The epidemiology of coeliac disease in East Dorset 1993-2002: an assessment of the 'coeliac iceberg', and preliminary evidence of case clustering.

BACKGROUND: Coeliac disease (CD) results from mucosal exposure to dietary gluten in genetically predisposed individuals, although other environmental factors may be involved. The seroprevalence of CD is approximately 1%, with a high ratio of undiagnosed to diagnosed cases, leading to the concept of a 'coeliac iceberg'. AIM: To provide contemporary estimates of the incidence of diagnosed CD and the size of the submerged 'coeliac iceberg', and to seek evidence of disease clustering. DESIGN: Prospective observational study in a defined local population. METHODS: Data were collected prospectively for all biopsy-proven cases diagnosed at Poole Hospital, 1993-2002. Age-specific incidence was calculated and point prevalence estimated for cases within the defined study zone. Evidence of disease clustering was sought using a space-time scan statistic based on a Poisson model. RESULTS: The overall incidence of CD was 8.7 cases/100,000/year (95%CI 7.4-10.1), with a median age at diagnosis of 53 years. Incidence increased progressively during the study period, and the estimated point prevalence of biopsy-proven CD rose from 0.18% to 0.4%. An area of significant space-time clustering was identified, with an incidence of 22.9 cases/100,000/year (95%CI 16.1-31.6), but there was no evidence of seasonality. DISCUSSION: The submerged component of the 'coeliac iceberg' may be diminishing due to increasing case ascertainment, with a projected ratio of undiagnosed to diagnosed cases as low as 1.5:1. Our identification of clustering must be interpreted with caution, but suggests that an additional environmental factor may influence the pathogenesis of CD.

Steroid-responsive subacute polymyositis in an adult following respiratory syncytial virus infection.

The role of viral infections in the aetiopathogenesis of polymyositis remains speculative. We report a case of profound subacute polymyositis with incipient ventilatory failure following serologically confirmed infection by respiratory syncytial virus (RSV), with a dramatic and sustained response to pulse corticosteroid therapy. We suggest a possible autoimmune mechanism to account for this sequence of events.

Adult endomysial antibody-negative coeliac disease and cigarette smoking.

OBJECTIVE: To determine the relative incidence and characteristics of endomysial antibody (EMA)-negative coeliac disease in adults. DESIGN: Retrospective analysis of prospectively collected data on adults with newly diagnosed coeliac disease, with determination of EMA status before gluten withdrawal. SETTING: District general hospital (secondary care institution). PARTICIPANTS: Sixty consecutive incident cases. MAIN OUTCOME MEASURES: (i) Proportion of cases who were EMA-negative; (ii) comparison of clinical and laboratory variables at diagnosis for EMA-positive and EMA-negative subjects. RESULTS: Fifteen subjects (25%, 95% CI 15-38%) were EMA negative, of whom only two were IgA deficient. There was clinical evidence in all 15 patients and histological evidence in 13 patients of a response to gluten withdrawal. No significant differences were found between EMA-positive and EMA-negative subjects with respect to histological features, age, gender, clinical manifestations, concurrent autoimmune disorders, family history of coeliac disease, or haemoglobin and albumin concentrations at diagnosis. However, EMA-negative status at diagnosis was associated strongly with current or recent cigarette smoking (OR 7.0, 95% CI 1.7-31.5, P= 0.003). CONCLUSIONS: A substantial minority of patients with otherwise typical coeliac disease are EMA negative, and most of these are IgA replete. The value of EMA as a screening tool is therefore limited. EMA status in untreated coeliac disease correlates strongly with cigarette smoking history: this may be of pathogenic significance, given the previously demonstrated association between smoking and the risk of coeliac disease.

Adult coeliac disease and cigarette smoking.

