(See also Overview of Immunodeficiency Disorders Overview of Immunodeficiency Disorders Immunodeficiency disorders involve malfunction of the immune system, resulting in infections that develop and recur more frequently, are more severe, and last longer than usual. Immunodeficiency... read more .)
There are several classes of immunoglobulins, such as immunoglobulin A (IgA), IgD, IgE, IgG, and IgM. Each class helps protect the body from infection in a different way (see also Antibodies Antibodies One of the body's lines of defense (immune system) involves white blood cells (leukocytes) that travel through the bloodstream and into tissues, searching for and attacking microorganisms and... read more 
).
The level of any immunoglobulin class may be low, but the most commonly affected class is IgA.
Selective IgA Deficiency
Most people with selective IgA deficiency have few or no symptoms, but some have chronic lung infections, sinusitis, and other disorders.
Doctors diagnose the disorder by measuring levels of immunoglobulins in the blood.
Antibiotics are used to treat or sometimes to prevent infections.
Selective IgA deficiency is the most common immunoglobulin abnormality. It may be caused by a mutation in a specific gene or by a drug, such as phenytoin (used to treat seizure disorders) or sulfasalazine (used to treat rheumatoid arthritis). How the gene mutation is inherited is unknown, but having a family member with selective IgA deficiency increases the risk by about 50 times
Symptoms of Selective IgA deficiency
Most people with selective IgA deficiency have few or no symptoms. Others develop chronic lung infections, sinusitis, allergies, asthma, nasal polyps, chronic diarrhea, or, rarely, autoimmune disorders Autoimmune Disorders An autoimmune disorder is a malfunction of the body's immune system that causes the body to attack its own tissues. What triggers autoimmune disorders is not known. Symptoms vary depending... read more , such as systemic lupus erythematosus (lupus) or inflammatory bowel disease (which usually causes gastrointestinal symptoms that often recur or that may be serious). A few people develop common variable immunodeficiency Common Variable Immunodeficiency (CVID) Common variable immunodeficiency is an immunodeficiency disorder characterized by very low antibody (immunoglobulin) levels despite a normal number of B cells (lymphocytes). People with common... read more over time.
Some people with selective IgA deficiency produce antibodies against IgA if they are exposed to IgA in blood transfusions or immune globulin (antibodies obtained from the blood of people with a normal immune system). Rarely, antibodies against IgA trigger a severe allergic (anaphylactic Anaphylactic Reactions Anaphylactic reactions are sudden, widespread, potentially severe and life-threatening allergic reactions. Anaphylactic reactions often begin with a feeling of uneasiness, followed by tingling... read more ) reaction the next time such people are given a blood transfusion or immune globulin.
Some people improve spontaneously. Life span is usually unaffected. If an autoimmune disorder or another immune disorder (such as common variable immunodeficiency) develops, life span may be shortened.
Diagnosis of Selective IgA deficiency
Blood tests to measure immunoglobulin levels before and after vaccinations
Doctors suspect selective IgA deficiency in people if they have
Recurring infections
An anaphylactic reaction to a blood transfusion or to immune globulin
Gastrointestinal symptoms that may result from inflammatory bowel disease
Family members who have selective IgA deficiency, common variable immunodeficiency, or an autoimmune disorder
Blood tests to measure immunoglobulin levels are done to confirm the diagnosis.
Normally, the body’s immune system responds to a vaccine by producing substances (such as antibodies Antibodies One of the body's lines of defense (immune system) involves white blood cells (leukocytes) that travel through the bloodstream and into tissues, searching for and attacking microorganisms and... read more ) and mobilizing white blood cells that recognize and/or attack the specific bacteria or virus represented in the vaccine. Then whenever people who have been vaccinated are exposed to the specific bacteria or virus, the immune system automatically produces these antibodies and takes other action to prevent or lessen illness. People with selective IgA deficiency do not produce antibodies in response to certain kinds of vaccines. Doctors measure IgA antibody (immunoglobulin) levels before and after vaccinations. Lack of increase in IgA after vaccination helps to make the diagnosis.
Treatment of Selective IgA deficiency
Antibiotics to treat or sometimes to prevent infections
Use of a medical identification bracelet or tag by people who have had an anaphylactic reaction to a blood transfusion or immune globulin
Usually, no treatment of selective IgA deficiency is needed.
Antibiotics are given to people who have an infection. If the disorder is severe, antibiotics are given in advance to prevent infections from developing.
People who have had an anaphylactic Anaphylactic Reactions Anaphylactic reactions are sudden, widespread, potentially severe and life-threatening allergic reactions. Anaphylactic reactions often begin with a feeling of uneasiness, followed by tingling... read more reaction to a blood transfusion or immune globulin should wear a medical identification bracelet or tag to alert doctors to take precautions against such reactions.
Selective IgA deficiency that results from taking a drug usually resolves if the drug is stopped.
More Information about Selective IgA deficiency
The following is an English-language resource that may be useful. Please note that THE MANUAL is not responsible for the content of this resource.
Immune Deficiency Foundation: Selective IgA deficiency: Comprehensive information on selective IgA deficiency, including information on diagnosis and treatment and advice for people affected
