Immunotyping provides equivalent results to immunofixation in a population with a high prevalence of monoclonal gammopathies Journal Article


Authors: Thoren, K. L.; McCash, S. I.; Murata, K.
Article Title: Immunotyping provides equivalent results to immunofixation in a population with a high prevalence of monoclonal gammopathies
Abstract: Background: Serum immunofixation (IF) is a common laboratory test used to diagnose and monitor patients with monoclonal gammopathies. Similarly, immunotyping (IT) by capillary electrophoresis can confirm the presence of a monoclonal protein (M-protein) and determine its isotype. The goal of this study was to compare the ability of IT and IF to detect M-proteins. Methods: IT and IF results for 1000 waste clinical serum samples were obtained. All results were interpreted blindly by reviewers who were experienced in each technique. Results were compared by band. Results were also compared to patient history to determine if the original clone was present. We determined the sensitivity of IT and IF alone and in combination with additional tests. Finally, we evaluated the impact of reviewer training on the sensitivity of IT. Results: IT and IF were concordant in 721/773 (93%) samples with a history of an intact M-protein and in 143/172 (83%) samples with a history of a free light chain (FLC) M-protein. IF was significantly more sensitive than IT for the detection of FLC M-proteins (P < 0.0001). However, IF was not more sensitive than IT for detection of intact M-proteins (P = 0.1272) or when each test was combined with the FLC ratio or urine immunofixation (P = 0.2812 and P= 0.6171, respectively). Finally, after training, inexperienced reviewers improved their IT sensitivity by 19%. Conclusion: IT provides equivalent results to IF for the detection of monoclonal proteins. Training and experience are critical to the accurate interpretation of IT.
Keywords: capillary; performance; electrophoresis; myeloma; agarose-gel
Journal Title: Journal of Applied Laboratory Medicine
Volume: 6
Issue: 6
ISSN: 2576-9456
Publisher: Amer Assoc Clinical Chemistry  
Date Published: 2021-11-01
Start Page: 1551
End Page: 1560
Language: English
ACCESSION: WOS:000717579800016
DOI: 10.1093/jalm/jfab067
PROVIDER: wos
PMCID: PMC8561783
PUBMED: 34329441
Notes: Article -- Source: Wos
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MSK Authors
  1. Kazunori Murata
    33 Murata
  2. Samuel Isaac McCash
    13 McCash
  3. Katie Lynn Thoren
    37 Thoren