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Updated on May 15, 2025
Primary immunodeficiency (PI) refers to a long list of genetic disorders that interfere with the normal functioning of the immune system. There are over 550 known types of PI, and that number has been increasing as improvements in genetic testing enable medical researchers to identify new types.
PI is a serious condition that can lead to serious health complications, especially when untreated or under-treated. People with PI often experience frequent infections, infections that are difficult to treat, severe infections, and uncommon infections.
Most types of PI are not curable, and the main treatment in most cases will be immunoglobulin replacement therapy. Also known as antibodies, immunoglobulins are proteins that circulate in the blood and help the body heal injuries and fight infections. Immunoglobulin replacement therapy involves regular infusions of solutions containing immunoglobulins collected from donors. Increasing the amount of immunoglobulin in the body helps the immune system fight and prevent infections.
There are multiple immunoglobulin replacement therapies available. There are immunoglobulin replacement therapies that can be administered with an infusion into a vein (IVIg), which is done by a healthcare provider at a healthcare provider’s office. There are also immunoglobulin replacement therapies that can be administered subcutaneously (SCIg), with a needle inserted into the subcutaneous tissue located beneath the skin, which can be self-administered or administered by a caregiver. Each approach has its advantages and disadvantages.
The importance of treatment adherence
Adherence means following a treatment plan as intended—in other words, taking every dose and taking every dose on time. This is the number one thing a person can do to get the most benefit from the therapies and medicines they are using.
Non-adherence refers to skipping doses of a therapy, taking doses inconsistently, or stopping treatment without being instructed to by a healthcare provider.
Because infusions only temporarily increase the amount of immunoglobulin in the body, non-adherence to immunoglobulin replacement therapy will lead to lower levels of immunoglobulin and lower immunity:
- Lower immunity increases the risk of infections and the risk of serious infections.
- Recurring infections can cause permanent damage to the body, including the lungs, digestive organs, nervous system, hearing, and eyes.
- Organ damage can result in chronic conditions, including chronic lung disease and chronic diarrhea.
- Infections and complications can lead to higher medical expenses (due to the need for additional medications, appointments, and in some cases, hospitalization).
- Low levels of Ig can increase the risk of certain cancers, like lymphoma.
- Uncontrolled or untreated PI can lead to growth and development delays in children.
- All of the above can decrease a person’s quality of life.
- Early death can occur.
Working with your healthcare provider
If you have missed appointments for IVIg or find that you are skipping doses of SCIg or taking SCIg inconsistently, talk to your healthcare provider as soon as possible. Be honest and speak openly about the challenges and difficulties that you are experiencing. Your healthcare provider is there to help you find solutions.
There are multiple immunoglobulin replacement options available. If one isn't working for you, ask your healthcare provider about the possibility of switching to another.
