Impact of Normalized Free Light Chain Ratio for Assessment of Monoclonal Protein in Patients with Light Chain Only and Oligosecretory Myeloma

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 2074-2074
Author(s):  
Kentaro Narita ◽  
Yoshiaki Usui ◽  
Yoshiaki Abe ◽  
Masami Takeuchi ◽  
Kosei Matsue
Keyword(s):  
Light Chain ◽  
Urine Analysis ◽  
Residual Disease ◽  
Response Assessment ◽  
Protein Electrophoresis ◽  
Free Light Chain ◽  
Reference Ranges ◽  
Immunofixation Electrophoresis ◽  
The Impact ◽  
Monoclonal Component

Abstract Background: Monitoring of serum free light chain (sFLC) ratio after treatment in multiple myeloma (MM) patients is valuable for assessing monoclonal component of free light chain (FLC). However, the recent International Myeloma Working Group guidelines did not recommend replacing 24-hour urine analysis with FLC analysis in diagnosis or response assessment of MM, and previous studies indicated discordance between urine analysis and sFLC levels in light chain-only MM (LCMM). This is clinically relevant because sFLC normalization was considered a surrogate for improved outcome in both LCMM and intact immunoglobulin MM (IIMM). The clinical impact of FLC ratio normalization on detection of monoclonal component may differ between LCMM or oligosecretory myeloma (OSMM) and IIMM. This study explored the utility of sFLC ratio as a surrogate for residual clonal monoclonal component compared with 24-hour urine immunofixation electrophoresis (uIFx) after treatment. We evaluated the impact of normalization of sFLC ratio in patients with LCMM/OSMM that obtained very good partial response (VGPR), complete response (CR), and immunophenotypic CR (iCR; sIFx/uIF negative plus ≤ 10-4 clonal PCs) determined by multicolor flow cytometry (MFC). Methods: We included 176 patients (51 with LCMM and OSMM, 125 with IIMM) treated between April 2006 and January 2016 at Kameda Medical Center, Japan. Immunoglobulin levels in serum and urine samples were examined by serum protein electrophoresis (SPEP), serum immunofixation electrophoresis (sIFx), urine protein electrophoresis (UPEP), uIFx, and sFLC for response assessment. Minimal residual disease (MRD) assessments after treatment were performed by 6-color MFC and the results were compared to other tests of monoclonal components, including SPEP, UPEP, sIFx, uIFx, and FLC. Agreement between sFLC normalization and MRD by MFC was assessed using kappa statistic. Disease response was evaluated using IMWG criteria. sFLC was measured by Fleelite® assay (The Binding Site Group Ltd.). Reference ranges for sFLC have been previously published. Statistical analyses were performed with EZR, which is a graphical user interface for R ver. 3.2.1. Ethical considerations: This study was approved by the local ethics committee and conducted in accordance with the Declaration of Helsinki and Good Clinical Practice Guidelines. Results: All of 51 LCMM/OSMM patients (100%) and 95 of the 125 IIMM patients (72%) had measurable and abnormal involved sFLC (≥ 100 mg/L) and positive uIFx at presentation. VGPR, CR, and iCR were obtained in 31 (61%), 25 (49%), and 14 (27%) patients with LCMM/OSMM, respectively, and normalization of sFLC ratio at VGPR, CR and iCR was seen in 1/31 (3%), 13/25 (48%), and 8/14 (57%) of these patients, respectively. Among the LCMM/OSMM patients with iCR, 4 patients obtained deeper iCR (≤ 10-5 clonal PCs) and all of them had normal sFLC ratio, while sFLC ratio remained abnormal in the rest of 10 iCR patients that did not achieve deeper iCR. In IIMM patients, VGPR, CR, and iCR were obtained in 78 (61%), 52 (42%), and 20 (16%) patients, respectively. In contrast to the LCMM/OSMM patients, normalization of the sFLC ratio at VGPR, CR, and iCR was seen in 52/78 (67%), 39/52 (75%), and 17/20 (85%) of IIMM patients, respectively. Thirteen of the 14 IIMM patients (93%) that obtained deeper iCR had normal sFLC ratio. Among the patients with IIMM, percentage of patients with normalized sFLC ratio did not differ between the response groups (p=0.11), while it was significantly different in LCMM/OSMM patients (p<0.001) (Figure 1). These observations indicated that the normalization of sFLC ratio is significantly associated with deeper response in LCMM/OSMM patients, but not in IIMM patients. Conclusions: Our observations indicated that sFLC test has greater sensitivity than urine immunofixation for detection of the monoclonal component of sFLC, especially in patients with LCMM/OSMM. In addition, we also showed that normalization of sFLC ratio is correlated with the depth of response assessed by MFC in patients with LCMM/OSMM, but not in IIMM patients. These findings suggest that FLC ratio provides greater sensitivity for residual disease monitoring than uPEP or uIFx in patients with LCMM and OSMM, and therefore could be considered as an alternative to urine analysis for monitoring of LCMM/OSMM patients. Disclosures No relevant conflicts of interest to declare.

