title: Validation for quantification of immunoglobulins by Fourier transform infrared spectrometry.
abstract: 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.
authors.affiliation: Centre National de Médecine et des Sciences du Sport, Unité de recherche Evaluation Sport Santé, Tunis, Tunisia.
authors.forename: Lamia
authors.initials: L
authors.lastname: Benezzeddine-Boussaidi
authors.forename: Georges
authors.initials: G
authors.lastname: Cazorla
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Melin
mesh_terms: D000465:Algorithms; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D007136:Immunoglobulins / Q000097:blood*; D016018:Least-Squares Analysis; D015203:Reproducibility of Results; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods*
chemical_list: D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D007136:Immunoglobulins