BACKGROUND: Genetic predisposition and gliadin exposure are known to be crucial factors in the development of coeliac disease. Circumstantial evidence suggests that other unidentified environmental factors may also be of pathogenetic importance. AIM: To define the relation between cigarette smoking and the risk of development of symptomatic adult onset coeliac disease. SUBJECTS: Eighty six recently diagnosed adult coeliac disease patients and 172 controls matched for age and sex. METHOD: Matched case control study, using a simple questionnaire to determine smoking history, and in particular smoking status at the time of diagnosis of coeliac disease. RESULTS: At the time of diagnosis, the proportion of current smokers was 7% in the coeliac group, and 32.6% in the control group, giving a matched odds ratio of 0.15 (95% confidence intervals 0.06, 0.38). The difference could not be accounted for by social class, nor by coeliac patients giving up smoking after the onset of symptoms as most non-smokers in the coeliac group had never smoked. CONCLUSION: Cigarette smoking, or a factor closely linked to it, seems to exert a major protective effect against the development of symptomatic adult onset coeliac disease. The implication is that gliadin exposure is not the only important environmental factor involved in the pathogenesis of this condition.

Langerhan's cell histiocytosis complicating small bowel Crohn's disease.

Langerhan's cell histiocytosis is a rare infiltrative disorder of unknown aetiology. A variety of tissues may be affected, but clinically evident intestinal involvement is unusual. An adult patient is described with Crohn's disease of the terminal ileum who subsequently developed Langerhan's cell histiocytosis with extensive infiltration of the small bowel.

Oral fluticasone propionate in active distal ulcerative colitis.

Fluticasone propionate is a new corticosteroid with low systemic bioavailability. This study reports the outcome of a double blind clinical trial comparing oral fluticasone propionate (5 mg four times daily) with placebo for the treatment of active distal ulcerative colitis. Sixty patients were treated for four weeks, with assessments at two and four weeks. One patient was withdrawn when she was found to have amoebiasis. Thus, results are presented for 29 patients who received placebo and 30 who received fluticasone propionate. The two groups were well matched for age, sex, length of history, and extent of disease. After four weeks of therapy the clinical, sigmoidoscopic, and histological responses were similar in the two groups. It is concluded that fluticasone propionate (5 mg four times daily) is not effective treatment for active distal ulcerative colitis.

Serum and tissue autoantibodies to colonic epithelium in ulcerative colitis.

Sera and colonic tissue-bound immunoglobulin extracts from patients with ulcerative colitis and disease controls were examined immunohistochemically and by killer cell cytotoxicity assay for the presence of anticolonic epithelial autoantibodies. IgG yields in the tissue extracts from patients with colitis and control subjects were similar, and the extracts were uniformly autoantibody negative. Of 41 sera from patients with inflammatory bowel disease, 'classical' anticolon antibody was present in 41% and was commoner in patients with sclerosing cholangitis. Cytotoxic anticolon antibody was present in 20% overall and was strongly associated with disease activity; it did not correlate with the presence of 'classical' anticolon antibody. The heterogeneous and non-universal antiepithelial autoantibody response and the failure to detect tissue bound autoantibody in vivo argue against the hypothesis that humoral autoimmunity is of major importance in the pathogenesis of ulcerative colitis.

Studies on the pathogenesis of the early dumping syndrome induced by intraduodenal instillation of hypertonic glucose.

A reaction indistinguishable from the early dumping syndrome was induced in four of nine normal volunteers by intraduodenal instillation of a hypertonic glucose meal. Tachycardia and marked peripheral vasodilatation were demonstrated in 'dumpers' by Doppler ultrasound measurements of the arterial blood flow signal. The dumping reaction was not detectably altered by the addition of guar to the meal. Plasma VIP concentration rose and plasma volume fell to a similar degree in 'dumpers' and 'non-dumpers', suggesting that neither event is an integral component of the dumping mechanism. In contrast, the rates of rise of blood glucose and enteroglucagon concentration were markedly greater in 'dumpers'. The results are inconsistent with the conventional explanation that the early dumping syndrome is caused by a large osmotic fluid shift, but are compatible with a mechanism involving an initial period of intestinal hypermotility.

The association of autoimmune disorders with inflammatory bowel disease.

