Serum/Plasma Free Light Chain Kappa to Lambda Ratio (Free Light Chain Ratio)

What Is a Free Light Chain Ratio Test Used For?

A free light chain ratio test is primarily used to detect and monitor conditions where plasma cells produce an excess of either kappa or lambda light chains, such as multiple myeloma, lymphoma, or other monoclonal gammopathies. It can also help evaluate kidney function indirectly by measuring protein levels in the blood.

How Is the Test Performed?

A blood sample is drawn from a vein in your arm. The sample is then processed to separate the free light chains (kappa and lambda) from other blood components. The test measures the concentration of these light chains using a specialized immunoassay method.

What Does the Test Result Mean?

Results are typically expressed as a ratio of kappa to lambda light chains. An abnormal ratio may indicate an underlying condition affecting plasma cells. Your healthcare provider will interpret the results in the context of your medical history and other test results.

Common Conditions Monitored

This test is often used to diagnose or monitor multiple myeloma, a cancer of plasma cells, as well as other conditions like Waldenström macroglobulinemia, lymphoma, or benign monoclonal gammopathies. It can also help assess kidney function in patients with these conditions.