Bertrand Meresse

Presentation and Long-Term Follow-up of Refractory Celiac Disease: Comparison of Type I With Type II

BACKGROUND & AIMS Refractory celiac disease (RCD) was recently subdivided into 2 subtypes (RCD I and II) based on a normal or abnormal phenotype of intraepithelial lymphocytes (IELs), respectively. It is not clear, however, if these 2 entities differ in their presentation at diagnosis or long-term outcome. We compared the clinical and biological characteristics of RCD I and RCD II at diagnosis, the risk of developing an overt lymphoma, and the predictive factors of survival. METHODS Medical files of 14 patients with RCD I and 43 with RCD II were analyzed retrospectively. Predictive factors of overt lymphoma and survival were studied in univariate and multivariate analyses. RESULTS At diagnosis, malnutrition, ulcerative jejunitis, and lymphocytic gastritis were more common in patients with RCD II than RCD I (P< .05). Overt lymphomas occurred in 2 patients with RCD I and 16 with RCD II. In the univariate analysis, abnormal IEL phenotype and increased age at diagnosis of RCD were predictive factors for overt lymphoma. Abnormal IEL phenotype (P< .01), clonality (P= .01), and overt lymphoma (P= .001) predicted short survival time. Only abnormal IEL phenotype (P= .03) and overt lymphoma (P= .04) were predictive in the multivariate analysis. The 5-year survival rate was 93% in patients with RCD I and 44% with RCD II. CONCLUSIONS RCD II has a much more severe presentation and prognosis than patients with RCD I; <44% of patients with RCD II survive 5 years after diagnosis. Abnormal IEL phenotype is a predictive factor but not a necessary condition for the development of overt lymphoma.

IL-15 triggers an antiapoptotic pathway in human intraepithelial lymphocytes that is a potential new target in celiac disease–associated inflammation and lymphomagenesis

Enteropathy-associated T cell lymphoma is a severe complication of celiac disease (CD). One mechanism suggested to underlie its development is chronic exposure of intraepithelial lymphocytes (IELs) to potent antiapoptotic signals initiated by IL-15, a cytokine overexpressed in the enterocytes of individuals with CD. However, the signaling pathway by which IL-15 transmits these antiapoptotic signals has not been firmly established. Here we show that the survival signals delivered by IL-15 to freshly isolated human IELs and to human IEL cell lines derived from CD patients with type II refractory CD (RCDII) - a clinicopathological entity considered an intermediary step between CD and enteropathy-associated T cell lymphoma - depend on the antiapoptotic factors Bcl-2 and/or Bcl-xL. The signals also required IL-15Rbeta, Jak3, and STAT5, but were independent of PI3K, ERK, and STAT3. Consistent with these data, IELs from patients with active CD and RCDII contained increased amounts of Bcl-xL, phospho-Jak3, and phospho-STAT5. Furthermore, incubation of patient duodenal biopsies with a fully humanized human IL-15-specific Ab effectively blocked Jak3 and STAT5 phosphorylation. In addition, treatment with this Ab induced IEL apoptosis and wiped out the massive IEL accumulation in mice overexpressing human IL-15 in their gut epithelium. Together, our results delineate the IL-15-driven survival pathway in human IELs and demonstrate that IL-15 and its downstream effectors are meaningful therapeutic targets in RCDII.

Impaired Control of Effector T Cells by Regulatory T Cells: A Clue to Loss of Oral Tolerance and Autoimmunity in Celiac Disease?

