a The levels of serum IL-4 and IL-17 in CIA rats and the effects of IgD-Fc-Ig. b The level of serum IL-1β in CIA rats and the effects of IgD-Fc-Ig. c The levels of serum IL-6 and IFN-γ in CIA rats and the effects of IgD-Fc-Ig. d The levels of serum MCP-1 and leptin in CIA rats and the effects of IgD-Fc-Ig. e The levels of serum TNF-α and TIMP-1 in CIA rats and the effects of IgD-Fc-Ig. f The expression levels of p-Lck, p-ZAP70, p-P38, and p-NF-κB65 in T cells in the spleens of CIA rats were analyzed by Western blotting. g Comparison of protein expression in different groups. The effects of IgD-Fc-Ig on the expression of p-Lck, p-ZAP70, p-P38, and p-NF-κB65. *P < 0.05, **P < 0.01 vs Normal, ##P < 0.01 vs CIA (n = 10).