ORM1 and arthritic joint disease: In addition to the clinical and histopathological manifestations, serum from rats that had received LN-derived T cells had elevated levels of cartilage oligomeric matrix protein (COMP) at day 124 post-transfer, indicating an active and ongoing cartilage degradation, as well as alpha-1-acid glycoprotein (AGP), an acute-phase protein whose levels are highly correlated with that of clinical arthritis in PIA [17, 18, 20] (Fig. 1d).