Medical records of patients with ulcerative colitis (n = 858), Crohn's disease (n = 378) and coeliac disease (n = 148) were examined to determine the prevalence of associated autoimmune disorders. Of outpatient controls (n = 300), 2 per cent had at least one autoimmune disorder, compared to 7 per cent with ulcerative colitis, 2 per cent with Crohn's disease and 6 per cent with coeliac disease. Inclusion of primary sclerosing cholangitis with the autoimmune disorders increased the overall prevalence in ulcerative colitis to over 9 per cent. The results provide further indirect evidence of involvement of autoimmune mechanisms in the pathogenesis of ulcerative colitis.

Peripheral blood and portal tract lymphocyte populations in primary sclerosing cholangitis.

The relative distribution of lymphocyte subpopulations in the blood and liver of patients with primary sclerosing cholangitis (PSC) and related diseases has been studied using immunoenzyme techniques. The peripheral blood CD4/CD8 T lymphocyte ratio was significantly higher in active ulcerative colitis (UC) and in PSC with inactive UC than in inactive UC alone. In contrast, no relationship with disease activity was seen in Crohn's disease. The portal tract t lymphocyte count per high power field (mean +/- S.D.) was higher in pre-cirrhotic PSC (173 +/- 105) and primary biliary cirrhosis (PBC: 210 +/- 110) than in histologically normal liver (42 +/- 27). However, the overall portal tract CD4/CD8 ratio was similar in PSC (1.49), PBC (1.89) and normal controls (1.63). The results are consistent with immunological involvement in the pathogenesis of PSC, but argue against the hypothesis that changes in the peripheral blood T cell subsets are due to sequestration at the site of tissue inflammation.

Anti-neutrophil nuclear antibody in ulcerative colitis, Crohn's disease and primary sclerosing cholangitis.

We have previously described circulating autoantibodies to a portal tract antigen in patients with primary sclerosing cholangitis. In this study the antigen has been shown by double-labelling studies to be specifically located in the nuclei of tissue neutrophils. Using isolated peripheral blood neutrophils and an immunoperoxidase technique, anti-neutrophil nuclear antibody (ANNA) was found in the serum of 84% of patients with primary sclerosing cholangitis (PSC: n = 32) with a median titre of 1/1000 and a peak titre of 1/500,000. ANNA was also detected in 86% of patients with inflammatory bowel disease alone (IBD: n = 76) with a median titre of 1/10 and a peak titre of 1/10,000. In contrast, only 12% of controls had ANNA, and in none was the titre greater than 1/10. In PSC the ANNA titre correlated with the serum aspartate transaminase concentration, suggesting that it is related to disease activity. In IBD the titre of ANNA was significantly higher in patients with recently active disease. There was no significant difference between the titres seen in ulcerative colitis and Crohn's disease. ANNA was not associated with neutropaenia. The results provide further evidence of involvement of autoimmune mechanisms in inflammatory bowel disease and primary sclerosing cholangitis.

Fibrolamellar hepatocellular carcinoma complicating ulcerative colitis with primary sclerosing cholangitis.

This case report describes the previously undocumented association between fibrolamellar hepatocellular carcinoma and ulcerative colitis complicated by primary sclerosing cholangitis.

Value of a simple biochemical ratio in distinguishing upper and lower sites of gastrointestinal haemorrhage.

59 cases of overt gastrointestinal haemorrhage were reviewed in which the source of bleeding was not initially evident but was identified by later investigation. The admission plasma urea to creatinine concentration ratio proved highly accurate in distinguishing upper and lower gastrointestinal sources of haemorrhage. Regardless of blood volume lost, 33 of 38 patients with upper gastrointestinal haemorrhage (87%) had a ratio of 100 or more, and 20 of 21 patients with lower gastrointestinal haemorrhage (95%) had a ratio of less than 100, an overall accuracy of 90%. Elevation of the ratio was not related to clinical evidence of hypovolaemia. This simple ratio may be valuable in determining the sequence of investigations in patients with an unidentified source of gastrointestinal haemorrhage.