Special Editors: Stefan Ehlers & Stefan H. E. Kaufmann
99th Dahlem Conference on Infection, Inflammation and Chronic Inflammatory Disorders: Darwinian medicine and the ‘hygiene’ or ‘old friends’ hypothesis
Article first published online: 11 MAR 2010
© 2010 British Society for Immunology
Clinical & Experimental Immunology
Volume 160, Issue 1, pages 70–79, April 2010
How to Cite
Rook, G. A. W. (2010), 99th Dahlem Conference on Infection, Inflammation and Chronic Inflammatory Disorders: Darwinian medicine and the ‘hygiene’ or ‘old friends’ hypothesis. Clinical & Experimental Immunology, 160: 70–79. doi: 10.1111/j.1365-2249.2010.04133.x
- Issue published online: 11 MAR 2010
- Article first published online: 11 MAR 2010
- Accepted for publication 18 January 2010
- Darwinian medicine;
- dendritic cells;
- ‘hygiene hypothesis’;
- ‘old friends’ hypothesis;
The current synthesis of the ‘hygiene hypothesis’ suggests that the recent increase in chronic inflammatory disorders is at least partly attributable to immunodysregulation resulting from lack of exposure to microorganisms that have evolved an essential role in the establishment of the immune system. This document provides a background for discussion of the following propositions.
- 1The essential role of these organisms is an example of ‘evolved dependence’.
- 2The most relevant organisms are those that co-evolved with mammals, and already accompanied early hominids in the Paleolithic.
- 3More recently evolved ‘childhood infections’ are not likely to have evolved this role, and recent epidemiology supports this contention.
- 4This mechanism is interacting with other modern environmental changes that also lead to enhanced inflammatory responses [inappropriate diet, obesity, psychological stress, vitamin D deficiency, pollution (dioxins), etc.].
- 5The range of chronic inflammatory disorders that is affected is potentially larger than usually assumed [allergies, autoimmunity, inflammatory bowel disease, but also vascular disease, some cancers, depression/anxiety (when accompanied by raised inflammatory cytokines), and perhaps neurodegenerative disorders and type 2 diabetes].