Physician Center

Free Light Chains (Serum)

Click here For other test information about Serum Free Light Chains.

To aid in the diagnosis of:

  • Light Chain (Bence Jones) Multiple Myeloma (LCMM)
  • Nonsecretory Multiple Myeloma (NSMM)
  • AL amyloidosis
  • Light Chain Deposition Disease (LCDD)
  • Waldenstöms Macroglobulinaemia

An aid to monitoring treatment and disease in:

  • Intact Immunoglobulin Multiple Myeloma (IIMM)
  • Light Chain Multiple Myeloma
  • Nonsecretory Multiple Myeloma
  • AL amyloidosis
  • Light Chain Depository Disease
  • Waldenstöms Macroglobulinaemia

 

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Serum kappa and lambda concentrations in a selection of clinical conditions. Patients are categorized according to serum free light chain concentrations and k/λ ratios. Diagonal lines separate monoclonal from polyclonal diseases.

 
plgG- polyclonal hypergammaglobulinaemia
Sector numbers refer to table opposite.

Freelite results should be considered under the following categories and investigated appropriately:
  1. Normal samples. Serum k, λ and k/λ ratio are all within the normal ranges. if accompanying serum electrophoretic tests are normal it is most unlikely that the patient has a monoclonal gammopathy.
  2. Abnormal k/λ ratios. Support the diagnosis of monoclonal gammopathy and require an appropriate tissue biopsy. Borderline elevated k/λ ratios occur with renal impairment and may require appropriate renal function tests.
  3. Low concentrations of k, λ or both. Indicate bone marrow function impairment.
  4. Elevated concentrations of both k and λ with normal k/λ ratio. May be due to the following:
    - Renal impairment (common)
    - Over-production of polyclonal FLCs from inflammatory conditions (common)
    - Biclonal gammopathies of different FLC types (rare)
  5. Elevated concentrations of both k and λ with an abnormal k/λ ratio. Suggest a combination of monoclonal gammopathy and renal impairment.


Serum Reference intervals and Diagnostic Ranges for Free k and λ Immunoglobulin Light Chains: Relative Sensitivity for Detection of Monoclonal Light Chains. Katzmann et al. Clin Chem 2002;48:1437-1444.

Monitoring Response

AL amyloidosis - Hematological response criteria


Definition of Organ Involvment and Treatment Response in Immunoglobulin Light Chain Amyloidosis (AL): A Consenus Opinion From The 10th International Symposium on Amyloid and Amyloidosis. Gertz et al. American Journal of Hematology 2005; 79:319-328


Monoclonal Gammopathies

Patients can be monitored serially using the light chain levels and the ratio. Recently the International uniform response criteria has indicated using the difference in values between the tumor involved light chain and the uninvolved light chain. These criteria provide standardization for clinical outcomes in trials.

 

Sections relevant to serum free light chain (FLC) measurements:


* where immeasurable by SPE, 24h UPE or quantitative immunoglobulin analysis.

International uniform response criteria for multiple myeloma
BGM Durie et al. Leukemia 2006;20(9):1467-1473