Replacement therapy in adults, and children and adolescents (0-18 years) in:• Primary immunodeficiency syndromes (PID) with impaired antibody production• Secondary immunodeficiencies (SID) in patients who suffer from severe or recurrent infections, ineffective antimicrobial treatment and either proven specific antibody failure (PSAF)* or serum IgG level of <4 g/l* PSAF = failure to mount at least a 2-fold rise in IgG antibody titre to pneumococcal polysaccharide and polypeptide antigen vaccines.Immunomodulation in adults, and children and adolescents (0-18 years) in:• Primary immune thrombocytopenia (ITP), in patients at high risk of bleeding or prior to surgery to correct the platelet count• Guillain Barré syndrome• Kawasaki disease (in conjunction with acetylsalicylic acid)• Chronic inflammatory demyelinating poliradiculoneuropathy (CIDP)• Multifocal motor neuropathy (MMN)