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Jerry A Katzmann - One of the best experts on this subject based on the ideXlab platform.
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long term biological variation of Serum Protein Electrophoresis m spike urine m spike and monoclonal Serum free light chain quantification implications for monitoring monoclonal gammopathies
Clinical Chemistry, 2011Co-Authors: Jerry A Katzmann, Vincent S Rajkumar, Melissa R Snyder, Robert A Kyle, Terry M Therneau, Joanne T Benson, Angela DispenzieriAbstract:BACKGROUND: We analyzed serial data in patients with clinically stable monoclonal gammopathy to determine the total variation of Serum M-spikes [Serum Protein Electrophoresis (SPEP)], urine M-spikes [urine Protein Electrophoresis (UPEP)], and monoclonal Serum free light chain (FLC). METHODS: Patients to be studied were identified by ( a ) no treatment during the study interval, ( b ) no change in diagnosis and <5 g/L change in Serum M-spike over the course of observation; ( c ) performance of all 3 tests (SPEP, UPEP, FLC) in at least 3 serial samples that were obtained 9 months to 5 years apart; ( d ) Serum M-spike ≥10 g/L, urine M-spike ≥200 mg/24 h, or clonal FLC ≥100 mg/L. The total CV was calculated for each method. RESULTS: Among the cohort of 158 patients, 90 had measurable Serum M-spikes, 25 had urine M-spikes, and 52 had measurable Serum FLC abnormalities. The CVs were calculated for serial SPEP M-spikes (8.1%), UPEP M-spikes (35.8%), and Serum FLC concentrations (28.4%). Combining these CVs and the interassay analytic CVs, we calculated the biologic CV for the Serum M-spike (7.8%), urine M-spike (35.5%), and Serum FLC concentration (27.8%). CONCLUSIONS: The variations in urine M-spike and Serum FLC measurements during patient monitoring are similar and are larger than those for Serum M-spikes. In addition, in this group of stable patients, a measurable Serum FLC concentration was available twice as often as a measurable urine M-spike.
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elimination of the need for urine studies in the screening algorithm for monoclonal gammopathies by using Serum immunofixation and free light chain assays
Mayo Clinic Proceedings, 2006Co-Authors: Jerry A Katzmann, Melissa R Snyder, Matthew F Plevak, Roshini S Abraham, John A Lust, Dirk R Larson, Angela Dispenzieri, Joseph L Melton, Vincent S RajkumarAbstract:OBJECTIVE To determine the relative diagnostic contribution of urine assays as part of the screening algorithm for monoclonal gammopathies. PATIENTS AND METHODS We identified 428 patients with a monoclonal gammopathy and monoclonal urinary Protein at initial diagnosis of plasma cell dyscrasia who had also undergone Serum immunofixation and Serum free light chain quantitation within 30 days of diagnosis. The laboratory results for Serum Protein Electrophoresis, Serum immunofixation, Serum free light chain, urine Protein Electrophoresis, and urine immunofixation were reviewed. RESULTS The patients had diagnoses of multiple myeloma, primary amyloid, monoclonal gammopathy of undetermined significance, smoldering multiple myeloma, solitary plasmacytomas, and other less frequently detected monoclonal gammopathies. All 428 had a monoclonal urine Protein, 85.7% had an abnormal Serum free light chain κ/λ ratio, 80.8% had an abnormal Serum Protein Electrophoresis, and 93.5% had an abnormal Serum immunofixation result. All 3 Serum assays were normal in only 2 patients, 1 of whom had monoclonal gammopathy of undetermined significance (idiopathic Bence Jones Proteinuria) and 1 whose urine sample contained an intact monoclonal immunoglobulin but whose Serum and subsequent urine samples showed no evidence of a monoclonal gammopathy. CONCLUSION Discontinuation of urine studies and reliance on a diagnostic algorithm using only Serum studies (Protein Electrophoresis, immunofixation, and free light chain quantitation) missed 2 (0.5%) of the 428 monoclonal gammopathies with urinary monoclonal Proteins, and these 2 cases required no medical intervention.
