Exposure to cats: update on risks for sensitization and allergic diseases

Impaired respiratory functions in children with cat sensitization in the early ages of childhood

BACKGROUND

To evaluate the respiratory functions in children with cat sensitization accompanying allergic respiratory diseases and to compare these with those of healthy controls, as well as within themselves by classifying according to their diseases, domestic cat exposure, and age groups.

METHODS

This prospective case-control study included 130 children aged 3-17 years with cat sensitization (CS group) accompanying respiratory allergic diseases and 70 age- and sex-matched healthy controls (HC group). The cases' demographic parameters were recorded, and respiratory functions were analyzed using IOS and spirometry.

RESULTS

At IOS evaluation, zR5, R5-20, Fres, and AX values were higher in children in the CS group compared to the HC group (p = 0.029, p = 0.008, p = 0.001, and p < 0.001, respectively), while zX5 and zX20 values were lower (p = 0.001 and p < 0.001). R5-20 and AX were higher in asthma compared to allergic rhinitis (p = 0.008, p = 0.015), but were insignificant compared to asthma and allergic rhinitis coexistent group (p > 0.05). R5-20, Fres, and AX were higher, and zX20 was lower in the preschool age group (p < 0.001). No correlation was found between zFEV1, zFVC, zFEV1/FVC, zFEF25-75, and zR5 values in the CS group (p > 0.05).

CONCLUSIONS

Pulmonary resistance was higher and reactance was lower in the entire and peripheral airways in children with cat sensitization accompanying respiratory allergic diseases compared to the healthy controls. Peripheral airway resistance and reactance were more impaired in the asthma group compared to allergic rhinitis. However, peripheral airway resistance and main airway reactance were more impaired in the preschool age group than in the older ones.

Association Between Pet Keeping and Current Asthma Among Adolescents Living in Yazd; Evidence from Global Asthma Network (GAN) 2020 Cross-sectional Study

BACKGROUND

The relationship between current pet keeping and allergic diseases, including bronchial asthma in adolescents, is controversial. This study was conducted to evaluate these associations among children aged 13-14 years in Yazd.

METHODS

This study is part of a multicenter cross-sectional study of the Global Asthma Network (GAN) in Yazd, Iran, in 2020, in which 5141adolescents enrolled. Information on respiratory symptoms and pet-keeping (dog/cat/birds) was obtained by a questionnaire derived from the GAN standard questionnaire.

RESULTS

Of 5141 participants who completed the study, 1800 (35%) children kept pets during the last year. Birds were the most common pet kept by adolescents (88%). Severe asthma was more common in bird and cat keepers (P=0.003 and P=0.034, respectively) than dog keepers. Furthermore, there was a statistically significant association between study-defined current asthma and cat keeping, but not bird or dog ownership (P=0.02). Moreover, we found that current any pet-keeping (birds, cats, dogs) was associated with a higher prevalence of asthma-related symptoms, including wheezing, night dry cough, and exercise-induced wheezing in the past year (P=0.002, P=0.000 and P=0.000 respectively).

CONCLUSION

Current any pet-keeping is associated with asthma-related symptoms. Additionally, cat keeping had a significant association with study-defined current asthma. The current keeping of birds, as the most common pet in our area, or cat keeping increases the risk of severe asthma in adolescents. Therefore, as an important health tip, this needs to be reminded to families by health care providers.

Environmental exposures in early-life and general health in childhood

BACKGROUND

Early-life environmental exposures are suspected to be involved in the development of chronic diseases later in life. Most studies conducted so far considered single or few exposures and single-health parameter. Our study aimed to identify a childhood general health score and assess its association with a wide range of pre- and post-natal environmental exposures.

METHODS

The analysis is based on 870 children (6-12 years) from six European birth cohorts participating in the Human Early-Life Exposome project. A total of 53 prenatal and 105 childhood environmental factors were considered, including lifestyle, social, urban and chemical exposures. We built a general health score by averaging three sub-scores (cardiometabolic, respiratory/allergy and mental) built from 15 health parameters. By construct, a child with a low score has a low general health status. Penalized multivariable regression through Least Absolute Shrinkage and Selection Operator (LASSO) was fitted in order to identify exposures associated with the general health score.