Evaluation of a new free light chain ELISA assay: bringing coherence with electrophoretic methods

2018 ◽  
Vol 56 (2) ◽  
pp. 312-322 ◽  
Author(s):  
Joannes F.M. Jacobs ◽  
Corrie M. de Kat Angelino ◽  
Huberdina M.L.M. Brouwers ◽  
Sandra A. Croockewit ◽  
Irma Joosten ◽  
...  
Keyword(s):  
Light Chain ◽  
Method Comparison ◽  
Protein Electrophoresis ◽  
Free Light Chain ◽  
Reference Ranges ◽  
Clinical Value ◽  
Serum Free Light Chain ◽  
Prognostic Stratification ◽  
Consistency Method ◽  
Assay Interference

Abstract Background: Serum free light chain (sFLC) measurements are increasingly important in the context of screening for monoclonal gammopathies, prognostic stratification, and monitoring of therapy responses. At the same time, analytical limitations have been reported with the currently available nephelometric and turbidimetric sFLC assays. We have evaluated a new quantitative sFLC ELISA for its suitability in routine clinical use. Methods: Reference ranges of the Sebia FLC assay were calculated from 208 controls. Assay interference, reproducibility, lot-to-lot variability, and linearity were assessed. Method comparison to the Freelite assay (Binding Site) was conducted by retrospective analysis of 501 patient sera. Results: Reference ranges of the Sebia κ/λFLC-ratio were 0.37–1.44. We observed good sensitivity (1.5 mg/L) and linearity in both polyclonal and monoclonal sFLC samples and never experienced antigen excess. Sebia FLC reproducibility varied between 6.7% and 8.1% with good lot-to-lot consistency. Method comparison with Freelite showed the following correlations: κFLC R=0.94, λFLC R=0.92 and κ/λFLC-ratio R=0.96. The clinical concordance of the κ/λFLC-ratio of both methods was 94%. Significant quantitative differences were observed between both methods, mainly in sera with high FLC concentrations. The Sebia monoclonal FLC concentrations were coherent with those obtained by serum protein electrophoresis (SPE). Freelite monoclonal FLC concentrations were consistently higher, with a mean 12-fold overestimation compared to SPE. Conclusions: The Sebia FLC assay provides a novel platform for sensitive and accurate sFLC measurements. The Sebia FLC showed good clinical concordance with Freelite. Further studies are warranted to confirm the clinical value of this assay.

Comparison of Free Light Chain Assay with Protein Electrophoresis for Screening and Monitoring PTLD

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 5883-5883 ◽  
Author(s):  
Deborah Kuhn ◽  
Ping Wang ◽  
Irene Shu ◽  
Jie Xuan ◽  
Zheng Cao ◽  
...  
Keyword(s):  
Liver Transplant ◽  
B Cell ◽  
Light Chain ◽  
Protein Electrophoresis ◽  
Free Light Chain ◽  
Healthy Population ◽  
Solid Organ ◽  
Reference Ranges ◽  
Time Points ◽  
Post Transplant

