Detection of serum free light chain and its clinical significance in nonsecretory multiple myeloma / 中华血液学杂志

ABSTRACT

<p><b>OBJECTIVE</b>To explore the clinical significance of serum free light chain (sFLC) levels in nonsecretory multiple myeloma (NSMM).</p><p><b>METHODS</b>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 kappalambda sFLC ratio. Meanwhile, serum immunoglobulin, total kappa and lambda light chain level were also determined in these patients.</p><p><b>RESULTS</b>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 kappalambda light chain ratios (1.32 - 2.20) were in the reference range. All the 9 patients had clonal IgH gene rearrangements.</p><p><b>CONCLUSION</b>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.</p>