Conclusion
In summary, in the current study we demonstrate for the first time an amelioration of CIA in mice with established arthritis using a treatment protocol.  We show herein a powerful anti-inflammatory potential of IVIG in attenuating the pathogenesis in CIA  in mice .The beneficial effect  was presented by reducing  the clinical score, reducing the titers  of anti-collagen type II antibodies and declining the concentrations of circulating cytokine . Our  study may pave the way for clinicians to reconsider the use of IVIG, as a safe and beneficial optional treatment in a subgroup of patients with rheumatoid arthritis.