Sickle Cell Disease Is an Inherent Risk for Asthma in a Sibling Comparison Study

Sickle cell disease (SCD) and asthma share a complex relationship. Although estimates vary, asthma prevalence in children with SCD is believed to be comparable to or higher than the general population. Determining whether SCD confers an increased risk for asthma remains challenging due to overlapping symptoms and the multifactorial nature of asthma. This study seeks to clarify the association by assessing asthma risk in children with SCD in comparison to their siblings, controlling for potential confounders.

A prospective, case-control sibling comparison study was conducted. Children with SCD aged 2-18 years seen at our outpatient comprehensive center, along with their non-SCD siblings, were determined for diagnosed with asthma through clinical assessment by a pediatric pulmonologist.

A total of 576 participants (248 SCD, 328 siblings) were included. Asthma prevalence was significantly higher in the SCD group (28.6% vs. 7.6%, p < 0.001) compared to siblings. In multivariate conditional logistic regression analysis, SCD status was the only factor associated with higher odds of asthma compared to their respective siblings, after adjusting for age and sex (odds ratio [OR]: 7.57, 95% confidence interval [CI]: 3.47-16.54, p < 0.0001). Multivariate logistic regression in the SCD group identified advancing age (OR: 1.19, 95% CI: 1.11-1.27, p < 0.001), males (OR: 2.0, 95% CI: 1.05-3.9, p = 0.04), family history of asthma (OR: 5.79, 95% CI: 2.68-12.51, p < 0.001), and hydroxyurea usage (OR: 2.11, 95% CI: 1.1-4, p = 0.02) as risk factors for asthma. Whereas males (OR: 3.32, 95% CI: 1.21-9.13, p = 0.02) and family history of asthma (OR: 2.43, 95% CI: 1.01-5.86, p = 0.048) remained risk factors for the siblings group. The inferences did not change even when age was restricted to 2-18 years in the sibling group.

SCD increases the risk for asthma, independent of familial and environmental factors. Age-related rise in prevalence highlights the importance of regular screening in this high-risk population.