| Definition: |
A lung disease with an unknown etiology affecting the lungs which results in bleeding from tiny alveolar capillaries. Examination of sputum and bronchoalveolar lavage fluid can disclose hemosiderin-laden alveolar macrophages (siderophages), and the lung biopsy shows numerous siderophages in the alveoli. Alveolar hemorrhage is characterized by hemoptysis, shortness of breath, alveolar infiltrates on chest radiograph, and various degrees of anaemia. Following a bleeding episode, the alveolar macrophages convert the hemoglobin's iron into hemosiderin within 36-72h. |