Last updated: Tuesday, 14, December, 2010
Investigation for immunodeficiency should be considered in patients with severe or recurrent infection, infection with unusual organisms (eg, Pneumocystis carinii), or unexplained chronic diarrhoea - especially if there is a family history of similar problems or if other symptoms and signs suggesting immunodeficiency are present.
Initial testing includes FBC, differential WCC, blood film; immunoglobulins G, A, M; blood group (including 'reverse group') with isohaemagglutinin titres; lymphocyte typing.
Further specialised testing is indicated if clinical suspicion is high and/or abnormalities have been detected on initial testing.
Primary immunodeficiency states are far less common than secondary immunodeficiency.See also Infection (increased susceptibility) and Opportunistic infections
|Molecular genetics may be of assistance - consult pathologist.|
Antibody deficiency, especially
Lymphocyte typing and surface markers - consult pathologist.
|IgG sub-classes and specific antibody responses (eg, following pneumococcal vaccination) are indicated if there is a significant history of infection; anti IgA antibodies.|
|IgG sub-classes and specific antibody responses are indicated if there is a significant history of infection.|
Cell mediated immunodeficiency, including
|Measurement of cytokines following lymphocyte activation; lymphocyte proliferative response - consult pathologist.|
|Calcium, phosphate, albumin, protein (total).|
Combined cell mediated and antibody deficiency, including
|Adenosine deaminase - red cell.|
|Associated eczema, thrombocytopenia, platelet dysfunction. Decreased IgM; increased IgA, IgE.|
|IgA levels are reduced.|
Neutrophil defects, especially
Complement defects, especially
|Complement CH50 or CH100: if abnormal, individual complement components should be measured.|
|Secondary immunodeficiency may be due to a number of mechanisms in any one patient, including breach of the integument, antibody deficiency, cell mediated immune defects, neutrophil dysfunction, neutropenia.|
Protein losing enteropathy, especially
|May be associated with severe lymphocytopenia.|
|See also AIDS|
|See Renal failure|