Autoantibodies recognizing cytokines arise in certain patients during the course of therapy with recombinant cytokines, although they may arise spontaneously as well. They are typically high avidity and in vitro neutralizing IgG antibodies present in picomolar to nanomolar concentrations. Methodology is therefore critical. Quantitative studies based on sound methodology strongly indicate that nanomolar levels of cytokine autoantibodies are likely to be involved in a number of "new" syndromes such as acquired immune deficiencies, lung diseases, and certain age-related manifestations. There are many ways in which the autoantibodies could be naturally induced, and they have been experimentally induced with ease. Therefore, a new therapeutic concept of inducing cytokine autoantibodies via anti-cytokine vaccination is currently rapidly emerging.