Immunoglobulin Free Light Chains, Serum

Clinical Use

Use

This test is useful for monitoring patients with monoclonal light chain diseases, such as multiple myeloma, light chain multiple myeloma, and other monoclonal gammopathies. It helps in the detection of free light chains in serum and is particularly beneficial when traditional M-protein is not present in significant concentrations. The test may also assist in the diagnosis of conditions like primary systemic amyloidosis, light chain deposition disease, and non-secretory myeloma, where standard immunofixation results may be negative.

Special Instructions

Not provided.

Limitations

Elevated levels of kappa and lambda free light chains may occur due to polyclonal hypergammaglobulinemia or impaired renal clearance. The test is not established for pediatric use, and extreme lipemic samples can interfere with the results. Undetected antigen excess may rarely affect outcomes, and so interpreting results should always consider other laboratory tests and clinical features. Awareness of assay-specific variability is crucial for reducing clinically meaningful misclassification.

Test Details

FDA Approved