Airway lesions and superoxide dismutase (SOD) distribution in bronchopulmonary dysplasia (BPD)

We examined 71 cases of bronchopulmonary dysplasia (BPD) at autopsy and divided them into five groups on the basis of the patients' survival time, studying on the histological changes in the airways for the purpose of clarifying the pathogenesis of BPD from hyaline membrane disease (HMD). Furthermore, bronchiolar occlusion was classified into four types: secretion, obliterative bronchiolitis, intraluminal plug, and hyperplasia of bronchiolar components. The same occlusive findings as in bronchioli and hyaline membrane were observed from respiratory bronchioles to alveolar ducts. However, there was no obvious correlation between airway lesions and accompanying alveolar lesions excepts three cases of obliterative bronchiolitis. Furthermore, immunohistochemical studies with anti-human SOD antibodies were performed. Mn-SOD was positive for alveolar macrophages in longer surviving infants without significant correlation with histological variation, whereas slightly positive or negative in infants who died within 1 week; CuZn-SOD was rarely positive in any cases. These results is highly correlated to the pathogenesis of BPD and to its pathological advancement with its clinical course.