Clinical Significance of Free Light Chain Tests for Multiple Myeloma Diagnosis

Objective Evaluation of the tests of Immunofixation Electrophoresis(IFE),urine light chain quantitive analysis and serum free light chain immunoassay for measurement of free light chain in multiple myeloma patients.Methods Turbidimetric method was used to quantify heavy chains,and total light chains(free and combined light chains),protein electrophoresis(PE) and IFE were used to identify and type the M proteins in 21 light chain multiple myeloma(LCMM)and 29 intact immunoglobulin multiple myeloma(IIMM)patients;.Detection rate and accuracy of the three kinds of tests were compared.Results In LCMM patients,the detection rate for immunofixation Electrophoresis,urine light chain quantitive analysis and serum free light chain immunoassay were 90.5 %(19/21);80.9 %(17/21);100%(21/21)and were20.7 %(6/29);41.4 %(12/29);82.7 %(24/29)in IIMM patients,and all the combining monoclonal light chains were detected by IFE.Conclusion Serum free light chain immunoassay was more sensitive than the other two,if combining with IFE,they will help to diagnose,monitor and improve prognosis of multiple myeloma patients.