mucor mucedo and Penicillium notatum. The participating patients were 2-18 years old, presented some type of allergic condition, and underwent immediate hypersensitivity tests to the fungi herein examined. Descriptive analysis and chi-squared distribution were used.

RESULTS

Of the 8794 patients included in the study, 14% showed a negative result to the entire panel of environmental allergens. The remaining 7565 individuals displayed sensitization to at least one fungus, which most frequently was Aspergillus, with a rate of 16.8%. When the patients were divided into age groups, the same trend was observed. The highest percentage of sensitization (58%) toward at least one type of fungus was found in 2014, and the lowest percentage (49.8%) in 2008.

CONCLUSION

The rate of sensitization to at least one type of fungus was presently over 50%, higher than that detected in other medical centers in Mexico. This rate was constant over the 11-year study, and Aspergillus exhibited the greatest frequency of sensitization among the patients.

High exposure to endotoxin in farming is associated with less new-onset pollen sensitisation

OBJECTIVES

Little is known about risk factors for new onset and loss of atopic sensitisation in adulthood. The aim is to examine the longitudinal effect of quantitatively assessed endotoxin exposures on changes in specific allergen sensitisation in young adults.

METHODS

The cohort consisted of 1113 young Danish farmers and rural controls, with a mean age of 19 years at baseline. Sensitisation to birch pollen, grass pollen, cat dander and house dust mite was measured by specific IgE levels in serum samples from baseline and at 15 years' follow-up. Changes in sensitisation were analysed in relation to cumulative endotoxin exposure during follow-up, considering early life farm exposure.

RESULTS

Endotoxin exposure during follow-up was significantly associated with less new onset of specifically grass and birch pollen sensitisation. For the highest versus lowest quartile of cumulative endotoxin exposure, the OR for new-onset IgE sensitisation was 0.35 (0.13-0.91) for birch and 0.14 (0.05-0.50) for grass. On the other hand, loss of pollen sensitisation showed a positive, although mostly non-significant, association with increased levels of endotoxin exposure. Endotoxin exposure was not associated with significant changes in cat dander and house dust mite sensitisation.

CONCLUSIONS

High exposure to endotoxin during young adulthood appears to protect against new onset of pollen sensitisation, independent of childhood farm exposure.

Dermatophagoides pteronyssinus: Changes in sensitisation in the past 11 years and comparison with other centres in Mexico

BACKGROUND

House dust mites are a ubiquitous air allergen in the human habitat. It has been shown that exposure to them is a fundamental factor in sensitisation and development of atopic disease. The objective of the study was to analyse changes in sensitisation to Dermatophagoides pteronyssinus (Der p.) in children treated in a tertiary level care hospital in Mexico City for a period of 11 years and compare with other studies carried out in Mexico.

METHODS

A retrospective study was performed at the Hospital Infantil de México Federico Gómez (HIMFG). Information was gathered from skin tests for Der p. performed in the Allergy Laboratory from January 2004 to April 2015. Patients 2-18 years old who presented for examination of some type of allergic condition and who had immediate hypersensitivity tests to Der p. were included in the study. Results were compared with prior reports from other institutions. Descriptive analysis and χ² statistics were used.

RESULTS

A total of 8794 patients were included in the study; 49.3% of the tests (95% CI 48-50) were positive for Der p. The percentage of monosensitised to mites was 2.7% for Der p. (95% CI 2-3). A significant difference was found between the results of older patients and those <6 years old. The frequency of sensitisation had a tendency to decrease during the 11 years analysed in all age groups.

CONCLUSIONS AND CLINICAL RELEVANCE

The frequency of sensitisation to Der p. increased with age until reaching adolescence. In the last 11 years a decrease in sensitisation to this air allergen was observed.

Increase in pollen sensitization in Swedish adults and protective effect of keeping animals in childhood

BACKGROUND

To date, most studies of the 'allergy epidemic' have been based on self-reported data. There is still limited knowledge on time trends in allergic sensitization, especially among adults.

OBJECTIVE

To study allergic sensitization, its risk factors and time trends in prevalence.

METHODS

Within West Sweden Asthma Study (WSAS), a population-based sample of 788 adults (17-60 years) underwent skin prick tests (SPTs) for 11 aeroallergens 2009-2012. Specific IgE was analysed in 750 of the participants. Those aged 20-46 years (n = 379) were compared with the European Community Respiratory Health Survey sample aged 20-46 year from the same area (n = 591) in 1991-1992.

RESULTS

Among those aged 20-46 years, the prevalence of positive SPT to pollen increased, timothy from 17.1% to 29.0% (P < 0.001) and birch from 15.6% to 23.7% (P = 0.002) between 1991-1992 and 2009-2012. Measurements of specific IgE confirmed these increases. Prevalence of sensitization to all other tested allergens was unchanged. In the full WSAS sample aged 17-60 years, any positive SPT was seen in 41.9%, and the dominating sensitizers were pollen (34.3%), animals (22.8%) and mites (12.6%). Pollen sensitization was strongly associated with rhinitis, whereas indoor allergens were more associated with asthma. Growing up with livestock or furred pets decreased the risk of sensitization, adjusted odds ratio 0.53 (0.28-0.995) and 0.68 (0.47-0.98), respectively.

CONCLUSION

Pollen sensitization has increased in Swedish adults since the early 1990s, while the prevalence of sensitization to other allergens has remained unchanged. This is one plausible explanation for the increase in rhinitis 1990-2008 in Swedish adults, during which time the prevalence of asthma, which is more associated with perennial allergens, was stable. Contact with animals in childhood seems to reduce the risk of sensitization well into adulthood. One major factor contributing to the rise in pollen allergy is a significant increase in levels of birch and grass pollen over the past three decades.

Changes in IgE sensitization and total IgE levels over 20 years of follow-up

Background

Cross-sectional studies have reported a lower prevalence of sensitization in older adults, but few longitudinal studies have examined whether this is an aging or a year-of-birth cohort effect.

Objective

We sought to assess changes in sensitization and total IgE levels in a cohort of European adults as they aged over a 20-year period.

Methods

Levels of serum specific IgE to common aeroallergens (house dust mite, cat, and grass) and total IgE levels were measured in 3206 adults from 25 centers in the European Community Respiratory Health Survey on 3 occasions over 20 years. Changes in sensitization and total IgE levels were analyzed by using regression analysis corrected for potential differences in laboratory equipment and by using inverse sampling probability weights to account for nonresponse.

