Pulmonary alveolar proteinosis
Pulmonary alveolar proteinosis is a rare disease in which a type of protein builds up in the air sacs (alveoli) of the lungs, making breathing difficult.
Alveolar proteinosis; Pulmonary alveolar phospholipoproteinosis
In some cases, the cause of pulmonary alveolar proteinosis is unknown. In others, it occurs with lung infection or an immune problem. It also can occur with cancers of the blood system, and after exposure to high levels of environmental substances, such as silica or aluminum dust.
People between 30 and 50 years old are affected. The condition is seen in men more often than in women. A form of the disorder is present at birth (congenital).
Symptoms may include any of the following:
Sometimes there are no symptoms.
Exams and Tests
The doctor will listen to the lungs with a stethoscope and may hear crackles (rales) in the lungs. Often, the physical examination is normal.
The following tests may be done:
- Bronchoscopy with saline wash of the lungs (lavage)
- Chest x-ray
- High-resolution CT scan of the chest
- Pulmonary function tests
- Open lung biopsy (surgical biopsy)
Treatment involves washing out the protein substance from the lung (whole-lung lavage) from time to time. Some persons may need a lung transplant. Avoiding dusts that might have caused the condition is also recommended.
Another treatment that may be tried is a blood-stimulating drug called granulocyte-macrophage colony stimulating factor (GM-CSF), which is lacking in some persons with alveolar proteinosis.
Some people with this condition go into remission. Others have respiratory failure that gets worse, and they may need a lung transplant. Up to 25% of people with this condition die within 5 years of being diagnosed.
When to Contact a Medical Professional
Call your health care provider if you develop serious breathing symptoms. Shortness of breath that gets worse over time may signal that your condition is developing into a medical emergency.
Levine SM. Alveolar filling disorders. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine. 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 91.
Trapnell BC, Luisetti M. Pulmonary alveolar proteinosis syndrome. In: Broaddus VC, Mason RJ, Ernst JD, et al, eds. Murray and Nadel's Textbook of Respiratory Medicine. 6th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 70.
Reviewed By: Denis Hadjiliadis, MD, MHS, Associate Professor of Medicine, Pulmonary, Allergy, and Critical Care, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.