Free light chains in plasma cell disorders: measurement and therapeutic implications

2009 ◽  
Vol 30 (1) ◽  
pp. 21-23
Author(s):  
Arthur R. Bradwell ◽  
Colin A. Hutchison ◽  
Paul Cockwell
Keyword(s):  
Plasma Cell ◽  
Light Chains ◽  
Free Light Chains ◽  
Therapeutic Implications ◽  
Plasma Cell Disorders

scholarly journals Recommendations for Use of Free Light Chain Assay in Monoclonal Gammopathies

2010 ◽  
Vol 29 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Vesna Radović
Keyword(s):  
Plasma Cell ◽  
Light Chain ◽  
High Sensitivity ◽  
Protein Electrophoresis ◽  
Free Light Chain ◽  
Light Chains ◽  
Free Light Chains ◽  
Bone Marrow Biopsies ◽  
Monoclonal Gammopathies ◽  
Plasma Cell Disorders

Recommendations for Use of Free Light Chain Assay in Monoclonal GammopathiesThe serum immunoglobulin free light chain assay measures levels of free κ and λ immunoglobulin light chains. There are three major indications for the free light chain assay in the evaluation and management of multiple myeloma and related plasma cell disorders. In the context of screening, the serum free light chain assay in combination with serum protein electrophoresis and immunofixation yields high sensitivity, and negates the need for 24-hour urine studies for diagnoses other than light chain amyloidosis. Second, the baseline free light chains measurement is of major prognostic value in virtually every plasma cell disorder. Third, the free light chain assay allows for quantitative monitoring of patients with oligosecretory plasma cell disorders, including AL, oligosecretory myeloma, and nearly twothirds of patients who had previously been deemed to have non-secretory myeloma. In AL patients, serial free light chains measurements outperform protein electrophoresis and immunofixation. In oligosecretory myeloma patients, although not formally validated, serial free light chains measurements reduce the need for frequent bone marrow biopsies. In contrast, there are no data to support using free light chain assay in place of 24-hour urine electrophoresis for monitoring or for serial measurements in plasma cell disorders with measurable disease by serum or urine electrophoresis.

Correlation Among Different Plasma Cell Disorders Markers and Immunoglobulin Heavy Light Chains (HLC)

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 3148-3148
Author(s):  
Ajay K. Nooka ◽  
Jonathan L. Kaufman ◽  
Nishi N Shah ◽  
Bilal Hassan ◽  
Lawrence H. Boise ◽  
...  
Keyword(s):  
Plasma Cell ◽  
Strong Correlation ◽  
Research Funding ◽  
Light Chains ◽  
Free Light Chains ◽  
Plasma Cell Disorders ◽  
Plasma Cell Disorder ◽  
Serum Free Light Chains ◽  
M Spike ◽  
Cell Disorder

Abstract Background Heavy light chain (HLC) assays allow for accurate quantification of involved and uninvolved immunoglobulins (Ig) of the affected isotype. HLC ratio is of particular interest in measuring low level disease where there is limited utility for serum protein electrophoresis (SPEP) to measure the low M-spike and challenging to quantify. Serum immunofixation (SIFx), being a non-quantitative test cannot accurately define the amount of disease. Limited data exists to understand the utility of HLC testing, hence we tried to study the correlation of this test to some of the established plasma cell disorder markers: serum free light chains (SFLC), SPEP (M-spike) and involved total Ig levels. Methods A total of 1098 samples from 480 patients with IgG [315 IgG Kappa (k) and 165 IgG Lambda (l)] plasma cell disorders (multiple myeloma, monoclonal gammopathy of undetermined significance, smoldering multiple myeloma and plasmacytoma) and 329 samples from 160 IgA (98 IgAk patients and 60 IgAl) plasma cell disorder patients were included in analysis. Correlation was determined between HLC levels, HLC ratio and SFLC levels for all patients. Correlation was determined for each isotype separately using non parametric Spearman Correlation co-efficient (SCC). Results In IgA patients, there is strong correlation between HLC levels (IgAk and IgAl) and M-spike (0.85; p<0.0001 and 0.82; p<0.0001, respectively) as well as involved Ig (0.99; p<0.0001; 0.99; p<0.0001, respectively). Similar strong correlation was seen between HLC ratios and M-spike and involved Ig. In IgG patients, there is strong correlation, but smaller than IgA, between HLC levels (IgGk and IgGl) and M-spike (0.72; p<0.0001 and 0.75; p<0.0001, respectively) as well as involved Ig (0.91; p<0.0001; 0.78; p<0.0001, respectively). Similar correlation was seen between HLC ratios and M-spike and involved Ig. We also observed a strong correlation of FLCk with IgAk (0.65; p<0.0001) as well as of FLCl with IgA l too (0.69; p<0.0001). Similarly, FLCk with IgGk (0.56; p<0.0001) and FLCl with IgG l (0.69; p<0.0001) exhibited strong correlation. Conclusion The presence of strong correlation between M-spike quantification, serum free light chains, as well as total involved immunoglobulins in the largest sample size reported to date, suggests the feasibility of detection of isotype bands with HLC antibodies and its potential role for clinical utility in disease staging and monitoring. Prognostic usefulness of this testing in identifying residual disease and its correlation with survival in myeloma patients will be presented at the meeting. Disclosures: Kaufman: Onyx: Consultancy; Celgene: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Janssen: Consultancy; Millenium: Consultancy; Merck: Research Funding. Boise:Onyx Pharmaceuticals: Consultancy. Lonial:Millennium: Consultancy; Celgene: Consultancy; Novartis: Consultancy; BMS: Consultancy; Sanofi: Consultancy; Onyx: Consultancy.