FINDINGS

The results of LASSO show that a lower general health score was associated with maternal passive and active smoking during pregnancy and postnatal exposure to methylparaben, copper, indoor air pollutants, high intake of caffeinated drinks and few contacts with friends and family. Higher child's general health score was associated with prenatal exposure to a bluespace near residency and postnatal exposures to pets, cobalt, high intakes of vegetables and more physical activity. Against our hypotheses, postnatal exposure to organochlorine compounds and perfluorooctanoate were associated with a higher child's general health score.

CONCLUSION

By using a general health score summarizing the child cardiometabolic, respiratory/allergy and mental health, this study reinforced previously suspected environmental factors associated with various child health parameters (e.g. tobacco, air pollutants) and identified new factors (e.g. pets, bluespace) warranting further investigations.

A Synopsis of Guidance for Allergic Rhinitis Diagnosis and Management From ICAR 2023

An updated edition of the International Consensus Statement on Allergy and Rhinology: Allergic Rhinitis (ICAR:AR) has recently been published. This consensus document, which included the participation of 87 primary authors and 40 additional consultant authors, who critically appraised evidence on 144 individual topics concerning allergic rhinitis, provides guidance for health care providers using the evidence-based review with recommendations (EBRR) methodology. This synopsis highlights topical areas including pathophysiology, epidemiology, disease burden, risk and protective factors, evaluation and diagnosis, aeroallergen avoidance and environmental controls, single and combination pharmacotherapy options, allergen immunotherapy (subcutaneous, sublingual, rush, cluster), pediatric considerations, alternative and emerging therapies, and unmet needs. Based on the EBRR methodology, ICAR:AR includes strong recommendations for the treatment of allergic rhinitis: (1) for the use of newer generation antihistamines compared with first-generation alternatives, intranasal corticosteroid, intranasal saline, combination therapy with intranasal corticosteroid plus intranasal antihistamine for patients not responding to monotherapy, and subcutaneous immunotherapy and sublingual tablet immunotherapy in properly selected patients; (2) against the use of oral decongestant monotherapy and routine use of oral corticosteroids.

[Are pets, dog or cat, a risk or a protector factor for the development or exacerbation of asthma? Systematic review of systematic reviews]

BACKGROUND

Preliminary studies have shown conflicting results on the association between exposure to pets (cat or dog) and asthma. Previous scientific evidence has not been clear to determine if avoiding or allowing the exposure to pets could prevent, improve, or worsen the development of asthma and its symptoms.

OBJECTIVE

To try to explain the controversial relationship between exposure to pets (dog or cat) and its effect on the development of asthma or the exacerbation of symptoms in both children and adults.

METHODS

A standardized search in five electronic databases by an independent reviewer was carried out. The final sample of studies included in the overview of systematic reviews was screened and synthesized through a master table. A narrative description of the results was made.

RESULTS

This systematic review of systematic found determined principally that having a cat could be a risk factor and having a dog a protective factor in the development of asthma. However, early exposure to both cats and dogs (before the age of two) reduces the probability of asthma symptoms and wheezing in the school years. Additionally, having antecedents of sensibilization to pets allergen could be a risk factor to exacerbate asthma in both children and adults.

Characteristics of children with cat sensitivity: a prospective cross-sectional study

BACKGROUND

Animal dander is one of the most common respiratory allergens in children, and there is evidence that cat sensitivity is a risk factor for asthma and allergic rhinitis. In this study, it was aimed to evaluate children with cat sensitivity and to identify their demographic and clinical characteristics.

METHODS

Patients who were found to be sensitive to cats following skin prick tests performed in our allergy clinic over a period of one year (and two control groups), were included in the study. Patients in the study and control groups filled in a questionnaire including demographic and clinical characteristics.

RESULTS

The prevalence of cat sensitivity in our allergy clinic was 6% (182/3033). The most common diagnoses in patients were 41.8% allergic rhinitis, 25.8% asthma, and 13.2% allergic rhinitis + asthma. Allergic rhinitis symptoms were the most prevalent symptom associated with cat contact (29.4%), whereas 28% of the patients were asymptomatic. Only 17.3% had a cat at home and 13.4% had cat exposure apart from home but having a cat at home was significantly higher than the control groups (p < 0.05). Eosinophilia was present in 54.6% of the patients, and 17.3% had blood tIgE levels of >1000 IU/mL. Eosinophilia and tIgE levels were significantly higher than both control groups (p < 0.05).

