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Updated: Sep 19, 2026
Capillary Electrophoresis Separation of Monoclonal Antibody Isoforms Using a Neutral Capillary
Published on: January 16, 2017
A capillary electrophoresis-derived nomogram for identifying IgM monoclonal proteins missed by serum protein
Fei Ding1, Shanshan Liang1, Yanhua Zhao1
1Department of the Laboratory Medicine, West China Hospital, Sichuan University, Chengdu 610041, China; Sichuan Clinical Research Centre for Laboratory Medicine, and Clinical Laboratory Medicine Research Centre of West China Hospital, Sichuan University, Chengdu 610041, China.
Objectives:
We developed and internally validated a quantitative nomogram integrating capillary electrophoresis (CE)-derived migration-time parameters with routine laboratory variables to differentiate IgM-type from non-IgM-type monoclonal gammopathy (MG) among SPE-negative but IFE-positive patients.
Methods:
This retrospective study included 346 patients with SPE-missed MG. Clinical, biochemical, and CE-derived time parameters were evaluated. Following LASSO regression screening, multivariate logistic regression identified independent predictors. The nomogram was internally validated using a training set (n = 242) and a test set (n = 104). Performance was assessed by area under the curve (AUC), calibration curves, and decision curve analysis (DCA).
Results:
Six predictors were retained: age, IgM level, LDL-C, α1 globulin, β2 globulin, and the albumin-α1 time difference, which was significantly prolonged in IgM cases (OR = 1.686, P = 0.004). The nomogram achieved an AUC of 0.863 (95% CI: 0.797-0.929) in the training set and 0.697 (95% CI: 0.556-0.838) in the held-out test set, with a test-set sensitivity of 38.9% and specificity of 80.2%. Internal resampling via bootstrapping yielded a corrected AUC of 0.858, which serves as an internal estimate rather than an independent result. Calibration and DCA demonstrated good agreement and net clinical benefit.
Conclusions:
CE-derived migration-time parameters add objective quantitative value to routine indices, facilitating pre-triage of occult IgM-type MG. This nomogram can be embedded into laboratory information systems for risk stratification, pending multi-center external validation.
