Current understanding and future directions

Since immunoglobulin (Ig) replacement therapy was first used for the treatment of X-linked agammaglobulinaemia (XLA) [1], the therapeutic use of immunoglobulins has expanded to encompass not only many primary and secondary immunodeficiencies, but also vasculopathies, autoimmune diseases and numerous inflammatory disorders. The diversity of clinical topics covered at this 6th International Immunoglobulin Symposium was extraordinary, ranging from neurological indications, such as Guillain–Barré syndrome, chronic inflammatory demyelinating polyneuropathy, Alzheimer's disease and multiple sclerosis, to blistering skin diseases, sepsis, transplantation and, of course, immunodeficiencies. The presentations featured reviews of current management strategies, as well as new clinical and basic science developments that will shape immunoglobulin therapy in the future. Although intravenous immunoglobulin (IVIg) therapy has been used for essentially 30 years, there is much still to be learned about the mechanisms of action of immunoglobulins. New avenues of investigation in this field have opened and were covered in depth at the Symposium. These included novel insights into the interactions of IgG with Fc receptors and complement components, the importance of immunoglobulin Fc sialylation in inhibitory signalling and idiotype/anti-idiotype dimers, as well as natural antibodies and monomeric IgA in modulating the immune response.