Results

Over the 20-year follow-up, the prevalence of sensitization to at least 1 of the 3 allergens decreased from 29.4% to 24.8% (−4.6%; 95% CI, −7.0% to −2.1%). The prevalence of sensitization to house dust mite (−4.3%; 95% CI, −6.0% to −2.6%) and cat (−2.1%; 95% CI, −3.6% to −0.7%) decreased more than sensitization to grass (−0.6%; 95% CI, −2.5% to 1.3%). Age-specific prevalence of sensitization to house dust mite and cat did not differ between year-of-birth cohorts, but sensitization to grass was most prevalent in the most recent ones. Overall, total IgE levels decreased significantly (geometric mean ratio, 0.63; 95% CI, 0.58-0.68) at all ages in all year-of-birth cohorts.

Conclusion

Aging was associated with lower levels of sensitization, especially to house dust mite and cat, after the age of 20 years.

Allergic sensitization is age-dependently associated with rhinitis, but less so with asthma

BACKGROUND

Epidemiologic data describing the association between allergic sensitization and asthma and allergic rhinitis in adults are scarce.

OBJECTIVE

To determine the prevalence and impact of specific sensitization to airborne allergens on asthma and allergic rhinitis among adults in relation to age.

METHODS

A random population sample (age 21-86 years) was examined with structured interview and analysis of specific IgE to 9 common airborne allergens. Of those invited, 692 (68%) subjects participated in blood sampling. IgE level of 0.35 U/mL or more to the specific allergen was defined as a positive test result.

RESULTS

Allergic sensitization decreased with increasing age, both in the population sample and among subjects with asthma and allergic rhinitis. In a multivariate model, sensitization to animal was significantly positively associated with asthma (odds ratio [OR], 4.80; 95% CI, 2.68-8.60), whereas sensitization to both animal (OR, 3.90; 95% CI, 2.31-6.58) and pollen (OR, 4.25; 95% CI, 2.55-7.06) was significantly associated with allergic rhinitis. The association between allergic sensitization and rhinitis was consistently strongest among the youngest age group, whereas this pattern was not found for asthma. The prevalence of allergic sensitization among patients with asthma decreased by increasing age of asthma onset, 86% with asthma onset at age 6 y or less, 56% at age 7 to 19 years, and 26% with asthma onset at age 20 years or more.

CONCLUSIONS

Sensitization to animal was associated with asthma across all age groups; allergic rhinitis was associated with sensitization to both pollen and animal and consistently stronger among younger than among older adults. Early onset of asthma was associated with allergic sensitization among adults with asthma.

Longitudinal increase in total IgE levels in patients with adult asthma: an association with poor asthma control

Background

Immunoglobulin (Ig) E is well-known to play a critical role in allergic diseases. We investigated the association between longitudinal change in total IgE level and the asthma control in patients with adult asthma.

Methods

For this retrospective study, 154 patients with asthma aged 21–82 years were recruited from the allergy and pulmonary units of the Showa University Hospital. Data on longitudinal changes in IgE over the preceding 10 years were collected and logarithmically transformed. Associations between longitudinal change in IgE and clinical characteristics including asthma control test (ACT) score, asthma control, pulmonary function test, and antigen specific IgE, were assessed.

Results

Patients with increased IgE tended to have significantly higher mean age, more episodes of acute exacerbation within a year, lower ACT scores, and used oral corticosteroids more frequently than those with decreased or unchanged IgE. The prevalence of uncontrolled asthma was higher in patients with increased IgE than in those with decreased or unchanged IgE. Mean %FEV₁ and FEV_1% were lower in patients with increased IgE than in those with decreased or unchanged IgE. Moreover, the prevalence of Aspergillus-specific IgE was higher in patients with increased IgE than in those with decreased or unchanged IgE.

Conclusions

These data suggest that a longitudinal increase in total IgE is associated with both poor asthma control and Aspergillus-specific IgE in patients with adult asthma.

Asthma in the elderly: what we know and what we have yet to know

In the past, asthma was considered mainly as a childhood disease. However, asthma is an important cause of morbidity and mortality in the elderly nowadays. In addition, the burden of asthma is more significant in the elderly than in their younger counterparts, particularly with regard to mortality, hospitalization, medical costs or health-related quality of life. Nevertheless, asthma in the elderly is still been underdiagnosed and undertreated. Therefore, it is an imperative task to recognize our current challenges and to set future directions. This project aims to review the current literature and identify unmet needs in the fields of research and practice for asthma in the elderly. This will enable us to find new research directions, propose new therapeutic strategies, and ultimately improve outcomes for elderly people with asthma. There are data to suggest that asthma in older adults is phenotypically different from young patients, with potential impact on the diagnosis, assessment and management in this population. The diagnosis of AIE in older populations relies on the same clinical findings and diagnostic tests used in younger populations, but the interpretation of the clinical data is more difficult. The challenge today is to encourage new research in AIE but to use the existing knowledge we have to make the diagnosis of AIE, educate the patient, develop a therapeutic approach to control the disease, and ultimately provide a better quality of life to our elderly patients.

Geographical variation in the prevalence of sensitization to common aeroallergens in adults: the GA(2) LEN survey

BACKGROUND

Geographical variation in the prevalence of sensitization to aeroallergens may reflect differences in exposure to risk factors such as having older siblings, being raised on a farm or other unidentified exposures.

OBJECTIVE

We wanted to measure geographical variation in skin prick test positivity and assess whether it was explained by differences in family size and/or farm exposure. We also compared prevalence in younger and older subjects.

METHODS

Within the Global Allergy and Asthma European Network (GA(2) LEN) survey, we measured the prevalence of skin prick positivity to a panel of allergens, and geometric mean serum total immunoglobulin E (IgE), in 3451 participants aged 18-75 years in 13 areas of Europe. Estimated prevalence was standardized to account for study design. We compared prevalence estimates in younger and older subjects and further adjusted for age, gender, smoking history, farm exposure, number of older siblings and body mass index (BMI).

RESULTS

Skin prick test positivity to any one of the measured allergens varied within Europe from 31.4% to 52.9%. Prevalence of sensitization to single allergens also varied. Variation in serum total IgE was less marked. Younger participants had higher skin prick sensitivity prevalence, but not total IgE, than older participants. Geographical variation remained even after adjustment for confounders.

