Lung-specific protein antigen (e.g., surfactant protein) in urine, measured by immunoassay

What This Test Measures

The test looks for specific proteins (like surfactant proteins A and B) that are normally found in lung tissue. When the lungs are injured or inflamed, these proteins can enter the bloodstream and appear in urine. This test helps doctors assess conditions such as pneumonia, lung infections, or other lung diseases.

Why It Might Be Ordered

Your healthcare provider may order this test if you have symptoms like shortness of breath, persistent cough, or if you’ve been diagnosed with a lung condition. It’s also used in research or specialized settings to monitor lung health in certain clinical scenarios.

Common Conditions Monitored

This test is less commonly used in routine care but may be part of specialized evaluations for conditions like acute respiratory distress syndrome (ARDS), severe pneumonia, or interstitial lung diseases.

Sample Collection and Preparation

A clean-catch urine sample is typically collected in the morning. You may be instructed to wash your hands and clean the urinary opening before urinating into a sterile container. The sample is then sent to a lab for analysis.