Table 1.

Potential mechanisms of action of IVIg.

(i) Anti-idiotypic binding that neutralizes auto-Abs
(ii) Competitive inhibition of binding to activating Fc-receptors
(iii) Upregulation of inhibitory Fc-receptors
(iv) Delayed clearance of Ab-coated blood cells
(v) Increased clearance of auto-Abs by reticuloendothelial system
(vi) Decreased half-life of auto-Abs due to competitive binding to FcRn