Deficient UDP-glucuronosyltransferase detoxification enzyme activity in the small intestinal mucosa of patients with coeliac disease.

BACKGROUND: Small intestinal malignancies in humans are rare; however, patients with coeliac disease have a relatively high risk for such tumours. Intestinal UDP-glucuronosyltransferases are phase II drug metabolism enzymes also involved in the detoxification of ingested toxins and carcinogens. As many toxins and carcinogens are ingested via food, the human gastrointestinal tract not only has an important role in the uptake of essential nutrients, but also acts as a first barrier against such harmful constituents of the food. Therefore, the gastrointestinal mucosa contains high levels of detoxification enzymes such as cytochromes-P450, glutathione S-transferases and UDP-glucuronosyltransferases. AIM: To compare the UDP-glucuronosyltransferase detoxification capacity in small intestinal mucosa of patients with coeliac disease vs. that in normal controls. METHODS: We assessed UDP-glucuronosyltransferase enzyme activities towards 4-methylumbelliferone in small intestinal biopsies of patients with coeliac disease (n = 22) and age- and sex-matched controls (n = 27). RESULTS: Small intestinal UDP-glucuronosyltransferase enzyme activity in controls was significantly higher than in patients with coeliac disease: 0.55 +/- 0.27 vs. 0.35 +/- 0.16 nmol/min mg protein, respectively (mean +/- s.d., P = 0.005). DISCUSSION: The low small intestinal UDP-glucuronosyltransferase detoxification activity in patients with coeliac disease may result in a deficient detoxification of potential carcinogens, and thus could explain in part the relatively high small intestinal cancer risk in these patients.

A microarray screen for novel candidate genes in coeliac disease pathogenesis.

BACKGROUND AND AIMS: The causative molecular pathways underlying the pathogenesis of coeliac disease are poorly understood. To unravel novel aspects of disease pathogenesis, we used microarrays to determine changes in gene expression of duodenal biopsies. METHODS: cDNA microarrays representing 19 200 genes were used to compare gene expression profiles of duodenal biopsies from 15 coeliac disease patients with villous atrophy (Marsh III) and seven control individuals with normal biopsies (Marsh 0). In addition, the specific effect of gluten was studied by comparing the expression profiles of Marsh III lesions of seven patients exposed to gluten with four patients on a gluten free diet. RESULTS: Comparing Marsh III with Marsh 0 lesions identified 109 genes that differed significantly (p<0.001) in expression levels between patients and controls. A large number of these genes have functions in proliferation and differentiation pathways and might be important for correct development of crypt-villous units. Alterations in these pathways may lead to the characteristic hyperplasia and villous atrophy seen in coeliac disease. The analyses also revealed 120 differentially expressed genes (p<0.005) when comparing patients on a gluten free diet with those exposed to gluten. These genes further strengthen our observation of increased cell proliferation in the presence of gluten. CONCLUSIONS: Our study provides new candidate genes in the pathogenesis of coeliac disease. Based on our results, we hypothesise that villous atrophy in coeliac disease patients is due to failure in cell differentiation. These genes are involved in pathways not previously implicated in coeliac disease pathogenesis and they may provide new targets for therapy.

Coeliac disease and (extra)intestinal T-cell lymphomas: definition, diagnosis and treatment.

Intestinal lymphomas encompass those lymphomas with a dominant or only localized occurrence in the intestinal tract. Coeliac disease is highly associated with enteropathy-associated T-cell lymphomas (EATLs). Coeliac disease-related lymphomas can appear at nodal or extranodal sites. EATL is often multifocal with ulcerative lesions, which explains the high perforation rate at presentation or during chemotherapy. Staging includes ear-nose-throat examination and CT scan of the chest and abdomen. Positron emission tomography (PET) scanning may be valuable. Accurate diagnosis based on endoscopic biopsies is preferable; if necessary, full thickness laparoscopic small-bowel biopsies are mandatory. Refractory coeliac disease (RCD) with aberrant T cells carries a high risk of development of EATLs. There is no satisfactory treatment for EATL, the only possibility of preventing EATL development in RCD being autologous bone marrow transplantation. EATLs can present in 20% of patients as extra-small-bowel T-cell lymphomas; such as subcutaneous panniculitis-like lymphoma, hepatosplenic gamma/delta lymphoma, nodal as well as sinus, gastric or colon disease and extraintestinal T-cell lymphomas. The majority of EATLs present as large cell lymphoma CD3+, CD8-, CD30+; however, they also present as small cell lymphoma CD3+, CD8+, CD30-. Sometimes gamma/delta lymphomas in CD are recognized. Work-up of EATL must include immunohistology, T-cell flow cytometry, T-cell rearrangement and adequate imaging with CT and PET scanning.

Azathioprine and prednisone combination therapy in refractory coeliac disease.

INTRODUCTION: Refractory coeliac disease (RCD) is a rare syndrome with a poor prognosis, defined by malabsorption due to gluten-related enteropathy after initial or subsequent failure of a strict gluten-free diet and after exclusion of any disorder mimicking coeliac disease. PATIENTS AND METHODS: Nineteen patients were included and treated. Based on intraepithelial T-lymphocyte(IEL) phenotyping, patients were recorded as having RCD type I with normal IELs, or RCD type II with phenotypically immature IELs defined by a lack of characteristic T-cell markers. Treatment consisted of azathioprine combined with prednisone for 1 year, which was tapered and, if possible, stopped. RESULTS: Clinical improvement was seen in nearly all patients in both groups. Eight of 10 RCD type I patients responded histologically, and complete normalization of villi was seen in four patients. In RCD type II, 6/8 patients developed enteropathy-associated T-cell lymphoma (EATL) and 7/8 patients died. CONCLUSIONS: For the first time we report a promising therapeutic treatment option for RCD type I. In RCD type II, azathioprine and prednisone therapy (APT) is not effective, therefore we suggest that other (chemo)therapeutic agents are considered. Not all RCD type II patients presented with a monoclonal TCRgamma-gene rearrangement and immunohistological changes as is currently reported in the literature. Therefore, immunophenotyping seems mandatory in the work-up of RCD.

