Support for PI

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Primary immune deficiency (PI) is actually the name for a group of over 150 diseases1 that:

  • Are usually inherited
  • Are caused by errors in the genes of the cells that make up the immune system
  • Have a wide range of symptoms from mild to severe

People with primary immune deficiency diseases have immune systems that lack one or more types of immune tissues, proteins, or cells.

The immune system protects the body from germs like bacteria and viruses. So, if part of your immune system is missing or not functioning correctly, you’ll be more likely to get infections, and you may take longer to recover, even with antibiotic treatment. You may have recurring infections.

Susceptibility to infection is one of the most common symptoms of primary immune deficiency. It can often be seen early in a child’s life. However, signs of immune deficiency may also occur in older children, teenagers, or adults.

Immune System
Discover how your immune system’s organs, tissues, and cells work to protect you from infection.
Symptoms of PI
Learn the signs that indicate you should be tested for PI.
Talking to Your Doctor
Questions to ask your doctor about testing for PI.
Types of PI
Read about types of PI, and how they differ in symptoms and treatment.
Read common questions about PI.
Glossary Terms
Gene: A unit of hereditary information that occupies a fixed position (locus) on a chromosome. Genes are formed from DNA and are responsible for the inherited characteristics that distinguish one individual from another.
Immune system: A complex system comprised of many organs and cells that defends the body against viruses, bacteria and other foreign substances.
  1. Geha R, Notarangelo L, Casanova JL, Conley ME, Chapel ME, Fischer A, Hammerstrom L, Nonoyama S, Ochs H, Puck J, Roifman C, Seger R, Wedgwood J. Primary immunodeficiency diseases: an update from the International Union of Immunological Societies Primary Immunodeficiency Diseases Classification Committee Meeting. Journal of Allergy and Clinical Immunology 2007; 120(4):776-794.