Pulmonary alveolar proteinosis (PAP) is a rare lung disorder affecting approximately seven in one million people in the US.

Autoimmune Pulmonary Alveolar Proteinosis (aPAP) is the most common form of this disorder; representing 85% to 90% of all PAP diagnoses. 1

aPAP occurs when proteins and other materials, together called surfactant, build up in the air sacs of the lungs, or alveoli, blocking the airways. This build-up is believed to be caused by a problem with granulocyte-macrophage colony-stimulating factor (GM-CSF), the substance needed for development of certain immune cells in the lung. Without these cells the alveoli cannot clear materials, leading to the build-up. 2

The disorder, most often found in individuals aged 30 to 60, is characterized by shortness of breath or difficulty breathing, and, in certain cases, can make even the most basic everyday tasks – getting dressed, showering, making dinner – extremely challenging. 1


While aPAP itself is a common form of the PAP disease family, it can be very difficult to diagnose. A recent study indicated the diagnosis can be delayed by more than a year following the onset of symptoms. 3

Current diagnostic options are limited and largely ineffective; they include a number of invasive procedures such as bronchoscopies, transbronchial biopsies, and open-lung biopsies, which can be life-threatening for some patients. 1

Fortunately, a relatively new non-invasive blood test now exists for routine clinical use to diagnose patients who may be living with aPAP – and it is 100% accurate. 4, 5 This test is currently available from two medical centers in the US; Cincinnati Children’s Hospital Medical Center and National Jewish Health in Denver, CO.