title: Mass Spectrometric Immunoassay for the qualitative and quantitative analysis of the cytokine Macrophage Migration Inhibitory Factor (MIF).
abstract: BACKGROUND
  The cytokine MIF (Macrophage Migration Inhibitory Factor) has diverse physiological roles and is present at elevated concentrations in numerous disease states. However, its molecular heterogeneity has not been previously investigated in biological samples. Mass Spectrometric Immunoassay (MSIA) may help elucidate MIF post-translational modifications existing in vivo and provide additional clarity regarding its relationship to diverse pathologies.
  
  
  RESULTS
  In this work, we have developed and validated a fully quantitative MSIA assay for MIF, and used it in the discovery and quantification of different proteoforms of MIF in serum samples, including cysteinylated and glycated MIF. The MSIA assay had a linear range of 1.56-50 ng/mL, and exhibited good precision, linearity, and recovery characteristics. The new assay was applied to a small cohort of human serum samples, and benchmarked against an MIF ELISA assay.
  
  
  CONCLUSIONS
  The quantitative MIF MSIA assay provides a sensitive, precise and high throughput method to delineate and quantify MIF proteoforms in biological samples.
authors.affiliation: The Biodesign Institute at Arizona State University, Tempe, AZ 85287 USA.
authors.forename: Nisha D
authors.initials: ND
authors.lastname: Sherma
authors.affiliation: The Biodesign Institute at Arizona State University, Tempe, AZ 85287 USA ; Department of Chemistry & Biochemistry at Arizona State University, Tempe, AZ 85287 USA.
authors.forename: Chad R
authors.initials: CR
authors.lastname: Borges
authors.affiliation: The Biodesign Institute at Arizona State University, Tempe, AZ 85287 USA.
authors.forename: Olgica
authors.initials: O
authors.lastname: Trenchevska
authors.affiliation: The Biodesign Institute at Arizona State University, Tempe, AZ 85287 USA.
authors.forename: Jason W
authors.initials: JW
authors.lastname: Jarvis
authors.affiliation: The Biodesign Institute at Arizona State University, Tempe, AZ 85287 USA.
authors.forename: Douglas S
authors.initials: DS
authors.lastname: Rehder
authors.affiliation: The Biodesign Institute at Arizona State University, Tempe, AZ 85287 USA.
authors.forename: Paul E
authors.initials: PE
authors.lastname: Oran
authors.affiliation: The Biodesign Institute at Arizona State University, Tempe, AZ 85287 USA.
authors.forename: Randall W
authors.initials: RW
authors.lastname: Nelson
authors.affiliation: The Biodesign Institute at Arizona State University, Tempe, AZ 85287 USA.
authors.forename: Dobrin
authors.initials: D
authors.lastname: Nedelkov
keywords: Biomarker discovery; Immunoassay; MALDI-TOF; MIF; Post-translational modifications; Proteomics; Quantification