Prather Pediatric and Allergy Center - Ask Doctor Brent

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Title: Immune Deficiencies

Category: Child Care


There are several immune deficiencies found in children. Some are congenital; that is, the children have them from the time of birth. Others are acquired or develop later in life. A typical child with immune deficiency will have mild to severe infections at an abnormally high frequency such as week in and week out sinus infections or recurrent pneumonia, sepsis or meningitis. In any child suspected of having an immune deficiency, certain things should be done. The most basic work up for immune deficiencies is to check antibody levels or immunoglobulins. The immunoglobulins screened include IGG, IGM and IGA. In the last few years we have found that some immune deficiencies involve sub fractions of IGG so we now check IGG-1, G-2, G-3 and G-4. Other basic tests done for immune deficiencies include delayed skin test to common antigens such as tetanus which has been received as a vaccine as part of the DPT vaccine. A small amount of tetanus is injected under the skin and, in the normal immune patient, a mosquito bite-like reaction will pop up in one to three days. In a patient who has T-cell deficiency or weakness, this will not occur. Other more sophisticated tests can be done at major medical centers such as tests of white blood cell migration, tests of white cell antibody killing, complement level tests which are a series of proteins important to fighting infection, and other more sophisticated tests. The simplest screen, however, is the simple tetanus intradermal screen test and the immunoglobulin levels.

The mildest immune deficiency is IGA deficiency. This can be a low level of IGA for the first few years of life or for the patient's entire life. There is no way to treat this with replacement of IGA and so the standard of care is to keep that patient on low dose antibiotics to prevent the frequent upper respiratory infections. Most patients with IGA deficiency do very well and many outgrow their condition as they get older. The important thing is that they are properly diagnosed and closely followed until they outgrow it.

A much more serious deficiency is IGG deficiency or IGG-2 sub-fraction deficiency. This requires IGG replacement, usually given as intravenous drip every two to four weeks. This is very costly, up to a thousand dollars plus for treatment, and potentially dangerous. These patients are carefully followed and treated under the guidance of an immunologist. Deficiencies of the white blood cells, such as T-cell deficiency, are much more rare and are also followed under the treatment of an immunologist usually in a major medical center. Compliment deficiencies are even more rare and white cell polymorphoneucleocyte white blood cell abnormalities. All of these rare conditions are treated under the direction of hematologists and oncologists.

One of the worst new deficiencies is called SCID or Severe Combined Immuno-Deficiency. This is a fatal condition unless treated by bone marrow transplantation and/or new genetic measures such as enzyme replacement. The first case of genetic enzyme replacement for an aminodeaminase patient was done successfully just a few months ago. It is hoped that more serious genetic diseases, and particularly immune deficiencies, will be able to be treated in this way in the future.

The great majority of patients who have frequent infections do not have immune deficiencies; however, it is always worth while checking immunoglobulin levels and T-cell function. It is also worth checking compliment levels and polymorphronucleocyte function in any patient who seems to have an abnormal frequency of infections particularly if they are serious (such as pneumonia, sepsis, meningitis or large abscesses). Your pediatrician can advise you in proper workup and referral of conditions.