DISCUSSION

Cat ownership can affect the development of cat sensitivity but the majority of patients with cat sensitivity are not cat owners. Elevated tIgE levels (> 1000 IU/mL) may be associated with cat sensitivity, these patients should be evaluated for cat sensitivity, even if they do not report symptoms with cat contact.

Human allergy to cats: A review for veterinarians on prevalence, causes, symptoms and control

PRACTICAL RELEVANCE

Human allergy to cats affects a substantial and growing proportion of the global population, and cat allergy is regarded as the third most common cause of human respiratory allergies, and the second most common indoor cause. Veterinarians will frequently encounter owners who are cat-allergic, and having an understanding of this disease and the methods available to help control the allergy will assist them in giving appropriate advice, alongside human healthcare professionals.

AIM

The aim of this review is to summarise currently available data on the prevalence, causes, symptoms and control of human allergy to cats. In terms of managing cat allergy, the emphasis is on reviewing current and emerging modalities to reduce environmental exposure to cat allergens rather than on pharmacotherapy or immunotherapy, as it is in these areas in particular that the veterinarian may be able to offer help and advice to complement that of human healthcare professionals.

EVIDENCE BASE

The information in this review is drawn from the current and historical literature on human allergy to cats, and approaches to reduce exposure to cat allergens and manage symptoms of cat allergy.

Abundance and Stability as Common Properties of Allergens

There have been many attempts to identify common biophysical properties which differentiate allergens from their non-immunogenic counterparts. This review will focus on recent studies which examine two such factors: abundance and stability. Anecdotal accounts have speculated that the elevated abundance of potential allergens would increase the likelihood of human exposure and thus the probability of sensitization. Similarly, the stability of potential allergens dictates its ability to remain a viable immunogen during the transfer from the source to humans. This stability could also increase the resilience of potential allergens to both gastric and endosomal degradation, further skewing the immune system toward allergy. Statistical analyses confirm both abundance and stability as common properties of allergens, while epidemiological surveys show a correlation between exposure levels (abundance) and allergic disease. Additional studies show that changes in protein stability can predictably alter gastric/endosomal processing and immunogenicity, providing a mechanistic link between stability and allergenicity. However, notable exceptions exist to both hypotheses which highlight the multifaceted nature of immunological sensitization, and further inform our understanding of some of these other factors and their contribution to allergic disease.

Human allergy to cats: A review of the impact on cat ownership and relinquishment

Practical relevance:

Cats have become increasingly common as companion animals, and in many countries their popularity now exceeds that of dogs. At the same time, human allergies (including allergy to cats) have been increasing and it has been estimated that globally up to 10-20% of human adults are sensitised to cats.

Aim:

This review summarises the available published data on how human allergy to cats affects cat ownership and considers the implications of the findings on the wider human-cat bond and how adverse effects can be minimised.

Evidence base:

Online databases were searched for all original studies up to December 2020 that had quantified the impact of human allergy to cats on ownership or relinquishment. Objective quantifiable data appeared to fall into three broad outcomes - (1) choosing to avoid cat ownership; (2) relinquishment of owned cats; and (3) return of cats after acquisition from a rehoming centre. The data retrieved on these topics are the focus of this review. In some studies, data from cats and dogs were combined and these have also been included in the review.

Clinical practice guidelines for the management of atopic dermatitis 2018

Atopic dermatitis (AD) is a disease characterized by relapsing eczema with pruritus as a primary lesion. The current strategies to treat AD in Japan from the perspective of evidence-based medicine consist of three primary measures: (i) the use of topical corticosteroids and tacrolimus ointment as the main treatment for the inflammation; (ii) topical application of emollients to treat the cutaneous barrier dysfunction; and (iii) avoidance of apparent exacerbating factors, psychological counseling and advice about daily life. The guidelines present recommendations to review clinical research articles, evaluate the balance between the advantages and disadvantages of medical activities, and optimize medical activity-related patient outcomes with respect to several important points requiring decision-making in clinical practice.

