The immune system protects the body from the invasion of foreign microorganisms such as bacteria and viruses. Primary immunodeficiency disease (PIDD) results either from absence or dysfunction of the immune system secondary to a genetic defect. More than 150 different types of PIDD have already been identified.
Serious PIDDs can be identified during the period of infancy itself. However, mild PIDDs may become apparent only when evaluating an individual with recurrent infection. Sometimes PIDDs are identified only after the patients reach adulthood.
Primary immunodeficiency disease (PIDD) results either from absence or dysfunction of the immune system secondary to a genetic defect.
Signs and symptoms
Immunodeficiency results in recurrent infection by opportunistic organisms that may not cause a disease in normal individuals. Hence immunodeficient individuals are more prone to ear infections, sinusitis and pneumonia. These recurrent infections can cause poor growth and loss of weight in affected children. Patients may also present with recurrent deep abscesses in the skin and other organs.
An allergist or immunologist can accurately diagnose the type of PIDD and devise an effective treatment plan. To diagnose PIDD the doctor may ask you about your medical history as well as history of any PIDD in your family. After a thorough physical examination the doctor may order some blood tests to identify the type of immune cells affected by the genetic defect as well as the nature of dysfunction. These tests include blood count, quantitative immunoglobulin assay, antibody response as well as complement and skin tests. Biological samples of the infected tissue may also be evaluated to identify the organism responsible for recurrent infection.
Prenatal test are available to identify any PIDD during pregnancy if there is already a history of a previous child with PIDD. In case of a positive result, treatment can be initiated immediately after birth.
These infections are resistant to treatment and may require either multiple courses of antibiotics or intravenous antibiotics for appropriate management. Treatment of PIDD involves:
- Boosting the immune system: Immunoglobulin therapy, gamma interferon therapy or growth factor therapy may help in supplementing the functioning of the immune system.
- Treating the infections with appropriate antibiotics and symptomatic management with appropriate drugs.
- Stem cell transplantation: Using stem cells obtained either from the patient’s placenta at birth or from the marrow of a matched donor, transplantation offers a permanent cure for a majority of PIDDs. However, in some cases the transplanted stem cells may be rejected by the recipient’s immune system.
- The role of gene therapy in management of PIDDs is being evaluated. This therapy involves the substitution of the defective gene with a normal gene. Trials are being conducted to evaluate the efficacy of this therapy.