Conflicting results between electrophoresis methods of serum M-proteins

• Published in: Electrophoresis 2004-06, Vol.25 (10-11), p.1548-1550
• Main Authors: Wuyts, Birgitte, Bossuyt, Xavier, Verhoef, Gregor, Blanckaert, Norbert, Delanghe, Joris R.
• Format: Article
• Language: English
• Subjects: Aged; Blood Protein Electrophoresis; Capillary zone electrophoresis; Electrophoresis, Agar Gel; Electrophoresis, Capillary; Humans; Immunoglobulin lambda-Chains - analysis; Immunoglobulin lambda-Chains - blood; Immunoglobulin M - analysis; Immunoglobulin M - blood; Male; Monoclonal protein; Paraproteinemias - immunology; Reproducibility of Results; Serum protein
• ISSN: 0173-0835; 1522-2683
• DOI: 10.1002/elps.200305871

The quantification of monoclonal immunoglobulins by protein electrophoresis has been helpful in determining the prognosis for the patient. In a 65‐year old man with documented IgG λ monoclonal gammopathy, a discrepancy in the detection and quantification of this M‐protein was found when studied by four different electrophoretic methods. On a high‐resolution agarose method with acid violet staining a prominent peak was seen in the fast γ‐region. A lower resolution agarose method using an amido black staining showed a small mid‐γ restriction, and no spike was detected by high‐resolution or lower resolution capillary zone electrophoresis. The discrepancy was not attributable to a migration in the β‐region leading to masking by transferrin or C3 peak, incorrect separation on CZE due to a high isoelectric point (pI > 8.5) or pentamerization of IgM M‐proteins. Therefore, other causes for discrepancies should be investigated.