Serum Free Light Chains

Department of Immunology

Notes

• Quantifies serum free light chains kappa and lambda, and their kappa: lambda ratio. When tumours produce a monoclonal excess of only one of the light chains the ratio becomes abnormal. When there is renal impairment or an increase in polyclonal production the ratio remains normal.
• Of value in the diagnosis and monitoring of patients with light chain myeloma, non-secretory myeloma and primary light chain amyloidosis (AL amyloidosis). Also automatically added to patients with a new diagnosis of multiple myeloma, particularly in those with poor renal function.
• After initial diagnosis it is only necessary to re-test every 6 months, unless under the care of Haematology.
• Test performed by Immunology, North Bristol NHS Trust.

Sample Requirements

Clotted blood. (No special patient preparation needed)

Adult

5ml Gold-top SST tube or 3.5ml Rust-top gel tube (Trust users only)

Paediatric

1ml Serum Sample

Time Limit for Add-ons

3 days

Turnaround Times

7 days

Reference Range

Free Kappa light chains: 3.3 - 19.4 mg/L

Free Lambda light chains: 5.7 - 26.3 mg/L

Serum Kappa: Lambda ratio: 0.26 - 1.65