Synonyms: Cryoglobulins
Clinical significance
Cold agglutinins are autoantibodies against red blood cells that can agglutinate red cells at temperatures below 20-25°C; the reaction is fully reversible when the temperature is brought back to 37°C.
High titres of cold agglutinins (antibodies against the red cell “I” antigen) are found in about 50% of cases of infection with Mycoplasma pneumoniae, Legionella and viruses.
Cold agglutinins can also be found in lymphomas, collagen diseases, chronic liver disease with marked hypergammaglobulinaemia and in cold agglutinin haemolytic anaemia.
Clinical indications
Cold agglutinin disease; haemolytic anaemias; infections with Mycoplasma pneumoniae, Legionella and viruses (mononucleosis), trypanosomiasis; lymphomas, collagen diseases, chronic liver disease.
Sample type
The patient must have a blood sample taken
Preparation
You must fast for at least 8 hours; a small amount of water is allowed. You must have been standing or sitting upright for at least 30 minutes.
Notes
Low titres of cold agglutinins can also be found in normal people.