Abstract Background: Post-transplant lymphoproliferative disorder (PTLD) is primarily diagnosed histologically using tissue biopsy. Free light chain (FLC) assay and serum protein electrophoresis (SPE) have both been studied as tools to screen and monitor PTLD. However, limited data are available to compare these two assays in a well characterized patient population. It is also not clear what reference ranges should be adopted for the FLC assay in a post-transplant population. Method: Blood samples from 169 patients receiving a variety of solid organ transplants were analyzed for FLCs and screened for gammopathies by SPE/IFE. Results: Compared with non-PTLD patients, PTLD patients had higher mean, median and upper 95 percentile range of both κ and λ FLCs (p ranging from 0.0002 to 0.024). The mean, median and 95 percentile range of κ:λ ratio were similar between the two groups. PTLD patients were more likely to have polyclonal or monoclonal FLC elevations (p = 0.04). They also showed a higher frequency of gammopathy abnormalities (p = 0.0052). Nonetheless, neither FLC assay nor SPE demonstrated a clear association with the timing of PTLD diagnosis. FLC concentrations in non-PTLD recipients were higher than those in the general healthy population (95 percentile range: κ, 0.60-8.33 mg/dL vs. 0.33-1.94 mg/dL; λ, 0.77-7.08 mg/dL vs. 0.571-2.63 mg/dL) but the κ:λ ratio was similar to that of the healthy group (0.26-1.65). Conclusions: Our results suggested that elevated FLC concentrations and gammopathy abnormalities were both associated with PTLD. Therefore, FLC assay and SPE should be used conjunctively for screening PTLD among solid organ transplant recipients. For this application, the data showed that a higher upper limit of κ and λ FLC levels and normal κ:λ ratio should be used as diagnostic reference ranges. Additionally, neither method was clearly associated with the timing of PTLD diagnosis, indicating that they may be unsuitable for monitoring PTLD in the post-transplant population. Table 1. Longitudinal measurements of serum/plasma free light chains and SPE/IFE in eight PTLD cases. Type of transplant and type of PTLD Samples Days from PTLD diagnosisa κ FLC, mg/dL λ FLC, mg/dL κ /λ SPE/IFE Liver transplant, B-cell PTLD 1.1 1.2 – 616 2.33b 1.82 4.96 6.01 0.47 0.303 no band –c Liver transplant, B-cell PTLD 2.1 2.2 2.3 2.4 2.5 -145* -126 84 141 428 0.338 0.79 0.335 0.476 2.53 0.62 1.02 1.06 1.15 1.98 0.545 0.775 0.316 0.414 1.28 no band no band 1 IgG ©µ, 1 IgG λ 1 IgG ©µ, 1 IgG λ no band Liver transplant, polymorphic hyperplasia 3.1 3.2 -77 208 4.19 7.18 5.9 3.38 0.71 2.12 2 IgG ©µ, 2 λ FLC– Liver transplant, B-cell PTLD 4.1 4.2 4.3 61 272 537 4.64 3.25 7.1 11.1 6.65 10.96 0.418 0.489 0.648 no band no band no band Liver transplant, B-cell PTLD 5.1 5.2 5.3 5.4 5.5 9 12 393 429 476 305.5 957 0.721 1.01 1.24 74.25 192 1.67 1.72 2.56 4.11 4.98 0.432 0.587 0.484 1 IgG ©µ, 1 λ FLC 2 IgM ©µ no band no band no band Liver transplant, B-cell PTLD 6.1 6.2 6.3 6.4 62 153 174 188 3.16 5.58 3.97 2.14 2.92 3.91 3.81 3.37 1.08 1.43 1.04 0.635 – 1 IgG ©µ 1 IgG ©µ 1 IgG ©µ Kidney transplant, PTLD 7.1 7.2 15 30 1.4 1.68 1.58 2.06 0.89 0.82 no band no band Lung transplant, Non-Hodgkin lymphoma 8.1 -60 4.28 4.58 0.94 no band a Positive values indicate time points before PTLD diagnosis, while negative values indicate time points after PTLD diagnosis. b Numbers in bold format indicates values above ULN. c SPE/IFE results not available due to insufficient sample volume. Disclosures Kuhn: The Binding Site, Inc: Employment.

