Primary immunodeficiency

Date Updated: 09/20/2025

Overview

Primary immunodeficiency disorders are a group of conditions that make it hard for the body to fight infections. They are sometimes called primary immune disorders or primary immunodeficiency.

Many people with primary immunodeficiency are born missing some of the body's immune defenses or with the immune system not working properly, which leaves them more susceptible to germs that can cause infections.

So far, researchers have found more than 300 forms of primary immunodeficiency disorders. Some forms are so mild they aren't noticed until adulthood. Other types are severe enough that they're discovered soon after an affected baby is born.

Treatments can boost the immune system in many types of primary immunodeficiency disorders. Research is ongoing, leading to improved treatments and enhanced quality of life for people with the condition.

Symptoms

One of the most common signs of primary immunodeficiency is having infections that are more frequent, longer lasting or harder to treat than are the infections of someone with a typical immune system. You also may get infections that a person with a healthy immune system likely wouldn't get. These are called opportunistic infections.

Symptoms differ depending on the type of primary immunodeficiency disorder, and they vary from person to person.

Symptoms of primary immunodeficiency can include:

Getting infections often, including pneumonia, bronchitis, sinus infections, ear infections, meningitis or skin infections.
Inflammation and infection of internal organs.
Blood disorders, such as low platelet count or anemia.
Digestive problems, such as cramping, loss of appetite, nausea and diarrhea.
Delayed growth and development.
Autoimmune disorders, such as lupus, rheumatoid arthritis or type 1 diabetes.

When to see a doctor

If you or your child has frequent, recurrent or severe infections or infections that don't respond to treatments, talk with a healthcare professional. Early diagnosis and treatment of primary immune deficiencies can prevent infections that can cause long-term problems.

Causes

Many primary immunodeficiency disorders are inherited — passed down from one or both parents. Problems in the genetic code that acts as a blueprint for producing the cells of the body (DNA) cause many of these immune system defects.

There are more than 300 types of primary immunodeficiency disorders, and researchers continue to find more. They can be broadly classified into six groups based on the part of the immune system that's affected:

B cell (antibody) deficiencies.
T cell deficiencies.
Combination B and T cell deficiencies.
Defective phagocytes.
Complement deficiencies.
Unknown, known as idiopathic.

Risk factors

The only known risk factor for primary immune deficiency disorder is having a family history of the condition. This increases the risk of having the condition.

If you have a type of primary immune deficiency disorder, you might want to seek genetic counseling if you plan to have a family.

Complications

Complications caused by a primary immunodeficiency disorder vary depending on what type you have. They can include:

Recurrent infections.
Autoimmune disorders.
Damage to the heart, lungs, nervous system or digestive tract.
Slowed growth.
Increased risk of cancer.
Death from serious infection.

Diagnosis

To diagnose a primary immunodeficiency disorder, a healthcare professional will ask about a history of illnesses and whether any close relatives have an inherited immune system disorder. A physical examination also will be done.

Tests used to diagnose an immune disorder include:

Blood tests. Blood tests can determine if you have typical levels of infection-fighting proteins, called immunoglobulins, in your blood. Blood tests also measure the levels of blood cells and immune system cells. Having numbers of certain cells in your blood that are outside of the standard range can mean an immune system defect.

Blood tests also can tell if your immune system is responding properly. A functioning immune system produces proteins, called antibodies, that find and kill foreign invaders such as bacteria or viruses.
Prenatal testing. Parents who have a child with a primary immunodeficiency disorder might want to be tested for certain immunodeficiency disorders during future pregnancies. Samples of the amniotic fluid, blood or cells from the tissue that will become the placenta, called chorion, are tested for problems.

In some cases, DNA testing is done to check for a genetic issue. Test results make it possible to prepare for treatment soon after birth, if necessary.

Treatment

Treatments for primary immunodeficiency involve preventing and treating infections, boosting the immune system, and treating the underlying cause of the immune problem. In some cases, primary immune disorders are linked to a serious illness, such as an autoimmune disorder or cancer, which also needs to be treated.

Managing infections

Treating infections. Infections need fast and aggressive treatment with antibiotics. Treatment might require a longer course of antibiotics than is usually prescribed. Infections that don't respond may require hospitalization and intravenous (IV) antibiotics.
Preventing infections. Some people need long-term antibiotics to prevent respiratory infections and permanent damage to the lungs and ears. Children with primary immunodeficiency might not be able to have vaccines containing live viruses, such as oral polio and measles-mumps-rubella (MMR).
Immunoglobulin therapy. Immunoglobulin consists of antibody proteins needed for the immune system to fight infections. It can either be injected into a vein through an IV line or inserted underneath the skin. IV treatment is needed every few weeks, and subcutaneous infusion is needed once or twice a week.