Prenatal and early-life exposure to indoor air-polluting factors and allergic sensitization at 2 years of age

BACKGROUND

Previous studies have suggested that exposures to indoor air-polluting factors during pregnancy and early life can influence childhood allergy development. These exposures have been investigated in singularity; however, the effect of simultaneous exposure to multiple factors remains unclear.

OBJECTIVE

To evaluate the effect of prenatal and early-life exposure to 7 air-polluting factors on allergic sensitization at 2 years of age.

METHODS

Mother-child pairs (n = 108) enrolled in the Kingston Allergy Birth Cohort were followed up from birth to 2 years of age. Exposure to air fresheners, candles, mold, cats, dogs, carpet, and environmental tobacco smoke (ETS) during the prenatal, 6-month, 1-year, and 2-year time points were obtained. A skin prick test (SPT) was performed on both the mother and the 2-year-old child.

RESULTS

Exposure to candles during the prenatal window, cats during the 6-month window, and ETS at 2 years significantly increased the odds ratio (OR) of a positive SPT result (candles: OR, 5.096; 95% CI, 1.69-13.86; P = .006; cat: OR, 4.267; 95% CI, 1.096-15.68; P = .048; and ETS: OR, 3.78; 95% CI, 1.189-11.18; P = .04). Children with a positive SPT result had significantly more exposures than SPT-negative children (prenatal P = .005, 1-year P = .03, and 2-year P = .008). As the total number of exposures increased, the percentage of SPT-positive children increased (prenatal P = .005, 1-year P = .03, and 2-year P = .01).

CONCLUSION

We have provided evidence supporting the role of the indoor environment on atopic disease development. The combined effect of multiple exposures may be more influential to allergy development than a single exposure.

Bedroom Allergen Exposure Beyond House Dust Mites

PURPOSE OF REVIEW

The review provides insight into recent findings on bedroom allergen exposures, primarily focusing on pet, pest, and fungal exposures.

RECENT FINDINGS

Large-scale studies and improved exposure assessment technologies, including measurement of airborne allergens and of multiple allergens simultaneously, have extended our understanding of indoor allergen exposures and their impact on allergic disease. Practical, streamlined methods for exposure reduction have shown promise in some settings, and potential protective effects of early-life exposures have been further elucidated through the investigation of specific bacterial taxa. Advances in molecular allergology have yielded novel data on sensitization profiles and cross-reactivity. The role of indoor allergen exposures in allergic disease is complex and remains incompletely understood. Advancing our knowledge of various co-exposures, including the environmental and host microbiome, that interact with allergens in early life will be crucial for the development of efficacious interventions to reduce the substantial economic and social burden of allergic diseases including asthma.

An update on molecular cat allergens: Fel d 1 and what else? Chapter 1: Fel d 1, the major cat allergen

Background

Cats are the major source of indoor inhalant allergens after house dust mites. The global incidence of cat allergies is rising sharply, posing a major public health problem. Ten cat allergens have been identified. The major allergen responsible for symptoms is Fel d 1, a secretoglobin and not a lipocalin, making the cat a special case among mammals.

Main body

Given its clinical predominance, it is essential to have a good knowledge of this allergenic fraction, including its basic structure, to understand the new exciting diagnostic and therapeutic applications currently in development. The recent arrival of the component-resolved diagnosis, which uses molecular allergens, represents a unique opportunity to improve our understanding of the disease. Recombinant Fel d 1 is now available for in vitro diagnosis by the anti-Fel d 1 specific IgE assay. The first part of the review will seek to describe the recent advances related to Fel d 1 in terms of positive diagnosis and assessment of disease severity. In daily practice, anti-Fel d 1 IgE tend to replace those directed against the overall extract but is this attitude justified? We will look at the most recent arguments to try to answer this question. In parallel, a second revolution is taking place thanks to molecular engineering, which has allowed the development of various forms of recombinant Fel d 1 and which seeks to modify the immunomodulatory properties of the molecule and thus the clinical history of the disease via various modalities of anti-Fel d 1-specific immunotherapy. We will endeavor to give a clear and practical overview of all these trends.