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elimination of the need for urine studies during diagnostic studies of monoclonal gammopathies by the combined use of Serum immunofixation and Serum free light chain assays
Blood, 2006Co-Authors: Jerry A Katzmann, Melissa R Snyder, Matthew F Plevak, Roshini S Abraham, John A Lust, Dirk R Larson, Angela Dispenzieri, Joseph L Melton, Vincent S RajkumarAbstract:Due to the diagnostic sensitivity of Serum free light chain quantitation for monoclonal light chain diseases, it has been suggested that urine assays no longer need be performed as part of the diagnostic algorithm for monoclonal Proteins. We reviewed our experience to determine the relative diagnostic contribution of urine assays. Methods: Patients with a monoclonal gammopathy and monoclonal urinary Protein at initial diagnosis who also had a Serum immunofixation and Serum free light chain quantitation within 30 days of diagnosis were identified (n = 428). The laboratory results for Serum Protein Electrophoresis, Serum immunofixation, Serum free light chain, urine Protein Electrophoresis, and urine immunofixation were reviewed. Results: The patients in this cohort had diagnoses of multiple myeloma, primary amyloid, monoclonal gammopathy of undetermined significance, smoldering multiple myeloma, solitary plasmacytomas, and other less frequently detected monoclonal gammopathies. By definition of the cohort, all 428 had a monoclonal urine Protein. 86% had an abnormal Serum free light chain K/L ratio, 81% had an abnormal Serum Protein Electrophoresis, and 94% had an abnormal Serum immunofixation. In only 2 patients, however, were all 3 Serum assays normal. Both of these were patients with monoclonal gammopathy of undetermined significance (idiopathic Bence Jones Proteinuria). Conclusion: Discontinuation of urine studies and reliance on a diagnostic algorithm using solely Serum studies (Protein Electrophoresis, immunofixation, and free light chain quantitation), missed 2 of the 428 monoclonal gammopathies (0.5 %) with urinary monoclonal Proteins, and these 2 cases required no medical intervention.
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differential diagnosis of gammopathies by capillary Electrophoresis and immunosubtraction analysis of Serum samples problematic by agarose gel Electrophoresis
Electrophoresis, 1998Co-Authors: Raynell Clark, Jerry A Katzmann, Robert A Kyle, Martin Fleisher, James P LandersAbstract:The capabilities of capillary Electrophoresis (CE) for Serum Protein Electrophoresis and immunotyping have been demonstrated. CE-based systems specifically designed for Serum Protein Electrophoresis and immunotyping via immunosubtraction (IS) are now available and are being evaluated for efficiency, specificity and sensitivity by several groups. The use of CE for Serum Protein Electrophoresis and immunotyping (IS) in the clinical laboratory compares well with agarose gel Electrophoresis (AGE) and immunofixation (IF) for the detection and characterization of monoclonal Proteins. In addition to routine use, this technology is useful for a subset of Serum samples that are difficult to interpret with conventional technology. In this study, sera abnormalities difficult to detect/interpret by AGE-IF are subdivided into four categories: (i) patients with polyclonal increases in immunoglobulin, (ii) point of application artifacts, (iii) abnormalities in the beta region, and (iv) patients with free light chains. CE is superior to AGE for evaluating samples characterized by the above abnormalities. Sera containing monoclonal Proteins within a polyclonal increase are easier to detect by CE as well as being easier to type by IS than by IF. Point-of-application artifacts, periodically observed with AGE, do not exist on CE since the point of detection is remote from the point of application. Enhanced resolution in the beta region allows for increased detection of monoclonal Proteins migrating in this region. Some free light chains are undetected by CE as a result of no apparent abnormalities on the CE Serum Protein profile and, thus, still require IF for detection. CE detects more Serum electrophoretic abnormalities than AGE in this clinically important group of patients with Bence Jones Proteinemia.
Vincent S Rajkumar - One of the best experts on this subject based on the ideXlab platform.
