No abstract

SummaryCeliac disease (CD) is most probably an immunological disease, precipitated in susceptible individuals by ingestion of wheat gliadin and related proteins from other cereals. The disease shows a strong human HLA association predominantly to the c/s or trans encoded HLA-DQ(o~I*O5OI,fll*0201) (DQ2) heterodimer. T cell recognition of gliadin presented by this DQ heterodimer may thus be of immunopathogenic importance in CD. We therefore challenged small intestinal biopsies from adult CD patients on a gluten-free diet in vitro with gluten (containing both gliadin and other wheat proteins), and isolated activated CD25 + T cells. Polyclonal T cell lines and a panel of T cell clones recognizing gluten were established. They recognized the gliadin moiety of gluten, but not proteins from other cereals. Inhibition studies with anti-HLA antibodies demonstrated predominant antigen presentation by HLA-DQ molecules. The main antigen-presenting molecule was established to be the CD-associated DQ(oel*0501, fl1"0201) heterodimer. The gluten-reactive T cell clones were CD4 +, CD8-, and carried diverse combinations of T cell receptor (TCR) Vc~ and Vfl chains. The findings suggest preferential mucosal presentation of gluten-derived peptides by HLA-DQ(c~I*OSO1,BI*0201) in CD, which may explain the HLA association.

Background: The prevalence of duodenal carcinoma is much higher in familial adenomatous polyposis (FAP) than in the background population, and duodenal adenomatosis is found in most polyposis patients. Aims: To describe the long term natural history of duodenal adenomatosis in FAP and evaluate if cancer prophylactic surveillance of the duodenum is indicated. Methods: A prospective five nation study was carried out in the Nordic countries and the Netherlands. Patients: A total of 368 patients were examined by gastroduodenoscopy at two year intervals during the period 1990-2001. Results: At the first endoscopy, 238 (65%) patients had duodenal adenomas at a median age of 38 years. Median follow up was 7.6 years. The cumulative incidence of adenomatosis at age 70 years was 90% (95% confidence interval (CI) 79-100%), and of Spigelman stage IV 52% (95% CI 28-76%). The probability of an advanced Spigelman score increased during the study period (p,0.0001) due to an increasing number and size of adenomas. Two patients had asymptomatic duodenal carcinoma at their first endoscopy while four developed carcinoma during the study at a median age of 52 years (range 26-58). The cumulative incidence rate of cancer was 4.5% at age 57 years (95% CI 0.1-8.9%) and the risk was higher in patients with Spigelman stage IV at their first endoscopy than in those with stages 0-III (p,0.01). Conclusions: The natural course of duodenal adenomatosis has now been described in detail. The high incidence and increasing severity of duodenal adenomatosis with age justifies prophylactic examination, and a programme is presented for upper gastrointestinal endoscopic surveillance.

A high proportion of CC cases is diagnosed within the first year after diagnosis of PSC. A long history of inflammatory bowel disease is a risk factor for CC development.

There is a strong association between PSC and IBD. PSC is the most common hepatobiliary lesion seen in association with IBD. Whether there are two subsets of PSC, one associated with IBD and one unassociated, is controversial. A lower male to female ratio in patients without IBD supports this view. The demonstration of the haplotype DRw52a in 100% of patients with PSC, irrespective of the absence of IBD, speaks against this view. Patients with isolated PSC tend to present with jaundice, pruritus, and fatigue more frequently than those with combined PSC and IBD. There may also be a difference in bile duct involvement between patients with and without IBD combined with PSC. Apart from usually being a total colitis, either Crohn's colitis or UC, the IBD associated with PSC cannot be distinguished from IBD without PSC with respect to symptoms and clinical course. Patients with combined IBD and PSC may have somewhat worse prognosis than those with isolated PSC. The majority of patients developing BDC have concomitant IBD, suggesting that patients without IBD represent a different subgroup of PSC and run a different clinical course. Most studies have, however, found no differences in epidemiology, pathogenetic factors, clinical findings related to the hepatobiliary disease and prognosis between those who present with PSC alone and those who present with combined PSC and IBD. A major problem when discussing the relationship between IBD and PSC is that the bowel is inadequately examined in many of the studies relating to this question.(ABSTRACT TRUNCATED AT 250 WORDS)

Mucosal specimens from active Crohn's disease (ileum, n=6; colon, n=6), active ulcerative colitis (n=9), normal ileum (n=6), and normal colon (n=6) were subjected to paired immunofluorescence staining for characterisation of macrophage subsets in situ. In the normal state, only few CD68+ macrophages (<10%) expressing the myelomonocytic LI antigen (calprotectin) were seen. In inflamed mucosa, especially near small vessels, the CD68+L1+ fraction increased with the degree of inflammation, near ulcers to median 65% (range 35-91%). Cells reactive with the monoclonal antibody RFD7 were also increased in inflammation but less than 5% of them costained for LI antigen. It is concluded that LI producing macro-

The association of primary sclerosing cholangitis (PSC) to HLA class II genes was studied by comparing patients from five different European populations. Deduced HLA-DRB1, DQA1, DQB1 haplotypes of 256 PSC patients from England, Italy, Norway, Spain and Sweden were compared to those observed in 764 ethnically-matched controls. Increased frequencies of the DRB1*03, DQA1*0501, DQB1*02 (RR=3.0, P<0.00001) and the DRB1*13, DQA1*0103, DQB1*0603 haplotypes (RR=2.4, P<0.0001) were observed in all five patient groups. A total of 16% of the PSC patients were homozygous for the DRB1*03, DQA1*0501, DQB1*02 haplotype compared to 1% of the controls (RR=20, P<0.0001). The DRB1*04, DQA1*03, DQB1*0302 haplotype was significantly reduced in frequency(RR=0.4, P<0.00001). Among Norwegian, Swedish and British patients that did not carry neither the DRB1*03, DQA1*0501, DQB1*02 nor the DRB1*13, DQA1*0103, DQB1*0603 haplotype, an increased frequency of the DRB1*15, DQA1*0102, DQB1*0602 haplotype was observed (RR=2.0, P<0.0001). Thus, PSC was found to be positively associated to three different HLA class II haplotypes (i.e. the DRB1*03, DQA1*0501, DQB1*02, the DRB1*15, DQA1*0102, DQB1*0602 and the DRB1*13, DQA1*0103, DQB1*0603 haplotypes) and negatively associated to one HLA class II haplotype (i.e. the DRB1*04, DQB1*0302 haplotype).

In order to evaluate the prevalence of duodenal adenomas in familial adenomatous polyposis (FAP) and the risk of carcinoma development, a multicenter study was initiated in Denmark, Finland, Holland, Norway and Sweden, which have national polyposis registers with an almost complete registration. Patients aged 20 years or more are being examined with biennial gastroduodenoscopy during 1990-2000. Multiple duodenal biopsies are examined by one pathologist from each country, and the endoscopic and histological criteria of Spigelman have been adopted. At the end of August 1992, 312 patients with a median age of 37 years (range 20-86) had completed their first endoscopy. The duodenum was examined in 310 patients, of whom 199 (64%) had duodenal adenomas. Twenty-two patients (11% of all patients with duodenal adenomas) had no endoscopically visible polyps. One patient had an asymptomatic adenocarcinoma. The Spigelman stage worsened significantly (P < 0.05) with time from the diagnosis of FAP, which may suggest an increasing risk of carcinoma by time.