Reactive arthritis

Ileocolonoscopy in seronegative spondylarthropathy

A prospective endoscopic and histologic study of terminal ileum and colorectum in 211 patients with seronegative spondylarthropathy revealed macroscopic inflammatory lesions varying from erythema to superficial erosions in 30% of the patients and microscopic inflammation in 61%. Two types of inflammation were observed: an acute inflammation resembling an infectious enterocolitis and a chronic inflammation. In idiopathic reactive arthritis both types of inflammation were equally present, whereas chronic inflammation predominated in patients with ankylosing spondylitis. In 32% of patients with chronic inflammation, the lesions particularly resembled early Crohn's disease. Repeat ileocolonscopy on 19 patients demonstrated a parallel evolution of joint symptoms and histologic lesions. All patients with acute inflammation went into clinical and histologic remission, whereas lesions persisted in patients with Crohn-like inflammation. In patients with chronic inflammation, remission and persistence were observed equally. This study identified a group of patients with seronegative spondylarthropathy which, even in the absence of gastrointestinal symptoms, showed evidence of gut inflammation, probably inducing an increased gut permeability with transgression of the oral tolerance and absorption of provocative antigens into the circulation. It is also possible that both diseases reflect a common underlying process.

Non-secretion of ABO blood group antigens as a host susceptibility factor in the spondyloarthropathies

Gram negative bacteria precipitate reactive arthritis and may be concerned in the pathogenesis of ankylosing spondylitis and other spondyloarthropathies. Susceptibility to many infectious agents is associated with ABO blood group or secretor state, or both. The distribution of the ABO blood group or secretor state, or both, was therefore determined in 87 patients with ankylosing spondylitis and 32 with other forms of spondyloarthropathy. The prevalence of non-secretors was significantly increased in the total patient group (54/114; 47%) and in the subgroup with ankylosing spondylitis (41/84; 49%) compared with local controls (89/334; 27%) (p less than 0.001). Other subgroups of patients showed a similarly increased prevalence of non-secretion (33-47%). The distribution of ABO blood groups did not differ between patients and controls. The association between non-secretor state and ankylosing spondylitis strengthens the hypothesis that ankylosing spondylitis is a form of reactive arthritis. It also suggests several pathogenic mechanisms which may be relevant to the initial hostparasite interaction in ankylosing spondylitis.

Reactive arthritis

Although sometimes used to refer to any sterile arthritis occurring in association with infection, the term 'reactive arthritis' is better reserved for arthritis following sexually acquired nonspecific urethritis or enteric infections with organisms such as Shigella, Salmonella, Yersinia and Campylobacter, because these arthropathies are unified by a number of shared clinical characteristics and an association with HLA B27. This review suggests that these arthropathies may also share a common pathogenic pathway, triggered by an ' arthritogenic factor' common to the diverse microbes which cause the disease and modified by genetic factors other than HLA B27. Although uncommon, reactive arthritis is important because it could provide the key to understanding the other seronegative arthropathies and mechanisms basic to chronic inflammatory synovitis.

Family studies in Bechterew's syndrome (ankylosing spondylitis) III. Genetics

The results of segregation analyses in 75 families where the proband had ankylosing spondylitis, are presented. Of the 278 adult, living first degree relatives, approximately 85% cooperated in the study. Clinical and radiographical examinations were performed and HLA typing was conducted. The results were in agreement with our hypothesis that ankylosing spondylitis is part of a syndrome where different genetic factors interact. Such known factors are HLA B27 associated disease susceptibility, susceptibility to psoriatic arthropathy and susceptibility to entero-arthropathy. Radiographical sacro-iliitis was restricted to HLA B27 positive relatives, and was more frequently found in relatives to probands with psoriasis than in relatives to probands without psoriasis. Environmental factors (intestinal bacteria) are known to trigger the disease at least in some persons, and we have postulated that all or most of them have the predisposition to develop disease. Thus, the syndrome has a multifactorial etiology. The phenotypic expressions of the different genetic predispositions involved, include sacro-iliitis, psoriasis, acute anterior uveitis, peripheral arthropathy and inflammatory bowel disease. We suggest the descriptive name HEREDITARY MULTIFOCAL RELAPSING INFLAMMATION (HEMRI) for this syndrome. Ankylosing spondylitis, psoriatic arthropathy and entero-arthropathy may be regarded as clinical sub-types of the syndrome.