Is there a threshold concentration of cat allergen exposure on respiratory symptoms in adults?

Age-related differences in IgE between childhood and adulthood allergic asthma: Analysis of NHANES 2005-2006

Background

Asthma exhibits varying clinical features in children and adults. However, previous studies have mainly focused on the clinical significance of immunoglobulin E (IgE) in the diagnosis and treatment of asthma, disregarding the characteristics of IgE and its relevant factors.

Objective

This study aimed to gain a better understanding of the differences in the characteristics of IgE between childhood and adulthood allergic asthma (AA).

Methods

Patients with AA from the 2005 to 2006 National Health and Nutrition Examination Survey (NHANES) were divided into 3 groups based on their current age and onset age of AA: childhood AA (Group 1), childhood-onset adult AA (Group 2), and adulthood-onset AA (Group 3). Intragroup analysis and intergroup comparison were carried out, focusing on the characteristics and relevant factors of IgE, as well as the clinical relevance of total IgE (total IgE, tIgE) and allergen-specific IgE (allergen-specific IgE, sIgE).

Results

A total of 424 patients were analyzed, including 187 with childhood AA, 132 with childhood-onset adult AA, and 105 with adulthood-onset AA. The concentration of tIgE was found to be higher in Group 1 (268.0, 118.0-686.0 kU/L) than in Group 2 (224.0, 78.0-494.0 kU/L) and Group 3 (165.0, 74.4-350.5 kU/L). The sensitization rates did not differ between Group 1 and Group 2 but were higher compared with Group 3, particularly for Alternaria-sIgE (50.3% and 46.2% vs 15.2%) and Aspergillus-sIgE (43.9% and 37.1% vs 16.2%). In Group 1, there was a negative correlation between pollen-sIgEs and indoor allergens, but this correlation was not commonly observed in Group 2 and Group 3. On the other hand, in Group 1, environmental chemicals such as phthalates, polyaromatic hydrocarbons, trihalomethanes, and phenols showed a positive correlation with IgE. However, a greater number of chemicals was observed in Group 2 and Group 3, including cotinine, metals, trihalomethanes, phthalates, phenols, and other volatile organic compounds (VOCs). Furthermore, in Group 1, IgE was positively correlated with asthma-related issues such as emergency visits, absenteeism, limited activities, and medication needs. These correlations were less common in Group 2 and Group 3, particularly in Group 3.

Conclusions

There are notable differences in the characteristics and environmental factors of IgE among childhood AA, childhood-onset adult AA, and adulthood-onset AA. Additionally, IgE plays a more significant role in childhood AA due to its higher concentration, fewer relevant environmental chemicals and greater clinical relevance. This may partially explain the age-related features of asthma.

Allergen Sensitization and Asthma Outcomes among World Trade Center Rescue and Recovery Workers

A large number of World Trade Center (WTC) rescue and recovery workers are affected by asthma. While physical and mental health comorbidities have been associated with poor asthma control in this population, the potential role of allergen sensitization is unknown. This study examined the association of indoor sensitization and exposure as a risk factor for increased asthma morbidity in WTC workers. We used data from a prospective cohort of 331 WTC workers with asthma. Sensitization to indoor allergens was assessed by measurement of antigen-specific serum immunoglobulin E (IgE) levels. We used validated tools to evaluate the exposure to indoor allergens. Asthma morbidity outcomes included level of control (Asthma Control Questionnaire, ACQ), quality of life (Asthma Quality of Life Questionnaire, AQLQ) and acute resource utilization. The prevalence of sensitization to cat, dog, mouse, dust mite, cockroach, and mold allergens were 33%, 21%, 17%, 40%, 17%, and 17%, respectively. Unadjusted and regression analyses showed no significant relationship between sensitization and increased asthma morbidity (p > 0.05 for all comparisons), except for sensitization to Aspergillus Fumigatus, cat and mouse epithelium, which were associated with decreased morbidity.

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.

Sensitization and Exposure to Pets: The Effect on Asthma Morbidity in the US Population

BACKGROUND

Although pets are found in more than 50% of US homes, the effect of pet allergen exposure on asthma morbidity in the US population is not well documented.

OBJECTIVE

To determine the effect of dog and cat allergen exposures on asthma morbidity in the US population.

METHODS

The National Health and Nutrition Examination Survey is a representative sample of civilian US population. Data on asthma, dog and cat allergen levels in bedroom dust, as well as specific IgE to dog and cat were analyzed for all participants 6 years or older.

RESULTS

Pets are common in the United States, with more that 50% of households having a dog or a cat or both. The prevalence of allergic sensitization in the National Health and Nutrition Examination Survey population was similar for dog and cat, with both being approximately 12%. Among those who were sensitized, exposure to elevated levels of pet allergens was associated with an increased prevalence of asthma and asthma attacks. Indeed, 44.2% of the asthma attacks were attributable to exposure to high levels of dog allergen in the bedroom among patients with asthma sensitive to dog and 30.3% were attributable to cat allergen exposure among the comparable cat-sensitive and exposed group. Projecting these results to the US population indicates more than 1 million increased asthma attacks each year for the dog-sensitive and exposed group and more than 500,000 increased asthma attacks for the cat-sensitive and exposed population of patients with asthma.

CONCLUSIONS

Exposure to elevated levels of dog and cat allergens among those sensitized individuals with asthma is associated with excess asthma attacks. Reducing pet allergen exposures has the potential for a significant decrease in asthma morbidity.

Asthma and Environmental Factors in Children

Asthma is one of the most prevalent atopic diseases in childhood. It is characterized by inflammation of conductive airways and bronchial hyperresponsiveness. Environmental factors introduced to child in early years of life may have a protective or harmful role in developing atopic diseases. To evaluate the influence of some environmental factors such as cat or dog ownership, smoking of mother or father and environmental pollution on prevalence of wheezing in children. Subjects and methods: This was a cross sectional retrospective study. A questionnaire was designed based on International Study of Asthma and Allergies in Childhood (ISAAC). Parents of the subjects were asked to fill in the questionnaires. Children’s wheezing association with keeping cats and dogs, smoking mother and father and frequency of truck passing in place of residence was investigated. 545 children were recruited in our study. Prevalence of wheezing was 9%. Keeping cats in first year of life and last year was associated with less wheezing. But the latter association was not statistically significant. Keeping dogs was so scarce in area of our study, so we could not perform a rightful analysis. Frequency of truck passing was significantly higher in those with wheezing. Keeping cats in first year of life was a significant protective factor, whereas residence in an area with frequent truck passing increased wheezing in children. Results of our study can emphasize the need to keep children away from polluted areas. Further studies are needed to investigate whether keeping a pet in household can benefit children regarding all possible concerns and benefits.