Part 1 Basic principles: clinical immunology - some perspectives; a simple or a complicated subject?; cells of the immune system; non-specific immunity; organs of the specific immune system; antigens and antigen-antibody binding; immunoglobulins; the humoral immune response; the cellular immune response; control of the immune response; the complement system. Part 2 Clinical conditions involving immunological mechanisms: hypersensitivity; immunodeficiency; autoimmune disease; the monoclonal gammopathies; transplantation immunology; tumour immunology; immunization; immunosuppression. Part 3 AIDS - the acquired immunodeficiency syndrome: background; the spectrum of disease caused by HIV; virological and immunological features of AIDS; clinical features of AIDS; AIDS - infection control in the hospital environment; prevention of community spread of HIV; the management of the HIV infected patient. Part 4 Immunological investigation: "in vivo" tests; "in vitro" tests; investigation of transplantation compatibility; production of antisera.