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long term biological variation of Serum Protein Electrophoresis m spike urine m spike and monoclonal Serum free light chain quantification implications for monitoring monoclonal gammopathies
Clinical Chemistry, 2011Co-Authors: Jerry A Katzmann, Vincent S Rajkumar, Melissa R Snyder, Robert A Kyle, Terry M Therneau, Joanne T Benson, Angela DispenzieriAbstract:BACKGROUND: We analyzed serial data in patients with clinically stable monoclonal gammopathy to determine the total variation of Serum M-spikes [Serum Protein Electrophoresis (SPEP)], urine M-spikes [urine Protein Electrophoresis (UPEP)], and monoclonal Serum free light chain (FLC). METHODS: Patients to be studied were identified by ( a ) no treatment during the study interval, ( b ) no change in diagnosis and <5 g/L change in Serum M-spike over the course of observation; ( c ) performance of all 3 tests (SPEP, UPEP, FLC) in at least 3 serial samples that were obtained 9 months to 5 years apart; ( d ) Serum M-spike ≥10 g/L, urine M-spike ≥200 mg/24 h, or clonal FLC ≥100 mg/L. The total CV was calculated for each method. RESULTS: Among the cohort of 158 patients, 90 had measurable Serum M-spikes, 25 had urine M-spikes, and 52 had measurable Serum FLC abnormalities. The CVs were calculated for serial SPEP M-spikes (8.1%), UPEP M-spikes (35.8%), and Serum FLC concentrations (28.4%). Combining these CVs and the interassay analytic CVs, we calculated the biologic CV for the Serum M-spike (7.8%), urine M-spike (35.5%), and Serum FLC concentration (27.8%). CONCLUSIONS: The variations in urine M-spike and Serum FLC measurements during patient monitoring are similar and are larger than those for Serum M-spikes. In addition, in this group of stable patients, a measurable Serum FLC concentration was available twice as often as a measurable urine M-spike.
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elimination of the need for urine studies in the screening algorithm for monoclonal gammopathies by using Serum immunofixation and free light chain assays
Mayo Clinic Proceedings, 2006Co-Authors: Jerry A Katzmann, Melissa R Snyder, Matthew F Plevak, Roshini S Abraham, John A Lust, Dirk R Larson, Angela Dispenzieri, Joseph L Melton, Vincent S RajkumarAbstract:OBJECTIVE To determine the relative diagnostic contribution of urine assays as part of the screening algorithm for monoclonal gammopathies. PATIENTS AND METHODS We identified 428 patients with a monoclonal gammopathy and monoclonal urinary Protein at initial diagnosis of plasma cell dyscrasia who had also undergone Serum immunofixation and Serum free light chain quantitation within 30 days of diagnosis. The laboratory results for Serum Protein Electrophoresis, Serum immunofixation, Serum free light chain, urine Protein Electrophoresis, and urine immunofixation were reviewed. RESULTS The patients had diagnoses of multiple myeloma, primary amyloid, monoclonal gammopathy of undetermined significance, smoldering multiple myeloma, solitary plasmacytomas, and other less frequently detected monoclonal gammopathies. All 428 had a monoclonal urine Protein, 85.7% had an abnormal Serum free light chain κ/λ ratio, 80.8% had an abnormal Serum Protein Electrophoresis, and 93.5% had an abnormal Serum immunofixation result. All 3 Serum assays were normal in only 2 patients, 1 of whom had monoclonal gammopathy of undetermined significance (idiopathic Bence Jones Proteinuria) and 1 whose urine sample contained an intact monoclonal immunoglobulin but whose Serum and subsequent urine samples showed no evidence of a monoclonal gammopathy. CONCLUSION Discontinuation of urine studies and reliance on a diagnostic algorithm using only Serum studies (Protein Electrophoresis, immunofixation, and free light chain quantitation) missed 2 (0.5%) of the 428 monoclonal gammopathies with urinary monoclonal Proteins, and these 2 cases required no medical intervention.
