Correlation of Serum Free Light Chain Levels with Other Parameters in Myeloma.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 5019-5019
Author(s):  
Regina Stein ◽  
Jayesh Mehta ◽  
Eric Vickrey ◽  
William Resseguie ◽  
Seema Singhal

Abstract Estimation of serum free light chains (SFLC; SFKLC - kappa, SFLLC - lambda, SFKLR - kappa:lambda ratio; normal 0.26–1.65.) is useful in selected patients with non-secretory myeloma, and in light chain disease with anuric renal failure. Its utility in other clinical situations is unclear. 489 SFLC levels in 135 myeloma patients were analyzed to see if there was a significant correlation between them and other, more conventional immunologic parameters such as serum total light chain (STLC; STKLC - kappa, STLLC - lambda) levels and immunoglobulin (Ig) levels. The underlying premise was that lack of significant correlation would suggest potential value of SFLC independent of standard tests, whereas significant correlation would suggest questionable independent value of SFLC. The table below shows SFLC and STLC levels and ratios. Parameter Median (range) Correlation with SFKLC Correlation with SFLLC Correlation with free k:l ratio SFKLC 14.4 (0.59–11525) SFLLC 18.2 (0.72–10100) Free k:l ratio 0.83 (0–1211.76) STKLC 745 (11–8810) r=0.08; P=0.07 STLLC 256 (11.6–11000) r=0.11; P=0.01 Total k:l ratio 2.51 (0–245) r=0.12; P=0.008 Poor correlation between free and total results within each light chain subtype (Figure 1 - log scale) and between free and total ratios (Figure 2- log scale) suggests that SFLC values provide information that is independent of STLC values because STLC values cannot be used to predict SFLC values. Figure Figure Figure Figure The table below shows correlation between Ig and SFLC/STLC levels. For these analyses, the total Ig of the specific heavy chain subtype and SFLC/STLC of the specific light chain subtype were studied (IgG and SFKLC with IgG kappa monoclonal protein, IgA and STLLC with IgA lambda monoclonal protein, etc). Very strong correlation between STLC and Ig levels suggests that STLC values do not provide information that is independent of Ig levels. On the other hand, poor correlation between SFLC and Ig levels suggests that SFLC values do provide information that is independent of Ig values. Monoclonal protein SFLC correlation STLC correlation IgG kappa r=0.04; P=0.66 r=0.89; P<0.0001 IgG lambda r=0.13; P=0.51 r=0.99; P<0.0001 IgA kappa r=0.49; P=0.004 r=0.77; P<0.0001 IgA lambda r=-0.04; P=0.89 r=0.94; P<0.0001 These data show that SFLC estimation provides information that is independent of standard quantitative serologic tests used in plasma cell dyscrasias. However, rigorous prospective evaluation of the test is needed to see if this additional information is of any clinical relevance in settings other than non-secretory disease and light chain disease with anuria.

2018 ◽  
Vol 93 (10) ◽  
pp. 1207-1210 ◽  
Author(s):  
Marcella Tschautscher ◽  
Vincent Rajkumar ◽  
Angela Dispenzieri ◽  
Martha Lacy ◽  
Morie Gertz ◽  
...  

2019 ◽  
Vol 23 (6) ◽  
pp. 763-772
Author(s):  
Olga Kukuy ◽  
Batia Kaplan ◽  
Sizilia Golderman ◽  
Alexander Volkov ◽  
Adrian Duek ◽  
...  

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 4856-4856
Author(s):  
Arthur R. Bradwell ◽  
Jean Garbincius ◽  
Earle W. Holmes

