Knee synovial fluid was collected from patients with an acute, painful meniscal injury, as well as asymptomatic volunteers. A combination of high-pressure chromatography, mass spectrometry and immunological techniques were used to enrich and identify the protein components representing the IFN-γ signal.
A protein complex of fibronectin and the aggrecan G3 domain was identified in the synovial fluid of patients with a meniscal tear and pain that was absent in asymptomatic controls. This protein complex correlated to the IFN-γ signal. A novel enzyme-linked immunosorbent assay (ELISA) was developed to specifically identify the complex in synovial fluid.
We have identified a protein complex of fibronectin and aggrecan G3 domain that is a candidate biomarker for pain associated with meniscal injury.