Pulmonary alveolar proteinosis is a lung condition marked by accumulation of protein in the lung's air sacs, which are called alveoli. It occurs only rarely and can affect men, women and children. This condition is more likely to develop in people between the ages of 30 and 50 years old, but it can be present when a child is born. Males are more likely to develop this condition.
Patients with pulmonary alveolar proteinosis may experience such symptoms as extreme tiredness, weight loss, dry cough and a low-grade fever. The condition may also cause patients to feel short of breath, especially when they exert themselves, and have a general feeling of being under the weather. Some people also experience coughing, which may produce mucus or blood, or blue discoloration of the skin.
Often, a person with pulmonary alveolar proteinosis develops symptoms gradually, and some don’t have symptoms at all. In fact, even those who have developed significant abnormalities in their lungs, as shown by diagnostic imaging, may not have symptoms. A doctor may perform diagnostic testing that reveals the presence of the condition because the patient tells the doctor about his symptoms or because x-rays taken for other reasons reveal lung abnormalities.
No one knows the exact causes of pulmonary alveolar proteinosis, but it develops when a substance in the lungs, called a surfactant, builds up to high levels. The surfactant normally lines the lungs, but when it reaches abnormal levels, it causes shortness of breath and other symptoms. Infections, immune system abnormalities and exposure to extremely high levels of dust may play a role in its development. Genetic defects may be at fault when a child is born with the condition.
In a small percentage of patients, pulmonary alveolar proteinosis may resolve on its own, and those with mild or absent symptoms may not require treatment at all. A procedure called whole lung lavage may be used to treat patients. This involves ventilating one lung while filling the other with saline solution and draining it repeatedly. The procedure is performed while the patient is on general anesthesia and is used to clean the air spaces within the lungs. Doctors may treat both lungs on the same day or provide separate appointments for each lung.
Patients may require repeated lavage treatments, but some get better after a single treatment. Most people with the condition survive for at least five years after diagnosis. When death occurs, it’s usually due to respiratory failure, a syndrome marked by blood oxygen levels that fall too low or carbon dioxide levels that rise too high.