OBJECTIVES:Regulatory T cells (Tregs) are instrumental for tolerance to self-antigens and dietary proteins. We have previously shown that interleukin (IL)-15, a cytokine overexpressed in the intestine of patients with celiac disease (CD), does not impair the generation of functional Tregs but renders human T cells resistant to Treg suppression. Treg numbers and responses of intestinal and peripheral T lymphocytes to suppression by Tregs were therefore compared in CD patients and controls.METHODS:Intraepithelial lymphocytes (IELs) and lamina propria lymphocytes (LPLs) were isolated from duodenal biopsy specimens of CD patients and controls. Concomitantly, CD4+CD25+ T lymphocytes (Tregs) were purified from blood. Responses of IELs and of LPLs, and peripheral lymphocytes (PBLs) to suppression by Tregs were tested by analyzing anti-CD3-induced proliferation and interferon (IFN)-γ production in the presence or absence of peripheral Tregs. Lamina propria and peripheral CD4+CD25+FOXP3+ T cells were assessed by flow cytometry.RESULTS:Although percentages of CD4+CD25+FOXP3+ LPLs were significantly increased in patients with active CD, proliferation and IFN-γ production of intestinal T lymphocytes were significantly less inhibited by autologous or heterologous Tregs in CD patients than in controls (P<0.01). In all tested CD patients, IEL were unable to respond to Tregs. Resistance of LPLs and PBLs to Treg suppression was observed in patients with villous atrophy who had significantly enhanced serum levels of IL-15 compared with patients without villous atrophy and controls.CONCLUSIONS:Our results indicate that effector T lymphocytes from active CD become resistant to suppression by Tregs. This resistance might cause loss of tolerance to gluten, but also to self-antigens.

Low ileal interleukin 10 concentrations are predictive of endoscopic recurrence in patients with Crohn's disease

Background: Endoscopic recurrence after surgery in Crohns disease is frequent and unpredictable. Abnormal intestinal production of pro- (interleukin (IL)-1β, tumour necrosis factor α (TNF-α)) and anti- (IL-10) inflammatory cytokines has been associated with severe outcome in experimental models of colitis. Patients and methods: We evaluated if ileal TNF-α, IL-1β, or IL-10 mRNA levels measured at the time of surgery predict endoscopic recurrence, and if ileal IL-10 levels are associated with particular IL-10 promoter alleles. Ileal biopsies were obtained peroperatively from the healthy neoileum of patients undergoing a right ileocolectomy for Crohns disease. Mucosal TNF-α, IL-1β, and IL-10 mRNA levels were quantified by competitive polymerase chain reaction. A cut off value was determined using a receiver operating curve. IL-10.G promoter haplotypes were analysed using a polymorphic dinucleotide repeat in the IL-10 promoter region. Results: Three months after surgery, 53% of patients had endoscopic recurrence while 47% remained free of disease. The risk of endoscopic recurrence correlated with ileal IL-10 mRNA concentrations (r2=0.81). Endoscopic recurrence occurred more frequently in patients classified as low IL-10 producers than in those that were high producers (80% v 40%) (p=0.02). Patients with at least one of the two alleles G7–8 or G10–13 produced, respectively, higher (p=0.006) and lower (p=0.029) ileal IL-10 mRNA. The distribution of IL-10.G microsatellite genotypes was similar in patients with or without endoscopic recurrence. Conclusion: Low ileal IL-10 mRNA concentration is a good marker of endoscopic recurrence in Crohns disease but the distribution of IL-10.G haplotypes cannot predict the postoperative evolution of the disease.

Enteropathy associated T cell lymphoma in celiac disease: A large retrospective study

Abstract Introduction Prognosis of enteropathy-associated T cell lymphoma is poor but predictors of survival remain ill-defined. How clinical presentation, pathological features and therapies influence outcome was evaluated in 37 thoroughly characterized patients with celiac disease and T-cell lymphoma. Patients and methods Medical files were studied retrospectively. Lymphoma and intestinal mucosa were analysed by histopathology, multiplex PCR and intestinal intraepithelial lymphocytes phenotyping. Survival and prognostic factors were analysed using Kaplan–Meier curves with Logrank test and Cox Model. Results Lymphoma complicated non clonal enteropathy, celiac disease (n =15) and type I refractory celiac disease (n =2) in 17 patients and clonal type II refractory celiac disease in 20 patients. Twenty-five patients underwent surgery with resection of the main tumour mass in 22 cases. In univariate analysis, non clonal celiac disease, serum albumin level>21.6g/L at diagnosis, chemotherapy and surgical resection predicted good survival (p =0.0007, p <0.0001, p <0.0001, p <0.0001, respectively). In multivariate analysis, serum albumin level>21.6g/L, chemotherapy and reductive surgery were all significantly associated with increased survival (p <0.002, p <0.03, p <0.03, respectively). Conclusions Our study underlines the prognostic value of celiac disease type in patients with T-cell lymphoma, and suggests that a combination of nutritional, chemotherapy and reductive surgery may improve survival.

