HL-A 27 in Crohn's disease.

There has been recent interest in the association between human leucocyte antigen-27 and ankylosing spondylitis. Brewerton, Caffrey, Hart, James, Nicholls, and Sturrock (1973) and Schlosstein, Terasaki, Bluestone, and Pearson (1973) demonstrated this antigen in 96% and 87% of ankylosing spondylitics, respectively, as compared with about 5%in normal controls. It is well known that recurrent Reiter's syndrome leads to spinal changes identical to those of ankylosing spondylitis and this prompted Brewerton to screen 33 patients with Reiter's disease of whom 25 were found to have HL-A 27. These results were confirmed (Aho, Ahvonen, Lassus, Sievers, and Tilikainen, 1973; Zachariae, Hjortsh0j, and Kissmeyer-Nielsen, 1973). It is also known that chronic inflammatory bowel disease, such as ulcerative colitis and Crohn's disease, are associated with sacroiliitis and ankylosing spondylitis (Acheson, 1960). Recently, Haslock (1973) investigated a series of patients with known Crohn's disease and their relatives and concluded that the spinal complications of Crohn's disease arise on a coincidental genetic basis, whereas the peripheral arthropathy is a direct complication of the bowel disease. Patients with Crohn's disease and ankylosing spondylitis have been screened for HL-A antigens (Asquith, MacKintosh, Stokes, Holmes, and Cooke, 1974). However, it seemed pertinent to investigate the HL-A profile of patients with Crohn's disease to determine whether those with HL-A 27 are more likely to have rheumatological disease.