C3F IS A POTENTIAL TOOL FOR THE STAGING OF OSTEOARTHRITIS

Abstract

An attractive method for osteoarthritis (OA) staging is the measurement of biochemical markersin biological fluids, which could reflect dynamic and quantitative changes in joint remodeling andtherefore disease progression. Proteome analysis has been recognized as one of the most effective toolsto explore biomarkers as it can furnish a wealth of information in both diagnosis and prognosis ofdiseases. We have recently described an innovative tool for peptidome and lipidome profiling of fluidsbased on mesoporous aluminosilicate (MPAS) and Matrix-Assisted Laser Desorption/Ionization timeof-flight Mass Spectrometry (MALDI-TOF MS). The aim of this study was to analyze peptide profilesof human synovial fluid in patients with different grade of OA using MALDI-TOF-MS technique inorder to identify potential markers of disease progression. Twenty-five patients older than 50 years andaffected by primary knee OA diagnosed according to clinical and radiological criteria were enrolled.For each patient a synovial fluid sample was aspirated from the affected knee and analyzed usingMALDI-TOF-MS technique. A statistically significant difference in the normalized area of two peaks(m/z=1865 and m/z=2021) was detected among different stages of OA. The 2 peaks were identified asComplement C3 peptide fragments: C3f and C3f Des-Arg. The expression levels of these two peptides(m/z=1865 and 2021) decreased with the progression of OA degrees severity (ρs=-0.434, p=0.03, andρs=-0.532, p=0.006, respectively). This marker may be a useful tool for assessing the severity of knee OAand it may be a novel target for drug discovery, specifically for the development of disease modifyingOA drugs. However further studies are required to clarify the role of C3f in OA pathogenesis.