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

2013 ◽  
Vol 2013 ◽  
pp. 331-332
Author(s):  
M.G. Bissell
2011 ◽  
Vol 57 (12) ◽  
pp. 1687-1692 ◽  
Author(s):  
Jerry A Katzmann ◽  
Melissa R Snyder ◽  
S Vincent Rajkumar ◽  
Robert A Kyle ◽  
Terry M Therneau ◽  
...  

BACKGROUND We analyzed serial data in patients with clinically stable monoclonal gammopathy to determine the total variation of serum M-spikes [measured with serum protein electrophoresis (SPEP)], urine M-spikes [measured with urine protein electrophoresis (UPEP)], and monoclonal serum free light chain (FLC) concentrations measured with immunoassay. 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 immunoassay) 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 analytical CVs, we calculated the biological 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.


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

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


Author(s):  
Stephen J. Harding ◽  
Graham P. Mead ◽  
Arthur R. Bradwell ◽  
Annie M. Berard

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.


2011 ◽  
Vol 412 (7-8) ◽  
pp. 562-568 ◽  
Author(s):  
Sacha N. Uljon ◽  
Paul G. Richardson ◽  
Peter H. Schur ◽  
Kenneth C. Anderson ◽  
Milenko J. Tanasijevic ◽  
...  

2018 ◽  
Vol 56 (2) ◽  
pp. 256-263 ◽  
Author(s):  
Joel Smith ◽  
Geoffrey Raines ◽  
Hans-Gerhard Schneider

Abstract Background: There are a variety of initial laboratory tests or combinations of tests that can be performed when a monoclonal gammopathy is suspected including serum protein electrophoresis (SPEP), urine protein electrophoresis (UPEP), serum immunofixation (IFE) and serum free light chain assays. Some groups have recently used simplified “screening” IFE methods for the detection of monoclonal gammopathies leveraging the greater sensitivity of IFE over SPEP alone to improve the detection of monoclonal gammopathies. These screening techniques have been predominantly evaluated against lower resolution agarose gel electrophoresis techniques. Methods: In this study we evaluated the diagnostic performance of the combined κ and λ light chain screening immunofixation (CLIF) in comparison to serum protein electrophoresis on a high-resolution (Sebia Hydragel 15 HR) agarose gel system. Each gel was interpreted by three adjudicators. A total of 156 patient samples were analysed. Adjudicated diagnoses based on the screening techniques were compared against the results of high resolution serum protein electrophoresis and high resolution standard immunofixation performed during routine laboratory operation. Where standard immunofixation was not performed a combination of a review of medical records, serum free light chains, UPEP and bone marrow aspirate and trephine and subsequent standard immunofixation and protein electrophoresis results where available were used to confirm the absence of a monoclonal gammopathy. Results: In this cohort a total of 65 (41%) patients had a paraprotein confirmed by standard immunofixation. HR SPEP had a sensitivity and specificity of 95% and 85%, respectively, while CLIF had a sensitivity and specificity of 88% and 97%, respectively. Conclusions: Overall we found that high-resolution gel serum protein electrophoresis using a Sebia Hydragel 15 HR system was more sensitive than a screening immunofixation method (CLIF) for the detection of paraproteins in patient serum in this patient cohort. The drawback of the greater sensitivity of HR SPEP was a higher false positive rate requiring an increased utilisation of follow up immunofixation electrophoresis.


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