Human intestinal flora and the induction of chronic arthritis : studies in an animal model.

The etiology of rheumatoid arthritis (RA), a chronic joint inflammation, is unknown. A microbial involvement is suspected, but no particular microorganism has been incriminated. The human intestinal microflora is an abundant and continuous source of bacterial antigens and may be involved in the induction or maintenance of chronic joint inflammation. In this introductory chapter I shall describe the possible relationship between joint inflammation, bowel flora and intestinal disease. Clinical syndromes which suggest this relationship are presented. Characteristics of the human intestinal flora are described, together with bacterial cell wall structures and their immunological properties. Several aspects of the hypothesis that intestinal bacterial antigens may pass the intestinal wall and give rise to inflammatory symptoms at distant locations are discussed. Animal models developed to study joint inflammation, including two models which use bacterial antigens to elicit arthritis, are presented. Finally, the experimental work of this thesis is introduced.