Reducing Respiratory Virus in Preemies Lessens Wheezing: Study

But preventing respiratory synctial virus comes with a hefty price tag

By Serena Gordon

HealthDay Reporter

WEDNESDAY, May 8 (HealthDay News) -- Many pre-term babies suffer recurrent episodes of wheezing. Now, researchers say a common infection is a likely culprit and they may be able to prevent the breathing problems.

Wheezing episodes in late pre-term babies often are caused by infection with the respiratory synctial virus (RSV), the researchers said. And they've found that injections of an expensive RSV medication can prevent the virus -- and the wheezing.

A study of more than 400 babies born late pre-term (between 33 and 35 weeks' gestation) found that days with wheezing dropped by more than 60 percent among those who received injections of palivizumab during RSV season. The effect lasted even after treatment ended.

"In pre-term babies, RSV illnesses seem to be a risk factor for wheezing, and this treatment reduced that risk," said Dr. Robert Lemanske Jr., a professor of pediatrics and medicine at the University of Wisconsin School of Medicine and Public Health, in Madison. Lemanske wrote an editorial accompanying the new study, which was published May 9 in the New England Journal of Medicine.

RSV is a global health threat in the first year of life and the second leading cause of death after malaria, said study lead author Dr. Louis Bont, a pediatric infectious disease specialist at the University Medical Center Utrecht in the Netherlands.

"The risk of hospitalization for RSV bronchiolitis in otherwise healthy late pre-term [babies] is 5 percent," Bont said. "For other pre-terms, it is higher. About half of all otherwise healthy late pre-terms develop wheezing illness."

RSV-related wheezing reduces quality of life, and it has been linked to the development of asthma, Bont said. It's not yet clear if using palivizumab to prevent RSV will lower rates of asthma, he added.

RSV season lasts about four to five months during the fall, winter or spring, but the exact timing in the United States varies by region, according to the U.S. Centers for Disease Control and Prevention. There is no vaccine for the virus, which causes only mild symptoms in adults and older children.

The study was funded by Abbott Laboratories and the Netherlands Organization for Health Research and Development. Abbott markets palivizumab in some foreign countries.

The researchers set out to determine if RSV was the cause of wheezing illness during the first year of life. Studying 429 babies in the Netherlands, they randomly assigned half to receive a monthly injection of palivizumab during RSV season. The other half received a placebo drug.

The babies in the treatment group had 61 percent fewer days of wheezing during the first year of life. This led the researchers to conclude that RSV is a likely contributor to wheezing illness in this group of children.

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Genes and Early Wheezing Tied to Childhood Asthma Risk

Common cold symptom increased odds for asthma in study

By Robert Preidt

HealthDay Reporter

WEDNESDAY, March 27 (HealthDay News) -- Certain genetic factors and wheezing early in life are associated with a greatly increased risk of asthma in children, a new study says.

Researchers examined data from nearly 500 children and found that about 90 percent of those who had two copies of a common genetic variation and who also experienced wheezing when they had a cold early in life developed asthma by age 6.

These children, all from families with a history of asthma or allergies, were nearly four times more likely to develop asthma than those who did not have the genetic variation and did not wheeze, according the study in the March 28 issue of the New England Journal of Medicine.

The genetic variation is found on chromosome 17 and is common. Half of the children in the study had one copy and 25 percent had two copies. The researchers also noted that colds are extremely common and affect nearly all infants.

The increased risk is associated with wheezing during colds caused by a human rhinovirus infection, the University of Chicago Medical Center researchers said.

"We found that the interaction between this specific wheezing illness and a gene or genes on a region of chromosome 17 determines childhood asthma risk," study author Carole Ober, a professor of human genetics at the University of Chicago, said in a medical center news release. "The combination of genetic predisposition and the child's response to this infection has a huge effect."

The researchers said it is not clear how this gene variation and wheezing interact to increase the risk of developing asthma. It also should be noted that the research showed only an association between them, and not a cause-and-effect relationship.

About 25 percent of children who had no wheezing from a human rhinovirus infection developed asthma, and 40 percent of those who experienced wheezing in the first three years of life but lacked the risk-related gene variants developed asthma.

That rose to nearly 60 percent among those with one copy of the gene variant and to 90 percent for those with two copies.

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