Impact of dilution factor on the concentrations of lipid classes.

Impact of dilution factor on the concentrations of lipid classes as expressed as percentage of uncorrected values ( = 100%). Lipids were determined by electrospray ionization tandem mass spectrometry or liquid chromatography coupled with tandem mass spectrometry, and corrected for possible dilution as outlined in Material and Methods. Values are median and interquartile range. eOA-early osteoarthritis, lOA-late osteoarthritis, RA-rheumatoid arthritis, SM-sphingomyelin, Cer-ceramide, HexCer-hexosylceramide (most likely glucosylceramide), Hex2Cer-dihexosylceramide (most likely lactosylceramide), PA-phosphatidic acid, LPA-lysophosphatidic acid, PG-phosphatidylglycerol, LPG-lysophosphatidylglycerol, BMP-bis(monoglycero)phosphate.