Gut inflammation in the spondyloarthropathies: clinical, radiologic, biologic and genetic features in relation to the type of histology. A prospective study.

Ileocolonoscopy was performed on 354 patients with spondyloarthropathies. Histologically, the population could be divided into 145 patients with normal gut histology, 88 patients with acute inflammatory lesions and 121 patients with chronic inflammatory lesions. A number of clinical, biologic, radiologic and genetic variables were determined before ileocolonoscopy. Chronic gut lesions were associated with a family history of ankylosing spondylitis (AS) and Crohn's disease, several episodes of diarrhea, an increased stool frequency, elevated inflammatory serum variables, reduced axial mobility, the presence of sacroiliitis, bamboo spine, destructive joint lesions, a diagnosis of AS and HLA-Bw62 positivity. As the frequency of HLA-Bw62 is also increased in proven Crohn's disease, this would suggest that chronic gut lesions are related to this disease. Acute inflammatory lesions were related to a higher fecal carriage of specific bacteria and to the diagnosis of undifferentiated spondyloarthropathy, especially the enterogenic forms of reactive arthritis. Consequently, these lesions also appear to be related to a bacterially induced gut inflammation. Gut histology was normal in urogenital inflammation and urogenital reactive arthritis, suggesting a different portal of entry for antigens. The 3 histologic pictures of the gut (normal, acute and chronic) inflammation seem to correlate with different clinical, biologic and radiologic manifestations of the disease concept of spondyloarthropathies.