BRONCHIAL HYPERREACTIVITY IN CHILDREN WITH SICKLE-CELL THALASSEMIA

Background: Pulmonary damage and frequent infections are common in chi ldren with thalassemia or sickle-cell disease, an inherited disorder o f 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 methacho line inhalation test in a group of 23 children with compound heterozyg ous sickle-cell disease (beta s beta+th/beta s beta oth), comparing th ese results with reference data from a group of normal children, obtai ned 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 30-24 90 mu g and measuring FEV1 after each inhalation in order to determine the dose of methacholine producing a 20% fall in FEV1 (PD20 value). B ronchoconstriction was reversed at this point, or at the end of the te st, by inhalation of 100 mu g salbutamol. Results: No adverse reaction s were observed as a result of the test procedure. In comparison to th e normal children, we found a significant reduction in basal FEV1 in t he study group, together with a significant increase in the reversibil ity 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 met hacholine inhalation test demonstrated a significant degree of bronchi al hyperreactivity in children with sickle-cell disease. (Pediatr Asth ma Allergy Immunol 1997;11[2]: 103-109.)