Quantification by Ultrafiltration and Immunofixation Electrophoresis Testing for Monoclonal Serum Free Light Chains

2020 ◽  
Vol 51 (6) ◽  
pp. 592-600 ◽  
Author(s):  
Gurmukh Singh ◽  
Roni Bollag
Keyword(s):  
Plasma Cell ◽  
Light Chain ◽  
Limit Of Detection ◽  
Light Chains ◽  
Total Serum ◽  
Reliable Estimate ◽  
Free Light Chains ◽  
Serum Free ◽  
Immunofixation Electrophoresis ◽  
Serum Free Light Chains

Abstract Objective Measurement of monoclonal immunoglobulins is a reliable estimate of the plasma cell tumor mass. About 15% of plasma cell myelomas secrete light chains only. The concentration of serum free light chains is insufficient evidence of the monoclonal light chain burden. A sensitive quantitative estimate of serum free monoclonal light chains could be useful for monitoring patients with light chain myeloma. We describe such an assay that does not require mass-spectrometry equipment or expertise. Methods Serum specimens from patients with known light chain myelomas and controls were subjected to ultrafiltration through a membrane with pore size of 50 kDa. The filtrate was concentrated and tested by immunofixation electrophoresis. The relative area under the monoclonal peak, compared to that of the total involved light chain composition, was estimated by densitometric scanning of immunofixation gels. The proportion of the area occupied by the monoclonal peak in representative densitometric scans was used to arrive at the total serum concentration of the monoclonal serum free light chains. Results Using an ultracentrifugation and concentration process, monoclonal serum free light chains were detectable, along with polyclonal light chains, in all 10 patients with active light chain myelomas. Monoclonal light chains were identified in serum specimens that did not reveal monoclonal light chains by conventional immunofixation electrophoresis. The limit of detection by this method was 1.0 mg/L of monoclonal serum free light chains. Conclusion The method described here is simple enough to be implemented in academic medical center clinical laboratories and does not require special reagents, equipment, or expertise. Even though urine examination is the preferred method for the diagnosis of light chain plasma cell myelomas, measurement of the concentration of serum free light chains provides a convenient, albeit inadequate, way to monitor the course of disease. The method described here allows effective electrophoretic differentiation of monoclonal serum free light chain from polyclonal serum free light chains and provides a quantitation of the monoclonal serum free light chains in monitoring light chain monoclonal gammopathies.

scholarly journals Kidney disease associated with plasma cell dyscrasias

Blood ◽  
2010 ◽  
Vol 116 (9) ◽  
pp. 1397-1404 ◽  
Author(s):  
Eliot C. Heher ◽  
Nelson B. Goes ◽  
Thomas R. Spitzer ◽  
Noopur S. Raje ◽  
Benjamin D. Humphreys ◽  
...  
Keyword(s):  
Kidney Disease ◽  
Plasma Cell ◽  
Molecular Mechanisms ◽  
Kidney Injury ◽  
Light Chains ◽  
Free Light Chains ◽  
Monoclonal Immunoglobulin ◽  
Plasma Cell Dyscrasias ◽  
Made In

Plasma cell dyscrasias are frequently encountered malignancies often associated with kidney disease through the production of monoclonal immunoglobulin (Ig). Paraproteins can cause a remarkably diverse set of pathologic patterns in the kidney and recent progress has been made in explaining the molecular mechanisms of paraprotein-mediated kidney injury. Other recent advances in the field include the introduction of an assay for free light chains and the use of novel antiplasma cell agents that can reverse renal failure in some cases. The role of stem cell transplantation, plasma exchange, and kidney transplantation in the management of patients with paraprotein-related kidney disease continues to evolve.

