lung and airway disorders
Pulmonary Alveolar Proteinosis
Diagnosis of Pulmonary Alveolar Proteinosis
Chest computed tomography Bronchoalveolar lavage Doctors do several tests, including a chest x-ray and computed tomography (CT) of the chest, and other tests to determine how well the lungs are functioning. A chest x-ray shows evidence of plugging of the alveoli. Computed tomography (CT) shows this plugging and other changes that suggest pulmonary alveolar proteinosis. Pulmonary Function Testing (PFT) reveals that the volume of air that the lungs can hold is abnormally small. Tests show low levels of oxygen in the blood, at first only during exercise but later also when the person is at rest. The elimination of carbon dioxide from the lungs may be impaired. Blood test results may show abnormalities that occur in pulmonary alveolar proteinosis as well as in other disorders. For example, levels of some substances (for example, lactic dehydrogenase, red blood cells, serum surfactant proteins, and gamma globulin) are often elevated. Tests for granulocyte macrophage colony stimulating factor (GM-CSF) antibodies can also be performed to help support the diagnosis of an autoimmune form of pulmonary alveolar proteinosis. To make a definitive diagnosis of pulmonary alveolar proteinosis, doctors examine a sample of the fluid from the alveoli. To obtain a sample, doctors use a Bronchoscopy to wash segments of the lung with a salt-water solution and then collect the washings (bronchoalveolar lavage). The washings are often opaque or milky because the fluid is rich in protein and fats. Sometimes doctors obtain a lung tissue sample for microscopic examination (lung biopsy) during bronchoscopy. Occasionally, a larger sample is needed, which must be removed surgically. 