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elimination of the need for urine studies during diagnostic studies of monoclonal gammopathies by the combined use of Serum immunofixation and Serum free light chain assays
Blood, 2006Co-Authors: Jerry A Katzmann, Melissa R Snyder, Matthew F Plevak, Roshini S Abraham, John A Lust, Dirk R Larson, Angela Dispenzieri, Joseph L Melton, Vincent S RajkumarAbstract:Due to the diagnostic sensitivity of Serum free light chain quantitation for monoclonal light chain diseases, it has been suggested that urine assays no longer need be performed as part of the diagnostic algorithm for monoclonal Proteins. We reviewed our experience to determine the relative diagnostic contribution of urine assays. Methods: Patients with a monoclonal gammopathy and monoclonal urinary Protein at initial diagnosis who also had a Serum immunofixation and Serum free light chain quantitation within 30 days of diagnosis were identified (n = 428). The laboratory results for Serum Protein Electrophoresis, Serum immunofixation, Serum free light chain, urine Protein Electrophoresis, and urine immunofixation were reviewed. Results: The patients in this cohort had diagnoses of multiple myeloma, primary amyloid, monoclonal gammopathy of undetermined significance, smoldering multiple myeloma, solitary plasmacytomas, and other less frequently detected monoclonal gammopathies. By definition of the cohort, all 428 had a monoclonal urine Protein. 86% had an abnormal Serum free light chain K/L ratio, 81% had an abnormal Serum Protein Electrophoresis, and 94% had an abnormal Serum immunofixation. In only 2 patients, however, were all 3 Serum assays normal. Both of these were patients with monoclonal gammopathy of undetermined significance (idiopathic Bence Jones Proteinuria). Conclusion: Discontinuation of urine studies and reliance on a diagnostic algorithm using solely Serum studies (Protein Electrophoresis, immunofixation, and free light chain quantitation), missed 2 of the 428 monoclonal gammopathies (0.5 %) with urinary monoclonal Proteins, and these 2 cases required no medical intervention.
Angela Dispenzieri - One of the best experts on this subject based on the ideXlab platform.
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long term biological variation of Serum Protein Electrophoresis m spike urine m spike and monoclonal Serum free light chain quantification implications for monitoring monoclonal gammopathies
Clinical Chemistry, 2011Co-Authors: Jerry A Katzmann, Vincent S Rajkumar, Melissa R Snyder, Robert A Kyle, Terry M Therneau, Joanne T Benson, Angela DispenzieriAbstract:BACKGROUND: We analyzed serial data in patients with clinically stable monoclonal gammopathy to determine the total variation of Serum M-spikes [Serum Protein Electrophoresis (SPEP)], urine M-spikes [urine Protein Electrophoresis (UPEP)], and monoclonal Serum free light chain (FLC). METHODS: Patients to be studied were identified by ( a ) no treatment during the study interval, ( b ) no change in diagnosis and <5 g/L change in Serum M-spike over the course of observation; ( c ) performance of all 3 tests (SPEP, UPEP, FLC) in at least 3 serial samples that were obtained 9 months to 5 years apart; ( d ) Serum M-spike ≥10 g/L, urine M-spike ≥200 mg/24 h, or clonal FLC ≥100 mg/L. The total CV was calculated for each method. RESULTS: Among the cohort of 158 patients, 90 had measurable Serum M-spikes, 25 had urine M-spikes, and 52 had measurable Serum FLC abnormalities. The CVs were calculated for serial SPEP M-spikes (8.1%), UPEP M-spikes (35.8%), and Serum FLC concentrations (28.4%). Combining these CVs and the interassay analytic CVs, we calculated the biologic CV for the Serum M-spike (7.8%), urine M-spike (35.5%), and Serum FLC concentration (27.8%). CONCLUSIONS: The variations in urine M-spike and Serum FLC measurements during patient monitoring are similar and are larger than those for Serum M-spikes. In addition, in this group of stable patients, a measurable Serum FLC concentration was available twice as often as a measurable urine M-spike.
