The presence of 14 different autoantibodies was determined in 65 persons, aged 95 years and older, without overt disease. The prevalence of positive anti-immunoglobulin latex tests, of autoantibodies against nuclear components and against thyroid microsomes was significantly increased. This selective increase of autoantibodies of low titre and without cluster formation is considered to be the result of a loss of control within the immune system due to ageing, rather than as a sign of latent disease.