Replacement therapy in adults, and children and adolescents (0-18 years) in: primary immunodeficiency syndromes with impaired antibody production; hypogammaglobulinaemia and recurrent bacterial infections in patients with chronic lymphocytic leukaemia, in whom prophylactic antibiotics have failed; hypogammaglobulinaemia and recurrent bacterial infections in plateau-phase-multiple-myeloma patients who have failed to respond to pneumococcal immunisation; hypogammaglobulinaemia in patients after allogeneic haematopoietic-stem-cell transplantation (HSCT); congenital AIDS and recurrent bacterial infections. 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; multifocal motor neuropathy (MMN).