Gender differences in collagen-induced arthritis (CIA) in mice

In this pilot study, we set a goal of developing collagen-induced arthritis (CIA) in normal mice of both sexes, and compared the susceptibility, prevalence and the degree of inflammation. To assess the grade of inflammation, CIA was evaluated by a visual scale, plethysmometer score and locomotor activity. Seventeen male mice (85%) and only two female mice (10%) developed symptoms of arthritis. None of the female mice that developed arthritis were rated ‘4’ on the visual scale, while 5 male mice (29.42%) were rated with ‘4’. Only animals with a degree of inflammation of ‘4’ and ‘3’ had a significant initial decrease in spontaneous locomotor activity compared to the unaffected animals. The results from this study showed that the susceptibility to development of arthritis was significantly higher in male mice compared to females.