Researcher scrutinizes lung cells’ response to RSV

Two-year-old Kendall Harrington was diagnosed with RSV when she was three months old. Although she has recovered, she now suffers from an acute case of asthma and has frequent respiratory infections.

RSV, or respiratory syncytial virus, is a major threat this time of year to infants and adults with weakened immune systems.

No active vaccine exists to prevent RSV infection, nor is there a medication proven to counter RSV illness after it begins. Hospitals stabilize tiny RSV patients with oxygen (through ventilators if necessary) and fluids. Most infants recover, but recent studies indicate they are at higher risk for asthma and apnea later in life.

That’s what makes the research of Santanu Bose, Ph.D., so important. Dr. Bose, assistant professor of microbiology and immunology, studies the instinctive response of lung cells to RSV. He is focusing on protective antiviral molecules that are produced in the lung cells in response to the infection.

Understanding this response could lead to a medication to effectively treat RSV, which can be spread by sneezing or coughing. “We have no active vaccine at this point, but we do have two products that protect at-risk infants by providing them with antibodies against RSV,” says Charles Leach, M.D., professor of pediatrics. “These shots are administered every month for five months. We give these to babies who have chronic lung disease, who are premature or who have significant congenital heart disease. We usually start in October, about a month before RSV season hits.”

RSV infection may result in pneumonia, bronchiolitis (inflamed bronchial tubes) and croup. Symptoms include fever, coughing and wheezing. “Youngsters are admitted for RSV throughout the winter months,” Dr. Leach says. “A lot of times, these children must be placed on mechanical ventilators to help them breathe. For some children, the RSV infection can be severe or even fatal.”

RSV’s connection to asthma is only poorly understood. “Clearly the link with reactive airway disease is there, but it is the old chicken-before-the-egg question,” Dr. Leach says. “Because they contracted RSV, does that make them more prone to developing asthma as they get older, or is it their propensity for asthma that makes them contract RSV infection serious enough to warrant hospitalization?”

Most RSV disease is treated on an outpatient basis. Only one in 100 RSV-infected patients is hospitalized, usually because of respiratory distress. Studies examining the relationship with asthma have been done in the patients requiring hospitalization.

“RSV changes the way the immune system develops in many infants and toddlers,” says Stephen Inscore, M.D., associate professor of pediatrics. “Though most cases resolve by the time a child is school-age, a good number never resolve. RSV in adults and older children presents as a mild cold illness, but to the young infant, RSV has devastating consequences.”

Dr. Bose points out the challenge of developing a vaccine against RSV. “A vaccine causes the body to remember that the virus is an invader of foreign origin,” Dr. Bose says. “But RSV is so smart that it causes the body to have a kind of amnesia, and not remember prior infections.”

Dr. Bose’s research has placed the Health Science Center on the front lines of the war with RSV.

How common is RSV?

•RSV is the leading cause of severe respiratory infections in children.
•More than 125,000 children and adults are hospitalized with RSV annually in the U.S.
•RSV infections claim the lives of 2,500 people per year.
•Most cases are in infants 6 months and younger.
•RSV-related bronchial inflammation hospitalizes 31 of every 1,000 children age 1 or younger.
•RSV is a contributing factor in the deaths of some adults 65 and older who have heart or lung problems.

Source: American Lung Association

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