Epithelial inflammation response induced by Shigella flexneri depends on mucin gene expression.

The protective effects of different mucin gene profiles on gut protection were assessed by the evaluation of TNFalpha production by intestinal epithelial cells infected by Shigella flexneri. Three HT-29 cell lines were used: HT29-G(-) (enterocyte-like cells, secreting no mucins), HT29-FU (highly expressing MUC2 and MUC4) and HT29-MTX (highly expressing MUC3 and MUC5AC). These cells were infected either by an invasive (M90T) or the control isogenic (BS176) strains of S. flexneri, and TNFalpha mRNA production was quantified by competitive PCR. In the HT29-G(-) cells, M90T induced an increased production of TNFalpha mRNA compared to BS176, giving a TNFalpha ratio of 5.6 +/- 3.3. In contrast, similar levels of TNFalpha mRNA were detected in HT29-FU and HT29-MTX cells stimulated with either M90T or BS176, giving ratios of 1.4 +/- 1.3 and 1.0 +/- 0.1, respectively. The results suggest that mucin genes have abilities to protect epithelial cells against S. flexneri. Furthermore, the difference in the TNFalpha ratio between the HT29-FU and HT29-MTX cells suggests distinct protective effects for these two mucin-secreting epithelial cells.

Interleukin-15, a Master Piece in the Immunological Jigsaw of Celiac Disease

Background: The immune response causing celiac disease (CD) depends on the activation of intestinal CD4+ T cells by gluten-derived peptides presented by HLA-DQ2 or HLA-DQ8 molecules, the main genetic risk factor. However, additional factors are necessary to impair immune tolerance to dietary gluten, to stimulate intraepithelial lymphocytes (IEL) and to induce intestinal damage. Key Messages: Current data point to a central role of interleukin-15 (IL-15). In situ and ex vivo studies indicate that IL-15 stimulates the accumulation and cytotoxic activation of CD8+ T IEL in active CD, and that of the malignant innate-like IEL in type II refractory CD (RCDII). Other studies show that IL-15 impairs the immunoregulatory control of effector T cells, notably CD8+. Recently, animal models have been designed to investigate the respective role of CD4+ T cells and IL-15 in CD. We discuss more particularly our results in such a model, which shows that IL-15 produced in excess in the intestine can cooperate with CD4+ T cells specific for a dietary antigen to trigger a celiac-like enteropathy. In this mouse model, CD4+ T cells activated by dietary ovalbumin secreted IL-2 which, along with IL-15, stimulated the expansion of noncognate intestinal cytotoxic CD8+ T cells containing large amounts of granzyme B. In the presence of IL-15, the latter cells did not respond to regulatory T cells, and accumulated in the intestine close to epithelial damage. Conclusion: On the basis of these data, we propose that, in CD, gluten-specific CD4+ T cells synthesize cytokines that synergize with IL-15 to license the expansion and activation of cytotoxic IEL, which drive tissue damage. We suggest that IL-15 is a meaningful therapeutic target, notably in patients with RCDII in which malignant IEL can respond to IL-15 independently of signals provided by CD4+ T cells.

Small Intestinal CD4+ T-Cell Lymphoma Is a Heterogenous Entity With Common Pathology Features

BACKGROUND & AIMS Little is known about intestinal CD4+ T-cell lymphoma; this rare malignancy is misdiagnosed frequently. We evaluated diagnostic criteria and factors that might affect its development and outcome. METHODS In a retrospective analysis, we analyzed medical records and intestinal specimens from 10 patients diagnosed with intestinal CD4+ T-cell lymphoma among 115 consecutive patients examined for severe enteropathy with villous atrophy. Samples were analyzed by histology, flow cytometry, and comparative genomic hybridization. RESULTS Small-intestine epithelial and lamina propria tissues from patients who presented with chronic diarrhea and malnutrition had variable levels of infiltration of CD3+ CD4+ T cells. Flow cytometry showed a high frequency of CD4+ intraepithelial cells, which frequently expressed a specific Vβ chain. T-cell receptor β clonality was confirmed by DNA sequencing. Two patients had HLA and serology results compatible with celiac disease and autoimmune enteropathy, respectively. Two patients were found to have antibodies against human T-cell leukemia virus and 2 patients had signs of a recent infection with the herpes viruses. Comparative genomic hybridization analyses showed heterogeneous chromosomal abnormalities. Symptoms were reduced in patients treated with steroids (n = 5), but not in patients given purine analogues or chemotherapy. Antibodies against CD52 produced clinical and histologic responses in 2 of 2 patients, whereas severe adverse effects developed in 1 patient. At the latest follow-up evaluation, all patients were alive. CONCLUSIONS There is much heterogeneity in the onset and genetic features of intestinal CD4+ T-cell lymphomas, despite their common presentation as indolent lymphoproliferations of the intestinal mucosa. Patients should be treated with steroids, and possibly antibodies against CD52 (for the most aggressive forms of this disorder).

