Conflicting results between electrophoresis methods of serum M-proteins.
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 lambda 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 gamma-region. A lower resolution agarose method using an amido black staining showed a small mid-gamma 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 beta-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.
Wuyts
Birgitte
B
Department of Clinical Chemistry, University Hospital Ghent, De Pintelaan 185, B-9000 Gent, Belgium.
Bossuyt
Xavier
X
Verhoef
Gregor
G
Blanckaert
Norbert
N
Delanghe
Joris R
JR
D000368:Aged; D001797:Blood Protein Electrophoresis; D004587:Electrophoresis, Agar Gel; D019075:Electrophoresis, Capillary; D006801:Humans; D007075:Immunoglobulin M / Q000032:analysis* / Q000097:blood; D007146:Immunoglobulin lambda-Chains / Q000032:analysis* / Q000097:blood; D008297:Male; D010265:Paraproteinemias / Q000276:immunology*; D015203:Reproducibility of Results
D007075:Immunoglobulin M; D007146:Immunoglobulin lambda-Chains