Abstract Serum free light chain measurements have been shown to be useful in the diagnosis and monitoring of patients with monoclonal gammopathies. The present study was undertaken to evaluate the effect of adding the measurement of serum free light chain kappa to lambda ratios to the serum protein electrophoresis evaluation that we typically use as an initial screen for the detection of monoclonal proteins. We retrospectively tested 347 consecutive samples from individuals who had no previous history of plasma cell dyscrasia and had not previously had a serum or urine electrophoresis or immunofixation electrophoresis test at our institution. The quantitative serum protein electrophoresis test that was ordered was performed using Hydragel Beta 1- Beta 2 gels and Hydrasis instrument (Sebia, Inc., Norcross, GA). The protein content of the electrophoresis zones were quantitated by scanning densitometry and the electrophoresis pattern of each sample was qualitatively examined for abnormal bands and suspicious findings by a single, experienced observer. Serum free light chain concentrations and the serum free light chain kappa to lambda ratios were determined using the Freelite Human Kappa and Lambda Kits (The Binding Site Ltd, Birmingham, UK) and the Immage analyzer (Beckman Coulter Inc., Brea, CA). The serum free light chain kappa to lambda ratios were outside the reference interval (0.25 to1.65) in 23 of the samples. Ten abnormal ratios were observed among a group of 57 samples that had either positive or suspicious qualitative evaluations for the presence of a restriction or that demonstrated hypo-gammaglobulinemia. Both abnormalities led to recommendations for follow-up testing, which confirmed the presence of a monoclonal protein in 21 of the samples. Six abnormal ratios were observed among a group of 159 specimens that had quantitative abnormalities in albumin or one or more of globulin fractions (hypo-gammaglobulinemia excepted) and normal qualitative evaluations. Seven abnormal ratios were observed among a group of 131 samples that had normal quantitative results and normal qualitative evaluations. Follow-up testing is not usually recommended for serum protein electrophoresis results like those in the latter two groups. We found that the addition of the serum free light chain kappa to lambda ratio to the serum protein electrophoresis test increased the number of abnormal screens that would have required further clinical and/or laboratory evaluation by 23%(i.e. from 57 to 70). Given the high specificity of the serum free light chain kappa to lambda ratio for monoclonal light chains, the additional 13 abnormal samples identified by this test are expected to have a high likelihood of harboring a monoclonal protein that would have otherwise eluded detection. Pending a definitive prospective study, we estimate that the addition of a serum free light chain kappa to lambda ratio to the serum protein electrophoresis screen would increase the rate of detection of serum monoclonal proteins by as much as 1.6-fold.


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 5048-5048
Author(s):  
Jayesh Mehta ◽  
Regina Stein ◽  
Eric Vickrey ◽  
William Resseguie ◽  
Seema Singhal

Abstract The serum free light chain (SFLC) assay is useful in detecting monoclonal protein when there no detectable M protein on immunofixation electrophoresis (IFE). There are limited data on its value when IFE is positive. In a small series of 5 patients achieving CR, normalization of SFKLR was found to precede IFE negativity by a few weeks (Moesbauer et al. ASH 2005). Results on 231 serum samples from myeloma patients (most on therapy) where serum IFE showed IgA κ (n=33), IgA λ (n=13), IgG κ (n=153), or IgG λ (n=32), and where simultaneous SFLC and immunoglobulin (Ig) estimation had been performed were analyzed. Samples with >1 monoclonal band or multiple oligoclonal bands were excluded. The serum free κ:λ ratio (SFKLR; normal 0.26–1.65) was abnormal in 113 (49%) and normal in 118 (51%). IgG and IgA levels were compared in the context of normal versus abnormal SFKLR within each of the 4 isotypes (IgA κ, IgAλ, IgG κ, IgG λ). The table below shows that involved Ig levels were higher with abnormal than with normal SFKLR. However, uninvolved Ig levels were higher with normal than with abnormal SFKLR suggesting that normalization of SFKLR may mark a response to therapy - improved uninvolved Ig levels being evidence of response. Monoclonal protein Immunoglobulin Abnormal SFKLR Normal SFKLR P IgA kappa IgA 1640 (190–4000) 515 (102–2230) 0.048 IgA kappa IgG 419 (118–1120) 404 (197–1740) 0.39 IgA lambda IgA 408 (159–696) 704 (180–779) 0.17 IgA lambda IgG 619 (495–1510) 1530 (533–1700) 0.025 IgG kappa IgA 42 (7–225) 94 (7–642) 0.0009 IgG kappa IgG 1490 (585–5560) 1260 (327–2690) 0.004 IgG lambda IgA 32 (7–121) 96 (19–562) 0.047 IgG lambda IgG 2060 (555–12300) 1050 (432–2830) 0.018 However, does normalization of SFKLR universally herald IFE negativity? This is an important unanswered question because SFKLR is normal in a high proportion of samples which still show monoclonal protein on IFE. The figures below show scatter plots of IgG and IgA for each of the 4 isotypes for normal vs abnormal SFKLR. Within each plot, there is no obvious pattern distinguishing normal (x) from abnormal (o) SFKLR. However, there are a number of normal SFKLR points with high involved and low uninvolved Ig levels where a normal SFKLR is difficult to explain. Figure Figure Figure Figure We conclude that the SFLC assay often reveals normal SFKLR even when there is a detectable monoclonal protein in the serum. Whether this always predicts eventual paraprotein clearance and achievement of IFE negativity in patients on therapy is unknown, and needs to be studied prospectively.


Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 4750-4750
Author(s):  
Fernanda Trigo ◽  
Cristina Guimaraes ◽  
Abilia Bodas ◽  
Armando Teixeira-Pinto ◽  
Jose E. Guimaraes

Abstract Serum free light chain (FLC) levels are a useful multiple myeloma (MM) marker and a indicator of tumour burden both for diagnosis and follow up purposes. A total of 311 patient samples were assayed in our laboratory for FLC and the kappa/lambda (κ/λ) chain ratio was calculated and compared with the classical methods for characterization of gammopathy (immunofixation, IMF, immunoglobulin levels and total light chain levels and respective ratio). Ig (A, G, M) and total κ and λ chain levels were assayed by nephlometry (Dade-Behring BNII). Immunofixation was performed in a Hydrasys (Sebia) setting. FLC assay was done using Binding Site reagents (Dade-Behring). Statistical analysis was performed by SPSS® for Windows v. 15. Concordance between IMF results and free κ/λ chain ratio was calculated. Sensitivity and specificity of the free κ/λ chain ratio in the identification of positive and negative IMF were also determined. Reference intervals used for free κ/λ and total κ/λ chain ratios were [0.26; 1.65] and [1.35; 2.65], respectively. Out of 311 patients with gammopathy studied, 235 had absence of monoclonality as defined by the immunoelectrophoretic profile. Inclusively, only 51% of the 53 patients with suspected MM and 66% of the 41 patients with a diagnosis of MGUS were IMF positive. Sensitivity and specificity of total κ/λ chain ratio for identification of positive or negative IMF were respectively 70% and 91% with a global concordance of 86%. In 215 (70%) patients, IMF and free κ/λ chain ratio were in agreement. However, 74 (32%) of IMF negative patients had abnormal free κ/λ chain ratio: 18% had a final diagnosis of chronic renal failure, 13% of CLL or NHL, 9% of MGUS, 7% of MM and 3% of amyloidosis; the remainder 50% were diagnosed as having a disease other than lymphoplasmacytic disorder. These results stress the value of free light chain determination in the diagnosis and follow up of gammopathies and its usefulness as a marker for multiple myeloma and associated monoclonal gammopathies.


Author(s):  
Richard B Fulton ◽  
Suran L Fernando

Background The potential for serum free light chain (sFLC) assay measurements to replace urine electrophoresis (uEPG) and to also diminish the need for serum immunofixation (sIFE) in the screening for monoclonal gammopathy was assessed. A testing algorithm for monoclonal protein was developed based on our data and cost analysis. Methods Data from 890 consecutive sFLC requests were retrospectively analysed. These included 549 samples for serum electrophoresis (sEPG), 447 for sIFE, and 318 for uEPG and urine immunofixation (uIFE). A total of 219 samples had sFLC, sEPG, sIFE and uEPG + uIFE performed. The ability of different test combinations to detect the presence of monoclonal proteins was compared. Results The sFLC κ/ λ ratio (FLC ratio) indicated monoclonal light chains in 12% more samples than uEPG + uIFE. The combination of sEPG and FLC ratio detected monoclonal proteins in 49% more samples than the combination of sEPG and sIFE. Furthermore, the sEPG + FLC ratio combination detected monoclonal protein in 6% more samples than were detected by the combined performance of sEPG, sIFE, uEPG and uIFE. However, non-linearity of the assay, the expense of repeat determinations due to the narrow measuring ranges, and frequent antigen excess checks were found to be limitations of the sFLC assay in this study. Conclusion The FLC ratio is a more sensitive method than uIFE in the detection of monoclonal light chains and may substantially reduce the need for onerous 24 h urine collections. Our proposed algorithm for the evaluation of monoclonal gammopathy incorporates the sFLC assay, resulting in a reduction in the performance of labour intensive sIFE and uEPG + uIFE while still increasing the detection of monoclonal proteins.


Author(s):  
Joannes F.M. Jacobs ◽  
Jillian R. Tate ◽  
Giampaolo Merlini

AbstractThe serum free light chain (FLC) assay has proven to be an important complementary test in the management of patients with monoclonal gammopathies. The serum FLC assay has value for patients with plasma cell disorders in the context of screening and diagnosis, prognostic stratification, and quantitative monitoring. Nonetheless, serum FLC measurements have analytical limitations which give rise to differences in FLC reporting depending on which FLC assay and analytical platform is used. As the FLC measurements are incorporated in the International Myeloma Working Group guidelines for the evaluation and management of plasma cell dyscrasias, this may directly affect clinical decisions. As new certified methods for serum FLC assays emerge, the need to harmonise patient FLC results becomes increasingly important. In this opinion paper we provide an overview of the current lack of accuracy and harmonisation in serum FLC measurements. The clinical consequence of non-harmonized FLC measurements is that an individual patient may or may not meet certain diagnostic, prognostic, or response criteria, depending on which FLC assay and platform is used. We further discuss whether standardisation of serum FLC measurements is feasible and provide an overview of the steps needed to be taken towards harmonisation of FLC measurements.


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