Laboratory testing requirements for diagnosis and follow-up of multiple myeloma and related plasma cell dyscrasias

2016 ◽  
Vol 54 (6) ◽  
Author(s):  
Maria A.V. Willrich ◽  
Jerry A. Katzmann
Keyword(s):  
Multiple Myeloma ◽  
Serum Protein ◽  
Plasma Cell ◽  
Light Chain ◽  
Cell Clone ◽  
Protein Electrophoresis ◽  
Free Light Chain ◽  
Molecular Weights ◽  
Immunofixation Electrophoresis ◽  
Monoclonal Proteins

AbstractMonoclonal immunoglobulins are markers of plasma cell proliferative diseases and have been described as the first (and perhaps best) serological tumor marker. The unique structure of each monoclonal protein makes them highly specific for each plasma cell clone. The difficulties of using monoclonal proteins for diagnosing and monitoring multiple myeloma, however, stem from the diverse disease presentations and broad range of serum protein concentrations and molecular weights. Because of these challenges, no single test can confidently diagnose or monitor all patients. Panels of tests have been recommended for sensitivity and efficiency. In this review we discuss the various disease presentations and the use of various tests such as protein electrophoresis and immunofixation electrophoresis as well as immunoglobulin quantitation, free light chain quantitation, and heavy-light chain quantitation by immuno-nephelometry. The choice of tests for inclusion in diagnostic and monitoring panels may need to be tailored to each patient, and examples are provided. The panel currently recommended for diagnostic screening is serum protein electrophoresis, immunofixation electrophoresis, and free light chain quantitation.

Quantification of β-region IgA monoclonal proteins – should we include immunochemical Hevylite® measurements? Point

2016 ◽  
Vol 54 (6) ◽  
Author(s):  
Josie A.R. Evans ◽  
Ellen L. Jenner ◽  
Hugh D. Carr Smith ◽  
Oscar Berlanga ◽  
Stephen J. Harding
Keyword(s):  
Light Chain ◽  
Residual Disease ◽  
Response Assessment ◽  
Protein Electrophoresis ◽  
Monoclonal Protein ◽  
Laboratory Staff ◽  
Additional Information ◽  
Significant Challenge ◽  
Alternative Methodology ◽  
Monoclonal Proteins

AbstractAccurate measurement of IgA monoclonal proteins presents a significant challenge to laboratory staff. IgA heavy/light chain (Hevylite, HLC) analysis is an alternative methodology for monoclonal protein assessment, giving an independent measure of IgAκ and IgAλ concentrations. Clonality is assessed by calculating the ratio of involved immunoglobulin to background uninvolved immunoglobulin concentrations (e.g. IgAκ/IgAλ in an IgAκ patient). Here we discuss the challenges faced by the laboratory in IgA monoclonal protein assessment, and compare the performance of Hevylite assays with electrophoresis and total IgA results. We present data which validates the use of Hevylite for response assessment: in most cases, Hevylite provides comparable response assignment to that provided by serum protein electrophoresis (SPE) and total IgA; in other cases Hevylite provides additional information, such as detection of residual disease or relapse.

scholarly journals Role of urine immunofixation in the complete response assessment of MM patients other than light-chain-only disease

Blood ◽  
2019 ◽  
Vol 133 (25) ◽  
pp. 2664-2668 ◽  
Author(s):  
Juan-José Lahuerta ◽  
Ana Jiménez-Ubieto ◽  
Bruno Paiva ◽  
Joaquín Martínez-López ◽  
José González-Medina ◽  
...  
Keyword(s):  
Light Chain ◽  
Residual Disease ◽  
Progression Free Survival ◽  
Response Assessment ◽  
Complete Response ◽  
M Protein ◽  
Positive Rate ◽  
Immunofixation Electrophoresis

