Evaluation of cartilage and bone degradation in a murine collagen antibody-induced arthritis model

The purpose of this work was to validate collagen antibody-induced arthritis (CAIA) model in two mice strains (Balb/c and CD-1) using clinical, biochemical, microstructural and histological techniques. We induced arthritis in mice using a cocktail of collagen type II (CII) antibodies followed by an injection with lipopolysaccharide (LPS) in different doses in Balb/c and CD-1 mice strains. Serum CTX-II levels were measured at study termination and correlated with microscopic severity of joint lesions as determined by a validated scoring systems. Bone involvement was assessed by microcomputer tomography (micro-CT). Balb/c mice developed rapid (day 6) and robust (100%) arthritis, whereas CD-1 mice showed only temporary macroscopic signs of disease. Serum CTX-II levels in Balb/c mice showed a significant increase in cartilage degradation in diseased animals (43-64% compared with non-diseased mice) and was decreased in animals receiving dexamethasone. Correlation of serum CTX-II with the microscopic score was statistically significant (P < 0.01). Micro-CT analysis demonstrated structural damage in bone in the CAIA Balb/c mice, which was prevented by dexamethasone. The CAIA-LPS model provides a useful supplement to currently available animal models of arthritis. This is a rapid onset and robust model; however, the choice of mouse strain should be evaluated carefully.