Children who suffer from asthma or allergic rhinitis have a diminished ability to stimulate dendritic cell interleukin-10 production (IL-10), which may contribute to the cause of their disease, according to research presented at the 60th Anniversary Meeting of the American Academy of Allergy, Asthma and Immunology (AAAAI) by allergic disease specialists at Allegheny General Hospital (AGH) in Pittsburgh.

Asthma and allergic rhinitis - or hay fever - are among the most common chronic disorders of childhood and account for significant limitations of daily activities, sleep difficulties, emergency doctor visits, hospitalizations and health care costs in the United States.

Swelling or inflammation in the nasal passages and lungs is the hallmark feature of asthma and allergic rhinitis. Because both conditions typically begin in very early childhood, researchers are focusing on trying to better understand the factors that control the swelling or inflammation, said Deborah Gentile, an AGH pediatric allergist and lead investigator in the study.

Lymphocytes are white blood cells that cause much of the swelling or inflammation in asthma and allergic rhinitis. IL-10 is an anti-inflammatory cytokine, a chemical naturally made in the body that influences lymphocytes. One action of IL-10 is to decrease airway swelling or inflammation in those with allergies and asthma. IL-10 production by specialized immune cells called dendritic cells is thought to be particularly important in the prevention of allergy and asthma.

Gentile, Rachel Schreiber, and colleagues from AGH and Children's Hospital of Pittsburgh tested the amount of IL-10 produced from dendritic cells in the blood of 60 children ages 6-12 years. Three groups of twenty were included: Group 1 consisted of children with neither asthma or allergic rhinitis, Group 2 consisted of children who suffered from allergic rhinitis only, and Group 3 included children who suffered from allergic rhinitis and asthma.

An analysis of the data showed that IL-10 levels in children with allergic rhinitis only and children with allergic rhinitis and asthma were significantly lower compared to those children without either condition. Seventy-five percent of the children without allergic rhinitis or asthma had detectable levels of IL-10, compared to 25% in those with allergic rhinitis only and 20% in those with allergic rhinitis and asthma.

Gentile has secured funding from the National Institutes of Health (NIH) to study dendritic cell IL-10 production in a larger group of children, including infants. If it is confirmed that dendritic cell IL-10 production is diminished in children with allergies and asthma, the result may be a better understanding of the causes of these disorders and the development of improved therapies to treat or even prevent them.