An update on molecular cat allergens: Fel d 1 and what else? Chapter 1: Fel d 1, the major cat allergen

Background

Cats are the major source of indoor inhalant allergens after house dust mites. The global incidence of cat allergies is rising sharply, posing a major public health problem. Ten cat allergens have been identified. The major allergen responsible for symptoms is Fel d 1, a secretoglobin and not a lipocalin, making the cat a special case among mammals.

Main body

Given its clinical predominance, it is essential to have a good knowledge of this allergenic fraction, including its basic structure, to understand the new exciting diagnostic and therapeutic applications currently in development. The recent arrival of the component-resolved diagnosis, which uses molecular allergens, represents a unique opportunity to improve our understanding of the disease. Recombinant Fel d 1 is now available for in vitro diagnosis by the anti-Fel d 1 specific IgE assay. The first part of the review will seek to describe the recent advances related to Fel d 1 in terms of positive diagnosis and assessment of disease severity. In daily practice, anti-Fel d 1 IgE tend to replace those directed against the overall extract but is this attitude justified? We will look at the most recent arguments to try to answer this question. In parallel, a second revolution is taking place thanks to molecular engineering, which has allowed the development of various forms of recombinant Fel d 1 and which seeks to modify the immunomodulatory properties of the molecule and thus the clinical history of the disease via various modalities of anti-Fel d 1-specific immunotherapy. We will endeavor to give a clear and practical overview of all these trends.

Influence of diet and dietary nanoparticles on gut dysbiosis

Human gut comprises of a huge mixture of microorganisms as they had co-existed for millions of years. The change in co-existence of microbial genera leads to dysbiosis, which creates several disorders in humans. Diet and diet associated agents can have a considerable influence on host health by regulating the gut microbiome, which can thereby maintain the homeostasis of the gut. Analysis of the gut microbiome and the agents that can have an influence on the gut need a profound understanding, which is the need of the hour. The current review therefore focuses on the influence of diet and dietary nanoparticles on the gut microbiota and their positive or adverse effect.

International Consensus Statement on Allergy and Rhinology: Allergic Rhinitis

BACKGROUND

Critical examination of the quality and validity of available allergic rhinitis (AR) literature is necessary to improve understanding and to appropriately translate this knowledge to clinical care of the AR patient. To evaluate the existing AR literature, international multidisciplinary experts with an interest in AR have produced the International Consensus statement on Allergy and Rhinology: Allergic Rhinitis (ICAR:AR).

METHODS

Using previously described methodology, specific topics were developed relating to AR. Each topic was assigned a literature review, evidence-based review (EBR), or evidence-based review with recommendations (EBRR) format as dictated by available evidence and purpose within the ICAR:AR document. Following iterative reviews of each topic, the ICAR:AR document was synthesized and reviewed by all authors for consensus.

RESULTS

The ICAR:AR document addresses over 100 individual topics related to AR, including diagnosis, pathophysiology, epidemiology, disease burden, risk factors for the development of AR, allergy testing modalities, treatment, and other conditions/comorbidities associated with AR.

CONCLUSION

This critical review of the AR literature has identified several strengths; providers can be confident that treatment decisions are supported by rigorous studies. However, there are also substantial gaps in the AR literature. These knowledge gaps should be viewed as opportunities for improvement, as often the things that we teach and the medicine that we practice are not based on the best quality evidence. This document aims to highlight the strengths and weaknesses of the AR literature to identify areas for future AR research and improved understanding.

Modifiable risk factors associated with bronchiolitis

BACKGROUND

We sought to clarify possibly modifiable risk factors related to pollution responsible for acute bronchiolitis in hospitalized infants.

METHODS

For this observational study, we recruited 213 consecutive infants with bronchiolitis (cases: median age: 2 months; age range: 0.5-12 months; boys: 55.4%) and 213 children aged <3 years (controls: median age: 12 months; age range: 0.5-36 months; boys: 54.5%) with a negative medical history for lower respiratory tract diseases hospitalized at 'Sapienza' University Rome and IRCCS Bambino Gesù Hospital. Infants' parents completed a standardized 53-item questionnaire seeking information on social-demographic and clinical characteristics, indoor pollution, eating habits and outdoor air pollution. Multivariate logistic regression analyses were run to assess the independent effect of risk factors, accounting for confounders and effect modifiers.

