Fast Five Quiz: Cold Agglutinin Disease

Salman Aljubran, MD


November 18, 2021

Figure 2. Macrophage destroying red blood cells. Colored scanning electron micrograph of a macrophage white blood cell (center) destroying the body's own red blood cells (smaller cells). The loss of red blood cells in this way causes a condition known as autoimmune hemolytic anemia.

Proper handling of specimens is essential when investigating for cold agglutinins. Blood should be kept warm until it is tested and not placed in a laboratory refrigerator.

Depending on the extent of hemolysis, elevated LDH values and total and direct bilirubin levels are seen in patients with CAD.

Cryoglobulin levels only need to be tested if vascular purpura or other atypical findings, such as elevated levels of IgM and/or hepatitis virus antibodies, are found.

Both cold agglutinin titer and direct Coombs test should be performed in the workup for CAD. Other blood studies that are used in the diagnosis of CAD include:

  • Complete blood cell count with differential

  • Peripheral blood smear

  • Reticulocyte count

  • Serum protein electrophoresis and serum immunoelectrophoresis (immunofixation)

Learn more about the workup of CAD.


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