Autoimmune haemolysis

Causes

Appropriate Tests

 

The following investigations are generally considered to constitute a haemolysis screen:

Full blood count and Blood film, Reticulocyte count. Direct antiglobulin test (Direct Coombs) and Indirect Coombs test. Lactate dehydrogenase, Haptoglobin. A Haemosiderin urine and Haemoglobin, might be performed to demonstrate intravascular haemolysis, if necessary.

The Direct antiglobulin test will usually be positive in autoimmune haemolysis, the pattern of positivity providing some indication of the thermal characteristics of the red cell autoantibody (ie, 'warm' or 'cold' antibody-mediated haemolysis).

Red cell compatibility testing may be difficult in patients with autoimmune haemolysis, so ABO Rh Blood group and antibody screen with an extended red cell phenotype should be requested at the time of the diagnosis and as far as possible prior to any transfusion; consult haematopathologist.

See also Haemolysis and Haemolysis (neonatal).

'Warm' antibody haemolysis

Direct antiglobulin test detects IgG antibodies bound to patient red cells, with or without complement present also.

SLE

 

Lymphoproliferative disorders, especially Chronic lymphocytic leukaemia

Haemolytic anaemia may precede the diagnosis of, be a presenting feature of, or complicate established lymphoproliferative disorder.

Peripheral blood immunophenotype (Flow cytometry); Bone marrow biopsy, aspiration and trephine, may be indicated if underlying malignancy (especially lymphoproliferative disorder) is suspected.

Drug-induced, especially methyldopa, penicillin, cephalosporins, quinidine

Ensure that the recent drug history is included on the laboratory request form. Indirect Coombs test, with in vitro addition of drug, if appropriate.

'Cold' antibody haemolysis

Usually due to IgM antibodies; Direct antiglobulin test usually detects complement only bound to red cells. Cold agglutinins.

Mycoplasma infection

Antibody has anti-I specificity.

Infectious mononucleosis

Antibody has anti-i specificity. Epstein-Barr virus serology.

Lymphoma (non-Hodgkin)

 

Idiopathic

 

  • Cold haemaglutinin disease

 

Paroxysmal cold haemoglobinuria

 

  • Viral infections

Donath-Landsteiner Ab

  • Syphilis