Abstract Response criteria for multiple myeloma (MM) require monoclonal protein (M-protein)–negative status on both serum immunofixation electrophoresis (sIFE) and urine (uIFE) immunofixation electrophoresis for classification of complete response (CR). However, uIFE is not always performed for sIFE-negative patients. We analyzed M-protein evaluations from 384 MM patients (excluding those with light-chain-only disease) treated in the GEM2012MENOS65 (NCT01916252) trial to determine the uIFE-positive rate in patients who became sIFE-negative posttreatment and evaluate rates of minimal residual disease (MRD)–negative status and progression-free survival (PFS) among patients achieving CR, CR but without uIFE available (uncertain CR; uCR), or very good partial response (VGPR). Among 107 patients with M-protein exclusively in serum at diagnosis who became sIFE-negative posttreatment and who had uIFE available, the uIFE-positive rate was 0%. Among 161 patients with M-protein in both serum and urine at diagnosis who became sIFE-negative posttreatment, 3 (1.8%) were uIFE positive. Among patients achieving CR vs uCR, there were no significant differences in postconsolidation MRD-negative (&lt;10−6; 76% vs 75%; P = .9) and 2-year PFS (85% vs 88%; P = .4) rates; rates were significantly lower among patients achieving VGPR. Our results suggest that uIFE is not necessary for defining CR in MM patients other than those with light-chain-only disease.

Serum free light chain immunoassay as an adjunct to serum protein electrophoresis and immunofixation electrophoresis in the detection of multiple myeloma and other B-cell malignancies

2009 ◽  
Vol 47 (3) ◽  
Author(s):  
Stephen J. Harding ◽  
Graham P. Mead ◽  
Arthur R. Bradwell ◽  
Annie M. Berard
Keyword(s):  
B Cell ◽  
Serum Protein ◽  
Light Chain ◽  
Protein Electrophoresis ◽  
Free Light Chain ◽  
Serum Protein Electrophoresis ◽  
B Cell Malignancies ◽  
Serum Free ◽  
Serum Free Light Chain ◽  
Immunofixation Electrophoresis

Abstract: Protein and immunofixation electrophoresis of serum and urine are established as diagnostic aids for identifying monoclonal gammopathies. However, many patient sera sent to laboratories are not accompanied by urine samples and recent reports suggest the use of serum free light chain (sFLC) analysis in combination with serum protein electrophoresis (SPE) and immunofixation electrophoresis (IFE) could eliminate the need for urinalysis. The aim of the study was to assess the utility of sFLC measurement in addition to serum protein electrophoresis in the identification of patients with B-cell malignancies.: A total of 952 serum samples were analysed by serum protein electrophoresis and those with abnormal bands were analysed by immunofixation. sFLCs were measured in a retrospective manner by automated assay.: In our study of 952 patient sera, it was found that FLC analysis identified 23 additional cases of B-cell malignancies which were missed by SPE.: The additional malignancies identified by sFLC analysis add support for its inclusion in the routine screening protocol for B-cell malignancies.Clin Chem Lab Med 2009;47:302–4.

Lambda monoclonal free light chain abnormalities detected by a serum immunofixation electrophoresis assay are underrepresented by quantitative serum free light chain results

2021 ◽  
Vol 156 (Supplement_1) ◽  
pp. S13-S14
Author(s):  
Rebecca Treger ◽  
Kathleen Hutchinson ◽  
Andrew Bryan ◽  
Chihiro Morishima
Keyword(s):  
Light Chain ◽  
Free Light Chain ◽  
Light Chains ◽  
Sample Population ◽  
Free Light Chains ◽  
Serum Free ◽  
Serum Free Light Chain ◽  
Immunofixation Electrophoresis ◽  
High Concordance ◽  
Polyclonal Antisera

