Anna Carrasco

The prevalence of coeliac disease is significantly higher in children compared with adults.

Background  Some limited studies of coeliac disease have shown higher frequency of coeliac disease in infancy and adolescence than in adulthood. This finding has remained unnoticed and not adequately demonstrated.

Intestinal Intraepithelial Lymphocyte Cytometric Pattern Is More Accurate than Subepithelial Deposits of Anti-Tissue Transglutaminase IgA for the Diagnosis of Celiac Disease in Lymphocytic Enteritis

Background & Aims An increase in CD3+TCRγδ+ and a decrease in CD3− intraepithelial lymphocytes (IEL) is a characteristic flow cytometric pattern of celiac disease (CD) with atrophy. The aim was to evaluate the usefulness of both CD IEL cytometric pattern and anti-TG2 IgA subepithelial deposit analysis (CD IF pattern) for diagnosing lymphocytic enteritis due to CD. Methods Two-hundred and five patients (144 females) who underwent duodenal biopsy for clinical suspicion of CD and positive celiac genetics were prospectively included. Fifty had villous atrophy, 70 lymphocytic enteritis, and 85 normal histology. Eight patients with non-celiac atrophy and 15 with lymphocytic enteritis secondary to Helicobacter pylori acted as control group. Duodenal biopsies were obtained to assess both CD IEL flow cytometric (complete or incomplete) and IF patterns. Results Sensitivity of IF, and complete and incomplete cytometric patterns for CD diagnosis in patients with positive serology (Marsh 1+3) was 92%, 85 and 97% respectively, but only the complete cytometric pattern had 100% specificity. Twelve seropositive and 8 seronegative Marsh 1 patients had a CD diagnosis at inclusion or after gluten free-diet, respectively. CD cytometric pattern showed a better diagnostic performance than both IF pattern and serology for CD diagnosis in lymphocytic enteritis at baseline (95% vs 60% vs 60%, p = 0.039). Conclusions Analysis of the IEL flow cytometric pattern is a fast, accurate method for identifying CD in the initial diagnostic biopsy of patients presenting with lymphocytic enteritis, even in seronegative patients, and seems to be better than anti-TG2 intestinal deposits.

Apoptosis resistance of mucosal lymphocytes and IL-10 deficiency in patients with steroid-refractory Crohn's disease.

Background: Apoptosis resistance of T‐cells is considered an abnormality of immune pathways in Crohns disease (CD). It has been previously shown that corticosteroids induce apoptosis of cells involved in inflammation. Thus, our aim was to assess the apoptosis of mononuclear cells and pro/antiinflammatory cytokines in the intestinal mucosa of patients with active CD, related to steroid response, and identify cellular and molecular factors that may predict this response to therapy. Methods: Patients with CD (n = 26), ulcerative colitis (UC) (n = 32), and controls (n = 10) were prospectively studied with mucosal biopsies before and 7‐10 days after corticosteroid treatment. Immunophenotype and apoptosis of T and B lymphocytes, plasma cells, and macrophages were assessed by flow cytometry, immunohistochemistry, and immunofluorescence. The cytokine expression pattern was evaluated by quantitative polymerase chain reaction (PCR). Results: Apoptosis resistance of T and B lymphocytes was observed only in steroid‐refractory and ‐dependent CD patients as compared to responsive patients (P = 0.032; P = 0.004, respectively), being evident after steroid treatment. Interleukin (IL)‐10 was markedly increased at baseline in steroid‐responsive patients compared to the nonresponders (P = 0.006; sensitivity: 88.8%; specificity: 66.6% to predict steroid response). Conclusions: Apoptosis resistance of mucosal T and B cells in steroid‐refractory and ‐dependent CD patients appears during the evolution of the acute phase, limiting its clinical application as a predictor marker. In contrast, increased expression of IL‐10 at an early stage of active steroid‐sensitive CD patients supports its usefulness at predicting a good steroid response. Steroid‐dependent and ‐refractory CD patients share similar molecular and cellular pathophysiological mechanisms. (Inflamm Bowel Dis 2010;)