RESULTS

In the 213 hospitalized infants the questionnaire identified the following risk factors for acute bronchiolitis: breastfeeding ⩾3 months (OR: 2.1, 95% confidence interval [CI]: 1.2-3.6), presence of older siblings (OR: 2.8, 95% CI: 1.7-4.7), ⩾4 cohabitants (OR: 1.5, 95% CI: 1.1-2.1), and using seed oil for cooking (OR: 1.7, 95% CI: 1.2-2.6). Having renovated their home in the past 12 months and concurrently being exposed daily to smoking, involving more than 11 cigarettes and two or more smoking cohabitants, were more frequent factors in cases than in controls ( p = 0.021 and 0.05), whereas self-estimated proximity to road and traffic was similar in the two groups.

CONCLUSIONS

We identified several risk factors for acute bronchiolitis related to indoor and outdoor pollution, including inhaling cooking oil fumes. Having this information would help public health authorities draw up effective preventive measures - for example, teach mothers to avoid handling their child when they have a cold and eliminate exposure to second-hand tobacco smoke.

Mould and grass pollen allergy as risk factors for childhood asthma in Zaragoza, Spain

OBJECTIVE

Examine the prevalence of asthma and associated predictive factors in a group of 468 students.

PATIENTS AND METHODS

A descriptive, cross-sectional observational study in a randomly selected population of 468 children aged 10-12, in the city of Zaragoza. We used the ISAAC questionnaire on asthma completed by children under supervision of the investigators. We assessed the genetic risk (family history of asthma) and environmental risks. The risk for atopy was assessed by the presence of positive skin prick tests.

RESULTS

25.3% of the children had symptoms consistent with asthma in the city of Zaragoza. Among them 33.1% reported a history of asthma in close relatives (OR=1.78, p<0.001). The history of hospitalisations for lower respiratory tract illness was strongly associated with the presence of asthma (OR=6.72, p<0.0001). Positive skin tests to Alternaria (OR=2.00, p<0.0001) and grass pollen (OR=1.76, p<0.001) were predictors of asthma. 63.6% of asthmatic children had presented clinical rhinitis in the previous 12 months, compared with 32% of non-asthmatics, and this difference was statistically significant (OR=3.89, p<0.0001). 47% of asthmatics presented with or previously had eczema, whereas only 26.9% of non-asthmatics presented with or previously had these types of lesions (p<0.0001).

CONCLUSION

The following are predictors of asthma: History of hospital admissions for lower respiratory tract illness, presence of rhinitis and/or eczema, positive prick test for certain aeroallergens, especially Alternaria and grass pollen, and family history of asthma.

Prevalence of Atopic Dermatitis in Chinese Children aged 1-7 ys

Prevalence of atopic dermatitis (AD) is increasing worldwide. Up to date, there has been no face-to-face nation-wide study in China. We aim to explore the prevalence of clinical diagnosed AD in children aged 1-7 ys in China. Twelve metropolises were chosen from different areas of China. In each region, we selected 4-10 kindergartens and 2-5 vaccination clinics randomly. A complete history-taking and skin examination were performed by dermatologists. The definite diagnosis of AD and the severity were determined by two or three dermatologists. All criteria concerned in UK diagnosis criteria, characteristic presentation of AD and atypical manifestations were recorded in detail. A total of 13998 children from 84 kindergartens and 40 vaccination clinics were included. The prevalence of AD was 12.94% by clinical diagnosis of dermatologists overall, with 74.6% of mild AD. Comparatively, prevalence of AD based on UK diagnostic criteria was 4.76%. This is the first face-to-face nation-wide study in Chinese children aged 1-7 ys, revealing that the prevalence of AD in children is closer to that of wealthier nations.

