Bronchial obstruction may predict poorer brain vessel outcomes in SCA
Study of 50 children identified age and stenosis severity as additional predictors
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Among children with sickle cell anemia (SCA) and cerebral macrovasculopathy (CV), or disease affecting the brain’s large and medium-sized blood vessels, age at CV diagnosis, the severity of blood vessel narrowing, and bronchial obstruction independently predicted CV reversal.
In this long-term follow-up study of 50 children receiving regular blood transfusions to reduce stroke risk, bronchial obstruction emerged as a newly identified factor associated with a lower rate of CV reversal.
This finding suggests that managing bronchial obstruction alongside standard transfusion care may improve blood vessel outcomes in the brain.
“We believe our data will be very useful in lowering the burden of CV in [sickle cell anemia] patients,” the researchers wrote.
Brain vessel disease can raise stroke risk in sickle cell
The study, “Identification of predictive factors for reversal of cerebral vasculopathy in an original longitudinal cohort study in newborns with sickle cell anaemia,” was published in the British Journal of Haematology.
In SCD, red blood cells adopt a sickle-like shape, which can become trapped in and block blood vessels. In the brain, this can lead to cerebral macrovasculopathy — disease, narrowing, or blockage of the large and medium-sized blood vessels that supply blood to the brain — raising the risk of stroke.
CV can be detected by transcranial Doppler ultrasound (TCD), a test that measures blood flow velocity in the brain’s blood vessels. Magnetic resonance angiography (MRA) can also be used to look for narrowing in those vessels.
Children with confirmed abnormal TCD results may receive regular blood transfusions to reduce the number of sickled red blood cells and lower stroke risk.
In this study, researchers in France sought to identify factors predicting CV reversal among 50 children with sickle cell anemia (SCA), the most common and severe form of SCD.
All children were treated at Robert-Debré University Hospital in Paris, were diagnosed with CV based on TCD and MRA criteria, and began regular blood transfusions. The median age at CV diagnosis was 4.9 years, and the children were followed for a median of 13.3 years.
Data showed that TCD and MRA results normalized in 35 children (70%), meeting the study’s definition of CV reversal, a median of three years after CV diagnosis. After TCD and MRA results normalized, all but one participant started treatment with hydroxyurea.
Statistical models estimated that 48% of the children would still have abnormal TCD and/or MRA results five years after CV diagnosis, falling to 25% at 10 years.
Three factors independently predicted vasculopathy reversal
Further statistical analyses adjusted for potential influencing factors showed that three factors independently predicted CV reversal: age at CV diagnosis, the severity of blood vessel narrowing (stenosis) in the brain, and bronchial obstruction.
Specifically, being older at the time of CV diagnosis was significantly associated with a 31% higher rate of CV reversal for each additional year of age, while each 10-percentage-point increase in blood vessel narrowing was significantly associated with a 28% lower rate of reversal.
Bronchial obstruction, defined using age-specific criteria that included wheezing or coughing and, when possible, lung function testing, was significantly associated with an 86% lower rate of CV reversal.
Notably, bronchial obstruction was present in nearly all children (94%). SCD patients can develop an asthma-like condition linked to inflammation and red blood cell breakdown, and this inflammation may persist even while patients are receiving regular transfusions, the team noted.
“Asthma-like conditions should be routinely explored and specific therapy for bronchial obstruction, also a risk factor for onset of CV, is recommended when appropriate,” the researchers wrote.
The researchers said that, to their knowledge, this was the first study to identify age and bronchial obstruction as new predictive factors for CV reversal. They also wrote that “beyond [blood transfusions], managing bronchial obstruction may improve vascular outcomes.”
“Larger … studies [following patients over time] may be warranted to corroborate this therapeutic approach,” the team wrote.
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