Potential coeliac disease markers and autoimmunity in olmesartan induced enteropathy: A population-based study

AIMS (1) Assess the population-based incidence of severe olmesartan-associated enteropathy. (2) To describe patients of the Spanish registry. (3) Evaluate markers of potential coeliac disease and associated autoimmunity. METHODS Crude incidence rates in the area of Terrassa (Catalonia) were calculated. Clinical characteristics of patients in the Spanish registry were collected. Duodenal lymphocyte subpopulations and anti-TG2 IgA deposits were assessed in a subset of patients. RESULTS Annual incidence rates (2011-2014) ranged from 0 to 22 cases per 10(4) treated patients. Twenty patients were included in the Spanish registry. Nineteen (95%) exhibited villous atrophy and 16 (80%) had severe enteropathy. Lupus-like disease occurred during olmesartan treatment in 3 patients. HLA-DQ2/DQ8 was positive in 64%. Markers of potential coeliac disease were present in 4 out of 8 patients (positive anti-TG2 deposits and/or increased CD3+gammadelta+ intraepithelial lymphocytes and reduced CD3-). Histopathological changes and clinical manifestations including autoimmune disorders improved after olmesartan discontinuation but not after gluten-free diet, irrespective of the presence or absence of coeliac markers. CONCLUSIONS Incidence of severe olmesartan-associated enteropathy was low. Autoimmune phenomena were present in a subset of cases and reversed after olmesartan removal. A genetic coeliac disease background and the presence of potential coeliac markers might uncover predisposing factors.

Is a gluten-free diet necessary in Marsh I intestinal lesions in patients with HLADQ2, DQ8 genotype and without gastrointestinal symptoms?

Purpose of review To describe whether a gluten-free diet (GFD) is indicated in Marsh I gluten-sensitive enteropathy where gastrointestinal symptoms are not present. Arguments are provided to prescribe a GFD to manage extraintestinal symptoms. By contrast, there are not enough reasons to prescribe a GFD to prevent long-term complications. Recent findings Population-based and prospective observational studies have found that lymphocytic duodenosis may be due to not just gluten-sensitive enteropathy but also due to other aetiologic factors. Marsh I type lesions may be the cause of iron-deficiency anaemia of unknown aetiology which is reverted by a GFD. A similar effect seems to occur with bone mineralization and hypertransaminasemia. The beneficial influence of a GFD reducing lymphoma and coeliac disease-related mortality remains controversial. Summary An appropriate differential diagnosis of the lymphocytic duodenosis is essential before a GFD is indicated. As a third of patients remained undiagnosed, in spite of genetic study and specific coeliac serology, flow cytometry and transglutaminase antibodies in duodenal tissue may be helpful in establishing gluten-sensitive enteropathy diagnosis. Future studies should assess whether lymphoma risk is reduced by a GFD in Marsh I patients. Also a more precise benefit in bone mineralization in this setting is needed.

Comparison of lymphocyte isolation methods for endoscopic biopsy specimens from the colonic mucosa

An ideal method of immune cell isolation should provide maximum cell yield without disturbing functional properties. Intestinal endoscopic biopsies, in contrast to surgical samples, allow the study of all disease stages but have the drawback of a minimum amount of tissue available, making protocol optimization mandatory. We compared for the first time two methods of separation of colonic epithelium and five methods of lamina propria cell isolation for colonic biopsy specimens (mechanical, enzymatic and organ culture protocols). Lymphocyte number, viability and phenotype (CD45+, CD103+, CD3+, CD4+, CD8+, CD19+, CD16-56+) were analyzed by flow cytometry. Neither of the two epithelial detachment protocols achieved proper epithelial separation, though the high intensity ion chelation method was more accurate. Maximum cell yield of lamina propria lymphocytes without phenotypic modification was obtained with overnight smooth enzymatic digestion. High dose collagenase incubation caused a marked decrease in CD4+ lymphocytes of the lamina propria as compared to low enzymatic method (p=0.004). Mechanical and biopsy culture are not advisable methods because of the low cell yield, and phenotypic alterations and high contamination rate, respectively.

