Validation for quantification of immunoglobulins by Fourier transform infrared spectrometry
Lamia Benezzeddine-Boussaidi1, Georges Cazorla, Anne-Marie Melin
1Centre National de Médecine et des Sciences du Sport, Unité de recherche Evaluation Sport Santé, Tunis, Tunisia.
Background:
The objective of this study was to develop a robust quantification method for simultaneously analyzing molecules in human plasma using the Fourier transform infrared (FT-IR) system with a partial least square (PLS) regression.
Methods:
Plasma spectra were analyzed from 4000 to 500 cm(-1) (with 2.0 cm(-1) of resolution and 32 scans), and the molecule concentrations (IgA, IgG, IgM) were measured blindly by using a cross-validation model prepared by PLS analysis of data from 135 samples.
Results:
There was a significant correlation between the FT-IR predicted concentration and the concentration obtained with the clinical reference method: R(2)=0.98 (IgA), R(2)=0.98 (IgG), and R(2)=0.97 (IgM). The root mean square error of prediction (RMSEP) was 0.05 g.L(-1) (IgA), 0.4 g.L(-1) (IgG), and 0.03 g.L(-1) (IgM). Variability of inter-experimenter reproducibility was less than 2%. The interchangeability of the two methods was studied by using the Bland-Altman method.
Conclusions:
Together with PLS analysis, FT-IR spectrometry appears to be an easy-to-use and accurate method to determine multianalyte concentrations in dried human plasma. It could be an alternative tool for rapidly quantifying many molecules after developing a specific predictive model.
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