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Diagnostic performance of routine electrophoresis and immunofixation for the detection of immunoglobulin paraproteins (M‐Proteins) in dogs with multiple myeloma and related disorders: Part 2—Toward improved diagnostic performance
Author(s) -
Moore A Russell,
Harris R. Adam,
Jeffries Christina,
Ashton Laura,
Avery Paul R.
Publication year - 2021
Publication title -
veterinary clinical pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.537
H-Index - 51
eISSN - 1939-165X
pISSN - 0275-6382
DOI - 10.1111/vcp.12940
Subject(s) - paraproteins , serum protein electrophoresis , immunofixation , capillary electrophoresis , myeloma protein , gel electrophoresis of proteins , multiple myeloma , antibody , albumin , immunoelectrophoresis , agarose gel electrophoresis , immunology , medicine , microbiology and biotechnology , biology , monoclonal , polyacrylamide gel electrophoresis , monoclonal antibody , biochemistry , gene , enzyme
Background The diagnostic performance of routine electrophoresis (agarose gel electrophoresis [AGE] and capillary zone electrophoresis [CZE]) and species‐specific immunofixation (IF) for the detection of immunoglobulin paraproteins (M‐proteins) and diagnosis of secretory myeloma‐related disorders (sMRD) can be improved. Available canine IF targets were IgG‐FC, IgA, IgM, light chain (LC), IgG4, and free LC (fLC) antibodies. Objective We aimed to review specific features associated with the presence of M‐proteins in canine serum samples and the common features causing inaccurate reporting of M‐proteins to improve the diagnostic performance of routine electrophoresis and IF for the detection of M‐proteins. Methods Features found in AGE, CZE, routine IF, IgG4 IF, and fLC IF of 100 canine serum samples from Part 1 of this study were evaluated by simple and multivariate logistic regression to identify factors associated with the presence of M‐proteins. Cases falsely called negative or positive for M‐proteins were reviewed to identify the common features that could be used to increase the diagnostic performance of SPE and IF for M‐protein detection. Results The presence of hypogammaglobulinemia or any peak taller than albumin was associated with an M‐protein. Total protein concentrations, globulin concentrations, or peaks wider than albumin were not associated with an M‐protein. Free LC sMRD cases were not diagnosed by SPE and routine IF. Cases with infectious and inflammatory etiologies had a restricted polyclonal gammopathy with multiple γ‐globulin restrictions resulting in some false‐positive results. SPE combined with all available IF results and the specific features identified in this study had an estimated sensitivity of 95.1% and specificity of 81.4%. Conclusions The identified criteria of this study increase the diagnostic performance of the electrophoretic evaluation for M‐proteins.