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.

Causes

In some cases, the cause of pulmonary alveolar proteinosis is unknown. In others, it is associated with infection or an immune problem. It also can occur with cancers of the blood system, and after exposure to high levels of dust.

This rare disorder generally affects people 30 - 50 years old and is seen in men more often than in women. A form of the disorder is present at birth (congenital).

Symptoms

• Cough
• Unintentional weight loss
• Fatigue
• Shortness of breath
• Fever

There may be no symptoms.

Exams and Tests

The doctor may hear crackles in the lungs. Often, the physical examination is normal.

The following tests may be done:

• Chest x-ray
• Arterial blood gases test
• Pulmonary function tests
• High-resolution CT scan of the chest
• Bronchoscopy with saline wash of the lungs (lavage)

Treatment

Treatment consists of periodically washing out the protein substance from the lung (whole-lung lavage). A lung transplant may be recommended for certain patients with this disease.

Recently, experimental data have showed some improvement with treatment using a blood-stimulating medication, which is known to be deficient in some patients who develop alveolar proteinosis.

Outlook (Prognosis)

Some people with this condition go into remission. Others develop worsening respiratory failure.

When to Contact a Medical Professional

Call your health care provider if you develop symptoms. Progressively worsening shortness of breath may signal that your condition is developing into a more serious medical emergency.

Alternative Names

Alveolar proteinosis