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Pulmonary Alveolar Proteinosis (PAP) (anti-GMCSF)

What is pulmonary alveolar proteinosis (PAP)? 

PAP happens when surfactant builds up in the tiny air sacs (alveoli) of the lungs.
Surfactant is important for normal lungs. Read more about normal surfactant here.
PAP can happen when the lungs make too much surfactant. It can also happen if the lungs can’t clear up the old
surfactant. The extra surfactant makes it harder for the lungs to move oxygen and carbon
dioxide. It can also cause lung inflammation and injury.
All forms of PAP in children are rare. It can affect 2 patients out of 1 million under age 18.

In babies and young children, PAP is usually caused by gene mutations. In older children and
adults, PAP is usually caused by an autoimmune disease. In both types there is a problem with surfactant build up or clearance. Other causes of PAP include infection, immune problems,
organ or bone marrow transplant, rheumatologic disease, lymphoma, and leukemia. Sometimes
the reason for PAP is never found.

*Video produced by NORD and RARE EDU.


PAP is possible when babies or children have trouble breathing and abnormal imaging. Several studies may need to be done. These include:


Treatment of PAP depends on the cause and age of the child. The main focus is to support breathing and nutrition. Children may need oxygen to help keep their oxygen levels normal. They may need positive pressure to help them breathe oxygen in and carbon dioxide out. Children who are very sick with PAP may need the intensive care unit for help breathing.

Some doctors may perform a whole lung lavage if symptoms are severe. A whole lung lavage is a special form of bronchoscopy done in the hospital. Each lung is flushed out separately with several liters of fluid to get rid of the extra surfactant. Sometimes repeat procedures might be needed. For some types of PAP, a medication called GM-CSF could be given. This medicine helps the body clear the extra surfactant. It works by increasing activity of the lung-cleaning cells(macrophages). GM-CSF can be given by an injection or inhaled into the lungs. There are other medications that are still under research and may be used.

Your medical team will help decide which medicines to use and how long to use them.

What does PAP mean for my child?

PAP can cause different levels of illness in children. Some children only have mild problems and may not be diagnosed until they are several years old. Their symptoms may be well-controlled and they may not need oxygen or other breathing support. Children with more severe disease may need oxygen or positive pressure during their whole life.

It is important to protect your child’s lungs from infection by making sure they get the recommended vaccines.

What to watch out for:

  • If your child is working hard to breathe, talk to a health care provider. If possible. ask to see a lung specialist who is experienced with these conditions.
  • Try to prevent infections from common childhood illnesses. Wash your hands often and ask your friends and family to let you know if they are sick before they are around your child.
  • Get your child’s vaccines and yearly flu shot.

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Author(s): Demet Toprak  Reviewer(s): Katelyn Krivchenia  Version: 1.0