Selective IgA Deficiency
What is selective IgA deficiency?
Immunoglobulin A (IgA) is a protein found in the blood. It protects the body against infections in the membranes (thin tissues) that line the airways, eyes, mouth and digestive system.
People with selective IgA deficiency don’t have this protein or have very low levels (deficiency) of the protein. Selective IgA deficiency is an immunodeficiency disease (a disease that involves a lack in the immune system). You might also see it called SIgAD.
Symptoms and Causes
What causes selective IgA deficiency?
Selective IgA deficiency is often inherited, meaning it is passed down through family members who have selective IgA deficiency or similar immune problems.
What are the symptoms of selective IgA deficiency?
Most people with selective IgA deficiency do not have any symptoms. Doctors often find the disorder when testing for another condition.
About 25% to 50% of people with selective IgA deficiency will have complications. Some people with selective IgA deficiency experience repeated infections. The most common areas of infection include:
- Airways (air passages in the lungs).
- Digestive tract (belly).
How common is selective IgA deficiency?
Selective IgA deficiency occurs most often in Caucasians (people of European descent). An estimated 1 in 500 Caucasians has the disorder, according to some studies. The incidence rate varies from location to location and depends on ethnic background.
What are the risk factors for selective IgA deficiency?
People are at higher risk of developing selective IgA deficiency if they have a family member with IgA deficiency or a similar immune problem.
Diagnosis and Tests
How is selective IgA deficiency diagnosed?
Immunologists, or doctors who specialize in the immune system, may send blood tests to evaluate a patient who with frequent infections or autoimmune disease. Low levels of IgA confirm the diagnosis of selective IgA deficiency. In many cases, the condition is identified when a patient undergoes blood testing for another condition, like celiac disease, and low levels of IgA are incidentally noted.
Management and Treatment
How is selective IgA deficiency treated?
Doctors manage selective IgA by treating the conditions associated with it. Your doctor may prescribe antibiotics to treat infections related to selective IgA deficiency. Selective IgA cannot be eliminated or cured, but some young children can outgrow the condition within the first few years of life
What complications are associated with selective IgA deficiency?
Most people with selective IgA deficiency are healthy, but some patients experience more frequent or severe infections. Patients with selective IgA deficiency have a slightly higher risk of having allergies (abnormal immune system reactions to environmental substances or food) and asthma (swollen airways in the lungs).
Some people with selective IgA deficiency develop autoimmune disorders (when the body’s immune system harms its own cells). These conditions may include:
- Celiac disease: A disorder where eating gluten (a protein in wheat) causes damage to the small intestine.
- Inflammatory bowel disease: Disorders that cause inflammation (swelling) and damage in the digestive tract, such as ulcerative colitis and Crohn’s disease.
- Rheumatoid arthritis: A condition that involves inflammation of the joints.
- Lupus: A disorder where the body’s immune system attacks healthy tissue.
In rare cases, people with selective IgA deficiency can develop a life-threatening condition called anaphylaxis (severe allergic reaction) if a doctor gives them blood products containing IgA.
Can selective IgA deficiency be prevented?
Because it is inherited, selective IgA deficiency cannot be prevented.
Outlook / Prognosis
What is the prognosis (outlook) for people with selective IgA deficiency?
The prognosis for people with selective IgA deficiency varies by the individual but tends to be good.
However, some people may develop more severe diseases as a result of the condition than others. Selective IgA deficiency tends to be a lifelong condition, but young children can outgrow the condition within the first few years of life.
When should you call your healthcare provider about selective IgA deficiency?
If you have frequent or repeated infections, your doctor may want to perform a blood test to see if selective IgA deficiency or another immune problem may be the cause.
What questions should you ask your healthcare provider about selective IgA deficiency?
If you have selective IgA deficiency, you may want to ask your doctor:
- How serious is selective IgA deficiency?
- What complications should I look out for?
- Should I wear a Medic Alert bracelet?
When can I go back to my regular activities?
In most cases, selective IgA deficiency does not interfere with daily life. If you experience an infection, your doctor will tell you how long you should wait after treatment before resuming certain activities.