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Published on: December 15, 2011
IgG2 class red cell antibodies and autoimmune haemolysis
R J Sokol1, R Stamps, D J Booker
1National Blood Service, Trent Centre, Sheffield, UK. robert.sokol@nbs.nhs.uk
Haematologia
|May 10, 2001
Summary
IgG2 autoantibodies rarely cause autoimmune haemolysis, typically requiring specific Fc receptor interactions and antigen presentation on red blood cells. Complement activation by IgG2 can also contribute to red cell destruction.
Area of Science:
- Immunohaematology
- Autoimmune diseases
Background:
- Autoimmune haemolysis involves autoantibodies targeting red blood cells.
- The specific role of IgG2 autoantibodies in this process is not fully understood.
Purpose of the Study:
- To investigate the contribution of IgG2 red cell autoantibodies to autoimmune haemolysis.
Main Methods:
- Review of immunohaematology case records.
- Detection of IgG2 autoantibodies using direct antiglobulin testing and red cell eluates.
Main Results:
- Two patients with IgG2 autoantibodies and complement deposition on red cells developed autoimmune haemolytic anaemia.
- IgG2 autoantibodies alone were detected in less than 1% of patients with warm autoantibodies.
Conclusions:
- IgG2 autoantibodies rarely cause haemolysis, but can contribute when specific conditions are met.
- Factors influencing IgG2-mediated haemolysis include Fc receptor polymorphisms (FCRIIA) and red cell antigen topography.
- Synergistic effects between IgG2 and complement (C3) can lead to significant red cell destruction.
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