CONCLUSION

Geographical variation in the prevalence of skin prick test positivity in Europe is unlikely to be explained by geographical variation in gender, age, smoking history, farm exposure, family size and BMI. Higher prevalence in younger, compared to older, adults may reflect cohort-associated increases in sensitization or the influence of ageing on immune or tissue responses.

Natural history of perceived food hypersensitivity and IgE sensitisation to food allergens in a cohort of adults

Background

No longitudinal studies exist on the natural history of food hypersensitivity and IgE sensitisation to food allergens in adults.

Objective

To examine the natural history of food hypersensitivity, the natural history of IgE sensitisation to food allergens and to investigate the risk factors for new onset food hypersensitivity.

Methods

Food hypersensitivity was questionnaire-assessed in 2307 individuals (aged 20–45 years) from Iceland and Sweden during the European Community Respiratory Health Survey both at baseline and follow-up 9 years later. IgE food and aeroallergen sensitisation were assessed in a subgroup of these individuals (n = 807). Values of 0.35 kU/L and above were regarded as positive sensitisation.

Results

Food hypersensitivity was reported by 21% of the subjects and this proportion remained unchanged at follow-up (p = 0.58). Fruits, nuts and vegetables were the three most common causes of food hypersensitivity, with a similar prevalence at baseline and follow-up. The prevalence IgE sensitisation to food allergens decreased in general by 56% (p<0.001) and IgE sensitisation to peanut decreased in particular by 67% (p = 0.003). The prevalence of timothy grass IgE sensitisation decreased by 15% (p = 0.003) while cat, mite and birch IgE sensitisation did not decrease significantly. Female sex, rhinitis, eczema and presence of IgE sensitisation to aeroallergens were independently associated with new onset food hypersensitivity.

Conclusion

The prevalence of food hypersensitivity remained unchanged while the prevalence of IgE sensitisation to food allergens decreased in adults over a 9-year follow-up period. The decrease in prevalence of IgE sensitisation to food allergens was considerably larger than the change in prevalence of IgE sensitisation to aeroallergens.

Invariant natural killer T cells recognize a fungal glycosphingolipid that can induce airway hyperreactivity

Aspergillus fumigatusis a saprophytic fungus that is ubiquitous in the environment and commonly associated with allergic sensitization and severe asthma in humans. Although A. fumigatus is recognized by multiple microbial pattern recognition receptors, we identified and synthesized an A. fumigatus glycosphingolipid, asperamide B, that directly activated invariant natural killer T (iNKT) cells in vitro in a CD1d-restricted, MyD88- and dectin-1-independent fashion. Moreover, asperamide B, when loaded into CD1d, directly stained, and was sufficient to activate, iNKT cells. In vivo, asperamide B rapidly induced airway hyperreactivity, a cardinal feature of asthma, by activating pulmonary iNKT cells in an IL-33-ST2-dependent fashion. Asperamide B is thus the first fungal glycolipid found to directly activate iNKT cells. These results extend the range of microorganisms that can be directly detected by iNKT cells to the Kingdom of Fungi, and may explain the effectiveness of A. fumigatus in causing severe chronic respiratory diseases in humans.

Quantification of atopy, lung function and airway hypersensitivity in adults

BACKGROUND

Studies in children have shown that concentration of specific serum IgE (sIgE) and size of skin tests to inhalant allergens better predict wheezing and reduced lung function than the information on presence or absence of atopy. However, very few studies in adults have investigated the relationship of quantitative atopy with lung function and airway hyperresponsiveness (AHR).

OBJECTIVE

To determine the association between lung function and AHR and quantitative atopy in a large sample of adults from the UK.

METHODS

FEV1 and FVC (% predicted) were measured using spirometry and airway responsiveness by methacholine challenge (5-breath dosimeter protocol) in 983 subjects (random sample of 800 parents of children enrolled in a population-based birth cohort enriched with 183 patients with physician-diagnosed asthma). Atopic status was assessed by skin prick tests (SPT) and measurement of sIgE (common inhalant allergens). We also measured indoor allergen exposure in subjects' homes.

RESULTS

Spirometry was completed by 792 subjects and 626 underwent methacholine challenge, with 100 (16.0%) having AHR (dose-response slope>25). Using sIgE as a continuous variable in a multiple linear regression analysis, we found that increasing levels of sIgE to mite, cat and dog were significantly associated with lower FEV1 (mite p = 0.001, cat p = 0.0001, dog p = 2.95 × 10-8). Similar findings were observed when using the size of wheal on skin testing as a continuous variable, with significantly poorer lung function with increasing skin test size (mite p = 8.23 × 10-8, cat p = 3.93 × 10-10, dog p = 3.03 × 10-15, grass p = 2.95 × 10-9). The association between quantitative atopy with lung function and AHR remained unchanged when we repeated the analyses amongst subjects defined as sensitised using standard definitions (sIgE>0.35 kUa/l, SPT-3 mm>negative control).

CONCLUSIONS

In the studied population, lung function decreased and AHR increased with increasing sIgE levels or SPT wheal diameter to inhalant allergens, suggesting that atopy may not be a dichotomous outcome influencing lung function and AHR.

Age-related changes in immune function: effect on airway inflammation

Immunosenescence is defined as changes in the innate and adaptive immune response associated with increased age. The clinical consequences of immunosenescence include increased susceptibility to infection, malignancy and autoimmunity, decreased response to vaccination, and impaired wound healing. However, there are several immune alterations that might facilitate persistence of asthma into late adulthood or development of asthma after the age of 50 to 60 years. Asthma in older patients is not uncommon, and this is a growing population as the average lifespan increases. Specific innate changes that might affect severity of asthma in older patients or be involved in the development of late-onset asthma include impaired mucociliary clearance and changes in airway neutrophil, eosinophil, and mast cell numbers and function. Additionally, age-related altered antigen presentation and decreased specific antibody responses might increase the risk of respiratory tract infections. Respiratory tract infections exacerbate asthma in older patients and possibly play a role in the pathogenesis of late-onset asthma. Furthermore, cytokine profiles might be modified with aging, with some investigators suggesting a trend toward T(H)2 cytokine expression. This review examines specific innate and adaptive immune responses affected by aging that might affect the inflammatory response in older adults with asthma.