Abstract Protein and immunofixation (IFIX) electrophoresis are used to diagnose and monitor monoclonal gammopathies. While IFIX detects clonal production of intact immunoglobulins and free light chains (FLC), the latter can also be quantified using a serum free light chain (SFLC) assay, in which polyclonal antisera detects epitopes specific for free kappa (KFLC) or lambda light chains (LFLC). An abnormal KFLC: LFLC ratio (KLR) serves as a surrogate for clonality. While the SFLC assay is highly sensitive, normal LFLC (&lt;2.63mg/dL) and KLR results (&gt;0.26 & &lt;1.65) were found in samples with distinct lambda monoclonal free light chains visualized by IFIX (X-LMFLC). To investigate this discordance, contemporaneous SFLC or KLR values were evaluated for their ability to accurately classify monoclonal FLCs identified by IFIX. We performed a retrospective analysis of serum and urine IFIX (Sebia Hydrasys) and SFLC (Freelite®, Binding Site) results from our institution between July 2010 through December 2020, using R 4.0.2 and Tidyverse packages. From among 9,594 encounters in which a single monoclonal component was initially identified by IFIX, 157 X-LMFLC and 131 X-KMFLC samples were analyzed. Elevated LFLC with normal KFLC was identified in 105/157 X-LMFLC samples (67%), while both LFLC and KFLC were elevated in 42/157 samples (27%). Concordance between X-KMFLC and KFLC was markedly higher, where 122/131 samples (93%) displayed elevated kappa FLC (&gt;1.94mg/dL) with normal LFLC, and only 7/131 X-KMFLC samples (5%) possessed both elevated KFLC and LFLC. The use of KLR to identify pathogenic monoclonal free light chains improved lambda concordance to 85%; however, 19/157 (12%) of X-LMFLC samples still exhibited normal KLR. High concordance of 98% was again observed for X-KMFLC with abnormal KLR. When samples were segregated according to normal or impaired renal function (eGFR &gt; or ≤60mL/min/1.73m², respectively), this disparate identification of X-LMFLC and X-KMFLC by the SFLC assay persisted, suggesting that renal dysfunction (as measured by eGFR) does not underlie this phenomenon. Lastly, we corroborated the above findings in a larger sample population by examining patients with urine Bence Jones FLC identified by IFIX who had free or intact monoclonal components in serum (N=724), grouped by lambda or kappa light chain involvement. The cause(s) of the discrepant performance by the Freelite® SFLC assay, relative to the Sebia Hydrasys IFIX assay, for identifying lambda FLC components is currently unclear. Possible contributory factors include assay reference range cutoffs, other patient disease parameters, and differences in assay-specific polyclonal antisera. Future analyses of these factors will help to further characterize SFLC assay performance and elucidate how interpretation of composite serum FLC test results can be improved to better guide patient management.

scholarly journals Depth of Response in Multiple Myeloma: A Pooled Analysis of Three PETHEMA/GEM Clinical Trials

2017 ◽  
Vol 35 (25) ◽  
pp. 2900-2910 ◽  
Author(s):  
Juan-Jose Lahuerta ◽  
Bruno Paiva ◽  
Maria-Belen Vidriales ◽  
Lourdes Cordón ◽  
Maria-Teresa Cedena ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Residual Disease ◽  
Bone Marrow Involvement ◽  
Progression Free Survival ◽  
Response Assessment ◽  
Pooled Analysis ◽  
Disease Stage ◽  
Cox Models ◽  
Depth Of Response ◽  
The Impact

Purpose To perform a critical analysis on the impact of depth of response in newly diagnosed multiple myeloma (MM). Patients and Methods Data were analyzed from 609 patients who were enrolled in the GEM (Grupo Español de Mieloma) 2000 and GEM2005MENOS65 studies for transplant-eligible MM and the GEM2010MAS65 clinical trial for elderly patients with MM who had minimal residual disease (MRD) assessments 9 months after study enrollment. Median follow-up of the series was 71 months. Results Achievement of complete remission (CR) in the absence of MRD negativity was not associated with prolonged progression-free survival (PFS) and overall survival (OS) compared with near-CR or partial response (median PFS, 27, 27, and 29 months, respectively; median OS, 59, 64, and 65 months, respectively). MRD-negative status was strongly associated with prolonged PFS (median, 63 months; P < .001) and OS (median not reached; P < .001) overall and in subgroups defined by prior transplantation, disease stage, and cytogenetics, with prognostic superiority of MRD negativity versus CR particularly evident in patients with high-risk cytogenetics. Accordingly, Harrell C statistics showed higher discrimination for both PFS and OS in Cox models that included MRD (as opposed to CR) for response assessment. Superior MRD-negative rates after different induction regimens anticipated prolonged PFS. Among 34 MRD-negative patients with MM and a phenotypic pattern of bone marrow involvement similar to monoclonal gammopathy of undetermined significance at diagnosis, the probability of “operational cure” was high; median PFS was 12 years, and the 10-year OS rate was 94%. Conclusion Our results demonstrate that MRD-negative status surpasses the prognostic value of CR achievement for PFS and OS across the disease spectrum, regardless of the type of treatment or patient risk group. MRD negativity should be considered as one of the most relevant end points for transplant-eligible and elderly fit patients with MM.

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