Immunodeficiency
What is it?
Immunodeficiency refers to a group of disorders in
which the immune system does not function normally. Our
bodies’ immune cells attack and kill what they see as
foreign invaders, usually bacteria, viruses, and fungi.
When the immune system does not work properly, a person is
more likely to suffer from frequent and longer lasting
infections, often from organisms that don’t normally make
most people sick. Congenital immunodeficiency is present
at birth. Another type of immunodeficiency disorder is
called acquired immunodeficiency, which develops later in
life.
Who gets it?
Infants can inherit immunodeficiency disorders.
Children with chronic diseases are more likely to develop
acquired immunodeficiency disorders. Children without a
spleen or with spleen problems, or without a thymus or an
underdeveloped thymus, are also likely to have
immunodeficiency disorders.
What causes it?
Different immunodeficiency diseases involve different
components of the immune system. The immune system is
composed of white blood cells (macrophages, neutrophils,
and lymphocytes), as well as substances called antibodies.
Congenital immunodeficiencies are hereditary, and may
occur as a result of defects in B lymphocytes, which make
antibodies; T lymphocytes, which help identify foreign
substances; or both, called severe combined
immunodeficiency disease (SCID). Or, immmunodeficiencies
can be caused by an antibody defect. There are five
classes of antibodies (igM, igG, IfA, IgE, and IgD) and
each type has a different function. Antibodies are also
called immunoglobulins. When immunodeficiency is caused by
problems with the thymus, it is called DiGeorge syndrome.
Newborns can also be infected with the human
immunodeficiency virus (HIV) during childbirth if their
mothers are infected. Acquired immunodeficiency is most
commonly caused by disease, such as malnutrition, sickle
cell anemia, cancers, and diabetes; infections, such as
measles, bacterial and fungal infections, and
cytomegalovirus; or as a side effect of certain drugs and
therapies used in the treatment of chronic disease. Burn
trauma can also affect the function of the immune system.
What are the symptoms?
Children with immunodeficiency disorders have frequent
infections, such as recurrent respiratory infections. A
simple sore throat or cold will lead to severe bacterial
infections, most commonly bronchitis, sinusitis, and ear
infections (otitis). Chronic bronchitis can develop into
pneumonia. It is common for children with
immunodeficiencies to develop thrush, a fungal infection
of the mouth, and other infections of the skin and mucous
membranes in the eyes, mouth, and genital area.
Gastrointestinal infections cause diarrhea, weight loss,
and failure to thrive. Other symptoms in children with
immunodeficiency disorders include hair loss, eczema,
areas of broken blood vessels near the surface of the
skin, enlarged lymph nodes, distended stomachs, and
unnaturally pale skin.
How is it diagnosed?
Congenital immunodeficiency is suspected in children
with recurring severe infections, especially when there is
a family history of recurring infections. Your doctor will
study you and your child’s medical history and perform a
thorough physical examination. He or she will look for a
history of adverse reactions to immunizations; surgeries,
especially those involving the spleen, tonsils, or
adenoids; or radiation therapy, particularly to the
thymus. Immunodeficiency disorders are diagnosed through
blood tests, which are studied for the presence of immune
components such as antibodies, lymphocytes, and
phagocytes. The doctor will also look at the blood cell
count and appearance. The results of these tests will
determine which additional tests are needed. Your doctor
will also look at the type of infections the child has had
to help determine the type of immunodeficiency disorder.
Delayed hypersensitivity skin tests are performed after
the age of two to determine how the body reacts to common
infectious organisms, which are injected under the skin.
What is the treatment?
There is currently no cure for immunodeficiency
disorders. The goal of treatment is to control infections
and maintain the patient’s quality of life. Infections are
treated with antibiotics, sometimes on a regular basis as
a preventive treatment. Children with low antibody levels
may be given injections of gamma globulin to increase
antibodies. Children with severe DiGeorge syndrome may
benefit from a bone marrow transplant or thymus
transplant. Bone marrow transplant is the recommended
treatment for severe combined immunodeficiency disease (SCID).
Children with HIV infection, which causes AIDS, are
treated with drugs called antivirals. Improving the
child’s general nutrition can reverse immunodeficiency
caused by malnutrition. Discontinuing treatments that
affect the immune system, such as chemo or radiation
therapy, also improves immune function.
Self-care tips
Although there is no way to prevent congenital
immunodeficiency disorders, you can help improve your
child’s health by making sure he or she follows a healthy
diet, avoids situations where he or she will be exposed to
infection, avoids eating undercooked food that can contain
bacteria, and practices good personal hygiene. Because
mouth infections are so common in someone who is
immunodeficient, good dental care is especially important.
Someone with a history of congenital immunodeficiency
disorder may want to seek genetic counseling before
deciding to start a family.
This information has been designed as a comprehensive and quick reference
guide written by our health care reviewers. The health information written
by our authors is intended to be a supplement to the care provided by your
physician. It is not intended nor implied to be a substitute for
professional medical advice.
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