Sex-specific differences in allergic sensitization to house dust mites: a meta-analysis

BACKGROUND

The prevalence of allergic airway diseases in childhood is higher in boys than in girls but switches toward a female predominance in adolescents and adults. The sex-specific prevalence of allergic sensitization to 1 of the most common allergens worldwide, house dust mite (HDM), has not been examined systematically by age group and species.

OBJECTIVE

To systematically review the literature to examine sex-specific differences in the prevalence of allergic sensitization to HDM.

METHODS

On the basis of a systematic MEDLINE search for population-based studies published between 1990 and 2007, we conducted meta-analyses of male to female ratios for sensitization to 2 different species of HDMs (Dermatophagoides pteronyssinus and Dermatophagoides farinae) separately for children and adults.

RESULTS

We included data from 7,822 children and 18,522 adults from 15 studies. The prevalence of sensitization to D pteronyssinus was significantly higher in boys vs girls (male to female ratio, 1.39; 95% confidence interval [CI], 1.13-1.71) and in men vs women (male to female ratio, 1.40; 95% CI, 1.22-1.61). For sensitization to D farinae, the significant male predominance in adults was even more pronounced (male to female ratio, 1.95; 95% CI, 1.37-2.79), but there were no sex-specific differences in children (male to female ratio, 0.90; 95% CI, 0.56-1.46).

CONCLUSIONS

In adults, the male predominance in sensitization to HDM seems to be contrary to the prevalence of allergic airway symptoms, which has a female predominance. The male predominance is even higher in allergic sensitization to D farinae than to D pteronyssinus. Further research is necessary regarding sex-specific differences in allergy and asthma.

Quantification of atopy and the probability of rhinitis in preschool children: a population-based birth cohort study

BACKGROUND

Atopy quantification using IgE levels/skin test diameter (SPT-MWD) may better predict the expression of rhinitis than using atopy as a dichotomous variable.

OBJECTIVE

To investigate the association between the presence, temporal pattern and severity of rhinitis in preschool children and specific IgE levels/SPT-MWDs.

METHODS

Children were followed prospectively to age 5 years in a whole-population birth cohort study. We administered questionnaires (n = 815), skin prick tested children (n = 717) and measured specific serum IgE (n = 478) to inhalant and food allergens. Main outcomes were current rhinitis (CR) and current rhinoconjunctivitis (CRC).

RESULTS

The prevalence of CR and CRC was 26.1% and 12.1%, respectively. The risk of CR and CRC increased significantly with increasing IgE to grass, mite and cat; CRC was also associated with increasing IgE to dog and peanut. Similarly, increasing SPT-MWDs to inhalant allergens were significantly associated with CR and CRC. This association was also shown for grass within the group of atopic children. Perennial and seasonal rhinitis were associated with increasing IgE/SPT-MWD to mite and grass, respectively. Moderate/severe rhinitis was associated with increasing IgE/SPT-MWD to grass. In a multivariate analysis, increasing levels of IgE/SPT-MWD to grass were the strongest independent predictors of both CR (for IgE: OR 1.42, 95% CI 1.23-1.64, P < 0.001) and CRC (for IgE: 1.51, 1.30-1.76, P < 0.001).

CONCLUSION

The probability of CR/CRC increases with increasing specific IgE levels or SPT-MWD. With respect to allergic rhinitis, the absolute levels of specific IgE antibody or the size of SPT wheal offer more information than just the presence/absence of sensitization.

Temporal trends of aeroallergen sensitization over twenty-five years

BACKGROUND

Little is known about time trends of allergic respiratory disease in adults, in particular in older adults. Furthermore, few trend studies have used objective measurements of IgE sensitization against inhalant allergens.

OBJECTIVES

To investigate time trends of aeroallergen sensitization in adults over a 25-year period.

METHODS

The study includes a total of 7820 persons, aged 30, 40, 50, and 60 years, who participated in three repeated cross-sectional studies of the general population of Copenhagen, Denmark, in 1976-1977, 1982-1984, and 1999-2001, respectively. Respiratory allergy was assessed by determination of specific IgE aeroallergen sensitization in stored serum samples.

RESULTS

Over this 25-year period, a marked and statistically significant increase in the prevalence of aeroallergen sensitization had occurred. This increase was seen in all age-groups challenging the notion that the allergy epidemic only affects generations born 1960 onwards. For example, in 40-year-olds the prevalence (with 95% confidence intervals) of aeroallergen sensitization was 14.9% (12.7-17.1), 19.7% (17.1-22.3), and 27.6% (25.1-30.1) in 1976-1977, 1982-1984, and 1999-2001, respectively.

CONCLUSIONS

Our results support that the allergy epidemic has spread to older adults resulting in a continuing increase in the overall prevalence of aeroallergen sensitization and an increase in the mean age of allergic patients.

Ladybug hypersensitivity among residents of homes infested with ladybugs in Kentucky

BACKGROUND

There have been isolated case reports of hypersensitivity to the ladybug species Harmonia axyridis. Entomologists now report a rapid increase in ladybug numbers, giving rise to increasing complaints of residential infestations.

OBJECTIVES

To determine whether ladybug infestation of homes causes hypersensitivity among residents and to estimate the prevalence of self-reported ladybug allergy in this population.

METHODS

This pilot observational study was conducted using an anonymous survey.

RESULTS

The participation rate was 59% (99/167). The incidence of self-reported allergy symptoms in this population was 77% (95% confidence interval [CI], 67%-85%). The prevalence of self-reported ladybug allergy was 50% (95% CI, 39%-60%). Of all the respondents, 19% (95% CI, 12%-28%) reported allergy symptoms on direct contact with ladybugs and 31% (95% CI, 22%-41%) reported the use of extra allergy medications during times of infestation. The correlation between worsening of allergy symptoms and time of infestation was significant for spring, fall, and winter infestations (P = .02, P = .001, and P < .001, respectively).

CONCLUSIONS

To our knowledge, this is the first study to estimate the prevalence of ladybug hypersensitivity, which was found to be 50% by self-report among people with home infestations. These results suggest that the ladybug could be a significant cause of respiratory allergy in heavily infested homes. Further studies using diagnostic testing to confirm allergy are now indicated. We recommend that patients with spring, fall, and winter allergies be asked about ladybug infestation and that ladybug reagents be made available for diagnostic testing.

