Overview
Primary immunodeficiency disorders — also called primary immune disorders or primary immunodeficiency — weaken the immune system, allowing infections and other health problems to occur more easily.
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 identified more than 300 forms of primary immunodeficiency disorders. Some forms are so mild they can go unnoticed 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 may also get infections that a person with a healthy immune system likely wouldn't get (opportunistic infections).
Signs and symptoms differ depending on the type of primary immunodeficiency disorder, and they vary from person to person.
Signs and symptoms of primary immunodeficiency can include:
- Frequent and recurrent 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 to your health care provider. 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 identify 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 (idiopathic)
Risk factors
The only known risk factor is having a family history of a primary immune deficiency disorder, which increases your 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
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 doctor 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 doctor about vaccinations. Find out which ones you should have.
Your immune system is your body’s defense against infections and other harmful invaders. Without it, you would constantly get sick from germs such as bacteria or viruses.
Your immune system is made up of special cells, tissues, and organs that work together to protect you.
The lymphatic system is a major part of the immune system. It's a network of lymph nodes and vessels. Lymphatic vessels are thin tubes that spread, like blood vessels, all over the body. They carry a clear fluid called lymph. Lymph contains tissue fluid, waste products, and immune system cells. Lymph nodes are small, bean-shaped clumps of immune system cells. They are connected by lymphatic vessels. They contain white blood cells that trap viruses, bacteria, and other invaders, including cancer cells.
White blood cells are the cells of the immune system. They are made in one of your lymph organs such as the spleen or thymus, and in the bone marrow.
What can go wrong with your immune system?
When your immune system doesn't work the way it should, it's called an immune system disorder. You may:
Be born with a weak immune system. This is called primary immune deficiency.
Get a disease that weakens your immune system. This is called acquired immune deficiency.
Have an immune system that is too active. This may happen with an allergic reaction.
Have an immune system that turns against you. This is called autoimmune disease.
Immune system disorders
Here are some common examples:
Severe combined immunodeficiency (SCID). This is an example of an immune deficiency that is present at birth. Children are in constant danger of infections from bacteria, viruses, and fungi. This disorder is sometimes called “bubble boy disease.” In the 1970s, a boy had to live in a sterile environment inside a plastic bubble. Children with SCID are missing important white blood cells. This disease is deadly without treatment.
Temporary acquired immune deficiencies. Your immune system can be weakened by certain medicines, for example. This can happen to people on chemotherapy or other medicines used to treat cancer. It can also happen to people after organ transplants who take medicine to prevent organ rejection. Also, infections such as the flu virus, mono (mononucleosis), and measles can weaken the immune system for a short time. Your immune system can also be weakened by smoking, alcohol, and poor nutrition.
AIDS. HIV, which causes AIDS, is an acquired viral infection that destroys important white blood cells and weakens the immune system. People with HIV/AIDS can become seriously ill with infections that most people can fight off. These infections are called “opportunistic infections” because they take advantage of weak immune systems.
An overactive immune system
If you are born with certain genes, your immune system may react to substances in the environment that are normally harmless. These substances are called allergens. Having an allergic reaction is the most common example of an overactive immune system. Dust, mold, pollen, and foods are examples of allergens.
Some conditions caused by an overactive immune system are:
Asthma. The response in your lungs can cause coughing, wheezing, and trouble breathing. Asthma can be triggered by common allergens like dust or pollen or by an irritant like tobacco smoke.
Eczema. An allergen causes an itchy rash known as atopic dermatitis.
Hay fever (allergic rhinitis). Sneezing, a runny nose, sniffling, and swelling of your nasal passages from indoor allergens such as dust and pets or outdoor allergens such as pollens or molds.
Food allergy. Severe allergic reactions that are caused by foods.
Autoimmune disease
In autoimmune diseases, the body attacks normal, healthy tissues. Experts don't know why. It's likely a combination of a person’s genes and something in the environment that triggers those genes.
Three common autoimmune diseases are:
Type 1 diabetes. The immune system attacks the cells in the pancreas that make insulin. Insulin removes sugar from the blood to use as energy.
Rheumatoid arthritis. This type of arthritis causes swelling and deformities of the joints. An auto-antibody called rheumatoid factor or anti-CCP is in the blood of some people with rheumatoid arthritis.
Lupus. This disease attacks body tissues, including the lungs, kidneys, and skin. Many types of auto-antibodies are found in the blood of people with lupus.
Experts don't know what causes autoimmune diseases but many different factors seem to be involved. If you have an immune system disorder, learn as much as you can about it and work closely with your healthcare providers to manage it.