Selective IgA deficiency
What is Selective IgA deficiency?
Selective IgA deficiency is the most common primary immunodeficiency. This means your immune system does not produce enough immunoglobulin A, or IgA for short. IgA is an antibody that protects the mucous membranes in your nose, throat, lungs, and digestive tract from infections.
When IgA levels are very low or absent, your body has a harder time fighting off bacteria and viruses that enter through these areas. Many people with selective IgA deficiency live normal, healthy lives without knowing they have it. Others may experience frequent respiratory or digestive infections.
This condition affects about 1 in 300 to 1 in 700 people, making it relatively common. Most cases are discovered by accident during routine blood work or when investigating repeated infections. Understanding your IgA levels helps you and your doctor take the right steps to protect your health.
Symptoms
- Frequent sinus infections or ear infections
- Recurring respiratory infections like bronchitis or pneumonia
- Chronic diarrhea or digestive problems
- Increased risk of food allergies or sensitivities
- Asthma or other lung problems
- Autoimmune conditions like celiac disease or rheumatoid arthritis
- Skin infections or rashes
Many people with selective IgA deficiency have no symptoms at all. Some only discover the condition during blood testing for other reasons. The severity of symptoms varies widely from person to person.
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Causes and risk factors
Selective IgA deficiency is usually genetic, meaning it runs in families. The exact genetic cause is not always clear, but it involves problems with the cells that produce IgA antibodies. Most cases appear to be inherited in a complex pattern that researchers are still studying.
Some medications can temporarily lower IgA levels, including certain anti-seizure drugs and immunosuppressants. Environmental factors may also play a role in triggering the condition in people who are genetically predisposed. Having a family history of immunodeficiency or autoimmune disorders increases your risk.
How it's diagnosed
Selective IgA deficiency is diagnosed through blood tests that measure your immunoglobulin levels. Your doctor will order tests for IgA, IgG, and IgM to see if only IgA is low while other antibodies remain normal. A diagnosis is made when IgA levels are below 7 milligrams per deciliter and other immunoglobulin levels are normal.
If you have symptoms like frequent infections or autoimmune conditions, talk to your doctor about specialized testing. Additional tests may check for antibodies to specific infections or screen for associated conditions like celiac disease. Keep in mind that people with IgA deficiency may have false-negative results on standard celiac disease tests.
Treatment options
- Prompt treatment of infections with antibiotics when needed
- Preventive antibiotics for people with frequent severe infections
- Vaccinations to prevent respiratory infections like flu and pneumonia
- Good hygiene practices to reduce infection exposure
- Nutritious diet rich in immune-supporting vitamins and minerals
- Regular exercise to support overall immune function
- Adequate sleep and stress management
- Monitoring for autoimmune conditions with regular checkups
- Avoiding blood products containing IgA to prevent allergic reactions
Frequently asked questions
Selective IgA deficiency is a condition where your body produces very low or no IgA antibodies. IgA protects the mucous membranes in your respiratory and digestive systems from infections. This is the most common type of primary immunodeficiency, affecting roughly 1 in 300 to 1 in 700 people.
Common symptoms include frequent sinus, ear, or respiratory infections, chronic diarrhea, and food allergies. Some people also develop autoimmune conditions like celiac disease or asthma. However, many people with this condition have no symptoms at all and live completely normal lives.
Diagnosis requires a blood test measuring immunoglobulin levels. Your doctor will check IgA, IgG, and IgM to confirm that only IgA is low. A diagnosis is made when IgA is below 7 milligrams per deciliter while other immunoglobulin levels remain normal.
There is no cure for selective IgA deficiency because it is a genetic condition. Treatment focuses on preventing and quickly treating infections. Most people manage the condition successfully with good hygiene, prompt medical care for infections, and regular health monitoring.
For most people, selective IgA deficiency is not dangerous. Many never have serious health problems. Some people experience more frequent infections that require treatment. A small percentage develop autoimmune conditions that need ongoing management.
Yes, selective IgA deficiency often runs in families and appears to have a genetic component. If you have a family history of immunodeficiency or autoimmune disorders, your risk is higher. The exact pattern of inheritance is complex and still being researched.
Yes, most people with selective IgA deficiency can and should receive vaccinations. Vaccines for flu, pneumonia, and other infections are especially important because they help protect you from illnesses your body may struggle to fight. Always discuss your vaccination schedule with your doctor.
Focus on good hygiene like regular handwashing to reduce infection exposure. Eat a nutritious diet rich in vitamins and minerals that support immune health. Get adequate sleep, manage stress, and exercise regularly to keep your overall immune system strong.
Yes, people with selective IgA deficiency may have false-negative results on standard celiac disease tests. These tests typically measure IgA antibodies to gluten proteins. If you have IgA deficiency, your doctor should order IgG-based celiac tests instead for accurate results.
Yes, always inform your healthcare providers about your IgA deficiency. This is especially important before receiving blood transfusions or blood products. Some people with this condition can develop antibodies against IgA, which can cause serious allergic reactions during transfusions.