The cytokine interleukin 21: a new player in coeliac disease?

In this issue of Gut ,1 Fina et al demonstrate that interleukin 21 (IL21) expression is increased in the intestinal mucosa of patients with active coeliac disease (CD) but not that of treated patients ( see page 887 ). The authors show that IL21 is produced by CD4+ lamina propria T cells, a finding consistent with previous work indicating that this cytokine is exclusively produced by CD4+ T cells. Using a neutralising anti-IL21 antibody, they observed that blocking IL21 activity reduced the increase in interferon γ mRNA induced by gliadin digests in intestinal organ cultures from treated CD patients. Since the anti-IL21 antibody also reduced the induction of mRNA for T-bet, the transcription factor that controls the differentiation of interferon γ-producing CD4+ T lymphocytes (so-called T helper cell type 1 or Th1 lymphocytes), the authors conclude that IL21 is an important contributor to the mucosal Th1 proinflammatory response.1 The mucosal Th1 response in CD is generally ascribed to lamina propria CD4+ T cells that recognise gluten peptides presented by the human leucocyte antigen (HLA)-DQ2/8 molecules at the surface of mucosal dendritic cells. This response accounts for the interplay between the major genetic risk factor, the MHC (major histocompatibility complex) class II genes encoding the HLA-DQ2/8 molecules, and the triggering environmental factor gluten, and is considered instrumental in the pathogenesis of CD enteropathy.2 These results are of particular interest following the first genome-wide association study recently carried out in CD by van Heel et al .3 The latter study has indeed provided convincing evidence that the chromosomal 4q27 region harbouring the genes encoding the IL2 and IL21 cytokines might be involved in CD. In this study based on the use of single-nucleotide polymorphisms (SNPs), several variants were highly significant when analysed in three distinct populations of UK, Dutch and …

Gastrointestinal Disorder Associated with Olmesartan Mimics Autoimmune Enteropathy

Background and Objectives Anti-hypertensive treatment with the angiotensin II receptor antagonist olmesartan is a rare cause of severe Sprue-like enteropathy. To substantiate the hypothesis that olmesartan interferes with gut immune homeostasis, clinical, histopathological and immune features were compared in olmesartan-induced-enteropathy (OIE) and in autoimmune enteropathy (AIE). Methods Medical files of seven patients with OIE and 4 patients with AIE enrolled during the same period were retrospectively reviewed. Intestinal biopsies were collected for central histopathological review, T cell Receptor clonality and flow cytometric analysis of isolated intestinal lymphocytes. Results Among seven olmesartan-treated patients who developed villous atrophy refractory to a gluten free diet, three had extra-intestinal autoimmune diseases, two had antibodies reacting with the 75 kilodalton antigen characteristic of AIE and one had serum anti-goblet cell antibodies. Small intestinal lesions and signs of intestinal lymphocyte activation were thus reminiscent of the four cases of AIE diagnosed during the same period. Before olmesartan discontinuation, remission was induced in all patients (7/7) by immunosuppressive drugs. After interruption of both olmesartan and immunosuppressive drugs in six patients, remission was maintained in 4 but anti-TNF-α therapy was needed in two. Conclusion This case-series shows that olmesartan can induce intestinal damage mimicking AIE. OIE usually resolved after olmesartan interruption but immunosuppressive drugs may be necessary to achieve remission. Our data sustain the hypothesis that olmesartan interferes with intestinal immuno regulation in predisposed individuals.