Replacement therapy in: Primary immunodeficiency syndromes such as:- congenital agammaglobulinaemia and hypogammaglobulinaemia- common variable immunodeficiency- severe combined immunodeficiency- Wiskott Aldrich syndromeMyeloma or chronic lymphocytic leukaemia with severe secondary hypogammaglobulinaemia and recurrent infections.Children with congenital AIDS and recurrent infections.Immunomodulation :Idiopathic thrombocytopenic purpura (ITP), in children or adults at high risk of bleeding or prior to surgery to correct the platelet count.Guillain Barré Syndrome.Kawasaki disease.Allogeneic bone marrow transplantation