The prevalence of atopy in asthmatic children correlates strictly with the prevalence of atopy among nonasthmatic children

BACKGROUND

Because asthma preferentially burdens persons with atopy, atopy is simplistically considered a primary 'cause' of asthma. Yet at the population level, the percentage of asthma cases 'attributable' to atopy ranges from less than 10% to more than 60%. Seeking to understand the rationale for the variability of atopy-attributable cases of asthma, we systematically reviewed the results of our own previous epidemiological studies and several studies conducted by others in children.

METHODS

From each of the 37 random pediatric populations selected by a Medline search combining the key words 'IgE or skin tests or hypersensitivity, immediate' with 'epidemiological studies, cross-sectional, case-control, prevalence, longitudinal, epidemiology of asthma' (12 from our previous pediatric surveys and a further 25 reported from 19 studies in children), we extracted the population prevalence of asthma and atopy among asthmatic subjects and among the nonasthmatic part of the population.

RESULTS

No correlation was found between the prevalence of asthma (range 1.8-44.1%) and atopy (range 5.8-63.9%) in these 37 populations of children (r = 0.052, p = 0.761). Nevertheless, the prevalence of atopy among asthmatics strictly correlated with the prevalence of atopy in nonasthmatics (r = 0.900, p < 0.001, slope 1.364).

CONCLUSION

The prevalence of asthma and atopy varies worldwide and at various time points and independently undergoes the influence of powerful environmental factors. The almost perfect correlation we found between atopy in asthmatics and atopy in the nonasthmatic part of the childhood population shows that the prevalence of atopy in asthma depends on environmental factors that simultaneously induce atopy in asthmatic and nonasthmatic subjects.

AlgPred: prediction of allergenic proteins and mapping of IgE epitopes

In this study a systematic attempt has been made to integrate various approaches in order to predict allergenic proteins with high accuracy. The dataset used for testing and training consists of 578 allergens and 700 non-allergens obtained from A. K. Bjorklund, D. Soeria-Atmadja, A. Zorzet, U. Hammerling and M. G. Gustafsson (2005) Bioinformatics, 21, 39-50. First, we developed methods based on support vector machine using amino acid and dipeptide composition and achieved an accuracy of 85.02 and 84.00%, respectively. Second, a motif-based method has been developed using MEME/MAST software that achieved sensitivity of 93.94 with 33.34% specificity. Third, a database of known IgE epitopes was searched and this predicted allergenic proteins with 17.47% sensitivity at specificity of 98.14%. Fourth, we predicted allergenic proteins by performing BLAST search against allergen representative peptides. Finally hybrid approaches have been developed, which combine two or more than two approaches. The performance of all these algorithms has been evaluated on an independent dataset of 323 allergens and on 101 725 non-allergens obtained from Swiss-Prot. A web server AlgPred has been developed for the predicting allergenic proteins and for mapping IgE epitopes on allergenic proteins (http://www.imtech.res.in/raghava/algpred/). AlgPred is available at www.imtech.res.in/raghava/algpred/.

Computational detection of allergenic proteins attains a new level of accuracy with in silico variable-length peptide extraction and machine learning

The placing of novel or new-in-the-context proteins on the market, appearing in genetically modified foods, certain bio-pharmaceuticals and some household products leads to human exposure to proteins that may elicit allergic responses. Accurate methods to detect allergens are therefore necessary to ensure consumer/patient safety. We demonstrate that it is possible to reach a new level of accuracy in computational detection of allergenic proteins by presenting a novel detector, Detection based on Filtered Length-adjusted Allergen Peptides (DFLAP). The DFLAP algorithm extracts variable length allergen sequence fragments and employs modern machine learning techniques in the form of a support vector machine. In particular, this new detector shows hitherto unmatched specificity when challenged to the Swiss-Prot repository without appreciable loss of sensitivity. DFLAP is also the first reported detector that successfully discriminates between allergens and non-allergens occurring in protein families known to hold both categories. Allergenicity assessment for specific protein sequences of interest using DFLAP is possible via ulfh@slv.se.

Endotoxin Exposure, CD14, and Allergic Disease

RATIONALE

High endotoxin exposure may reduce the risk of allergic sensitization.

OBJECTIVE

To determine the relationship between a promoter polymorphism in the CD14 gene (CD14/-159 C to T) and endotoxin exposure in relation to the development of allergic sensitization, eczema, and wheeze within the setting of a birth cohort.

METHODS

We genotyped 442 children (CD14/-159 C to T; rs2569190). We assessed children for allergic sensitization (IgE > 0.2 kU/L to at least one of seven allergens), eczema (physical examination), and parentally reported wheeze. Endotoxin was measured in house dust.

MAIN RESULTS

Genotype frequencies were consistent with other populations (TT, 25%; CT, 47%; CC, 28%). Sensitization (present in 33% of children) was not associated with genotype. For children with TT and CT genotypes, there was no association between endotoxin and sensitization (odds ratio [OR], 0.95; 95% confidence interval [CI], 0.71-1.23; p = 0.7; and OR, 0.90; 95% CI, 0.77-1.04; p = 0.16, respectively) or endotoxin and eczema (OR, 0.99; 95% CI, 0.81-1.20; p = 0.89; and OR, 1.38; 95% CI, 0.83-2.30; p = 0.22, respectively). In children with the genotype CC, increasing endotoxin load was associated with a marked and significant reduction in the risk of sensitization (OR, 0.70; 95% CI, 0.55-0.89; p = 0.004) and eczema (OR, 0.73; 95% CI, 0.56-0.95; p = 0.02). However, we observed an increased risk of nonatopic wheeze with increasing endotoxin exposure in children with the CC genotype (OR, 1.42; 95% CI, 1.01-1.99; p = 0.04) but not other genotypes. No effect was seen for atopic wheeze.

CONCLUSIONS

Increasing endotoxin exposure is associated with reduced risk of allergic sensitization and eczema but with increased risk of nonatopic wheeze in children with the CC genotype at -159 of the CD14 gene. The impact of environmental endotoxin may be enhanced in individuals with this genotype.

Total serum IgE: adult reference values in Valencia (1981-2004). Usefulness in the diagnosis of allergic asthma and rhinitis

BACKGROUND

The reference values for total serum IgE are accepted to vary according to the geographical area involved. In 1981 we published the reference values for a donor population in the city of Valencia (Spain) and its metropolitan area. Since then, we have noted an increase in the prevalence of asthma and rhinitis in countries with a Western lifestyle, including Spain.

AIM

To update the adult reference values for total serum IgE in the city of Valencia and its metropolitan area, and to determine their diagnostic usefulness in asthma and allergic rhinitis.

