Immunodeficiency

Last updated: Tuesday, 14, December, 2010
CausesAppropriate Tests

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.

See also Table 2 Reference intervals for immunoglobulins G, A, M (g/L)

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

Primary immunodeficiency

Molecular genetics may be of assistance - consult pathologist.

Antibody deficiency, especially

  • Common variable immunodeficiency

Lymphocyte typing and surface markers - consult pathologist.

  • Transient hypogammaglobulinaemia of infancy
  • X-linked hypogammaglobulinaemia (Bruton)
  • Selective IgA deficiency
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 subclass deficiency
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.
  • Di George syndrome (thymic aplasia)
Calcium, phosphate, albumin, protein (total).
  • Chronic mucocutaneous candidiasis
Candidiasis

Combined cell mediated and antibody deficiency, including

  • Severe combined immunodeficiency (SCID)
Molecular testing.
  • SCID with adenosine deaminase deficiency
Adenosine deaminase - red cell.
  • Wiskott-Aldrich syndrome
Associated eczema, thrombocytopenia, platelet dysfunction. Decreased IgM; increased IgA, IgE.
  • Ataxia telangiectasia
IgA levels are reduced.

Neutrophil defects, especially

  • Congenital neutropenia
  • Neutrophil dysfunction, especially
    • Chronic granulomatous disease
    • Myeloperoxidase deficiency
  • Lazy leucocyte syndrome
  • Job’s syndrome
  • Chediak-Higashi syndrome
  • Leucocyte adhesion deficiency

 


Neutrophil function studies.

 


Immunoglobulin E.
Blood film, platelet count; platelet aggregation/release studies.

Complement defects, especially

  • C1q, C4, C2 (SLE-like syndromes)
  • C3 (recurrent infections)
  • C5, C6, C7 or C8 (recurrent infections with Neisseria sp
  • C1 inhibitor deficiency
Complement CH50 or CH100: if abnormal, individual complement components should be measured.

Secondary immunodeficiency

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.

Malignant disorders

Multiple myeloma

Chronic lymphocytic leukaemia

Hodgkin's disease

Hypoproteinaemic states

Malnutrition

Protein losing enteropathy, especially

  • Intestinal lymphangiectasia
May be associated with severe lymphocytopenia.

Nephrotic syndrome

Following plasmapheresis

Iatrogenic, especially

  • Glucocorticoids
  • Cytotoxic drugs
  • Irradiation

Infection, especially

See also AIDS

Metabolic, especially

  • Chronic renal failure
See Renal failure

Others, including

  • Trauma
  • Surgery, anaesthesia
  • Extremes of age
  • Hyper IgM syndrome

Flow cytometry