What are Primary Immune Deficiencies?

Defects in immunity can be classified into:

• Primary disorders, due to an inherent defect in the immune system.
   
• Secondary, i.e. acquired in relation to a known medical condition.
   
• Auto-immune, i.e. the immune system reacting against  the patient´s own body

They may involve specific or non specific immune mechanisms.
However, many defects may be subtle or transient or defy classification.

Immunodeficiency should be suspected in every patient, irrespective of age, who has recurrent, persistent, severe or unusual infections.

The World Health Organization recognizes approximately 70 primary immune deficiencies including X-Linked Agammaglobulinemia (Bruton's Disease), Common Variable Immune Deficiency (also called Hypogammaglobulinemia), Selective IgA Deficiency, and Severe Combined Immune Deficiency (boy-in-the-bubble disease).

Some disorders such as Selective IgA Deficiency can be quite common, occurring as often as 1/500 to 1/1000 individuals. Others may be as rare as 1 individual affected per million. Untreated primary immune deficiencies are characterized by frequent life-threatening infections and debilitating illnesses.

Because of advances in our medical understanding and treatment of primary immune deficiency diseases, many patients who in the past would not have survived childhood are now able to live nearly normal lives. Most primary immune deficient patients require life long therapies including intravenous gammaglobulin infusion, aggressive antibiotic therapies, or bone marrow transplantation.