Replacement therapy in adults and children in primary immunodeficiency syndromes such as: - congenital agammaglobulinaemia and hypogammaglobulinaemia - common variable immunodeficiency - severe combined immunodeficiency and Wiskott-Aldrich syndrome - IgG subclass deficiencies with recurrent infectionsReplacement therapy in myeloma or chronic lymphocytic leukaemia with severe secondary hypogammaglobulinaemia and recurrent infections.