Immunochemical Evaluation of Monoclonal Gammopathies: Heavy Chain to Light Chain Ratio is of Little Practical Value for Detecting IgD Myelomas and Free Light Chains

1992 ◽  
Vol 38 (2) ◽  
pp. 317-319
Author(s):  
P Bianchi ◽  
E MacNamara ◽  
M R Bergami ◽  
C Gasparro ◽  
R Jones ◽  
...  
Keyword(s):  
Heavy Chain ◽  
Light Chain ◽  
Light Chains ◽  
Free Light Chains ◽  
Monoclonal Gammopathies

Biclonal Multiple Myeloma with Monoclonal Free IgG3 Heavy Chain and kappa Free Light Chains.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 4768-4768
Author(s):  
Alex G. Richter ◽  
Stephen Harding ◽  
Steve Rimmer ◽  
Guy Pratt ◽  
Aarnoud Huissoon ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Western Blot ◽  
Heavy Chain ◽  
Light Chain ◽  
Lymphoproliferative Disorder ◽  
Plasma Cells ◽  
Light Chains ◽  
Cell Transplant ◽  
Free Light Chains ◽  
Night Sweats

Abstract Background: Heavy chain disease (HCD) is a rare lymphoproliferative disorder characterized by a monoclonal heavy chain (HC) unattached to a light chain (LC). IgGHCD or γHCD typically presents as a lymphoproliferative disorder with lymphadenopathy and hepatosplenomegaly. Myeloma has been described associated with γHCD but only with a second intact Ig paraprotein. This report describes a unique presentation of multiple myeloma with monoclonal free γ3HC and kappa free light chains. Case: A 34 year old gentleman presented with mild persistent neutropenia following two episodes of pneumonia, 18 months previously. He admitted to persistent night sweats but no other significant history. Baseline investigations revealed a mild anaemia, neutropenia and a large IgG paraprotein with no associated light chain. Bone marrow aspirate and trephine confirmed myeloma. The patient was treated with cyclophosphamide, thalidomide and dexamethasone and has had a very good partial remission. He is awaiting a sibling allogeneic peripheral blood stem cell transplant. Investigations and results: Serum Electrophoresis confirmed a large IgG paraprotein (23g/l) with no associated light chain in the serum and identified as γ3 subclass by radial immunodiffusion. Western blot showed the γ3HC was truncated with a large deletion. Markedly elevated free kappa (κ) LC (503.58 mg/l [3.30–19.4]) were found in the serum with gross skewing of the kappa/lambda ratio. Urine electrophoresis revealed separate γHC and κ LC paraproteins. Western blot of the fractionated urine protein demonstrated different sized κLC aggregates. Flow cytometry of the marrow aspirate revealed an unusual staining pattern; CD5,19,38,45+ve and CD20,22,23,34,56,138 –ve plasma cells. Cytoplasmic staining revealed 2 distinct populations of plasma cells, the first producing γ3HC and the second only free κLC. Cytogenetics and FISH analysis for 14q, p53 and c-myc abnormalities were normal. Discussion: This is the first description of a Biclonal Myeloma with separate plasma cell populations producing γ3HC and κLC paraproteins. The biclonality confirms the free HC occurs as a result of abnormal synthesis not cleavage. The clinical and immunological findings are clearly different to typical findings in both γ3HCD and Myeloma. HCD has an appalling prognosis and this case is likely to have been ‘smouldering’ for 18 months, evidenced by the 2 pneumonias and persistent night sweats. There is no lymphadenopathy or organomegaly associated with γ3HCD. The immunophenotype of the malignant plasma cells is unique. Other atypical features include frank proteinuria, with a HC in the urine, but normal renal function and no radiological or biochemical evidence of bone involvement. We propose that this unique biclonal myeloma has distinct immunological and clinical features.

scholarly journals Serum Free Light Chains: An Alternative to the Urine Bence Jones Proteins Screening Test for Monoclonal Gammopathies

2006 ◽  
Vol 52 (9) ◽  
pp. 1743-1748 ◽  
Author(s):  
Peter G Hill ◽  
Julia M Forsyth ◽  
Baldeep Rai ◽  
Stewart Mayne
Keyword(s):  
Light Chain ◽  
False Positive ◽  
False Positive Rate ◽  
Light Chains ◽  
Free Light Chains ◽  
Serum Free ◽  
Monoclonal Gammopathies ◽  
Positive Serum ◽  
Positive Rate ◽  
Serum Free Light Chains

