Inability to Measure M-Protein With Capillary Zone Electrophoresis (CAPPILLARYS 2) in Tracings With NonDiscernable Peaks.

Background: We performed a retrospective study to illustrate the challenges with quantifying monoclonal (M)-protein in the cases of serum protein capillary zone electrophoresis (SPCZE) where no discernable peak is apparent.

Materials And Methods: We retrospectively reviewed 160 serum immunofixation electrophoresis (SIFE) that were performed at Memorial Hermann Hospital-Texas Medical Center between October 2013 and November 2013 and we identified the positive SIFE results. The corresponding SPCZE of the positive SIFE were retrieved and evaluated for the ability to quantify M-proteins in them. We define the ability to quantify M-protein as the ability for the operator of the SPCZE to identify a discernable peak and to be able to manually gate the area under the peak.

Results: Twenty-two cases of SIFE detected a monoclonal immunoglobulin. Of the corresponding 22 SPCZE, we could not quantify the M-protein in 6 (27.3%) of the cases.

Conclusion: We have shown several cases where we were not able to quantify the M-protein with SPCZE. This poses a challenge in the diagnosis and management of these patients.