Autoimmune diabetes and the germ theory of disease.

Abstract

The terms autoaggression and autoimmune attack reflect a long held view that autoimmune disease is caused by a dysregulated immune system which inappropriately attacks healthy tissue [1]. There is evidence, however, for an alternative, indeed opposite, view that autoimmunity represents the response to a primary lesion in the target tissue and that autoimmunity, like alloimmunity, is physiological, appropriate and protective [2]. The tissue damage and cell death which result are characteristic of an inflammatory response programmed to eliminate immunogen, remove detritus and isolate the lesion. Inflammation was recognised at least three and a half thousand years ago, and was long thought to be the cause of The reasoning seemed so logical that it endured to the beginning of the nineteenth century: caused distress and its resolution led to cure. However, we now accept the opposite, that is a physiological, appropriate and above all protective response to John Hunter was among the first to perceive that has a secondary rather than primary role. In A Treatise on the Blood, Inflammation and Gunshot Wounds [3], Hunter wrote that inflammation in itself is not to be considered as a disease, but as a salutary operation consequent either to some violence or some disease. The wide application of light microscopy during the nineteenth century, and the demonstration that was caused by microbes, firmly established the relationship between the microbe as pathogen and the as protective response. The modern view is enshrined in Pasteur's Germ Theory of Disease [4]. It is nevertheless important to recognise that the destruction of healthy tissue associated with infection is mediated