Bronchial Hyperreactivity in Children With Sickle Cell Thalassemia

Abstract

Background

: Pulmonary damage and frequent infections are common in children with thalassemia or sickle-cell disease, an inherited disorder of hemoglobin structure.

Objective

: Although bronchial hyperreactivity is widely used in the assessment of other pulmonary diseases, such as asthma, it has not previously been studied in relation to sickle-cell disease.

Methods

: We investigated the bronchial response to a methacholine inhalation test in a group of 23 children with compound heterozygous sickle-cell disease (βsβ+th/βsβoth), comparing these results with reference data from a group of normal children, obtained in an earlier control study. Asthmatic patients were excluded on the basis of diagnostic history, past and present therapies, clinical assessment, and evidence of basal FEV₁ less than 80% of that predicted for the age (range 6-12 years). Increasing doses of methacholine were inhaled at 2-min intervals, allowing a cumulative dose range of 30–2490 μg and measuring FEV₁ after each inhalation in order to determine the dose of methacholine producing a 20% fall in FEV₁ (PD₂₀ value). Bronchoconstriction was reversed at this point, or at the end of the test, by inhalation of 100 μg salbutamol.

Results

: No adverse reactions were observed as a result of the test procedure. In comparison to the normal children, we found a significant reduction in basal FEV₁ in the study group, together with a significant increase in the reversibility of methacholine-induced bronchoconstriction with salbutamol. There was also an increased frequency of positive methacholine tests in the children with sickle-cell disease.

Conclusion

: The results of the methacholine inhalation test demonstrated a significant degree of bronchial hyperreactivity in children with sickle-cell disease.