The spondylitis of inflammatory bowel disease. Evidence for a non-HLA linked axial arthropathy.

Of 12 patients with inflammatory bowel disease (IBD) and ankylosing spondylitis (AS) or sacroiliitis (SI), only 4 (32%) had HLA-B27. Family studies revealed 3 B27-negative relatives with AS, 1 with SI, 1 with SI and IBD, and 1 with IBD alone. HLA haplotypes did not segregate with disease. These data suggest a non-HLA linked genetic predisposition to IBD which also confers susceptibility to spondylitis, even in the absence of expression of bowel disease.