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elimination of the need for urine studies in the screening algorithm for monoclonal gammopathies by using Serum immunofixation and free light chain assays
Mayo Clinic Proceedings, 2006Co-Authors: Jerry A Katzmann, Melissa R Snyder, Matthew F Plevak, Roshini S Abraham, John A Lust, Dirk R Larson, Angela Dispenzieri, Joseph L Melton, Vincent S RajkumarAbstract:OBJECTIVE To determine the relative diagnostic contribution of urine assays as part of the screening algorithm for monoclonal gammopathies. PATIENTS AND METHODS We identified 428 patients with a monoclonal gammopathy and monoclonal urinary Protein at initial diagnosis of plasma cell dyscrasia who had also undergone Serum immunofixation and Serum free light chain quantitation within 30 days of diagnosis. The laboratory results for Serum Protein Electrophoresis, Serum immunofixation, Serum free light chain, urine Protein Electrophoresis, and urine immunofixation were reviewed. RESULTS The patients had diagnoses of multiple myeloma, primary amyloid, monoclonal gammopathy of undetermined significance, smoldering multiple myeloma, solitary plasmacytomas, and other less frequently detected monoclonal gammopathies. All 428 had a monoclonal urine Protein, 85.7% had an abnormal Serum free light chain κ/λ ratio, 80.8% had an abnormal Serum Protein Electrophoresis, and 93.5% had an abnormal Serum immunofixation result. All 3 Serum assays were normal in only 2 patients, 1 of whom had monoclonal gammopathy of undetermined significance (idiopathic Bence Jones Proteinuria) and 1 whose urine sample contained an intact monoclonal immunoglobulin but whose Serum and subsequent urine samples showed no evidence of a monoclonal gammopathy. CONCLUSION Discontinuation of urine studies and reliance on a diagnostic algorithm using only Serum studies (Protein Electrophoresis, immunofixation, and free light chain quantitation) missed 2 (0.5%) of the 428 monoclonal gammopathies with urinary monoclonal Proteins, and these 2 cases required no medical intervention.
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elimination of the need for urine studies during diagnostic studies of monoclonal gammopathies by the combined use of Serum immunofixation and Serum free light chain assays
Blood, 2006Co-Authors: Jerry A Katzmann, Melissa R Snyder, Matthew F Plevak, Roshini S Abraham, John A Lust, Dirk R Larson, Angela Dispenzieri, Joseph L Melton, Vincent S RajkumarAbstract:Due to the diagnostic sensitivity of Serum free light chain quantitation for monoclonal light chain diseases, it has been suggested that urine assays no longer need be performed as part of the diagnostic algorithm for monoclonal Proteins. We reviewed our experience to determine the relative diagnostic contribution of urine assays. Methods: Patients with a monoclonal gammopathy and monoclonal urinary Protein at initial diagnosis who also had a Serum immunofixation and Serum free light chain quantitation within 30 days of diagnosis were identified (n = 428). The laboratory results for Serum Protein Electrophoresis, Serum immunofixation, Serum free light chain, urine Protein Electrophoresis, and urine immunofixation were reviewed. Results: The patients in this cohort had diagnoses of multiple myeloma, primary amyloid, monoclonal gammopathy of undetermined significance, smoldering multiple myeloma, solitary plasmacytomas, and other less frequently detected monoclonal gammopathies. By definition of the cohort, all 428 had a monoclonal urine Protein. 86% had an abnormal Serum free light chain K/L ratio, 81% had an abnormal Serum Protein Electrophoresis, and 94% had an abnormal Serum immunofixation. In only 2 patients, however, were all 3 Serum assays normal. Both of these were patients with monoclonal gammopathy of undetermined significance (idiopathic Bence Jones Proteinuria). Conclusion: Discontinuation of urine studies and reliance on a diagnostic algorithm using solely Serum studies (Protein Electrophoresis, immunofixation, and free light chain quantitation), missed 2 of the 428 monoclonal gammopathies (0.5 %) with urinary monoclonal Proteins, and these 2 cases required no medical intervention.
Christopher R Mccudden - One of the best experts on this subject based on the ideXlab platform.