Double-Blind Randomized Clinical Trial: Gluten versus Placebo Rechallenge in Patients with Lymphocytic Enteritis and Suspected Celiac Disease

Background The role of gluten as a trigger of symptoms in non-coeliac gluten sensitivity has been questioned. Aim To demonstrate that gluten is the trigger of symptoms in a subgroup of patients fulfilling the diagnostic criteria for non-coeliac gluten sensitivity (NCGS), which presented with lymphocytic enteritis, positive celiac genetics and negative celiac serology. Methods Double-blind randomized clinical trial of gluten vs placebo rechallenge. Inclusion criteria: >18 years of age, HLA-DQ2/8+, negative coeliac serology and gluten-dependent lymphocytic enteritis, and GI symptoms, with clinical and histological remission at inclusion. Eighteen patients were randomised: 11 gluten (20 g/day) and 7 placebo. Clinical symptoms, quality of life (GIQLI), and presence of gamma/delta+ cells and transglutaminase deposits were evaluated. Results 91% of patients had clinical relapse during gluten challenge versus 28.5% after placebo (p = 0.01). Clinical scores and GIQLI worsened after gluten but not after placebo (p<0.01). The presence of coeliac tissue markers at baseline biopsy on a gluten-free diet allowed classifying 9 out of the 18 (50%) patients as having probable ‘coeliac lite’ disease. Conclusion This proof-of-concept study indicates that gluten is the trigger of symptoms in a subgroup of patients fulfilling the diagnostic criteria for NCGS. They were characterized by positive celiac genetics, lymphocytic enteritis, and clinical and histological remission after a gluten-free diet. Trial Registration ClinicalTrials.gov NCT02472704

Immunological Differences between Lymphocytic and Collagenous Colitis.

BACKGROUND Lymphocytic (LC) and collagenous (CC) colitis are the two major forms of microscopic colitis (MC). The aim of this study was to identify similarities and differences in their mucosal immune characteristics. METHODS Colonic biopsies from 15 CC, 8 LC, and 10 healthy controls were collected. Mucosal lymphocytes were assessed by flow cytometry. Tissue gene expression and protein levels were determined by real-time PCR and ELISA, respectively. RESULTS LC patients had lower numbers of CD4(+) and double-positive CD4(+)CD8(+)mucosal T lymphocytes, and higher numbers of CD8(+) and CD4(+)TCRγδ(+) mucosal T cells, compared with controls and CC patients. Regulatory Treg (CD4(+)CD25(+)FOXP3(+)) and double-negative (CD3(+)CD4(-)CD8(-)) T cell percentages were higher in both CC and LC compared with controls, coupled with higher levels of the anti-inflammatory IL-10, both at mRNA and protein levels. By contrast, Th1 and Th17 cells were lower in both CC and LC, although gene expression of Th1/Th17 cytokines was higher in both. CONCLUSION CC and LC share some regulatory and effector mechanisms, but not others. Higher IL-10 levels and higher Treg and double-negative T cell percentages, found in both CC and LC, could be responsible for the lack of progression of structural damage and the blockade of proinflammatory cytokine production. However, CC and LC are revealed as separate, independent entities, as they show clearly different mucosal lymphocyte profiles, which could be caused by different luminal triggers of the two diseases. Hence, CC and LC are two closely related but independent intestinal disorders.

