[Detection of serum free light chain and its clinical significance in nonsecretory multiple myeloma].
OBJECTIVE
To explore the clinical significance of serum free light chain (sFLC) levels in nonsecretory multiple myeloma (NSMM).


METHODS
Nine NSMM patients were hospitalized in our department from Feb 2002 to Sep 2006 and no M-components was found in their serum and urine by immunofixation electrophoresis (IFE). sFLC was assayed by immuno-nephelometry. The clonality of sFLC was estimated by serum kappa:lambda sFLC ratio. Meanwhile, serum immunoglobulin, total kappa and lambda light chain level were also determined in these patients.


RESULTS
Increased serum concentrations of either kappa or lambda sFLC (and abnormal kappa/lambda ratios) were detected in 6 of 9 patients with NSMM although their serum immunoglobulin levels were not elevated and total kappa:lambda light chain ratios (1.32 - 2.20) were in the reference range. All the 9 patients had clonal IgH gene rearrangements.


CONCLUSIONS
Quantification of sFLC by immuno-nephelometry is more sensitive than that of serum total light chain measurement and is helpful in estimating the clonality of the light chain in patients with NSMM.
Chen
Hai-Fei
HF
Department of Hematology, Changzheng Hospital, Shanghai 200003, China.
Hou
Jian
J
Yuan
Zhen-Gang
ZG
Wang
Dong-Xing
DX
Fu
Wei-Jun
WJ
Chen
Yu-Bao
YB
D000328:Adult; D005260:Female; D006801:Humans; D007147:Immunoglobulin Light Chains / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000097:blood*; D009391:Nephelometry and Turbidimetry; D012680:Sensitivity and Specificity
D007147:Immunoglobulin Light Chains