About Primary Immunodeficiency (PI)
What is PI?
PI is an umbrella term used to describe a group of more than 400 disorders that are caused by an immune system that is missing parts or does not work correctly. The immune system in people with PI does not make enough antibodies to protect them from infection. So, they may take longer to recover from infections. Some people with PI also have infections that return often or that are unusually severe.
PI can't be caught or spread. It's not contagious. Usually PI is inherited, which means it may run in families. Some types of PI may be caused by both genetic and environmental factors. PI is different from secondary immunodeficiencies, which are caused by other conditions (such as diseases or consequences of certain types of medications).
PI can affect anyone, regardless of age or gender.
- Due to the immune system not working the way it should
- Sometimes inherited/genetic
- Diagnosed in men and women of all ages
PI is not:
- A secondary immune deficiency (such as HIV/AIDS)
- An autoimmune disease
How common is PI?
PI was once thought to be very rare, but now it is considered more common. As PI awareness with physicians continues to grow, more people are being diagnosed. In fact, PI can affect as many as 1 in 1200 people, which is more common than cystic fibrosis.
PI is more common than people think in the United States...
What about undiagnosed PI?
Although some types of PI are diagnosed at birth or soon after, other types are often not recognized and diagnosed until later in life. That means some people with PI live many years with frequent infections before they are accurately diagnosed. This may happen because some types of PI are mistaken for a variety of conditions such as skin rashes, diarrhea, or allergies.
Average time from symptom onset to PI diagnosis*
People with undiagnosed PI tend to have a poorer quality of life and may experience one or more of the following:
- Severe infections
- Days with chronic infections
- Visits to physicians and/or emergency
- Days spent in the hospital
- Days of school and/or work
- Organ damage
Testing for PI
When testing for PI, doctors will typically ask about your family history and do a physical exam. They may order blood tests to check if your red and white blood cells, antibodies, and immune system are working properly. These tests are important for your doctor to confirm a diagnosis of PI.
If you have been diagnosed, these tests help determine which type of PI you may have. Once the PI diagnosis is confirmed, your doctor will talk to you about the different treatment options available and work with you to identify the option that best meets your medical needs and personal preferences.