Sensitive quantification of the HIV-1 reservoir in gut-associated lymphoid tissue

Background The implementation of successful strategies to achieve an HIV cure has become a priority in HIV research. However, the current location and size of HIV reservoirs is still unknown since there are limited tools to evaluate HIV latency in viral sanctuaries such as gut-associated lymphoid tissue (GALT). As reported in the so called “Boston Patients”, despite undetectable levels of proviral HIV-1 DNA in blood and GALT, viral rebound happens in just few months after ART interruption. This fact might imply that current methods are not sensitive enough to detect residual reservoirs. Showing that, it is imperative to improve the detection and quantification of HIV-1 reservoir in tissue samples. Herein, we propose a novel non-enzymatic protocol for purification of Lamina Propria Leukocytes (LPL) from gut biopsies combined to viral HIV DNA (vDNA) quantification by droplet digital PCR (ddPCR) to improve the sensitivity and accuracy of viral reservoir measurements (LPL-vDNA assay). Methods Endoscopic ileum biopsies were sampled from 12 HIV-1-infected cART-suppressed subjects. We performed a DTT/EDTA-based treatment for epithelial layer removal followed by non-enzymatic disruption of the tissue to obtain lamina propria cell suspension (LP). CD45+ cells were subsequently purified by flow sorting and vDNA was determined by ddPCR. Results vDNA quantification levels were significantly higher in purified LPLs (CD45+) than in bulk LPs (p<0.01). The levels of vDNA were higher in ileum samples than in concurrent PBMC from the same individuals (p = 0.002). As a result of the increased sensitivity of this purification method, the Poisson 95% confidence intervals of the vDNA quantification data from LPLs were narrower than that from bulk LPs. Of note, vDNA was unambiguously quantified above the detection limit in 100% of LPL samples, while only in 58% of bulk LPs. Conclusion We propose an innovative combined protocol for a more sensitive detection of the HIV reservoir in gut-associated viral sanctuaries, which might be used to evaluate any proposed eradication strategy.

Regional Specialisation of T Cell Subsets and Apoptosis in the Human Gut Mucosa: Differences Between Ileum and Colon in Healthy Intestine and Inflammatory Bowel Diseases

BACKGROUND AND AIMS There is very limited information regarding region-specific immunological response in human intestine. We aimed to determine differences in immune compartmentalisation between ileum and colon in healthy and inflamed mucosa. METHODS T cell profile and its apoptosis were measured by flow cytometry, Th1, Th17, Treg [CD4(+)CD25(+)FOXP3(+)], double positive [DP, CD3(+)CD4(+)CD8(+)] and double negative T cells [DN, CD3(+)CD4(-)CD8(-)], immunohistochemistry [FOXP3, caspase-3], and real-time polymerase chain reaction [PCR] [IFN-γ, IL-17-A, and FOXP3] on biopsies from different regions of healthy intestine and of intestine in inflammatory bowel diseases. RESULTS Healthy colon showed higher percentages of Treg, Th17, and DN, and lower numbers of DP T cells compared with ileum [p < 0.05]. Some but not all region-specific differences were lost in inflammatory conditions. Disease-specific patterns were found: a Th1/Th17 pattern and a Th17 pattern in Crohns disease and ulcerative colitis respectively, whereas a reduction in Th1/Th17 was found in microscopic colitis. In colonic Crohns disease and microscopic colitis, DN T cells had a pattern inverse to that of Th1/Th17 (increase in microscopic colitis [p < 0.05] and decrease in Crohns disease [p < 0.005]). Higher levels of lymphocyte apoptosis were found in healthy colon compared with the ileal counterparts [p = 0.001]. All forms of colonic inflammation presented a dramatic decrease in apoptosis compared with healthy colon. By contrast ileal Crohns disease showed higher levels of cleaved-Caspase(+) CD3(+) cells. CONCLUSIONS Immunological differences exist in healthy gastrointestinal tract. Inflammatory processes overwhelm some location-specific differences, whereas others are maintained. Care has to be taken when analysing immune response in intestinal inflammation, as location-specific differences may be relevant.