Serum or Plasma Free Light Chain Immunoassay (kappa and lambda)

Why This Test Might Be Ordered

Your healthcare provider may order this test if you have symptoms like unexplained fatigue, frequent infections, kidney problems, or unexplained bone pain. It’s also used to monitor conditions like multiple myeloma, lymphoma, or other blood cancers. Sometimes, it’s part of a broader evaluation for kidney disease or other systemic illnesses affecting plasma cells.

What to Expect Before the Test

No special preparation is needed. You may have a small needle inserted into your arm or vein to draw blood. If you’re taking blood from your own arm, you might use a tourniquet to help make the vein more visible. The process usually takes a few minutes.

What the Test Results Mean

High levels of free light chains can indicate conditions like multiple myeloma, where plasma cells produce too many abnormal proteins. Low or normal levels are less concerning but may still be checked in certain situations. Your healthcare provider will discuss the results in the context of your overall health and symptoms.

Common Conditions Monitored or Diagnosed

This test is often used to diagnose or monitor multiple myeloma, lymphoma, or other blood cancers. It can also help detect kidney problems caused by abnormal protein buildup or evaluate conditions like monoclonal gammopathy of undetermined significance (MGUS).