Serum or plasma free light chains (kappa and lambda) by nephelometry

Why Is This Test Done?

Your healthcare provider may order this test if you have symptoms like unexplained fatigue, frequent infections, bone pain, or kidney problems. It may also be used to monitor conditions like multiple myeloma, lymphoma, or other plasma cell disorders. Sometimes, it’s part of a broader evaluation for unexplained anemia or kidney function issues.

What Does the Test Measure?

The test measures two types of free light chains: kappa and lambda. These are protein fragments that normally come from the breakdown of heavy and light chains in antibodies. When plasma cells (a type of white blood cell) produce too many antibodies or abnormal proteins, these light chains can build up in the blood.

How Is the Test Performed?

A blood sample is drawn from a vein, usually in your arm. The sample is sent to a lab where special equipment measures the concentration of free light chains using a technique called nephelometry, which detects light scattering caused by the proteins.

What Do Results Mean?

Results are reported as separate values for kappa and lambda light chains. Elevated levels of one or both can indicate conditions like multiple myeloma, where plasma cells produce abnormal proteins. Very high levels may also suggest other disorders affecting plasma cells or kidney function. Normal results mean no significant abnormalities were detected in this test alone.