Recent Understandings of Pet Allergies

Allergic reactions to pets have been recognized for at least a hundred years. Yet our understanding of the effects of all of the interactions between pet exposures and human immune responses continues to grow. Allergists, epidemiologists, and immunologists have spent years trying to better understand how exposures to pet allergens lead to allergic sensitization (the production of allergen-specific immunoglobulin class E [IgE] antibodies) and subsequent allergic disease. A major new development in this understanding is the recognition that pet exposures consist of not only allergen exposures but also changes in microbial exposures. Exposures to certain pet-associated microbes, especially in the neonatal period, appear to be able to dramatically alter how a child’s immune system develops and this in turn reduces the risk of allergic sensitization and disease. An exciting challenge in the next few years will be to see whether these changes can be developed into a realistic preventative strategy with the expectation of significantly reducing allergic disease, especially asthma.

Allergy associations with the adult fecal microbiota: Analysis of the American Gut Project

BACKGROUND

Alteration of the gut microbial population (dysbiosis) may increase the risk for allergies and other conditions. This study sought to clarify the relationship of dysbiosis with allergies in adults.

METHODS

Publicly available American Gut Project questionnaire and fecal 16S rRNA sequence data were analyzed. Fecal microbiota richness (number of observed species) and composition (UniFrac) were used to compare adults with versus without allergy to foods (peanuts, tree nuts, shellfish, other) and non-foods (drug, bee sting, dander, asthma, seasonal, eczema). Logistic and Poisson regression models adjusted for potential confounders. Odds ratios and 95% confidence intervals (CI) were calculated for lowest vs highest richness tertile. Taxonomy associations considered 122 non-redundant taxa (of 2379 total taxa) with ≥ 0.1% mean abundance.

RESULTS

Self-reported allergy prevalence among the 1879 participants (mean age, 45.5 years; 46.9% male) was 81.5%, ranging from 2.5% for peanuts to 40.5% for seasonal. Fecal microbiota richness was markedly lower with total allergies (P = 10(-9)) and five particular allergies (P ≤ 10(-4)). Richness odds ratios were 1.7 (CI 1.3-2.2) with seasonal, 1.8 (CI 1.3-2.5) with drug, and 7.8 (CI 2.3-26.5) with peanut allergy. These allergic participants also had markedly altered microbial community composition (unweighted UniFrac, P = 10(-4) to 10(-7)). Total food and non-food allergies were significantly associated with 7 and 9 altered taxa, respectively. The dysbiosis was most marked with nut and seasonal allergies, driven by higher Bacteroidales and reduced Clostridiales taxa.

INTERPRETATION

American adults with allergies, especially to nuts and seasonal pollen, have low diversity, reduced Clostridiales, and increased Bacteroidales in their gut microbiota. This dysbiosis might be targeted to improve treatment or prevention of allergy.

The Calcium Goes Meow: Effects of Ions and Glycosylation on Fel d 1, the Major Cat Allergen

The major cat allergen, Fel d 1, is a structurally complex protein with two N-glycosylation sites that may be filled by different glycoforms. In addition, the protein contains three putative Ca2+ binding sites. Since the impact of these Fel d 1 structure modifications on the protein dynamics, physiology and pathology are not well established, the present work employed computational biology techniques to tackle these issues. While conformational effects brought upon by glycosylation were identified, potentially involved in cavity volume regulation, our results indicate that only the central Ca2+ ion remains coordinated to Fel d 1 in biological solutions, impairing its proposed role in modulating phospholipase A2 activity. As these results increase our understanding of Fel d 1 structural biology, they may offer new support for understanding its physiological role and impact into cat-promoted allergy.

The Calcium Goes Meow: Effects of Ions and Glycosylation on Fel d 1, the Major Cat Allergen

The major cat allergen, Fel d 1, is a structurally complex protein with two N-glycosylation sites that may be filled by different glycoforms. In addition, the protein contains three putative Ca²⁺ binding sites. Since the impact of these Fel d 1 structure modifications on the protein dynamics, physiology and pathology are not well established, the present work employed computational biology techniques to tackle these issues. While conformational effects brought upon by glycosylation were identified, potentially involved in cavity volume regulation, our results indicate that only the central Ca²⁺ ion remains coordinated to Fel d 1 in biological solutions, impairing its proposed role in modulating phospholipase A₂ activity. As these results increase our understanding of Fel d 1 structural biology, they may offer new support for understanding its physiological role and impact into cat-promoted allergy.

