A comparative evaluation of the metabolic profiles of normal and inflammatory knee‐joint synovial fluids by high resolution proton NMR spectroscopy

Abstract
High resolution 1H NMR spectroscopy has been employed to investigate the metabolic profile of heatlhy human knee-joint synovial fluid (SF) and the biochemical data acquired have been compared with those of matched serum, and inflammatory knee-joint SF samples. Results obtained indicate that the healthy human knee-joint has a hypoxic status (high lactate level when expressed relative to that of paired serum) that is milder than that of the inflamed human knee-joint. Moreover, normal SF differs from that of inflammatory SF in that it contains little or no NMR-detectable lipoprotein-associated fatty acids and ‘acute-phase’ glycoproteins, an observation reflecting the limited passage of these macromolecules from plasma into the synovial space in healthy subjects.