**6.1. IVIg**

The mechanism of action and the optimal dose of IVIg that should be administered in ABMR are poorly understood.[42], but it is thought to have an immunomodulatory effect. The proposed beneficial properties include compliment inhibition, suppression of immunoglobu‐ lin synthesis.[43, 44] High dose IVIg inhibits C3 convertase and the ability to absorb comple‐ ment activation fragments (e.g. C3a,C5a and C4b).[45]

There have been retrospective studies reporting improved one year graft survival in cases of steroid and antithymocyte resistant ABMR treated with protocols incorporating IVIg and plasmapheresis/ plasma exchange.[46-49] The need to combine plasma exchange is however, unclear.[42]
