Airway hyperreactivity in children with sickle cell disease

MA Leong, C Dampier, L Varlotta, JL Allen - The Journal of pediatrics, 1997 - Elsevier
MA Leong, C Dampier, L Varlotta, JL Allen
The Journal of pediatrics, 1997Elsevier
Progressive restrictive defect with increasing age, obstructive lung disease, and
bronchodilator responsiveness have been reported in sickle cell disease (SCD). Because
airway hyperreactivity (AHR) can be underestimated when assessed by bronchodilator
responsiveness in patients with normal baseline lung function, the aim of this study was to
investigate the prevalence of AHR in SCD by cold-air bronchial provocation testing, and to
assess whether AHR can be present in symptom-free patients with SCD. Forty patients aged …
Progressive restrictive defect with increasing age, obstructive lung disease, and bronchodilator responsiveness have been reported in sickle cell disease (SCD). Because airway hyperreactivity (AHR) can be underestimated when assessed by bronchodilator responsiveness in patients with normal baseline lung function, the aim of this study was to investigate the prevalence of AHR in SCD by cold-air bronchial provocation testing, and to assess whether AHR can be present in symptom-free patients with SCD. Forty patients aged 6 to 19 years (mean, 10.7 years ± 3.5 SD) performed pulmonary function tests. Eighteen were known to have a history of reactive airway disease (RAD group), and 22 had no known history of RAD (non-RAD group). A control group, aged 6 to 17 years (mean, 10.5 ± 3.1 years), consisted of 10 siblings of the non-RAD SCD group. There were no significant differences in age and height among the groups. If the forced expiratory volume in 1 second (FEV 1 ) was greater than 70%, cold air challenge (CACh) was performed; if the FEV 1 was less than 70%, aerosolized bronchodilator therapy was given. A decrease in FEV 1 of more than 10% after CACh or an increase in FEV 1 of 12% or greater after bronchodilator inhalation was considered evidence of AHR. In the RAD group, the total lung capacity was 88.9% ± 14.0% of race-corrected predicted values, the forced vital capacity was 91.2% ± 12.6%, and FEV 1 was 85.3% ± 16.2%. The mean maximal percent fall in FEV 1 after CACh ( n = 13) was 18.5% ± 9.6% and was greater than 10% in 11 of 13 patients. The mean increase in FEV 1 after bronchodilator therapy ( n = 5) was 11.5% ± 8.3%, and it was greater than 12% in 4 of 5 patients. In the non-RAD group the baseline total lung capacity was 101.6% ± 11.7%, forced vital capacity was 95.5% ± 10.2%, and FEV 1 was 93.3% ± 13.2%. The mean maximal percent fall in FEV 1 after CACh ( n = 19) was 14.1% ± 8.8% and was greater than 10% in 13 of 19 patients. The mean increase in FEV 1 after bronchodilator therapy ( n = 3) was 14.7% ± 11.3%, and was 12% or greater in 1 of 3 patients. In the control group the baseline total lung capacity was 105.7% ± 12.1%, forced vital capacity was 96.2% ± 11.1%, and FEV 1 was 92.9% ± 10.3%. The mean maximal percent fall in FEV 1 was 5.0% ± 2.5%, and was greater than 10% in none of 10 patients. The prevalence of AHR in the control group, the RAD group, and the non-RAD group was zero, 83%, and 64%, respectively ( p < 0.0001). The overall prevalence in the SCD group was 73%. We conclude that there is a high prevalence of AHR in children with SCD and that airway hyperreactivity may exist in patients with SCD even in the absence of the clinical symptoms of RAD. AHR may be a significant component of sickle cell lung disease. (J Pediatr 1997;131:278-83 )
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