Treatment to restore the immune system

Stem cell transplantation. Stem cell transplantation offers a permanent cure for several forms of life-threatening immunodeficiency. Healthy stem cells are transferred to the person with immunodeficiency, which results in a typically functioning immune system. Stem cells can be harvested through bone marrow, or they can be obtained from a placenta at birth. This process is known as cord blood banking.

The stem cell donor — usually a parent or other close relative — must have body tissues that are a close biological match to those of the person with primary immunodeficiency. Even with a good match, however, stem cell transplants don't always work.

The treatment often requires that functioning immune cells be destroyed using chemotherapy or radiation before the transplants, leaving the transplant recipient temporarily even more vulnerable to infection.
Gene therapy. This type of treatment involves taking stem cells from the person with primary immunodeficiency and correcting the gene in the cells. The corrected stem cells are returned to the person via an intravenous infusion. With gene therapy, there is no need to find a suitable donor, as the person's own cells are used. Currently, this treatment is used to treat only a few primary immunodeficiencies, but clinical trials are underway for many other types.

Depending on the type of disorder, treatment may involve other therapies. These include enzyme replacement therapy or transplantation of the thymus, an organ located behind the breastbone (sternum) that produces T cells.

Coping and support

Most people with primary immunodeficiency can go to school and work like everyone else. Still, you might feel as if no one understands what it's like to live with the constant threat of infections. Talking to someone who faces similar challenges may help.

Ask your healthcare professional if there are support groups in the area for people with primary immunodeficiency or for parents of children with the disease. The Immune Deficiency Foundation has a peer support program as well as information on living with primary immunodeficiency.

Prevention

Because primary immune disorders are caused by genetic changes, there's no way to prevent them. But when you or your child has a weakened immune system, you can take steps to prevent infections:

Practice good hygiene. Wash your hands with mild soap after using the toilet and before eating.
Take care of your teeth. Brush your teeth at least twice a day.
Eat right. A healthy, balanced diet can help prevent infections.
Be physically active. Staying fit is important to your overall health. Ask your healthcare professional what activities are appropriate for you.
Get enough sleep. Try to go to sleep and get up at the same time daily, and get the same number of hours of sleep every night.
Manage stress. Some studies suggest that stress can hamper your immune system. Keep stress in check with massage, meditation, yoga, biofeedback or hobbies. Find what works for you.
Avoid exposure. Stay away from people with colds or other infections and avoid crowds.
Ask your healthcare professional about vaccinations. Find out which ones you should have.

Preparing for your appointment

You'll likely start by seeing your family doctor or another healthcare professional. You might then be referred to a doctor who specializes in disorders of the immune system, called an immunologist.

Here's some information to help you get ready for your appointment.

What you can do

Write down symptoms, including any that may seem unrelated to the reason for your appointment, and when they began.
Bring copies of records from hospitalizations and medical test results, including X-rays, blood test results and culture findings.
Ask family members about the family medical history, including whether anyone was diagnosed with primary immunodeficiency, or if your family has babies or children who died of unknown causes.
Make a list of medicines, vitamins and supplements you or your child takes, including doses. If possible, list all of the antibiotic prescriptions and the dosages you or your child has taken for the past several months.
Write down questions to ask during your appointment.

Ask a family member or friend to come with you, if possible, to help you remember the information you're given.

For primary immunodeficiency, questions to ask include:

What's the most likely cause of these symptoms?
Are there other possible causes?
What tests are needed? Do these tests require special preparation?
What's the prognosis?
What treatments are available, and which do you recommend?
I have other health problems. How do I manage them together?
Are there alternatives to the primary approach you're suggesting?
Are there activity restrictions?
Are there brochures or other printed material I can have? What websites do you recommend?

Don't hesitate to ask any other questions, as well.

What to expect from your doctor

You or your child's healthcare professional is likely to ask you questions, including:

When did the symptoms begin?
Have symptoms been continuous or occasional?
How many infections have you or your child had during the past year?
How long do these infections usually last?
Do antibiotics usually clear up the infection?
How many times has your child taken antibiotics during the last year?