MATERIAL AND METHODS

We studied two groups of 69 and 100 individuals each. One group comprised apparently healthy blood donors, as assessed by a routine blood bank study protocol and the application of a questionnaire to exclude perceived allergic or parasitic diseases, while the other group consisted of individuals with atopic respiratory disease (bronchial asthma and allergic rhinitis) studied in our service in the same time period (spring 2004). Total serum IgE was determined by the UniCAP method developed by Pharmacia.

RESULTS

The geometric mean of total serum IgE among blood donors was 46.65 kU/l (95% CI: 15.5-77.8) versus 204.29 kU/l (95% CI: 93.3-515) among allergic subjects. The difference between the two groups was statistically significant. No significant difference was found between our donor sample in 1981 and the sample in the present study. Establishing an arbitrary cut-off point of 1.65 standard deviations (SD)(equivalent to 95 % of the donor population), we obtained a figure of > 183 kU/l whereby 44% of all allergic individuals presented a value below this cut-off point. To practical effects, these allergic patients behaved as low responders (LRs) in relation to total IgE, whereas the remaining individuals were high responders (HRs) in relation to total IgE.

CONCLUSIONS

Our data confirm the current validity of the reference values obtained in 1981, which continue to be significantly different from those of the UniCAP method for Swedish donors. The population of allergic subjects can be divided into two subgroups: subjects with total IgE levels similar to those of the donors, which we refer to as LRs, and which represent 44% of all allergic subjects, and a second subgroup with total IgE values above those of the donors (HRs), who would therefore be the only subjects that would be identified by individual serum IgE study.

Phenotype definition, age, and gender in the genetics of asthma and atopy

When studying genetics of complex diseases it is important to have a clearly described and objective phenotype. When drawing conclusions in association studies, age and gender of the population should be considered. Until we know what causes phenotypic differences between males and females and between children and adults, we should try to study longitudinal cohorts with phenotype assessment at different time points and stratify our analyses for gender. To acquire sufficient power for these types of analyses, international collaboration may be the only way to elucidate the intricate, gene-environmental interactions in atopy and asthma in an age- and gender-dependent manor.

IgE antibody quantification and the probability of wheeze in preschool children

BACKGROUND

IgE-mediated sensitization is usually considered a dichotomous variable (either sensitized or not). Quantitative IgE antibody analysis may better predict the expression of wheeze.

OBJECTIVE

Within the context of a population-based birth cohort, we investigated the association among wheeze, lung function, and specific IgE antibody levels.

METHODS

Children (n = 521) were followed to age 5 years with repeated questionnaires, skin testing, and measurement of lung function (specific airway resistance) and specific serum IgE (ImmunoCAP).

RESULTS

Using specific IgE as a continuous variable, the risk of current wheeze increased significantly with increasing IgE to mite, cat, and dog (P < .0001). When IgE levels to these 3 allergens were summed, the probability of current wheeze increased 1.33-fold (95% CI, 1.21-1.47; P < .0001) per logarithmic unit increase, corresponding to an odds ratio of 3.1 at 10 and 4.25 at 30 kU(A)/L (kilo units of Allergen per liter). Similarly, increasing sum of mite-specific, cat-specific, and dog-specific IgE was associated with reduced lung function (P = .004). Among sensitized children (n = 184), the sum of mite, cat, and dog IgE was the strongest associate of current wheeze (odds ratio, 1.28; 95% CI, 1.13-1.46; P < .001), corresponding to an odds ratio of 2.56 at 10 and 3.32 at 30 kU(A)/L. There was no association between current wheeze and the size of skin test wheal. Furthermore, the sum of IgE to mite, cat, and dog at age 3 years increased the risk of persistent wheeze by age 5 years (2.15-fold/logarithmic unit increase in the specific IgE).

CONCLUSION

IgE-mediated sensitization is not an all or nothing phenomenon. The probability of wheeze and reduced lung function increases with increasing specific IgE antibody levels.

Isocyanates, polyurethane and childhood asthma

Isocyanates are the most prominent and well-studied cause of occupational asthma. Over the decades, airborne isocyanates have been regulated to extremely low levels in the workplace, some of the lowest for any organic compound. Yet the incidence of isocyanate-induced occupational asthma remains high and the role of dermal exposure in disease etiology is only slowly being recognized. Almost completely overlooked is the potential relationship between isocyanates in consumer products and increasing prevalence of asthma in the general population, especially children. The steady rise in asthma over the past decades points strongly to a potential role of environmental exposures in its development. Imbalances in the immune system favoring respiratory diseases have been linked to biological and chemical stressor exposures early in life. Evidence for the presence of isocyanates in many polyurethane-containing materials, especially polyurethane foams, is presented as a possible contributor to the increase in asthma. Polyurethane foam is ubiquitous in western societies and used in bedding, furniture, automobile seats, footwear, etc., and numerous medical materials. Theoretical, epidemiologic, experimental and clinical evidence of a role for isocyanates and polyurethanes in the genesis of non-occupational allergy and respiratory disease are reviewed. These data all point to the urgent need for additional research on the links between isocyanates, polyurethanes and the role of the skin in non-occupational asthma.

The allergy epidemic extends beyond the past few decades

BACKGROUND

Increased prevalence of allergic diseases in western societies has been described as an epidemic. The precise turning point for the epidemic and the antigens responsible for it remain obscure.

OBJECTIVE

To evaluate how the prevalence of atopic disease has changed in terms of detectable sensitization to aeroallergens and dietary allergens in a cross-sectional comparison of subjects from birth cohorts more than 60 years apart.

METHODS

We studied four groups of 100 subjects each (at ages 7, 27, 47 and 67 years), representing those born in 1990, 1963-66, 1943-46 and in 1923-26, respectively. Serum total and specific IgE concentrations against aeroallergens and dietary allergens were determined. A questionnaire elicited information on symptoms, allergic diseases and medication.

RESULTS

The proportion of subjects with detectable IgE antibodies against aeroallergens increased consistently from the oldest to the youngest birth cohorts; chi2 trend=56.809, P<0.0001. Similar progression was not seen in sensitization to dietary allergens. The proportion of those with diagnosed asthma differed significantly (chi2=13.45, P=0.004) across the birth cohorts. The lowest prevalence of asthma and sensitization to dietary allergens was detected in those born in 1943-46, i.e. during or immediately after World War II.

