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Lung diseases

Pulmonary alveolar proteinosis (PAP)

A rare disease in which a fatty, protein-rich substance builds up in the air sacs of the lungs. Less oxygen passes into the blood. Shortness of breath increases slowly.

Not part of the panel of Türkiye's National Newborn Screening Programme (heel-prick test). Source

Prepare an emergency card

This page is translated from the Turkish original.

This disease is followed through the “Lung diseases” group.

Understanding the disease

This section has not yet been reviewed by a physician. It summarises patient information from sources such as MedlinePlus, Orphanet and the NHS in plain language. The disease can differ from person to person; talk to your doctor about diagnosis and treatment.

What happens in this disease?

The air sacs contain a slippery substance called surfactant. Normally, special cleaning cells remove any excess. In this disease, this cleaning does not work and the substance builds up. Oxygen cannot pass well into the blood. The most common form is autoimmune; the body makes antibodies against a substance that stimulates the cleaning cells.

Which symptoms can occur?

Some people have no symptoms at all.

  • Slowly increasing shortness of breath (most common)
  • Cough
  • Tiredness and weight loss
  • Fever if there is a lung infection
  • Bluish lips and fingers in advanced stages

How is it diagnosed?

A CT scan of the lungs can show a typical pattern. With a bronchoscopy, washing fluid is taken from the lungs and examined. An antibody blood test shows the autoimmune form. In inherited forms, a genetic test is done.

Treatment and care

The main treatment is whole lung lavage. In this procedure, the built-up substance is washed out of the lungs. For some people once is enough; others need it again. Protection from the dust that causes it is important. An inhaled treatment is being studied; the approval process is ongoing. In severe cases, a lung transplant may be considered. The doctor who follows the disease decides which treatment is suitable.

For the family: inheritance and genetic counselling

The most common, autoimmune form is not inherited. The inherited form is very rare and is passed on recessively. For a carrier couple, the chance of an affected child in each pregnancy is 1 in 4. This chance can be higher when parents are related by blood. In forms present from birth, inheritance depends on the gene. Genetic counselling is recommended.

Source: MedlinePlus: Pulmonary alveolar proteinosis · NORD: Pulmonary Alveolar Proteinosis · Orphanet: Autoimmune pulmonary alveolar proteinosis (ORPHA:747)

Key facts

How common is it?
Prevalence: 1-9 per 1 000 000 (Worldwide)
When does it usually start?
Adolescence, Adulthood, Childhood
Gene(s) involved
HLA-DRB1
Reliable sources
Orphanet

These facts are taken from Orphanet and MedlinePlus records (last checked: October 7, 2026). Frequency values are approximate ranges.

You are not alone: patient associations in Türkiye

Non-profit patient and family organizations in Türkiye working on this disease or disease group. Links are for information; Doktorclub is not affiliated with these organizations and does not endorse them.

We could not find a patient association specific to this disease.

For all rare diseases: Nadir Hastalıklar Federasyonu

Support and help

Doktorclub does not diagnose, recommend treatments or refer you to hospitals or doctors. These pages are meant to help you talk with your doctor.

News about PAP

Clinical trials (ClinicalTrials.gov)

A clinical trial is a regulated study that tests whether a new treatment is safe and whether it works, in patients who volunteer. Most trials look for a certain age, genetic change and health condition. Taking part is voluntary.

This list is not a treatment recommendation. Treatments tested in phase 1–3 trials are investigational (experimental): their efficacy and safety have not yet been proven and they are not approved treatments. Taking part depends on each trial’s criteria and a physician’s assessment; the first step is to talk to the doctor who manages your care.

Questions you can ask your doctor

  • Could this trial be suitable for us?
  • If we take part, how would current treatment and check-ups be affected?
  • Where does the trial take place, and how are travel and accommodation handled?
  • What happens if we want to leave the trial?

ClinicalTrials.gov lists 5 active interventional studies for this disease. 2 are recruiting now; 1 has a site in Türkiye. Last checked: October 7, 2026.

Selected records (studies with a site in Türkiye first):

See all studies on ClinicalTrials.gov · Joining clinical trials

Lung diseases: other news

Medical codes (for talking with your doctor and finding sources)

These codes identify the disease in international classifications and databases. They can help when you talk with your doctor or look for reliable sources.

Orphanet code: ORPHA:747

No separate ICD-11 code; WHO classifies this disease under: CB04.31

Codes checked against WHO ICD-11 and Orphanet on October 7, 2026.

This page provides general information and does not replace diagnosis or treatment. Talk to your doctor about symptoms, diagnosis and treatment.

The information on these pages is for general information only and does not replace medical advice. Talk to your doctor about diagnosis and treatment decisions. In an emergency in Türkiye, call 112.

Every update is based on an open source and labeled with its level of evidence. No advertising and no drug brand names. Our scientific principles

This page was translated from Turkish by the Doktorclub editorial team.