Correlation of Serum Free Light Chains and Bone Marrow Plasma Cell Infiltration in Multiple Myeloma.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 4865-4865
Author(s):  
Graham P. Mead ◽  
Steven D. Reid ◽  
Bradley M. Augustson ◽  
Mark T. Drayson ◽  
Arthur R. Bradwell ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Plasma Cell ◽  
Light Chain ◽  
Free Light Chain ◽  
Cell Infiltration ◽  
Light Chains ◽  
Normal Bone Marrow ◽  
Free Light Chains ◽  
Serum Free ◽  
Normal Bone

Abstract Diagnostic criteria for multiple myeloma include abnormal plasma cell infiltration of the bone marrow plus the presence of monoclonal immunoglobulin in the serum and/or monoclonal free light chains in the urine. However, recent studies have indicated that measurement of free light chains in the serum (sFLC) is more sensitive than urine assays. Also, because of the slow clearance of IgG from serum (half-life ~20 days compared with 2–6 hours for sFLC) intact immunoglobulin assays can be slow to reflect the full extent of response to treatment. The aim of this study was to compare the relative sensitivity and specificity of serum free light chain (sFLC) measurement, urine free light chain measurement (uFLC) and serum immunofixation (sIFE) with bone marrow analysis for assessment of myeloma. All 45 patients studied were enrolled in the UK MRC Myeloma VII trial and 75 serum samples were selected for sFLC measurement and sIFE. The sera had been collected at various times before, during and after treatment but all within 4 days of a bone marrow assessment and uFLC measurement (by radial immunodiffusion assay). sFLC results were classified as abnormal if the kappa/lambda ratio was outside the normal range and for uFLC, if there was &gt;40mg/L. The bone marrow assessment was called abnormal if 5% or greater plasma cell infiltration was recorded in aspirate or trephine, in accordance with the EBMT criteria. The results of the comparisons are summarised in the table. Summary of paraprotein assays Bone Marrow Normal Abnormal Serum Free Light Chains Normal 19 4 Abnormal 5 47 Urine Free Light Chains Normal 21 21 Abnormal 3 30 Serum Immunofixation Normal 10 5 Abnormal 14 46 Of the three paraprotein assays, sFLC had the highest concordance with bone marrow biopsy. Compared with the bone marrow assessment, the relative sensitivity and specificity of the sFLC assays was 92% and 79% respectively. For uFLC the values were 59% and 88%, respectively and for sIFE, 90% and 42% respectively. Of the 5 sera abnormal by the sFLC assays but with concurrent normal bone marrow results, all were abnormal by sIFE. Of the 4 patients with normal sFLC results but abnormal marrows, 3 were sIFE positive and of the 5 with negative sIFE results but abnormal marrows, 4 had abnormal sFLC ratios. Only 1 patient had an abnormal marrow with normal sFLC and sIFE results. In this comparison sFLC measurement showed a good degree of correlation with bone marrow assessments of myeloma, while uFLC assays were considerably less sensitive. Both sFLC and sIFE assays appeared to identify disease in 5 patients who had normal bone marrow assessments. This was presumably because the serum assays sample monoclonal protein produced throughout the body while distribution of the disease in the bone marrow is occasionally “patchy”. The sIFE results were positive in a much higher number (14) of bone marrow-negative patients. The 9 “extra” positives, which had normal bone marrow results and free light chain ratios, might result from a greater sensitivity for detecting tumours producing intact immunoglobulin with low levels of free light chains. Some of the 9 subsequently became sIFE negative so the slow clearance of monoclonal intact immunoglobulin is an alternative explanation for the discordant results. This could not be proven, however, as all patients had some form of treatment in the intervening period.

scholarly journals Biosynthesis of the carbohydrate portions of immunoglobulin M

1971 ◽  
Vol 125 (1) ◽  
pp. 235-240 ◽  
Author(s):  
R. M. E. Parkhouse ◽  
Fritz Melchers
Keyword(s):  
Plasma Cell ◽  
Early Stage ◽  
Tumour Cells ◽  
Immunoglobulin M ◽  
Cell Tumour ◽  
Light Chains ◽  
Free Light Chains ◽  
Mouse Plasma

Incorporations of radioactive mannose, galactose and fucose into MOPC 104E mouse plasma-cell tumour suspensions suggest a stepwise addition of carbohydrate residues to immunoglobulin M (IgM) during the process of secretion. Mannose and glucosamine residues are added at an early stage, whereas galactose and fucose are added just before, or at the time that, IgM leaves the cell. Free light chains secreted in excess by the same tumour cells incubated with mannose, galactose or fucose contained barely detectable amounts of radioactivity.