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an international multi center Serum Protein Electrophoresis accuracy and m Protein isotyping study part i factors impacting limit of quantitation of Serum Protein Electrophoresis
Clinical Chemistry and Laboratory Medicine, 2020Co-Authors: Katherine A Turner, Christopher R Mccudden, Maria Stella Graziani, David F Keren, Joannes F. M. Jacobs, Jody L Frinack, Michael W Ettore, Jillian R Tate, Ronald A Booth, Julio C DelgadoAbstract:Background Serum Protein Electrophoresis (SPEP) is used to quantify the Serum monoclonal component or M-Protein, for diagnosis and monitoring of monoclonal gammopathies. Significant imprecision and inaccuracy pose challenges in reporting small M-Proteins. Using therapeutic monoclonal antibody-spiked sera and a pooled beta-migrating M-Protein, we aimed to assess SPEP limitations and variability across 16 laboratories in three continents. Methods Sera with normal, hypo- or hypergammaglobulinemia were spiked with daratumumab, Dara (cathodal migrating), or elotuzumab, Elo (central-gamma migrating), with concentrations from 0.125 to 10 g/L (n = 62) along with a beta-migrating sample (n = 9). Provided with total Protein (reverse biuret, Siemens), laboratories blindly analyzed samples according to their SPEP and immunofixation (IFE) or immunosubtraction (ISUB) standard operating procedures. Sixteen laboratories reported the perpendicular drop (PD) method of gating the M-Protein, while 10 used tangent skimming (TS). A mean percent recovery range of 80%-120% was set as acceptable. The inter-laboratory %CV was calculated. Results Gamma globulin background, migration pattern and concentration all affect the precision and accuracy of quantifying M-Proteins by SPEP. As the background increases, imprecision increases and accuracy decreases leading to overestimation of M-Protein quantitation especially evident in hypergamma samples, and more prominent with PD. Cathodal migrating M-Proteins were associated with less imprecision and higher accuracy compared to central-gamma migrating M-Proteins, which is attributed to the increased gamma background contribution in M-Proteins migrating in the middle of the gamma fraction. There is greater imprecision and loss of accuracy at lower M-Protein concentrations. Conclusions This study suggests that quantifying exceedingly low concentrations of M-Proteins, although possible, may not yield adequate accuracy and precision between laboratories.
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an international multi center Serum Protein Electrophoresis accuracy and m Protein isotyping study part ii limit of detection and follow up of patients with small m Proteins
Clinical Chemistry and Laboratory Medicine, 2020Co-Authors: Joannes F. M. Jacobs, Christopher R Mccudden, Maria Stella Graziani, David F Keren, Katherine A Turner, Jody L Frinack, Michael W Ettore, Jillian R Tate, Ronald A Booth, Julio C DelgadoAbstract:Background Electrophoretic methods to detect, characterize and quantify M-Proteins play an important role in the management of patients with monoclonal gammopathies (MGs). Significant uncertainty in the quantification and limit of detection (LOD) is documented when M-Proteins are <10 g/L. Using spiked sera, we aimed to assess the variability in intact M-Protein quantification and LOD across 16 laboratories. Methods Sera with normal, hypo- or hyper-gammaglobulinemia were spiked with daratumumab or elotuzumab, with concentrations from 0.125 to 10 g/L (n = 62) along with a beta-migrating sample (n = 9). Laboratories blindly analyzed samples according to their Serum Protein Electrophoresis (SPEP)/isotyping standard operating procedures. LOD and intra-laboratory percent coefficient of variation (%CV) were calculated and further specified with regard to the method (gel/capillary Electrophoresis [CZE]), gating strategy (perpendicular drop [PD]/tangent skimming [TS]), isotyping (immunofixation/immunosubtraction [ISUB]) and manufacturer (Helena/Sebia). Results All M-Proteins ≥1 g/L were detected by SPEP. With isotyping the LOD was moderately more sensitive than with SPEP. The intensity of polyclonal background had the biggest negative impact on LOD. Independent of the method used, the intra-laboratory imprecision of M-Protein quantification was small (mean CV = 5.0%). Low M-Protein concentration and high polyclonal background had the strongest negative impact on intra-laboratory precision. All laboratories were able to follow trend of M-Protein concentrations down to 1 g/L. Conclusions In this study, we describe a large variation in the reported LOD for both SPEP and isotyping; overall LOD is most affected by the polyclonal immunoglobulin background. Satisfactory intra-laboratory precision was demonstrated. This indicates that the quantification of small M-Proteins to monitor patients over time is appropriate, when subsequent testing is performed within the same laboratory.
