What is PAP?
Our lungs are responsible for oxygenating blood and removing carbon dioxide from the bloodstream. This process normally happens in a matter of milliseconds every time we breathe in and out. This exchange occurs in the alveoli in the lungs (air sacs).
Oxygen and carbon dioxide pass through the alveoli walls, which are normally protected by a thin film of surfactant - a protein- and lipid-based material, which the alveoli produce. If the alveoli produce too much of this fluid, the result is pulmonary alveolar proteinosis.
Facts and Symptoms of Pulmonary Alveolar Proteinosis
According to rarediseasesnetwork.epi.usf.edu, pulmonary alveolar proteinosis affects less than 10,000 patients in the United States. It does not discriminate between male or female, young or old, but is most commonly found in people aged 20-40.
Of the three types of PAP - primary (idiopathic), secondary, and congenital - idiopathic is the most common form and is responsible for 90 percent of cases. Secondary PAP usually develops as a result of exposure to toxic inhalants. Congenital PAP affects infants who have a genetic disorder that interferes with the production or break down of surfactant.
Because oxygen is no longer being sufficiently supplied to the blood, most patients experience shortness of breath with exertion. Some may experience breathing difficulties at rest, as well.
Other symptoms include:
- weight loss
- low-grade fever
- non-productive cough
- clubbing of fingers (advanced stages)
- cyanosis (bluish tinge) of fingernails
Diagnosis and Treatment of PAP
Diagnostic tests include blood tests, chest X-rays (computed tomography - CT), bronchoscopy (to retrieve fluid for fluid analysis or biopsy), and lung biopsy, although the latter is not normally required for most patients.
Idiopathic PAP develops without a person knowing until sufficient surfactant has built up and they begin to experience a feeling of breathlessness.