CONCLUSION

Prevalence of sensitization to airborne allergens, unlike that to dietary allergens, has increased over a long period of time. Our results support the concept of the immune function being programmed by external factors early in life. They also call for caution when interpretations of the pace and possible causes of the allergy epidemic are made on the basis of short-term studies.

Effects of infection with transmissible gastroenteritis virus on concomitant immune responses to dietary and injected antigens

Normal piglets weaned onto soy- or egg-based diets generated antibody responses to fed protein. Concurrent infection with transmissible gastroenteritis virus (TGEV) did not affect the responses to dietary antigens at weaning, nor did it affect the subsequent development of tolerance. However, TGEV infection did enhance the primary immunoglobulin M (IgM) and IgG1, but not IgG2, antibody responses to injected soy in comparison to those of uninfected animals. Paradoxically, TGEV-infected animals showed an enhanced primary IgG1 antibody response to injected soy at 4 weeks of age, but they subsequently showed a reduced secondary response after an intraperitoneal challenge at 9 weeks of age in comparison to uninfected animals. The results suggest that an enteric virus, either used as a vaccine vector or present as a subclinical infection, may not have significant effects on the development of dietary allergies but may have effects both on the primary response and on the subsequent recall response to systemic antigens to which the animal is exposed concurrently with virus antigens.

Prevalence of seafood allergy in the United States determined by a random telephone survey

BACKGROUND

Seafood allergy is potentially severe, but the prevalence of this group of food allergies in the US population has not been determined.

OBJECTIVE

To estimate the prevalence of seafood (fish, shellfish) allergy in the United States.

METHODS

We performed a nationwide, cross-sectional, random telephone survey by using a standardized questionnaire. Criteria were established in advance to define seafood allergy by report of convincing symptoms and physician evaluation.

RESULTS

A total of 5529 households completed the survey (67.3% participation rate), representing a census of 14,948 individuals. Fish or shellfish allergy defined by established criteria was reported in 5.9% (95% CI, 5.3%-6.6%) of households and among individuals as follows: 2.3% (95% CI, 2%-2.5%) for any seafood allergy, 2% for shellfish, 0.4% for fish, and 0.2% for both types. Seafood allergy was more common in adults compared with children (2.8% vs 0.6%; P <.001) and in women compared with men (3.6% vs 2%; P <.001). Recurrent reactions were reported by 58%, dyspnea or throat tightness was reported by more than 50%, and 16% were treated with epinephrine. Despite this level of acuity, only 8.6% were prescribed self-injectable epinephrine. The rate of reactions to multiple fish among those with any fish allergy was 67%; for Crustacea the rate was 38%, and for mollusks the rate was 49%; only 14% with crustacean allergy reported a mollusk allergy.

CONCLUSIONS

Physician-diagnosed and/or convincing seafood allergy is reported by 2.3% of the general population, or approximately 6.6 million Americans. Affected individuals typically report recurrent and sometimes severe reactions, indicating that seafood allergy represents a significant health concern.

Does maternal immunoglobulin E decrease with increasing order of live offspring? Investigation into maternal immune tolerance

BACKGROUND

Identifying the protective effect of a higher number of siblings is a significant finding in understanding the aetiology of allergic sensitization, asthma, eczema, and hayfever. Knowledge about causes behind the sibling effect may allow us to prevent atopic manifestations.

OBJECTIVE

We tested the hypothesis that rising order of live offspring increases maternal immune tolerance (immune non-reactivity) against allergens. To this end, we investigated whether maternal IgE levels are associated with the number of live offspring.

METHODS

In a cohort of 1456 newborns recruited between January 1989 and February 1990 on the Isle of Wight, UK, we determined maternal and cord serum IgE, and the order of live offspring. The data were analysed by means of linear and path analysis.

RESULTS

Maternal and cord serum IgE were available in 820 mother-infant pairs with birth order information. We found that the number of live offspring significantly reduces maternal IgE. The decline was more prominent in mothers with atopy (n=268). The geometric means of IgE after the first, second, and third or higher delivery were 74.4, 66.6, and 43.0 kU/L, respectively. Findings of path analysis suggest a significant direct effect of birth order on maternal IgE, but no direct effect of birth order on cord serum IgE.

CONCLUSION

The findings support that maternal immune tolerance against allergens may increase with increasing order of live offspring and thus pass on a lower risk of developing atopy in children of higher birth order.

The utility of specific immunoglobulin E measurements in primary care

BACKGROUND

The identification of atopic patients may not be considered a necessary step in the diagnosis process in primary care. This study investigated the impact of the addition of a specific immunoglobulin E (IgE) antibody test on the current management by primary-care physicians of patients with respiratory and skin symptoms.

METHODS

The study had a prospective before-after design. It was conducted in two geographic areas of Italy and Spain and consisted of two parts, Part I and Part II. In each part patients were recruited according to inclusion and exclusion criteria. After the clinical examination, the patients were classified into one of the following categories using a physician's classification: allergic, nonallergic or uncertain. A blood sample was taken from each included patient for specific IgE antibody determination using a Pharmacia CAP System, including either Phadiatop Infant (0-5 years of age) or Phadiatop and food mix (fx5e) (>5 years of age). If a positive result was found, an additional 6-26 specific IgE tests were performed. In Part I the result of the specific IgE antibody determinations was not available before the physician's classification was made. In contrast, in Part II, the result of the IgE test was available at the time when the physician's classification was made. Between Part I and Part II an educational intervention for physicians to improve their knowledge of blood testing for IgE-mediated allergy was carried out.

RESULTS

A total of 721 patients were included in the study. The agreement between classifications based on clinical data and IgE antibody results changed from a kappa coefficient of 0.13 in Part I to 0.86 in Part II. With regard to the allergic status the proportion of uncertain cases was reduced from 26.3% in Part I to 4.1% in Part II. The proportion of patients that were advised to avoid allergens increased from 18% in Part I to 62% in Part II in the group of patients classified both by the clinician and the IgE test.

CONCLUSIONS

The use of specific IgE antibody determinations improves the clinical management of patients with allergy related symptoms in primary care, allowing advice to be given on specific allergen avoidance. However, the applicability of this diagnostic tool in different areas and countries should be further assessed in cost-effectiveness studies.