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evaluation of digital images for identification and characterization of monoclonal immunoglobulins by immunofixation
Clinical Biochemistry, 2013Co-Authors: Laura M Bender, Steven W Cotten, Yuri Fedoriw, Monte S. Willis, Christopher R MccuddenAbstract:Abstract Objectives High resolution digital imaging systems were recently introduced to capture and visualize Serum Protein Electrophoresis results. In this study, we compared the performance of five, experienced interpreters using digital images and physical gels to identify and characterize monoclonal gammopathies by immunofixation. Design and methods Immunofixation gels were generated using Sebia's HYDRASYS and digital images were captured with Sebia's Gelscan system. Interpreters blindly reviewed 200 consecutively obtained immunofixation results using physical gels, low resolution (LR) images, and high resolution (HR) images. Results Interpretations of the physical gels were significantly more sensitive (p ≤ 0.01) than LR and HR images, and significantly more specific (p Conclusions Interpreters using digital images had significantly different performance than when using physical agarose gels. Differences were most pronounced for low concentration monoclonal gammopathies (
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interference of monoclonal antibody therapies with Serum Protein Electrophoresis tests
Clinical Chemistry, 2010Co-Authors: Christopher R Mccudden, Peter M Voorhees, Shirley A. Hainsworth, Herbert C. Whinna, John F. Chapman, Catherine A Hammettstabler, Monte S. WillisAbstract:To the Editor: During routine Serum Protein Electrophoresis (SPE), we recently detected an apparent IgG heavy-chain immunoglobulin in a 51-year-old woman with a 5-year history of IgDκ multiple myeloma. Other relevant laboratory values at the time included the following: Serum creatinine, 159 μmol/L (reference interval, 62–97 μmol/L); IgG, 2.55 g/L (reference interval, 6.00–17.00 g/L); IgM, <0.25 g/L (reference interval, 0.35–2.90 g/L); and IgA, 0.40 g/L (reference interval, 0.40–4.00 g/L). The rarity of an IgG heavy-chain gammopathy in combination with an IgDκ and a low quantitative IgG value raised suspicion of an interference. Consultation with the treating physician revealed that the patient was enrolled in a phase II clinical trial of dexamethasone and siltuximab for the treatment of refractory myeloma. Siltuximab (Centocor), a high-affinity antibody to human interleukin-6, is currently being used in clinical trials for the treatment of a number of malignancies, including multiple myeloma. Siltuximab is a chimeric immunoglobulin comprising the variable antigen-binding region of a mouse antibody and the constant region of human IgG1κ (1). It binds to human interleukin-6, a survival factor for myeloma cells (2). We obtained siltuximab from the manufacturer …
Melissa R Snyder - One of the best experts on this subject based on the ideXlab platform.
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long term biological variation of Serum Protein Electrophoresis m spike urine m spike and monoclonal Serum free light chain quantification implications for monitoring monoclonal gammopathies
Clinical Chemistry, 2011Co-Authors: Jerry A Katzmann, Vincent S Rajkumar, Melissa R Snyder, Robert A Kyle, Terry M Therneau, Joanne T Benson, Angela DispenzieriAbstract:BACKGROUND: We analyzed serial data in patients with clinically stable monoclonal gammopathy to determine the total variation of Serum M-spikes [Serum Protein Electrophoresis (SPEP)], urine M-spikes [urine Protein Electrophoresis (UPEP)], and monoclonal Serum free light chain (FLC). METHODS: Patients to be studied were identified by ( a ) no treatment during the study interval, ( b ) no change in diagnosis and <5 g/L change in Serum M-spike over the course of observation; ( c ) performance of all 3 tests (SPEP, UPEP, FLC) in at least 3 serial samples that were obtained 9 months to 5 years apart; ( d ) Serum M-spike ≥10 g/L, urine M-spike ≥200 mg/24 h, or clonal FLC ≥100 mg/L. The total CV was calculated for each method. RESULTS: Among the cohort of 158 patients, 90 had measurable Serum M-spikes, 25 had urine M-spikes, and 52 had measurable Serum FLC abnormalities. The CVs were calculated for serial SPEP M-spikes (8.1%), UPEP M-spikes (35.8%), and Serum FLC concentrations (28.4%). Combining these CVs and the interassay analytic CVs, we calculated the biologic CV for the Serum M-spike (7.8%), urine M-spike (35.5%), and Serum FLC concentration (27.8%). CONCLUSIONS: The variations in urine M-spike and Serum FLC measurements during patient monitoring are similar and are larger than those for Serum M-spikes. In addition, in this group of stable patients, a measurable Serum FLC concentration was available twice as often as a measurable urine M-spike.
