The hypothesis that abnormal fibronectin metabolism in Crohn's disease could be an important mechanism leading to stricture formation or postoperative infection was tested in three related studies. (1) Lower concentrations of plasma fibronectin (p<0.05) were found in 20 patients with small and large bowel Crohn's disease (mean 0.24 g/l) compared with 13 patients with more limited disease confined to only small or only large bowel (mean 0.27 g/l) or 20 healthy controls (mean 0.29 g/l). (2) In 25 patients followed for 10 days after operation for Crohn's disease, there was a significant fall in fibronectin concentrations of 43% (p<001, Wilcoxon's rank-sum test). This fall was maximal on the second postoperative day and was more marked in patients undergoing more major operative procedures. (3) The predictive value of plasma fibronectin for subsequent stricture formation or progression was studied for one year; during which 10 patients developed strictures requiring operative treatment. Higher plasma fibronectin concentrations were related to stricture formation, although there was not a complete, predictive relationship. In this study we found that plasma fibronectin concentrations were low in patients with extensive or severe Crohn's disease, fall after operation and may be related to the risk of stricture formation. This relationship is unlikely to be of clinical value, although it shows the potential significance of fibronectin in the pathogenesis of strictures.

The hypothesis that abnormal fibronectin metabolism in Crohn's disease could be an important mechanism leading to stricture formation or postoperative infection was tested in three related studies. (1) Lower concentrations of plasma fibronectin (p less than 0.05) were found in 20 patients with small and large bowel Crohn's disease (mean 0.24 g/l) compared with 13 patients with more limited disease confined to only small or only large bowel (mean 0.27 g/l) or 20 healthy controls (mean 0.29 g/l). (2) In 25 patients followed for 10 days after operation for Crohn's disease, there was a significant fall in fibronectin concentrations of 43% (p less than 0.01, Wilcoxon's rank-sum test). This fall was maximal on the second postoperative day and was more marked in patients undergoing more major operative procedures. (3) The predictive value of plasma fibronectin for subsequent stricture formation or progression was studied for one year; during which 10 patients developed strictures requiring operative treatment. Higher plasma fibronectin concentrations were related to stricture formation, although there was not a complete, predictive relationship. In this study we found that plasma fibronectin concentrations were low in patients with extensive or severe Crohn's disease, fall after operation and may be related to the risk of stricture formation. This relationship is unlikely to be of clinical value, although it shows the potential significance of fibronectin in the pathogenesis of strictures.

The precise specificity of the R1 anti-reticulin antibody (ARA) associated with untreated gluten sensitive enteropathy (GSE) is unknown. Collagen type III, fibronectin and the non-collagenous reticulin component (NCRC) of Pras & Glynn (1973) co-distribute in tissues in a manner consistent with their being components of reticulin. We therefore used purified preparations of these connective tissue components in studies of the specificity of the ARA. Our results show that the ARA found in GSE does not react with collagen type III, fibronectin or NCRC.

The incidence of rice bodies (RB) in synovial effusions has been studied in 36 patients with rheumatoid arthritis (RA) and in 12 patients with seronegative inflammatory arthritis (7 cases of Still's disease, 3 of psoriatic arthritis, and 2 of ankylosing spondylitis). In the RA group 50 joints were aspirated before and after saline lavage with a specially designed wide-bore needle. RB were found in 72% overall of the joints studied in this group, 14% on initial simple aspiration and an additional 58% after lavage. In contrast no rice bodies were found in 31 aspirations with lavage by an identical technique in the 12 patients with seronegative synovitis. The RB in RA synovitis occurred both early and late in the course of the disease and were not related to the severity of clinical or radiological changes. However, removal of rice bodies was accompanied by clinical improvement and reduction of synovitis. Macroscopically RB varied in shape and size, some being so large as to preclude effective removal by needles of the gauge customarily employed for joint aspirations. Microscopically the majority of RB were composed of coarsely reticular material reacting immunologically with antifibrinogen and antifibronectin and containing mononuclear cells. Some showed vacuolation suggestive of fibrinolysis, but many showed organisation like that seen in established connective tissues, with the formation of mature collagen, reticulin, and elastin. These findings are discussed in relation to the origin, development, and significance of rice bodies in rheumatoid synovitis.