A Thermal Amplitude Blood Test can be used to help confirm a diagnosis of Cold Agglutinin Disease.
This is a very non-technical explanation of the Thermal Amplitude Blood Test, in the simplest of terms. In technical laboratory terms there is far more to this.
The thermal amplitude test measures the temperatures at which red blood cells clump together in the case of a CAD patient. Measuring the temperature point, at which Agglutination (Clumping) occurs.
Normal blood should not create clumping during a thermal amplitude test.
The blood sample of people with CAD will cause clumping of red cells at temperatures below 98.6°F/37°C. The closer to body temperature clumping occurs, the more harmful or cold react-able, the patient’s cold agglutinin’s are.
This test often makes notable observations at various temperatures down to 40°F/4.4°C, to identify where clumping starts taking place.
For people who exhibit a thermal amplitude that is very high [as in, clumping occurs at high temperatures…approaching body temperature] special blood collection and handling may be needed to prevent the blood from clumping as it is collected for the test.
We often talk about alternate protocols for blood testing throughout our material, especially when collecting and testing RBC/CBC. This Thermal Amplitude Blood Test falls in this category as well.
Though this test might identify at which temperature the blood will start to clump in the lab, it would be difficult to translate that to the exact air temperature a CAD would need to avoid. It is not directly relatable.
Clothing, cold exposure length, even ones health circulation or lack there of. As well as numerous other factors, will all come into play.
The higher the temperature you test at for clumping, the more you should be concerned about the cold though. Even down to cold drinks, cold foods, swimming, and wet/damp evaporation type hazards. That is just a list of a few.