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elimination of the need for urine studies in the screening algorithm for monoclonal gammopathies by using Serum immunofixation and free light chain assays
Mayo Clinic Proceedings, 2006Co-Authors: Jerry A Katzmann, Melissa R Snyder, Matthew F Plevak, Roshini S Abraham, John A Lust, Dirk R Larson, Angela Dispenzieri, Joseph L Melton, Vincent S RajkumarAbstract:OBJECTIVE To determine the relative diagnostic contribution of urine assays as part of the screening algorithm for monoclonal gammopathies. PATIENTS AND METHODS We identified 428 patients with a monoclonal gammopathy and monoclonal urinary Protein at initial diagnosis of plasma cell dyscrasia who had also undergone Serum immunofixation and Serum free light chain quantitation within 30 days of diagnosis. The laboratory results for Serum Protein Electrophoresis, Serum immunofixation, Serum free light chain, urine Protein Electrophoresis, and urine immunofixation were reviewed. RESULTS The patients had diagnoses of multiple myeloma, primary amyloid, monoclonal gammopathy of undetermined significance, smoldering multiple myeloma, solitary plasmacytomas, and other less frequently detected monoclonal gammopathies. All 428 had a monoclonal urine Protein, 85.7% had an abnormal Serum free light chain κ/λ ratio, 80.8% had an abnormal Serum Protein Electrophoresis, and 93.5% had an abnormal Serum immunofixation result. All 3 Serum assays were normal in only 2 patients, 1 of whom had monoclonal gammopathy of undetermined significance (idiopathic Bence Jones Proteinuria) and 1 whose urine sample contained an intact monoclonal immunoglobulin but whose Serum and subsequent urine samples showed no evidence of a monoclonal gammopathy. CONCLUSION Discontinuation of urine studies and reliance on a diagnostic algorithm using only Serum studies (Protein Electrophoresis, immunofixation, and free light chain quantitation) missed 2 (0.5%) of the 428 monoclonal gammopathies with urinary monoclonal Proteins, and these 2 cases required no medical intervention.
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elimination of the need for urine studies during diagnostic studies of monoclonal gammopathies by the combined use of Serum immunofixation and Serum free light chain assays
Blood, 2006Co-Authors: Jerry A Katzmann, Melissa R Snyder, Matthew F Plevak, Roshini S Abraham, John A Lust, Dirk R Larson, Angela Dispenzieri, Joseph L Melton, Vincent S RajkumarAbstract:Due to the diagnostic sensitivity of Serum free light chain quantitation for monoclonal light chain diseases, it has been suggested that urine assays no longer need be performed as part of the diagnostic algorithm for monoclonal Proteins. We reviewed our experience to determine the relative diagnostic contribution of urine assays. Methods: Patients with a monoclonal gammopathy and monoclonal urinary Protein at initial diagnosis who also had a Serum immunofixation and Serum free light chain quantitation within 30 days of diagnosis were identified (n = 428). The laboratory results for Serum Protein Electrophoresis, Serum immunofixation, Serum free light chain, urine Protein Electrophoresis, and urine immunofixation were reviewed. Results: The patients in this cohort had diagnoses of multiple myeloma, primary amyloid, monoclonal gammopathy of undetermined significance, smoldering multiple myeloma, solitary plasmacytomas, and other less frequently detected monoclonal gammopathies. By definition of the cohort, all 428 had a monoclonal urine Protein. 86% had an abnormal Serum free light chain K/L ratio, 81% had an abnormal Serum Protein Electrophoresis, and 94% had an abnormal Serum immunofixation. In only 2 patients, however, were all 3 Serum assays normal. Both of these were patients with monoclonal gammopathy of undetermined significance (idiopathic Bence Jones Proteinuria). Conclusion: Discontinuation of urine studies and reliance on a diagnostic algorithm using solely Serum studies (Protein Electrophoresis, immunofixation, and free light chain quantitation), missed 2 of the 428 monoclonal gammopathies (0.5 %) with urinary monoclonal Proteins, and these 2 cases required no medical intervention.
