National Institute of Allergy and Infectious Diseases
Research on allergies is focused on understanding what happens to the human body during the allergic process, the sequence of events leading to the allergic response and the factors responsible for allergic diseases.
Scientists supported by NIAID found that, during the first years of their lives, children raised in a house with two or more dogs or cats may be less likely to develop allergic diseases as compared with children raised without pets. The striking finding here is that high pet exposure early in life appears to protect some children from not only pet allergy but also other types of common allergies, such as allergy to house dust mites, ragweed, and grass. This new finding is changing the way scientists think about pet exposure. Scientists must now figure out how pet exposure causes a general shift of the immune system away from an allergic response.
The results of this and a number of other studies suggest that bacteria carried by pets may be responsible for holding back the immune system’s allergic response. These bacteria release molecules called endotoxin. Some researchers think endotoxin is the molecule responsible for shifting the developing immune system away from responding to allergens through a class of lymphocytes called Th-2 cells. (These cells are associated with allergic reactions.) Instead, endotoxin may stimulate the immune system to block allergic reactions.
If scientists can find out exactly what it is about pets or the bacteria they carry that prevents the allergic response, they might be able to develop a new allergy treatment.
Some studies are seeking better ways to diagnose as well as treat people with allergic diseases and to better understand the factors that regulate IgE production to reduce the allergic response. Several research institutions are focusing on ways to influence the cells that participate in the allergic response.
NIAID supports a network of Asthma, Allergic and Immunologic Diseases Cooperative Research Centers throughout the United States. The centers encourage close coordination among scientists studying basic and clinical immunology, genetics, biochemistry, pharmacology, and environmental science. This interdisciplinary approach helps move research knowledge as quickly as possible from the lab into the hands of doctors and their allergy patients.
Educating patients and health care providers is an important tool in controlling allergic diseases. All of these research centers conduct and evaluate education programs focused on methods to control allergic diseases. Since 1991, researchers participating in NIAID’s Inner-City Asthma Study have been examining ways to treat asthma in minority children living in inner-city environments. Asthma, a major cause of illness and hospitalizations among these children, is provoked by a number of possible factors, including allergies to airborne substances.
The success of NIAID’s model asthma program led the U.S. Centers for Disease Control and Prevention to award grants to help community-based health organizations throughout the United States implement the program.
Based on the success of the first National Cooperative Inner-City Asthma Study, NIAID and the National Institute of Environmental Health Sciences, also part of NIH, started a second cooperative multicenter study in 1996. This study recruited children with asthma, aged 4 to 11, to test the effectiveness of two interventions. One intervention uses a novel communication and doctor education system. Information about the children’s asthma severity is provided to their primary care physicians, with the intent that this information will help the doctors give the children the best care possible.
The other intervention involves educating families about reducing exposure to passive cigarette smoke and to indoor allergens, including cockroach, house dust mite, and mold. Researchers are assessing the effectiveness of both interventions by evaluating their capacity to reduce the severity of asthma in these children.
Early data show that by reducing allergen levels in children’s beds by one-third, investigators reduced by nearly one-quarter (22 percent) both the number of days the children wheezed and the number of days the children missed school.
(extracted from Airborne Allergens: Something in the Air)