Prevalence of peanut and tree nut allergy in the United States determined by means of a random digit dial telephone survey: a 5-year follow-up study

BACKGROUND

Allergy to peanuts and tree nuts (TNs) is the leading cause of fatal and near-fatal food allergic reactions. Peanut allergy appears to be increasing in prevalence.

OBJECTIVES

We sought to determine the prevalence of self-reported peanut and TN allergy among the general population of the United States in 2002 by sex and age and to compare the results with prevalence estimates obtained 5 years earlier.

METHODS

We performed a nationwide, cross-sectional, random telephone survey by using a standardized questionnaire.

RESULTS

A total of 4855 households participated (53% participation rate), representing a census of 13,493 individuals. Peanut allergy, TN allergy, or both was self-reported in 166 (1.2%; 95% CI, 1.0%-1.4%) individuals in 155 (3.2%; 95% CI, 2.7%-3.7%) households, overall prevalence rates similar to those reported in 1997. Also similar to the 1997 survey, the severity level was high, with 79% reporting respiratory or multiple organ system reactions and 66% experiencing more than 5 lifetime reactions. Despite the severity and reaction frequency, only 74% of the children and 44% of the adults sought evaluation for the allergy, and fewer than half who did were prescribed self-injectable epinephrine. Applying conservative rules to adjust for persons with unconvincing reactions and a false-positive rate of the survey instrument (7%), a final prevalence estimate of 1.04% (95% CI, 0.9%-1.24%) was obtained. A male predominance of peanut-TN allergy was reported in children younger than 18 years (1.7% vs 0.7%, P =.02), and a female predominance was reported among adults (1.7% vs 0.9%, P =.0008). Although the rate of peanut allergy, TN allergy, or both was not significantly different from 1997 to 2002 among adults, the rate increased from 0.6% to 1.2% among children, primarily as a result of an increase in reported allergy to peanut (0.4% in 1997 to 0.8% in 2002, P =.05).

CONCLUSIONS

Self-reported peanut allergy has doubled among children from 1997 to 2002, and peanut allergies, TN allergies, or both continue to be reported by more than 3 million Americans. Considering that reactions are severe and the allergy is persistent, these allergies represent an increasing health concern.

Is there a causative role for tetanus toxoid vaccination in the development of allergy-like symptoms and in the increasing prevalence of atopic diseases?

Allergic diseases are a worldwide health problem. They mainly affect people living in developed countries where an increasing prevalence of allergy symptoms has been recorded in the last 20-30 years. The cause of this increase is still disputed, and, among others, the "hygiene hypothesis" supported the concept that relevant changes in lifestyle could have a relationship with the phenomenon. More recently the recorded parallel increase in autoimmune diseases has suggested to consider the "hygiene hypothesis" as a cause of a more general disregulation of the immune system leading to both allergy and to autoimmunity. Here are reported a series of observations, evidence, and data from the literature leading to a different hypothesis. The key points are: (1) the presence of two subsets of patients having allergy symptoms based on an IgE-mediated mechanism or not; (2) the positive results obtained with the autologous serum skin test in either cutaneous or respiratory affected subjects, mainly in children and adult females; (3) the presence of IgG autoantibodies against the alpha-chain of the high affinity IgE receptor (FcepsilonRIalpha) in non-IgE-mediated urticaria and even in respiratory subjects; (4) the cross-reactivity between epitopes of the tetanus toxoid molecule and the FcepsilonRIalpha detected by means of an alpha-chain affinity purified IgG fraction; (5) the positive skin reactivity obtained using IgG anti-tetanus toxoid preparations in allergic and non-allergic volunteers. The presence of IgG autoantibodies actively generated by the population-based vaccination with tetanus toxoid could induce both mediator release from activated mast cell and Th2 cytokine production early in life. There are epidemiological evidences that tetanus toxoid vaccination could be linked with an increased tendency to have allergy symptoms. The different epidemiological distribution of non-IgE-mediated symptoms, mainly affecting young infants would be in agreement with the present hypothesis. The prevalent mother-to-child relationship in terms of risk for allergy symptoms could be explained with the trans-placenta transfer of IgG. A similar transfer could also take place through the mother milk during breast feeding. It may thus be hypothesized that the increased prevalence of allergic diseases could be caused by the generalized tetanus toxoid immunization procedure, progressively extended to most of the countries worldwide in the last 30-40 years. Both the induction of non-IgE-mediated symptoms caused by the mast cell activation via the anti-FcepsilonRIalpha IgG and the long lasting Th2 inflammation of affected tissues would be the inducing mechanisms. This hypothesis would re-configure part of the allergic diseases as a Th2 phenotypic expression of an autoimmune disease.

Measuring dietary fatty acid intake:validation of a food-frequency questionnaire against 7 d weighed records

There are few validated methods of measuring dietary fatty acid intake that are suitable for epidemiological research. The purpose of the present study was to develop and validate a food-frequency questionnaire (FFQ) developed to measure individual dietary fatty acid intakes against 7 d weighed dietary records, in a sample of thirty-one healthy adult volunteers. The FFQ was based on a previously validated questionnaire (DIETQ; Tinuviel Software, Warrington, Ches., UK), adapted to include greater detail on those foods from which the majority of dietary fatty acids are obtained. The FFQ and weighed records were analysed using food nutrient data from McCance and Widdowson's Food Composition Tables, supplemented with a food fatty acid content database (Foodbase, London, UK). Results from the two dietary assessment methods were compared by correlation coefficients and limits of agreement. The mean intake of individual fatty acids tended to be lower when assessed by FFQ. Correlation coefficients comparing unadjusted individual fatty acid intakes assessed by FFQ and weighed records ranged from 0.29 for 18 : 1n-9 to 0.71 for 20 : 4n-6. Adjusting for energy intake tended to increase the correlation coefficients between saturated fatty acids and decrease those between unsaturated fatty acids. In conclusion, this food-frequency method provides reliable estimates of dietary intake of many individual fatty acids for use in epidemiological studies.

Advances in childhood asthma: hygiene hypothesis, natural history, and management

There is significant interest in early identification and intervention in childhood asthma. Current asthma guidelines identify inhaled corticosteroids (ICS) as the preferred initial long-term control therapy even in young children. ICS clearly improve asthma control in children with mild to moderate persistent asthma, but it is not clear that they can alter the natu-ral history and progression of asthma. New insights regarding the origins of asthma and allergy and their natural history will continue to stimulate questions regarding the appropriate time for intervention and will stimulate the design of new treatment strategies and the discovery of new medications.