At a glance
Also known as
B2M; β2-Microglobulin; Thymotaxin
Why get tested?
To help evaluate the severity and of multiple myeloma, leukaemia, or lymphoma; to distinguish between kidney disorders; and to detect kidney damage
When to get tested?
When you have been diagnosed with multiple myeloma or certain other cancers; sometimes to monitor treatment; when you have signs associated with kidney dysfunction
A blood sample drawn from a vein in your arm; sometimes a ; rarely, a sample
Test preparation needed?
What is being tested?
Beta2-microglobulin (B2M) is a that is found on the surface of almost all cells in the body. It is present in most body fluids and is increased in the blood with cancers such as multiple myeloma, leukaemia and lymphoma, and with inflammatory disorders. This test measures B2M in the blood, urine or rarely, in the .
In the kidneys, B2M passes through blood filtering units, the , and is then reabsorbed by the - these are structures that reclaim water, proteins, vitamins, minerals and other substances that are useful to the body. Normally, only small amounts of B2M are present in the urine but when the renal tubules become damaged or diseased, concentrations increase due to a decrease in resorption. In people with kidney disease who are undergoing , B2M can form long protein chains that can be deposited in joints and tissues, causing stiffness and pain. This condition is called B2M dialysis-associated amyloidosis.
B2M levels can be increased in the CSF of patients with blood cell cancers involving the brain, such as leukaemia and lymphoma, but also with some disorders such as multiple sclerosis, and with viral infections such as HIV.
How is the sample collected for testing?
A blood sample is obtained by inserting a needle into a vein in the arm. A can also be collected. Rarely, a sample can be collected by a doctor from the lower back using a procedure called a or spinal tap.
Is any test preparation needed to ensure the quality of the sample?
No test preparation is needed