Idiopathic pulmonary hemosiderosis. Ultrastructural studies and response to azathioprine

Two boys are presented who fulfulled criteria for a diagnosis of idiopathic pulmonary hemosiderosis. A lung biopsy specimen from the first patient showed alveolar capillary basement membrane abnormalities, together with abnormalities of capillary endothelial cells and hemosiderin laden macrophages. A lung biopsy specimen from the second patient showed mainly capillary endothelial abnormalities and interstitial fibrosis. Both patients had a noticeable improvement in symptoms and relative stabilization of their roentgenographic and pulmonary function abnormalities following azathioprine therapy.