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Pneumocystis Jirovecii (Tissue, Fluid)

Does this test have other names?

 P. jirovecii, PCP, pneumocystis pneumonia

What is this test?

This test looks for P. jirovecii fungus in your lung tissue or in fluid from a lung.

P. jirovecii causes pneumocystis pneumonia. It is spread through the air from someone who is infected with it. But most people who are infected with P. jirovecii don't get pneumonia. People who do get it often have a weakened immune system. This can be because of:

  • AIDS/HIV, cancer, or another health problem

  • Medicines that can weaken the immune system

  • Organ or stem-cell transplant

 P. jirovecii used to be known as Pneumocystis carinii.

Why do I need this test?

You may need this test if your healthcare provider believes that you have pneumonia caused by this fungus. Symptoms include:

  • Trouble breathing, especially when you exercise

  • Coughing, often dry

  • Fever

  • Chills

  • Severe tiredness (fatigue)

  • Tightness or pain in the chest

  • Collapsed lung (spontaneous pneumothorax)

What other tests might I have along with this test?

You may also need other tests to help diagnose pneumonia. These include:

  • Blood tests to look for infections in your blood

  • Arterial blood gases

  • X-ray or CT scan of your chest

  • Sputum test to look at the mucus that you have coughed up

  • Bronchoscopy to look inside your lungs

  • Thoracentesis to look at the fluid collecting in the space around your lungs

  • Pulse oximetry to measure the oxygen in your blood

What do my test results mean?

Test results may vary depending on your age, gender, health history, the method used for the test, and other things. Your test results may not mean you have a problem. Ask your healthcare provider what your test results mean for you. 

Normal results are negative, meaning that no P. jirovecii was found and that you don't have pneumonia caused by this fungus.

Positive results mean that P. jirovecii was found and that you may have pneumocystis pneumonia. But some healthy people may carry the organism in their lungs without being sick.

If you are sick but your test results don't find P. jirovecii, you may have pneumonia caused by another organism.

How is this test done?

This test is done with a sample of fluid or tissue from your lungs. Your healthcare provider will collect lung fluid in a procedure called a bronchoalveolar lavage. They will place a long, flexible tube with a camera on the end (bronchoscope) through your mouth or nose and into your lungs. The provider will gently spray saltwater (saline) into an area of lung to dislodge P. jirovecii and then collect the fluid.

If a biopsy is needed, your provider will also use the bronchoscope to collect a tissue sample. They may insert a needle or a tool called forceps to collect the sample.

Does this test pose any risks?

This test may pose some risks, including:

  • Bleeding from your respiratory tract when your healthcare provider takes the sample

  • Hoarseness or sore throat

  • Low oxygen levels

  • Pain where the needle or tube was inserted

  • Infection

  • Collapsed lung, but this is quite rare

What might affect my test results?

Other factors aren't likely to affect your results.

How do I get ready for this test?

Follow any directions you are given for not eating or drinking before the test. Tell your healthcare provider about all medicines, herbs, vitamins, and supplements you are taking. This includes medicines that don't need a prescription and any illegal drugs you may use.

Medical Reviewers:

  • Chad Haldeman-Englert MD
  • Maryann Foley RN BSN
  • Raymond Turley Jr PA-C