Intestinal histological and ultrastructural inflammatory changes in spondyloarthropathy and rheumatoid arthritis

To determine the prevalence of morphologic bowel lesions in patients with inflammatory rheumatic diseases and to better define the interactions between intestinal and articular pathology, 177 patients [39 with reactive arthritis (ReA), 40 with psoriatic arthritis (PsA), 23 with ankylosing spondylitis (AS), 21 with undifferentiated spondyloarthropathy (USpA) and 54 with rheumatoid arthritis (RA)] underwent ileocolonoscopy followed by multiple biopsies of the large bowel and the ileum and ileocecal valve. Biopsies were then examined with light and electron microscopy. During the endoscopic examination various degrees of gut inflammation were observed in 13% of ReA, 5% of PsA, 26% of AS, 14% of USpA and 11% of RA patients. At the histological examination those percentages were respectively 51%, 45%, 48%, 38%, and 15%, and at the electron microscopic examination 76%, 53%, 90%, 60%, and 50%. Our results show that an involvement of the gut is a factor in a large percentage of patients with spondyloarthropathy and, to a lesser extent, with RA. The involvement of the intestine in RA manifests itself mainly in ultrastructural lesions, thus this involvement is not so obvious as in the spondyloarthropathies; however, it could nonetheless play an important role in the etiopathogenesis of this disease.