Dog and cat exposure and respective pet allergy in early childhood

BACKGROUND

The association of dog and cat exposure in early childhood with the incidence of respective allergies has remained controversial. The aim of the study was to obtain population-based evidence on the association of early exposure to dog or cat, or both, with dog and cat allergies.

METHODS

The study population was identified from the nationwide population register comprising all children aged 1-4 yr (N = 4779) born between 2001 and 2005 and living in the province of South Karelia, Finland. Cross-sectional questionnaire data on pet exposure in infancy and physician-diagnosed pet allergies were obtained from 3024 participants and merged with longitudinally accumulated data on sIgE and skin prick tests indicating allergic sensitization abstracted from all patient records in the area.

RESULTS

The adjusted relative incidence of positive test results (with 95% confidence intervals) was 2.69 (1.45-5.02) for dog and 5.03 (2.47-10.2) for cat allergens among children exposed to a respective pet alone compared with children without such exposure. The corresponding adjusted prevalence odds ratios for diagnosed dog and cat allergies were 1.75 (0.77-3.79) and 5.13 (2.30-11.4), respectively. The association between pet exposure and the incidence of positive test results was independent of parents' allergies.

CONCLUSIONS

Early exposure to dog and cat at home is associated with a higher incidence of respective pet allergy during the first four years of life. Further evidence from population-based studies with longer follow-up is required to justify any recommendation concerning early pet contacts with a view to preventing pet allergies later in life.

Allergy to furry animals: New insights, diagnostic approaches, and challenges

The prevalence of allergy to furry animals has been increasing, and allergy to cats, dogs, or both is considered a major risk factor for the development of asthma and rhinitis. An important step forward in the diagnosis of allergy to furry animals has been made with the introduction of molecular-based allergy diagnostics. A workshop on furry animals was convened to provide an up-to-date assessment of our understanding of (1) the exposure and immune response to the major mammalian allergens, (2) the relationship of these responses (particularly those to specific proteins or components) to symptoms, and (3) the relevance of these specific antibody responses to current or future investigation of patients presenting with allergic diseases. In this review research results discussed at the workshop are presented, including the effect of concomitant exposures from other allergens or microorganisms, the significance of the community prevalence of furry animals, molecular-based allergy diagnostics, and a detailed discussion of cat and dog components.

Modifiable exposures to air pollutants related to asthma phenotypes in the first year of life in children of the EDEN mother-child cohort study

Background

Studies have shown diverse strength of evidence for the associations between air pollutants and childhood asthma, but these associations have scarcely been documented in the early life. The purpose of this study was to evaluate the impacts of various air pollutants on the development of asthma phenotypes in the first year of life.

Methods

Adjusted odds ratios were estimated to assess the relationships between exposures to air pollutants and single and multi-dimensional asthma phenotypes in the first year of life in children of the EDEN mother-child cohort study (n = 1,765 mother-child pairs). The Generalized Estimating Equation (GEE) model was used to determine the associations between prenatal maternal smoking and in utero exposure to traffic-related air pollution and asthma phenotypes (data were collected when children were at birth, and at 4, 8 and 12 months of age). Adjusted Population Attributable Risk (aPAR) was estimated to measure the impacts of air pollutants on health outcomes.

Results

In the first year of life, both single and multi-dimensional asthma phenotypes were positively related to heavy parental smoking, traffic-related air pollution and dampness, but negatively associated with contact with cats and domestic wood heating. Adjusted odds ratios (aORs) for traffic-related air pollution were the highest [1.71 (95% Confidence Interval (CI): 1.08-2.72) for ever doctor-diagnosed asthma, 1.44 (95% CI: 1.05-1.99) for bronchiolitis with wheezing, 2.01 (95% CI: 1.23-3.30) for doctor-diagnosed asthma with a history of bronchiolitis]. The aPARs based on these aORs were 13.52%, 9.39%, and 17.78%, respectively. Results persisted for prenatal maternal smoking and in utero exposure to traffic-related air pollution, although statistically significant associations were observed only with the asthma phenotype of ever bronchiolitis.

Conclusions

After adjusting for potential confounders, traffic-related air pollution in utero life and in the first year of life, had a greater impact on the development of asthma phenotypes compared to other factors.