Cold antibody

• Immediate spin screen and panel cell reactions will be postive (W+ to 4+). The auto control may also be positive.
• AHG reactions may be weakly positive if the cold antibody is bound strongly to the red cells.
• Prewarming should prevent binding from occuring. So, prewarm panels and tests should have negative reactions.

Warm antibody

• Immediate spin screen, panel cell and auto control usually not positive.
• AHG reactions will be positive including auto control (W+ to 4+).
• Prewarming of sample and reagents will not change positive reactions since they react best at 37°C and AHG phase. So, reactions will still be positive.
• Elution and autoadsorption techniques may be used to help further identify the antibody or to help identify other clinically significant antibodies that may be present.

Autoadsorption

Autoadsorption is a technique that involves adsorbing unbound autoantibody from the patient's serum using the patient's own red cells. Once the autoantibody is removed, then testing can be performed to determine if any clinically significant antibodies are present.