Primary Immunodeficiency Disease (PIDD)

What is Primary Immunodeficiency Disease (PIDD)?

Primary Immunodeficiency Diseases (PIDD) are a group of more than 300 diseases. These conditions are due to defects in the body’s defenses (immune system).

In most cases, PIDD are associated with acute or recurrent infections, depending on the portion of the immune system affected. Most PIDD are inherited in our genes, so they are present at birth, but they often do not become apparent or diagnosed until late in childhood–or even in adult life. It often takes time for a pattern of recurrent infections or other symptoms to develop before a PIDD is suspected. There are more than 200 different genetic causes of PIDD.

Common Symptoms

  • Recurrent, unusual, or difficult to treat infections
  • Poor growth or loss of weight
  • Recurrent pneumonia, ear infections or sinusitis
  • Multiple courses of antibiotics or IV antibiotics necessary to clear infections
  • Recurrent deep abscesses of the organs or skin
  • A family history of PIDD
  • Swollen lymph glands or an enlarged spleen


Research in primary immunodefeciency is making great strides, improving treatment options and enhancing the quality of life for most people with these complex conditions. Treatment options are targeted toward the specific immune defects and can include transplantation (bone marrow, stem cell, thymus), immunoglobulin (antibody) replacement, preventative antibiotics and strategies to manage autoimmune disease. Gene therapy has been successful in specific types of PIDD.