Thesis presented October 19, 2023
Abstract:
The aim was to develop and apply protein quantification methods. Firstly, plasma biomarkers for fibrosis were discovered and validated in patients with MASLD, a metabolic liver disease affecting 25% of the world's population, for which the reference diagnostic test has a number of drawbacks. ALS and LG3BP were validated in two independent cohorts and then introduced into a panel based on FibroTest. The second project involved optimising absolute LC-MS quantifications based on the use of isotopically-labelled standards (PSAQ). The originality of PSAQ+1 consisted in introducing a protein assimilated to the endogenous protein that contains only one 13C in the arginines and lysines prior to LC-MS/MS analysis. The results showed that a single mass window was required to quantify the light and labelled protein. This technique could provide greater specificity, sensitivity and precision for absolute quantification by LC-MS/MS using isotopic standards.
Keywords:
Proteomics, NAFLD, quantification, fibrosis, biomarker, liver