Bronchiolitis Obliterans in Children: A Single Institution Experience / 소아알레르기및호흡기학회지

ABSTRACT

PURPOSE: Although bronchiolitis obliterans (BO) most often occurs after infection, the incidence of post-transplant BO has recently increased due to the increase of organ and bone marrow transplantation. However, there is limited data on the responses to treatment using measurements of pulmonary function in patients with BO. This study aimed to describe clinical characteristics and pulmonary function in children with BO from a single institute and to compare the responses according to treatment modalities in children with post-infectious BO. METHODS: This study was conducted on 22 children who were diagnosed with BO from January 2005 to December 2010. Based on the medical chart, treatment courses and prognosis of the patients were examined retrospectively. The severity of clinical symptoms was determined by the Denver symptom score, basal pulmonary function, and responses to bronchodilators; all parameters were measured and compared between the time of diagnoses and follow-up six months later. RESULTS: The mean age of the patients when diagnosed with BO was 8.3+/-6.6 years; of those patients, sixteen were boys and six were girls. Nineteen cases of BO were associated with acute infection, and the most common cause of those cases was adenovirus. Three cases of BO occurred following allogeneic bone marrow transplantation for acute myelogenous leukemia. The Denver symptom scores at the time of diagnosis were averaged to 3.95+/-0.63, and the average symptom score after follow-up of six months was 2.15+/-0.73. The averages of the % forced vital capacity (FVC), % forced expiratory volume in 1 second (FEV1), and % forced expiratory flow, midexpiratory phase (FEF25-75%) at the time of diagnosis were 69+/-13%, 40.5+/-12.7%, and 17.6+/-7.8%, respectively, and FEV1/FVC was 56.7+/-10.9%. The averages of %FVC, % FEV1, and %FEF25-75% six months after diagnosis were 78+/-17.3%, 62.5+/-16.5%, and 35.6+/-9.5%, respectively, and FEV1/FVC was improved to 70.7+/-18.9%. Symptom scores of the group treated with high dose systemic steroids decreased significantly compared to those of the group treated with inhaled corticosteroids (P<0.05). Likewise, improvement of FEV1/FVC after treatment was greater in the group treated with high dose systemic steroids than in the group treated with inhaled corticosteroids (P<0.05). CONCLUSION: Infections are the more frequent causes of BO in our institute, and adenovirus ismost common. Six-month follow-up study results suggest high dose systemic steroids could lead to better improvement of clinical symptoms and pulmonary function in children with post-infectious BO.