Lactobacillus GG prevents recurrence of colitis in HLA-B27 transgenic rats after antibiotic treatment.

BACKGROUND AND AIMS: Bacteroides vulgatus induces colitis in gnotobiotic HLA-B27 transgenic (TG) rats while broad spectrum antibiotics prevent and treat colitis in specific pathogen free (SPF) TG rats although disease recurs after treatment ends. Lactobacilli treat human pouchitis and experimental colitis. We investigated if Lactobacillus rhamnosus GG (L GG) can prevent colitis in TG rats monoassociated with B vulgatus and if L GG or Lactobacillus plantarum 299v (LP 299v) can treat established colitis in SPF TG rats and prevent recurrent disease after antibiotics were stopped. METHODS: Germfree B27 TG rats were monoassociated with B vulgatus for four weeks following two weeks of colonisation with L GG or no bacteria. SPF B27 TG rats received oral vancomycin and imipenem for two weeks, or water alone, followed by four weeks of treatment with oral L GG, LP 299v, or water only. Disease activity was quantified by blinded gross and histological scores, caecal myeloperoxidase (MPO) activity, and levels of interleukin (IL)-1 beta, tumour necrosis factor (TNF), transforming growth factor beta, and IL-10. RESULTS: L GG did not prevent colitis in B vulgatus co-associated TG rats or treat established disease in SPF rats. However, L GG but not LP 299v prevented colitis relapse in antibiotic treated rats with reduced gross and histological scores, caecal MPO, IL-1 beta, and TNF whereas caecal IL-10 was increased. CONCLUSIONS: L GG does not prevent colitis in gnotobiotic TG rats or treat established disease in SPF rats, but is superior to LP 299v in the prevention of recurrent colitis. These studies suggest that antibiotics and probiotic agents provide synergistic therapeutic effects, perhaps mediated by altered immunomodulation with selective activity of different lactobacillus species.

Coeliac disease: changing views on gluten-sensitive enteropathy.

BACKGROUND: The continuing flow of scientific development in coeliac disease in the past decade points to the need for the formulation of a new concept of pathophysiology and clinical approach to the coeliac condition. Immunogenetic studies have shown a correlation of the disease to the HLA region on the short arm of chromosome 6; immunological research has led to the concept of a T-cell-driven immunologic response of the small intestine, with the identification of highly sensitive and specific antibodies; and our understanding of the histopathology of coeliac disease has changed dramatically, initiated by the proposition of a spectrum of gluten-sensitive enteropathy by Marsh in 1992. Clinical studies report a significant change in patient characteristics and epidemiology. The incidence of the disease has shifted to a majority of adult coeliacs, and it may present with less severe symptoms of malabsorption. Screening studies suggest an overall prevalence of up to 1 in 200-300. METHODS: Update on histopathology concentrating on the work of our research group. RESULTS: We specifically describe the work of our group in Arnhem concerning the identification and validation of the spectrum of intestinal histopathology in gluten-sensitive enteropathy, i.e. lymphocytic enteritis (Marsh I lesion), lymphocytic enteritis with crypt hyperplasia (Marsh II lesion), and villous atrophy, subdivided into partial villous atrophy (Marsh IIIA), subtotal villous atrophy (Marsh IIIB) and total villous atrophy (Marsh IIIC). Special attention is given to a subgroup of 'refractory coeliacs', including the identification of (pre-)malignant aberrant T cells in the intestinal mucosa of these patients. CONCLUSION: New data on immunogenetics, epidemiology, histopathology and patient characteristics point to a significant change of view on coeliac disease.

Helicobacter hepaticus does not induce or potentiate colitis in interleukin-10-deficient mice.

Helicobacter hepaticus has been reported to induce colitis, hepatitis, and hepatocellular carcinoma in several different murine models. The aim of this study was to determine if H. hepaticus will cause colitis in monoassociated mice lacking the interleukin-10 gene (IL-10(-/-) mice) and potentiate colitis in specific-pathogen-free (SPF) IL-10(-/-) mice. Germfree IL-10(-/-) mice on either a mixed (C57BL/6 x 129/Ola) or inbred (129/SvEv) genetic background were monoassociated with H. hepaticus ATCC 51448 by oral feeding and rectal enemas. In a second experiment, germfree IL-10(-/-) mice were colonized with stool from SPF mice that harbored or did not harbor endogenous H. hepaticus. After 7 to 9 weeks of colonization, weight loss and mortality were assessed, the colon was isolated for histology and IL-12 secretion, and mesenteric lymph node cells were assessed for T-cell activation markers. It was found that IL-10(-/-) mice monoassociated with H. hepaticus for up to 16 weeks showed almost no histologic colitis or increased IL-12 production. SPF IL-10-knockout mice had no significant difference in weight loss, mortality rate, histologic scores, colonic IL-12 secretion, or T-cell activation with or without H. hepaticus. We conclude that H. hepaticus does not induce or potentiate disease in our IL-10(-/-) mice and therefore is not required to induce colitis in genetically susceptible hosts.