Improved Method for Estimating M-Spike Proteins in Serum Protein Electrophoresis
Received Date: Mar 25, 2014 / Accepted Date: Jun 24, 2014 / Published Date: Jun 26, 2014
Abstract
Context: Serum monoclonal immunoglobulin (M-spike) in multiple myeloma is measured by gel electrophoresis (SPE) followed by densitometric scanning of the gel. The current standard methods delimit the M-spike component based on the projected gel image on screen (current standard method, CSM). However, the M-spike could also be selected by delimiting the peak(s) in the scanned curve (densitometry based method, DBM).
Objective: The current study will correlate the results with these two approaches and to investigate which method may yield a result more close to the actual M-spike in the serum.
Designs: Forty-one consecutive SPE files from 2010-2011 with positive M-spike were analyzed simultaneously with methods CSM and DBM. Serum monoclonal IgG from a myeloma patient with essentially no background polyclonal immunoglobulins was purified using protein G sepharose column and quantified using UV spectrophotometry. The measured concentration of purified IgG using methods CSM and DBM was compared to true IgG levels in spiked samples.
Results: The measurements of 41 M-spikes using methods CSM and DBM correlated significantly (r=0.988, p<0.01). However, the measurement using method DBM was consistently higher than that using method CSM (49% ± 24%) In the measurement of purified monoclonal IgG, compared to method CSM, method DBM gave consistently closer results to the true IgG levels in spiked samples.
Conclusions: The current method (CSM) underestimates the amount of serum M-spike. The revised method (DSB) based on the densitometric peak more accurately reflects serum M-spike levels using SPE.
Keywords: Serum monoclonal immunoglobulin; Serum protein electrophoresis; M-spike proteins
Citation: Zhang S, Wu XX, Ostrovsky I, Rand JH (2014) Improved Method for Estimating M-Spike Proteins in Serum Protein Electrophoresis. J Clin Exp Pathol 4:178. Doi: 10.4172/2161-0681.1000178
Copyright: © 2014 Zhang S, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.