Primary Immunodeficiency

What is primary immunodeficiency?

Primary immunodeficiency refers to a group of more than 400 disorders that affect your immune system. These disorders prevent your immune system from functioning properly. This can make you more susceptible to infection and certain diseases, including autoimmune diseases and cancers. Other names for primary immunodeficiency include:

• Primary immunodeficiency disease.
• Primary immunodeficiency disorder (PIDD).
• Inborn errors of immunity (IEI).

Genetic mutations (changes) cause primary immunodeficiency. They’re usually inherited, or passed down, within families, but can sometimes pop up sporadically. Providers treat primary immunodeficiency by preventing and managing infections and replacing missing or defective immune system components.

What are examples of primary immunodeficiency?

There are more than 400 types of primary immunodeficiency. These types vary in severity, which affects the age of onset (when they develop). Some types of PIDD cause problems during infancy and are discovered shortly after a baby is born. Other types are mild, and you may not receive a diagnosis until adulthood. Examples of primary immunodeficiency include:

• Common variable immunodeficiency (CVID).
• Ataxia-telangiectasia.
• Chronic granulomatous disease (CGD).
• DiGeorge syndrome.
• Hemophagocytic lymphohistiocytosis.
• Selective IgA deficiency.
• X-linked agammaglobulinemia.

What are the symptoms of primary immunodeficiency?

Having repeated, persistent or unusual infections that are difficult to treat are often the first signs of primary immunodeficiency for many people. They may be severe infections and/or shared with other family members. Other primary immunodeficiency symptoms may include:

• Multiple courses of antibiotics needed to overcome infections.
• Developing problems after receiving a live vaccine.
• Enlarged spleen.
• Swollen lymph nodes.
• Weight loss or poor growth.
• Digestive issues like chronic diarrhea.
• Autoimmune diseases.

What causes primary immunodeficiency?

Primary immunodeficiency results from genetic mutations affecting one or several components of your immune system, including cells and proteins. These mutations may cause parts of your immune system to be:

• Less active than usual.
• Defective.
• Totally absent.

In 50% to 60% of cases, primary immunodeficiency relates to defects in B lymphocytes (B cells). These immune system cells make antibodies, specific proteins in your body. Your immune system uses antibodies to destroy pathogens (disease-causing agents) like bacteria or viruses.

What are the risk factors for primary immunodeficiency?

Anyone can develop PIDD, but if you have a biological family history of the condition, you’re more likely to be affected. People usually develop primary immunodeficiencies before they’re 20 years old. Primary immunodeficiency is more common in males.

What are the complications of primary immunodeficiency?

Primary immunodeficiency may increase your risk for developing complications later in life. You might develop an autoimmune disorder or certain types of cancer. PIDD may result in unusually severe infections if it’s not treated.

How is primary immunodeficiency diagnosed?

Your healthcare provider will diagnose PIDD based on your personal and family medical history, a physical examination and laboratory testing.

To confirm your diagnosis, your provider may order tests that include:

• Blood tests to identify specific immune system abnormalities.
• Genetic tests to find mutations on genes.
• Flow cytometry, which uses a special laser to examine samples of immune system cells.

In addition, all U.S. states include testing for a type of PIDD called severe combined immunodeficiency (SCID) as part of newborn screening.

How is primary immunodeficiency treated?

If you’ve received a primary immunodeficiency diagnosis, your treatment goals will include managing current infections and preventing future infections. Your exact primary immunodeficiency treatment depends on the type of infection.

Your healthcare provider may prescribe medications, including:

• Antibiotics to prevent or clear bacterial infections.
• Antivirals to help you recover from infections caused by viruses.
• Immune globulin, which you may receive in a vein (intravenously [IV]) or under your skin (subcutaneously), to replace some types of immune system components.

Occasionally, people need surgery to manage complications from infections. For instance, a surgeon can drain an abscess to relieve discomfort and help you heal. An abscess is a collection of pus that forms inside body tissues or organs. Pus is made of dead white blood cells leftover from your body fighting an infection.

In some cases, your provider may recommend stem cell transplantation to replace defective or absent immune system components. During a stem cell transplant, your provider uses stem cells (cells that can turn into other kinds of cells) from a donor and transfers them into your body. These stem cells eventually become typical immune system cells.

Gene therapy has also been a successful treatment option for specific types of PIDD.

Can primary immunodeficiency be prevented?

Genetic mutations cause most PIDD disorders, so there’s no way to prevent them. If primary immunodeficiency runs in your family, you may want to consider genetic counseling.

What is the prognosis (outlook) for people with primary immunodeficiency?

With treatment, most people with PIDD live healthy lives. In some cases, you’ll have to take medication for the rest of your life. You should also try to avoid infection. Some tips for doing this include:

• Practicing good hand hygiene — wash your hands with soap and water. Do this before and after eating, after using the toilet, after touching pets and after touching anything dirty.
• Avoiding crowds and people who are sick.
• Following your healthcare provider’s instructions on vaccinations.
• Making sure to get enough rest.
• Following a diet and exercise plan that’s healthy for you.

When should I call my healthcare provider if I have or think I have primary immunodeficiency?

If you have an infection that doesn’t go away, is unusually severe or keeps coming back, contact your healthcare provider for an evaluation to determine if you have PIDD. If you know you have PIDD, contact your provider immediately if you have a fever or infection. This is necessary to prevent complications.

What questions should I ask my healthcare provider?

• What kind of primary immunodeficiency do I have?
• Can I pass it on to my biological children?
• Which treatments do you recommend?
• What side effects of the treatment should I watch out for?
• What complications can this condition cause?