Asthma in sickle cell disease.

In recent years, evidence has increased that asthma predisposes to complications of sickle cell disease (SCD), such as pain crises, acute chest syndrome, pulmonary hypertension, and stroke, and is associated with increased mortality. An obstructive pattern of pulmonary function, along with a higher-than-expected prevalence of airway hyper-responsiveness (AHR) when compared to the general population, has led some researchers to suspect that underlying hemolysis may contribute to the development of a pulmonary disease similar to asthma in patients with SCD. While the pathophysiologic mechanism in atopic asthma involves up-regulation of Th2 cytokines, mast cell- and eosinophil-driven inflammation, plus increased activity of inducible nitric oxide synthase (iNOS) and arginase in airway epithelium resulting in obstructive changes and AHR, the exact mechanisms of AHR, obstructive and restrictive lung disease in SCD is unclear.

Quantitative air-trapping analysis in children with mild cystic fibrosis lung disease.

The purpose of this study was to compare quantitative computed tomography air trapping (AT) and pulmonary function measurements between subjects with mild cystic fibrosis lung disease (MCF; forced expiratory volume in 1 sec (FEV1) > 70% predicted) and normal age-matched controls. Quantitative AT measurements at different levels of expiration were evaluated. Ten subjects from the MCF group and 10 normal subjects underwent inspiratory and expiratory spirometer-triggered chest high-resolution computed tomography (HRCT) and pulmonary function tests.