Daycare attendance associated with lower IgE levels, perennial aeroallergen sensitization

Key takeaways:

• Total IgE levels were 142 IU/mL lower among children who went to daycare.
• Odds ratios for sensitization included 0.56 for food and 0.57 for perennial aeroallergen with daycare attendance.

WASHINGTON — Attending daycare early in life had a protective effect against sensitization to perennial aeroallergens, according to a poster presented at the American Academy of Allergy, Asthma & Immunology Annual Meeting.

These children also had clinically significant lower total IgE levels, Jonathan Witonsky, MD, MAS, assistant professor, department of pediatrics, division of pediatric allergy, immunology and bone marrow transplant, University of California, San Francisco, and colleagues wrote.

“The correlation between daycare attendance, total IgE levels, and the onset of allergies/asthma is firmly established within scientific literature,” Witonsky told Healio.

Jonathan Witonsky

Previously, Witonsky said, he and his colleagues found a protective effect with daycare attendance in a meta-analysis of 32 studies, including a 34% reduction in odds for the development of childhood asthma.

“Our abstract’s results serve to reinforce these conclusions within a demographic particularly vulnerable to asthma — Puerto Rican children,” Witonsky said.

Compared with their white counterparts in the United States, Witonsky said, children in Puerto Rico face significantly higher risks, with a threefold higher likelihood of asthma diagnosis and over fivefold greater risk for asthma-related mortality.

“Our preliminary findings shed light on a nuanced perspective regarding early-life daycare attendance,” Witonsky said.

Beyond a correlation between daycare attendance and total IgE levels, he continued, these findings indicate a potential link between daycare attendance and diminished allergic sensitization to peanut, milk, egg and other foods, as well as reduced sensitization to environmental allergens such as cat dander, dog dander and dust mites.

“Moreover, our analysis suggests that the timing of daycare enrollment, particularly during the infant’s first year, may play a pivotal role in shaping these outcomes, hinting that daycare attendance alone is unlikely the sole determinant,” Witonsky said.

The study included 435 children in the Puerto Rican Infant Metagenomic and Epidemiologic Study of Respiratory Outcomes (PRIMERO) birth cohort at Hospital Interamericano de Medicina Avanzada-San Pablo. The researchers began enrolling participants in March 2020.

“These findings are some of the first of many likely to come from the PRIMERO Birth Cohort, the first prospective observational birth cohort study of Puerto Rican children established to explore early-life asthma origins, emphasizing prenatal and postnatal social, environmental and genetic exposures in children,” Witonsky said.

After surveillance during the first 2 years of each child’s life, the researchers took blood samples for total IgE and perennial allergen-specific IgE during the year 2 visit. Also, 96 of the children (22.1%) had attended daycare.

On average, the children who had attended daycare had total IgE levels that were an average of 142 IU/mL lower than those who had not (P = .03; P = 0.4 after adjustment for cofounders).

The odds for perennial aeroallergen sensitization were 0.57 times higher (95% CI, 0.35-0.91) for the children who had attended daycare compared with those who had not. After adjustment, odds remained 0.57 times higher (95% CI, 0.33-0.97).

Additionally, the children who had attended daycare had less food sensitization (OR = 0.56; 95% CI, 0.36-0.85).

Based on these findings, the researchers concluded that daycare attendance early in life had a protective effect against perennial aeroallergen sensitization, with the potential to reduce risks for asthma and other allergic diseases later.

“At present, the oldest participants have yet to reach the age of 4 years and are still too young for an asthma diagnosis to be reliably established,” Witonsky said.

“Our objective is to continue monitoring these children until they reach at least 7 years of age, at which point we can conduct the requisite clinical assessments to definitively determine the primary outcome of asthma diagnosis,” he continued.

Also, Witonsky said, these findings may inform adjustments to guidance for daycare attendance, including considerations regarding the appropriate age for enrollment.

Along with additional studies designed to validate these findings, Witonsky said, further investigation is needed for a deeper understanding of the mechanisms behind this relationship.

“Specifically, factors such as genetic predisposition, epigenetic modifications, early-life immune development, the microbiome of daycare environments, allergen or pollution exposures, and viral pathogens are likely influential in shaping the observed relationships,” he said. “These aspects warrant thorough exploration to elucidate their roles and contributions accurately.”

References:

• 2018 National Health Interview Survey (NHIS) data. https://www.cdc.gov/asthma/nhis/2018/table4-1.htm. Published Dec. 17, 2019. Accessed Feb. 16, 2024.
• Akinbami LJ, et al. Trends in asthma prevalence, health care use, and mortality in the United States, 2001-2010. NCHS Data Brief. https://stacks.cdc.gov/view/cdc/12331. Published May 2012. Accessed Feb. 16, 2022.
• Early-life daycare attendance potentially linked to lower risk of asthma and allergic diseases. https://www.aaaai.org/about/news/news/2024/daycare. Published Feb. 5, 2024. Accessed Feb. 15, 2024.
• Swartz A, et al. J Asthma. 2019;doi:10.1080/02770903.2018.1445268.
• Witonsky J, et al. J Allergy Clin Immunol. 2024;doi:10.1016/j.jaci.2023.11.789.

For more information:

Jonathan Witonsky, MD, MAS, can be reached at Jonathan.witonsky@ucsf.edu.