Key Information
Children with sickle cell diseaseexternal link, opens in a new tab (SCD) are about seven times more likely to have asthma than their unaffected siblings, with odds increasing with age, according to a study in the U.S.
These findings highlight the importance of more frequent screening to protect the lungs and prevent asthma-related complications in children with SCD.
“Interval screening [between routine visits] should be implemented to capture cases at all ages,” researchers wrote.
The study, “Sickle Cell Disease Is an Inherent Risk for Asthma in a Sibling Comparison Studyexternal link, opens in a new tab,” was published in Pediatric Blood & Cancer.
Researchers’ question: Does SCD increase risk of asthma?
SCD occurs due to the production of a faulty version of hemoglobinexternal link, opens in a new tab, the protein in red blood cells that carries oxygen. This faulty protein causes red blood cells to take on a sickle-like shape, making them more prone to breakage and blocking blood flow in small vessels, reducing the amount of oxygen delivered to tissues.
Asthma, which is thought to be driven by complex genetic and environmental interactions, causes the airways to become inflamed and narrowed, making breathing difficult. Some of its manifestations overlap with SCD symptomsexternal link, opens in a new tab, which can also cause shortness of breath.
“Asthma is a clinical diagnosis with poorly defined objective criteria,” and “it remains unclear whether a subjective physician’s diagnosis of asthma in children with SCD reflects the same constellations of clinical features observed in children without SCD,” the researchers wrote.
In addition, it remains unclear whether children with SCD have asthma as often as, or more often than, the general population.
In this study, a team of researchers in the U.S. set out to determine whether SCD increases the risk of asthma, while controlling for potential influencing factors such as genetics and the environment. They used a sibling case-control study design, meaning each child with SCD was compared with full- and half-siblings who did not have SCD.
The study included 248 children with SCD (57.7% boys), ages 2 to 18 years, and 328 unaffected siblings (55.5% males), ages 0 months to 33 years. Among the siblings, 240 were between 2 and 18 years old.