Agammaglobulinemia

Definition

Agammaglobulinemia is an inherited disorder in which there are very low levels of protective immune system proteins called immunoglobulins. People with this disorder repeatedly develop infections.

Alternative Names

Bruton's agammaglobulinemia; X-linked agammaglobulinemia

Causes, incidence, and risk factors

Agammaglobulinemia is a rare disorder that mainly affects males. It is the result of a genetic abnormality that blocks the development of normal, mature immune system cells called B lymphocytes.

As a result, the body produces very little (if any) immunoglobulins in the bloodstream. Immunoglobulins play a major role in the immune response, which protects against illness and infection.

Without protective immunoglobulins, people with agammaglobulinemia repeatedly develop infections. People with this disorder are particularly susceptible to bacterial infections caused by Haemophilus influenzae, pneumococci (Streptococcus pneumoniae), and staphylococci, as well as to repeated viral infections. Common sites of infection include:

• Gastrointestinal tract
• Lungs
• Skin
• Upper respiratory tract

People with this condition may have a family history of agammaglobulinemia (or another immune disorder).

Symptoms

Symptoms include frequent episodes of:

• Bronchitis
• Chronic diarrhea
• Conjunctivitis (eye infection)
• Otitis media (middle ear infection)
• Pneumonia
• Sinusitis
• Skin infections
• Upper respiratory tract infections

Infections typically appear in the first 4 years of life.

Other symptoms include:

• Bronchiectasis (a disease in which the small air sacs in the lungs become damaged and enlarged)
• Unexplained asthma

Signs and tests

The disorder is confirmed by laboratory measurement of blood immunoglobulins.

Tests include:

• Flow cytometry to measure circulating B lymphocytes
• Immunoelectrophoresis - serum
• Quantitative immunoglobulins - IgG, IgA, IgM (usually measured by nephelometry)

Treatment

The goal of treatment is to reduce the number and severity of infections, and to provide genetic counseling to affected families.

Receiving immunoglobulins (IVIG) through a vein (intravenously) helps boost the immune system by providing the body with the antibodies that are decreased or missing. Routine treatment with IVIG is central to the treatment of this disorder.

Antibiotics are often needed to treat bacterial infections.

Support Groups

Expectations (prognosis)

Treatment with IVIG has greatly improved the health of people with agammaglobulinemia. Without treatment, most severe infections are fatal.

Complications

• Arthritis
• Chronic sinus or pulmonary disease
• Eczema
• Intestinal malabsorption syndromes

Calling your health care provider

Call for an appointment with your health care provider if:

• You or your child has experienced frequent infections
• You have a family history of agammaglobulinemia or another immunodeficiency disorder and you are planning to have children (ask the provider about genetic counseling)

Prevention

Genetic counseling should be offered to prospective parents with a family history of agammaglobulinemia or other immunodeficiency disorders.

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References

Azar AE. Evaluation of the adult with suspected immunodeficiency. Am J Med. 2007;120(9):764-768.

Ballow M. Primary immunodeficiency diseases. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier;2007:chap 271.

Morimoto Y. Immunodeficiency overview. Prim Care. 2008;35(1):159-173.