Protein oxidation, nitration and glycation biomarkers for early-stage diagnosis of osteoarthritis of the knee and typing and progression of arthritic disease

Table 1 Homotypic correlation of protein oxidation, nitration and glycation adducts in synovial fluid and plasma compartments

Study group	Protein adduct residue	Free adduct
eOA	CML (r = 0.60, P < 0.05), CEL (r = 0.82, P < 0.001), MetSO (r = 0.61, P < 0.05), DT (r = 0.53, P < 0.05)	CEL (r = 0.59, P < 0.05), 3DG-H (r = 0.62, P < 0.05), pentosidine (r r = 0.71)
aOA	FL (r = 0.58, P < 0.05), MG-H1 (r = 0.80, P < 0.001)	FL (r = 0.75, P < 0.01), CEL (r = 0.63, P < 0.05), G-H1 (r = 0.71, P < 0.01), MG-H1 (r = 0.91, P < 0.001), NFK (r = 0.73, P < 0.05)
aOA	3DG-H (r = 0.72, P < 0.01), MetSO (r = 0.63, P < 0.05)
eRA	Pentosidine (r = 0.82, P < 0.01)	FL (r = 0.87, P < 0.01), CML (r = 0.67, P < 0.05), CEL (r = 0.81, P < 0.01), MG-H1 (r = 0.92, P < 0.001), 3DG-H (r = 0.83, P < 0.01), CMA (0.72, P < 0.05), pentosidine (r = 0.78, P < 0.01)
aRA	CML (r = 0.56, P < 0.05), CEL (r = 0.70, P < 0.01), G-H1 (r = 0.52, P < 0.05), MG-H1 (r = 0.86, P < 0.001), 3DG-H (r = 0.86, P < 0.001), CMA (0.50, P < 0.05), pentosidine (r = 0.83, P < 0.01), NFK (r = 0.56, P < 0.05), DT (r = 0.64, P < 0.01)	G-H1 (r = 0.53, P < 0.05), MG-H1 (r = 0.87, P < 0.001)
aRA		3DG-H (r = 0.73, P < 0.01), 3-NT (0.67, P < 0.01)
Non-RA	Pentosidine (r = 0.76, P < 0.05)	CEL (r = 0.73, P < 0.05), MG-H1 (r = 0.76, P < 0.05), MOLD (r = 0.81, P < 0.01)

eOA early osteoarthritis, aOA advanced osteoarthritis, eRA early rheumatoid arthritis, aRA advanced rheumatoid arthritis, CML N_ε-carboxymethyl-lysine, CEL N_ε-(1- carboxyethyl)-lysine, MetSO methionine sulfoxide, DT dityrosine, FL N_ε-fructosyl-lysine, MG-H1 methylglyoxal-derived hydroimidazolone, 3DG-H 3-deoxyglucosone-derived hydroimidazolone isomers, NFK N-formylkynurenine, 3-NT 3-nitrotyrosine, G-H1 glyoxal-derived hydroimidazolone, CMA N_ω-carboxymethylarginine

ISSN: 1478-6362