Abstract Background: Retrospective analyses have established the role of quantitative serum free light chains (FLCs) in the diagnosis of monoclonal light chain disorders. The aims of this study were to assess (a) whether the addition of serum FLCs to serum protein electrophoresis (SPEP) identified additional patients with monoclonal gammopathies; (b) whether serum FLC measurements could replace urinalysis for Bence Jones protein (BJP); and (c) the cost/quality implications of routinely measuring serum FLCs. Methods: Serum FLCs were added to consecutive requests for SPEP from August to November 2004 and measured by automated immunoassay. Results: Seventy-one of 923 patients had abnormal serum FLC ratios. Seven patients with monoclonal gammopathies and 1 patient with malignant lymphoma (but no monoclonal band) were detected among 43 patients with negative SPEP but positive serum FLC ratios. Thirty-five patients with negative SPEP had false-positive serum FLC ratios. The false-positive rate for a ratio >1.65 was higher than previously described and associated with polyclonal increases in immunoglobulins and renal impairment. Serum FLC ratios were normal in 2 of 13 patients with low-level persistent urine BJP. However, no significant pathology would have been missed by replacing BJP with serum FLCs. Revenue and manpower savings offset 60% of the costs of serum FLCs. Conclusions: Additional diagnostic information is gained by adding serum FLCs to SPEP as first-line tests for investigating possible B-cell disorders. The quality of the diagnostic service is enhanced by more confident exclusion of light chain disorders and improved interpretive assessment of SPEP and immunofixation electrophoresis.

scholarly journals The occurrence of disulphide bonds in purified clathrin light chains

1989 ◽  
Vol 257 (3) ◽  
pp. 775-781 ◽  
Author(s):  
P Parham ◽  
F M Brodsky ◽  
K Drickamer
Keyword(s):  
Heavy Chain ◽  
Light Chain ◽  
Reduced Form ◽  
Light Chains ◽  
Cysteine Residues ◽  
Free Light Chains ◽  
Clathrin Heavy Chain ◽  
Disulphide Bonds ◽  
Antigenic Properties ◽  
Reduced Forms

Three forms of clathrin light chain contain two cysteine residues. These are the predominant brain-specific forms of LCa and LCb and the non-brain form of LCb. After purification in the absence of thiols they contain intramolecular disulphide bonds. The reduced and the oxidized forms show differences in electrophoretic mobility, explaining the variable and heterogeneous patterns observed on electrophoresis. Accessibility of the thiol groups in the free light chains is greater than when they are associated with the heavy chain. In contrast the cysteine residues of the clathrin heavy chain are completely inaccessible in the absence of denaturants and are not found in disulphide bonds. The antigenic properties of the oxidized and the reduced forms of the clathrin light chains are similar, as is their capacity to bind to the clathrin heavy chain. After isolation in the presence of 10 mM-iodoacetamide, the light-chain cysteine residues are fully alkylated. The results are consistent with the reduced form being the native state and the light-chain disulphide bonds an artifact of isolation.

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.

Serum and Urine Protein Electrophoresis and Serum-Free Light Chain Assays in the Diagnosis and Monitoring of Monoclonal Gammopathies

2020 ◽  
Vol 5 (6) ◽  
pp. 1358-1371
Author(s):  
Gurmukh Singh
Keyword(s):  
Light Chain ◽  
Protein Electrophoresis ◽  
Free Light Chain ◽  
Light Chains ◽  
Free Light Chains ◽  
Urine Protein ◽  
Serum Free ◽  
Monoclonal Gammopathies ◽  
Serum Free Light Chain ◽  
Serum Free Light Chains

Abstract Background Laboratory methods for diagnosis and monitoring of monoclonal gammopathies have evolved to include serum and urine protein electrophoresis, immunofixation electrophoresis, capillary zone electrophoresis, and immunosubtraction, serum-free light chain assay, mass spectrometry, and newly described QUIET. Content This review presents a critical appraisal of the test methods and reporting practices for the findings generated by the tests for monoclonal gammopathies. Recommendations for desirable practices to optimize test selection and provide value-added reports are presented. The shortcomings of the serum-free light chain assay are highlighted, and new assays for measuring monoclonal serum free light chains are addressed. Summary The various assays for screening, diagnosis, and monitoring of monoclonal gammopathies should be used in an algorithmic approach to avoid unnecessary testing. Reporting of the test results should be tailored to the clinical context of each individual patient to add value. Caution is urged in the interpretation of results of serum-free light chain assay, kappa/lambda ratio, and myeloma defining conditions. The distortions in serum-free light chain assay and development of oligoclonal bands in patients‘ status post hematopoietic stem cell transplants is emphasized and the need to note the location of original monoclonal Ig is stressed. The need for developing criteria that consider the differences in the biology of kappa and lambda light chain associated lesions is stressed. A new method of measuring monoclonal serum-free light chains is introduced. Reference is also made to a newly defined entity of light chain predominant intact immunoglobulin monoclonal gammopathy. The utility of urine testing in the diagnosis and monitoring of light chain only lesions is emphasized.

Immunoparesis in IgM gammopathies as a useful biomarker to predict disease progression

2017 ◽  
Vol 55 (10) ◽  
Author(s):  
Marcio Andrade-Campos ◽  
Ilda Murillo-Flórez ◽  
Ramón García-Sanz ◽  
Pilar Giraldo
Keyword(s):  
Light Chain ◽  
Progressive Increase ◽  
Light Chains ◽  
Separate Analysis ◽  
Time To Progression ◽  
Disease Mechanism ◽  
Free Light Chains ◽  
Monoclonal Gammopathies ◽  
Serum Free Light Chains ◽  
Predict Disease Progression

