TY - JOUR
T1 - The relationship between the serum free light chain assay and serum immunofixation electrophoresis, and the definition of concordant and discordant free light chain ratios
AU - Singhal, Seema
AU - Vickrey, Eric
AU - Krishnamurthy, Jairam
AU - Singh, Veerpal
AU - Allen, Sharon
AU - Mehta, Jayesh
PY - 2009
Y1 - 2009
N2 - "Stringent" complete remission in myeloma has been defined by a normal serum free light chain ratio (SFLCR) in addition to the standard criteria for CR. 2648 serial samples from 122 IgG or IgA myeloma patients were studied to explore the relationship between SFLCR and serum immunofixation electrophoresis (SIFE). SFLCR was normal in 34% of cases with positive SIFE and abnormal in 66%. SFLCR was normal in 69% of cases with negative SIFE and abnormal in 31%. When evaluated with SIFE as the benchmark, the sensitivity of SFLCR was 66% and specificity was 69%. These findings were unchanged when abnormal SFLCR values were classified as concordant (< 0.26 for λ disease and > 1.65 for κ) or discordant (< 0.26 for κ disease and > 1.65 for λ). Additional studies are required to determine the temporal relationship between SFLCR normalization and paraprotein clearance. Until then, the role of SFLCR in defining response remains controversial.
AB - "Stringent" complete remission in myeloma has been defined by a normal serum free light chain ratio (SFLCR) in addition to the standard criteria for CR. 2648 serial samples from 122 IgG or IgA myeloma patients were studied to explore the relationship between SFLCR and serum immunofixation electrophoresis (SIFE). SFLCR was normal in 34% of cases with positive SIFE and abnormal in 66%. SFLCR was normal in 69% of cases with negative SIFE and abnormal in 31%. When evaluated with SIFE as the benchmark, the sensitivity of SFLCR was 66% and specificity was 69%. These findings were unchanged when abnormal SFLCR values were classified as concordant (< 0.26 for λ disease and > 1.65 for κ) or discordant (< 0.26 for κ disease and > 1.65 for λ). Additional studies are required to determine the temporal relationship between SFLCR normalization and paraprotein clearance. Until then, the role of SFLCR in defining response remains controversial.
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U2 - 10.1182/blood-2009-02-205807
DO - 10.1182/blood-2009-02-205807
M3 - Article
C2 - 19411633
AN - SCOPUS:67651046994
SN - 0006-4971
VL - 114
SP - 38
EP - 39
JO - Blood
JF - Blood
IS - 1
ER -