Exome Sequencing To Define A Genetic Signature Of Plasma Cells In Systemic AL Amyloidosis

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 3098-3098 ◽  
Author(s):  
Brian A Walker ◽  
Dorota Rowczienio ◽  
Eileen M Boyle ◽  
Christopher P Wardell ◽  
Sajitha Sachchithanantham ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Exome Sequencing ◽  
Plasma Cell ◽  
Copy Number ◽  
Monoclonal Gammopathy ◽  
Plasma Cells ◽  
Chromosomal Abnormalities ◽  
Light Chains ◽  
Al Amyloidosis ◽  
Plasma Cell Disorders

Abstract Systemic amyloid light chain amyloidosis (AL) is characterized by the deposition of immunoglobulin light chains as amyloid fibrils in different organs, where they form toxic protein aggregates. Most AL patients have relatively low levels of circulating free light chains and bone marrow plasmacytosis. The underlying disease is a plasma cell disorder, likely a monoclonal gammopathy, but limited data are available on the biology of the plasma cell clone underlying AL and existing studies have concentrated on chromosomal abnormalities. Many of the chromosomal abnormalities identified in AL are also seen in other plasma cell disorders, such as monoclonal gammopathy of undetermined significance (MGUS) and myeloma. These abnormalities include translocations involving the IGH locus, gains of 1q and deletions of 13q and 17p. Fluorescence in situhybridization studies have identified the translocation t(11;14) to be more frequent in AL and hyperdiploidy to be rare. The causal link between genetic changes in plasma cells and light chain instability remains unknown and progression to symptomatic myeloma is rare. We report the initial findings of the first exome sequencing to define the plasma cell signature in AL and compared this to MGUS and myeloma. CD138+ cells were selected using either EasySep (Stem Cell Technologies) or MACSort (Miltenyi) from the bone marrow of 18 AL patients and 5 MGUS patients. DNA was extracted from the CD138+ cells using the AllPrep kit (Qiagen). Non-involved DNA was isolated from peripheral white blood cells using the Flexigene kit (Qiagen). 200 ng DNA was subjected to exome sequencing using NEBNext kit (NEB) and SureSelect Human All Exon kit v5 and sequenced using 76-bp paired end reads. Fastq files were aligned to the reference genome using BWA and Stampy aligners. BAM files were recalibrated using the GATK and deduplicated using Picard. Paired tumour/normal BAMs were realigned together using the GATK indel realigner and SNVs were called using Mutect. Copy number data were estimated using the R package ExomeCNV. The median depth across all samples was 42x with 97% of the exome covered at 1x and 72% covered at 20x. Exome data to determine the cytogenetic groups of AL samples identified 42% hyperdiploid and 21% with t(11;14). The AL samples with t(11;14) did not contain any other copy number abnormalities. Exome sequencing on samples from patients with MGUS and myeloma was also performed to compare the genetic makeup and mutation spectrum of these well characterised plasma cell neoplasias with AL samples. MGUS samples had a median of 30 acquired nonsynonymous variants (range 24-189) and AL amyloidosis samples had a median of 17 acquired nonsynonymous variants (range 4-44). The AL samples had four recurrent mutations in PCMTD1 (n=3; L267F, P266S and M187I), C21orf33 (n=2; E72K), NLRP12 (n=2; L1018P, W959* ) and NRAS (n=2; Q61R, Q61H). In this small dataset, only 5 genes were mutated in both the MGUS and AL samples (DNMBP, FRG1, HIST1H1B, KRTAP4-11 and MCCC1). In order to assess the similarity (or differences) of plasma cells in AL to malignant plasma cells in general, we compared them to a random sampling of 20 multiple myeloma samples which had also been exome sequenced (median number of acquired nonsynonymous variants = 39 vs. 17 in AL samples). This revealed that the AL contained 21 mutated genes in common with the myeloma cohort, including DIS3 and NRAS. There were two DIS3 mutations in one AL sample at c.379D>E (p.D479E) and c.1999A>T (p.M667L), both of which were in the Ribonuclease II/R catalytic domain. Data on correlation of gene mutations and organ involvement in AL amyloidosis will be presented. We conclude that exome sequencing identifies a genetic signature of AL amyloidosis which is similar to other plasma cell disorders. This not only includes copy number abnormalities and translocations but also a similar number of nonsynonymous mutations to MGUS and fewer than the advanced myeloma samples. Study of further samples is in progress. Disclosures: No relevant conflicts of interest to declare.

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