Serum or Plasma Free Light Chain (Total) with Immunofixation Support

Why This Test Is Done

Your healthcare provider may order this test if you have symptoms like unexplained fatigue, frequent infections, or kidney problems. It can also be part of a broader evaluation for blood cancers, such as multiple myeloma, or conditions like amyloidosis. Sometimes, it’s used alongside immunofixation to confirm specific types of light chain abnormalities.

What to Expect Before the Test

No special preparation is needed. You’ll provide a blood sample, usually drawn from a vein in your arm. If you’re on blood thinners, let your provider know before the test.

What the Test Results Mean

Results show the total free light chain levels in your blood. High levels may indicate conditions like multiple myeloma, where plasma cells produce too many light chains. Low levels are less common but can occur in rare immune system disorders. Your provider will interpret results in the context of your symptoms and other tests.

Common Conditions Linked to Abnormal Results

Elevated free light chains are most often linked to plasma cell disorders, such as multiple myeloma or monoclonal gammopathy of undetermined significance (MGUS). They can also appear in other conditions like chronic lymphocytic leukemia or certain autoimmune diseases. Immunofixation testing helps identify whether the light chains are monoclonal (abnormal) or polyclonal (normal).