Related Experiment Video
Updated: Jul 17, 2026
Experimental Approaches for Biochemical Analysis of Glial Fibrillary Acidic Protein and Its Disease-associated Variants
Published on: November 28, 2025
Cross-platform comparison of blood glial fibrillary acidic protein quantification in healthy controls and multiple
Anne Ladwig1, Antje Torge2, Kim Kristin Falk2
1Department of Neurology, University Hospital Schleswig-Holstein, Kiel, Germany.
Background:
Glial fibrillary acidic protein (GFAP) is an astrocyte marker increasingly recognized as a biomarker of disease progression in multiple sclerosis (MS). While highly sensitive assays are available, cross-platform harmonization remains insufficient, limiting routine clinical implementation.
Objective:
To compare three fully automated GFAP assays, assess their analytical agreement and clinical performance across MS subtypes and healthy controls, and evaluate cross-platform conversion approaches.
Methods:
Serum samples from 435 individuals (298 healthy controls, 51 relapsing-remitting MS (RRMS), 41 primary/secondary progressive MS (PPMS/SPMS)) were analyzed using three automated platforms: Simoa HD-X (Quanterix), Elecsys (Roche), and Lumipulse G600 (Fujirebio). Correlation analyses, Passing-Bablok regression, and Lin's concordance coefficients were applied. Published regression formulas were compared with study-derived equations.
Results:
Strong correlations were observed across all platforms (r > 0.90 with outliers; r > 0.95 without; p < 0.001), though minor systematic biases were detected. Progressive MS patients showed significantly higher GFAP concentrations than RRMS and controls. Conversion to a single-platform scale improved agreement, but regression formulas differed substantially from previously published equations.
Conclusion:
Serum GFAP measurements demonstrate high clinical comparability across automated platforms despite systematic differences in absolute values. Robust harmonization strategies and externally validated conversion models are required before broad implementation in routine MS diagnostics.
