Lab Test: Cold Agglutinin Titer Level
- Titers less than 1:32 are nondiagnostic* (PDR)
- Screen: negative
- Titer: no agglutination ≤ 1:64
- Cold autoimmune hemolytic anemia:
- Markedly elevated,
usually in the range of 1:1,024 to 1:512,000.
- Titer decreases after treatment.
- Suspected Mycoplasma pneumoniae pneumonia:
- An initial titer of 1:128, or a four-fold increase
between the acute and convalescent sera, suggests mycoplasma pneumonia.
- A negative titer does not necessarily exclude the diagnosis.
- Cold agglutinins are antibodies (usually IgM) to erythrocytes. All individuals have circulating antibodies directed against red blood cells, but their concentrations are often too low to trigger disease or symptoms (titers < 1:64). In individuals with cold agglutinin syndrome, these antibodies are much higher (> 1:512). At body temperatures of 28-31°C, these antibodies can cause a variety of symptoms (from chronic anemia caused by intravascular hemolysis or extravascular sequestration of affected RBCs leading to acrocyanosis of the ears, fingers, or toes because of local blood stasis in the skin capillaries).
- Hemolysis occurs in association with very high cold agglutinin titers (greater than 1:500).
- Increased levels may indicate:
- Mycoplasma pneumoniae infection, viral illness, infectious mononucleosis, multiple myeloma, scleroderma, cirrhosis, staphylococcemia, thymic tumor, influenza, rheumatoid arthritis, lymphoma, systemic lupus erythematosus, or primary cold agglutinin disease.
- Mycoplasma pneumonia Antibodies - the serologic identification of IgG and IgM antibodies to Mycoplasma are used to support the clinical diagnosis of the infection.
- Results increased in blood dyscrasias, liver disease, or collagen vascular diseases
- Some antibiotics (penicillin and cephalosporins) can interfere with the development of cold agglutinins.
- Transport the specimen immediately to the laboratory.
- Keep sample at 37°C8 (PDR)
- Under no circumstances should be cold agglutinin specimen be refrigerated. (Mosby's)
- Explain the procedure to the patient.
- Tell the patient that no fasting is required.
Indications & Uses
Storage and Handling
What To Tell Patient Before & After
MESH Terms & Keywords