Patients with sickle cell disease and asthma have a higher risk for acute chest syndrome: A systematic review and meta‑analysis of observational studies

Sickle cell disease (SCD) is a hereditary hematologic disorder characterized by abnormal hemoglobin polymerization, leading to vaso‑occlusion, hemolysis and multi‑organ complications. Acute chest syndrome (ACS) is a severe pulmonary complication and a leading cause of morbidity and mortality in patients with SCD. Asthma, a prevalent comorbidity in SCD, has been implicated in worsening disease outcomes, including increased ACS risk. This systematic review and meta‑analysis aimed to evaluate the association between asthma and ACS in patients with SCD by synthesizing data from observational studies. A comprehensive search of the PubMed, Cochrane Library and Scopus databases, as well as gray literature, identified 13 eligible studies, 12 of which were included in the quantitative synthesis. The meta‑analysis demonstrated that patients with SCD and asthma had a significantly higher risk of ACS (risk ratio=2.27, 95% confidence interval: 1.61‑3.20, P=0.0003) compared to patients with SCD without asthma, with substantial heterogeneity observed (I²=74%). The underlying mechanisms linking asthma and ACS may include chronic airway inflammation, increased susceptibility to infections, oxidative stress and endothelial dysfunction. Despite variations in study design and population characteristics, the findings underscore the need for vigilant asthma management in patients with SCD to mitigate ACS risk. Further research is required to elucidate the pathophysiological interactions and develop targeted interventions to improve patient outcomes.