There were three proteins that could potentially differentiate patients with OA from controls and perhaps be used to diagnose OA. These were: complement 3, which is involved in inflammation; inter-alpha-trypsin inhibitor heavy chain I, which is involved in the stability of the extracellular matrix; and S100 calcium-binding protein A6, which has a role in chondrocyte differentiation and thus bone remodeling.
“Compared to rheumatoid arthritis patients, we observed that the level of complement 3 and inter-alpha-trypsin inhibitor heavy chain I are significantly increased in osteoarthritis patients,” said the presenting study author Lucía Maria Lourido Salas, PhD. “This suggests the potential of these two proteins as specific proteins for osteoarthritis,” she proposed. A further 28 proteins were found that might also help to differentiate OA from RA; 16 of these were increased and 12 decreased in OA patients. Together these 30 proteins could potentially help identify a specific serum protein signature of OA, Dr. Salas said.
Dr. Kraus and Dr. Salas did not report having any financial disclosures. Dr. Kraus’ research is funded by the Duke Biomarker Factory.