Prevalence and reversibility of lower airway obstruction in children with sickle cell disease

To determine the prevalence and reversibility of lower airway obstruction (LAO) in children and adolescents with hemoglobin SS sickle cell disease (HbSS SCD).

Retrospective evaluation of lung function in a cross-section of 35 African American and 28 Hispanic children and adolescents with HbSS SCD. Lung function was evaluated with maximal respiratory flow-volume curves and body plethysmography. Each patient was assigned to 1 of 3 patterns of lung function (normal, obstructive, or restrictive). Airway hyperresponsiveness was assessed by means of a trial with bronchodilator.

Normal pattern was detected in 57% of the patients, LAO in 35%, and restrictive lung disease in 8%. Positive response to bronchodilator was documented in 30% of those with normal pattern of lung function, 78% in those with LAO, and 67% of those with restrictive lung disease. The pattern of lung function was not associated with race or with history of vaso-occlusive crises, acute chest syndrome, reactive airways disease/asthma, or long-term transfusion therapy.

Obstructive lung disease possibly precedes the development of restrictive lung disease, and airway reactivity may be part of the pathogenic mechanism.