AbstractBackground:The management of IgM monoclonal gammopathies undetermined significance (IgM-MGUS) and Waldenstrom’s macroglobulinemia (WM) may be challenging. Modern immunoassays that quantify specific monoclonal heavy and light chain immunoglobulins are promising for their use in these applications.Methods:Ninety consecutive patients (39 IgM-MGUS, 32 indolent WM [iWM], and 19 WM) seen between January 2007 and March 2014 were analyzed. Heavy/light chain (HLC) and serum free light chains assays (FLC) were determined at diagnosis to study their utility as biomarkers in IgM monoclonal gammopathies.Results:The HLC involved to uninvolved IgM ratios (iHLC/uHLC) showed a progressive increase when going from IgM-MGUS, to iWM and to WM (p=0.002). Furthermore, an iHLC/uHLC>62 identified a group of iWM patients with a shorter time-to-progression (TTP) (108 vs. 133 months, p=0.033). Separate analysis of the involved and uninvolved components showed that only the suppression of the uninvolvedimmunoglobulin was predictive of shorter TTP (HR=3.04, p=0.03) suggesting that it could be the majorcontributor to the prognostic value of the Hevylite assay. Additionally, a multivariate analysis showed that immunosuppression (either classical immunoparesis or Hevylite immunosuppression) was an independent prognostic factor (p=0.016) reinforcing its relevance in the disease mechanism. Finally, monoclonal sFLC levels were highest in WM patients, with 83% presenting values>60 mg/L.Conclusions:The results suggest that the levels of immunosuppression and/or the iHLC/uHLC ratio of IgM immunoglobulins measured by Hevylite are associated with greater disease activity which significantly impacts in the outcome of WM patients and may also help in the differentiation of IgMMGUS from iWM.

Serum Versus Urine Free Light Chains for Assessment of Monoclonal Gammopathies

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 5307-5307
Author(s):  
Montgomery Lobe ◽  
Donald Pasquale
Keyword(s):  
Multiple Myeloma ◽  
Light Chain ◽  
Conflicts Of Interest ◽  
Medical Center ◽  
Statistical Significance ◽  
Serum Immunoglobulin ◽  
Light Chains ◽  
Total Serum ◽  
Free Light Chains ◽  
Monoclonal Gammopathies

Abstract Introduction Monoclonal gammopathies comprise a spectrum of disorders including Monoclonal Gammopathy of Undetermined Significant (MGUS), Smoldering Multiple Myeloma (SMM), and Active Multiple Myeloma (MM) characterized by production of monoclonal immunoglobulin heavy and/or light chains. Prior to availability of the FREELITE™ (Binding Site Ltd; Birmingham, UK) assay for measurement of immunoglobulin free light chains (FLC), laboratory monitoring of these disorders used predominantly SPEP, quantitation of immunoglobulin heavy chains (quantitative immunoglobulins), and 24 urine collection for total protein and UPEP to extrapolate production of immunoglobulin light chains. The FREELITE™ assay has up to 3-log increased sensitivity (1.5-3.0 mg/L) for detection of free light chains over standard electrophoresis (500-2,000 mg/L) and immunofixation (150-500 mg/L), and since its introduction, has been an integral tool in diagnosis and monitoring of monoclonal gammopathies. This assay detects more plasma cell disorders than SPEP, UPEP and IFE combined due to its higher sensitivity and ability to derive the ratio of affected to unaffected light chain. Measurement of urine FLC using FREELITE™ has not been integrated into standard practice due to presumed variability in FLC concentration due to changes in glomerular filtration, variability in tubular reabsorption of light chains, and lack of data regarding this use. In our practice, we routinely use random urine samples instead of 24 hour urine collections which are cumbersome and suffer from poor patient compliance. Methods: The study was approved by the Stratton VA Medical Center Institutional Review Board. As it has been our practice to obtain both random urine along with serum for FLC, we retrospectively reviewed patients diagnosed with monoclonal gammopathies and compared random urine free light chains measured by FREELITE™ to serum FLC and serum quantitative immunoglobulins. Data was analyzed for correlation using Pearson product moment correlation. P values of >0.05 were considered significant. Results: We identified 23 individuals, all male (consistent with VA population). Mean (±SD) age was 68±10 years at diagnosis, creatinine 1.3±0.5 mg/dl, and 9±6 pairs of data points per patient. Five (5) had MGUS, 5 SM, and 13 MM (2 light chain only). Results are illustrated in the Table. Normalization of urine results using concurrent serum and urine creatinine did not change the statistical significance of any of the results. Table. Correlation (p<0.05) between affected serum immunoglobulin, urine FLC, and serum FLC Serum Immunoglobulin Urine FLC Serum FLC #(%) of Patients YES YES no 2(10) YES no YES 6(29) YES YES YES 5(24) No no no 7(33) YES YES 11(48) Discussion While serum FLC is adequate in the majority of patients for monitoring monoclonal gammopathies, urine FLC correlates as well as serum FLC in about ½ of the patients. In addition, in a small number of individuals, urine FLC correlates with serum total serum immunoglobulin better than serum FLC. We feel that random urine FLC is useful for monitoring monoclonal gammopathies, and in a minority of instances, provides more accurate assessment of disease activity than serum. Disclosures No relevant conflicts of interest to declare.

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