Hypogammaglobulinemia is a problem with the immune system that prevents it from making enough antibodies called immunoglobulins. Antibodies are proteins that help your body recognize and fight off foreign invaders like bacteria, viruses, and fungi.
Without enough antibodies, you’re more likely to get infections. People with hypogammaglobulinemia can more easily catch pneumonia, meningitis, and other infections that a healthy immune system would normally protect against. These infections can damage organs and lead to potentially serious complications.
People with this condition get more frequent infections than usual. Common infections include:
Some of these infections can be serious.
Babies that are born with THI first show symptoms about 6 to 12 months after birth. The main symptom is frequent ear, sinus, and lung infections.
Which symptoms you or your child has will depend on what infections you get, but they can include:
- sore throat
- ear pain
- sinus pain
- nausea and vomiting
- abdominal cramps
- joint pain
Several gene changes (mutations) have been linked to hypogammaglobulinemia.
One such mutation affects the BTK gene. This gene is needed to help B cells grow and mature. B cells are a type of immune cell that makes antibodies. Immature B cells don’t make enough antibodies to protect the body from infection.
THI is more common in premature infants. Babies normally get antibodies from their mother through the placenta during pregnancy. These antibodies protect them from infections once they’re born. Babies that are born too early don’t get enough antibodies from their mother.
A few other conditions can cause hypogammaglobulinemia. Some are passed down through families and start at birth (congenital). These are called primary immune deficiencies.
- ataxia-telangiectasia (A-T)
- autosomal recessive agammaglobulinemia (ARA)
- common variable immunodeficiency (CVID)
- hyper-IgM syndromes
- IgG subclass deficiency
- isolated non-IgG immunoglobulin deficiencies
- severe combined immunodeficiency (SCID)
- specific antibody deficiency (SAD)
- Wiskott-Aldrich syndrome
- x-linked agammaglobulinemia
More often, hypogammaglobulinemia develops as a result of another condition, called secondary or acquired immune deficiencies. These include:
- blood cancers such as chronic lymphocytic leukemia (CLL), lymphoma, or myeloma
- nephrotic syndrome
- poor nutrition
- protein-losing enteropathy
- organ transplant
Certain medications can also cause hypogammaglobulinemia, including:
- medicines that suppress the immune system, such as corticosteroids
- chemotherapy drugs
- antiseizure medications
Doctors treat bacterial infections with antibiotics. People who get severe or frequent bacterial infections may need to take antibiotics for several months at a time to prevent them.
If your hypogammaglobulinemia is severe, you may get immune globulin replacement therapy to replace what your body isn’t making. You get this treatment through an IV. The immune globulin comes from the blood plasma of healthy donors.
Some people only need a single injection of immune globulin replacement. Others will need to stay on this treatment for a year or more. Your doctor will do blood tests every few months to check your levels until they get up to normal.
Complications depend on what caused hypogammaglobulinemia, and what types of infections are involved. They can include:
- autoimmune disorders such as Crohn’s disease and ulcerative colitis
- damage to the heart, lungs, nervous system, or digestive tract
- increased risk for cancer
- repeated infections
- slowed growth in children
Getting treated for infections and taking immune globulin therapy can reduce the risk of these complications.
Life expectancy and prognosis
The life expectancy for this condition depends on how severe it is, and how it’s treated. People who get many severe infections will have a worse outlook than those who don’t get as many infections.
Babies with THI usually grow out of it. The infections will often stop by their first birthday. Immunoglobulin usually reaches normal levels by age four.
Catching this condition early and getting on antibiotics or immune globulin treatment can limit infections, prevent complications, and improve your life expectancy.