Mucin Expression Profiles in Ulcerative Colitis: New Insights on the Histological Mucosal Healing.

A structural weakness of the mucus barrier (MB) is thought to be a cause of ulcerative colitis (UC). This study aims to investigate the mucin (MUC) composition of MB in normal mucosa and UC. Ileocolonic biopsies were taken at disease onset and after treatment in 40 patients, including 20 with relapsing and 20 with remitting UC. Ileocolonic biopsies from 10 non-IBD patients were included as controls. Gut-specific MUC1, MUC2, MUC4, MUC5B, MUC12, MUC13, MUC15, and MUC17 were evaluated immunohistochemically. The promoters of mucin genes were also examined. Normal mucosa showed MUC2, MUC5B, and MUC13 in terminal ileum and colon, MUC17 in ileum, and MUC1, MUC4, MUC12, and MUC15 in colon. Membranous, cytoplasmic and vacuolar expressions were highlighted. Overall, the mucin expression was abnormal in UC. Derangements in MUC1, MUC4, and MUC5B were detected both at onset and after treatment. MUC2 and MUC13 were unaffected. Sequence analysis revealed glucocorticoid-responsive elements in the MUC1 promoter, retinoic-acid-responsive elements in the MUC4 promoter, and butyrate-responsive elements in the MUC5B promoter. In conclusion, MUCs exhibited distinct expression patterns in the gut. Their expression was disrupted in UC, regardless of the treatment protocols. Abnormal MUC1, MUC4, and MUC5B expression marked the barrier dysfunction in UC.

Amoebic colitis and liver abscess: A rare case of autochthonous invasive infection due to Entamoeba histolytica.

We report an unusual and confirmed case of invasive amebiasis in a non-endemic area where the source of infection remains unknown. During her admission, the patient developed amebic colitis and extraintestinal liver abscess with a favorable outcome following the antiparasitic therapy.

Histological healing as a predictor of sustained clinical remission in paediatric ulcerative colitis.

BACKGROUND: The study aimed to assess the longitudinal impact of endoscopic healing (EH) and histological healing (HH) in a cohort of paediatric patients affected by ulcerative colitis (UC). METHODS: This was a retrospective single-centre longitudinal study. 86 children with UC who underwent endoscopic re-assessment while in clinical and biochemical remission were included. Partial EH was defined as a Mayo Endoscopic Subscore (MES) of 1 and complete EH was defined as a MES of 0. HH was defined as the absence of active inflammation in all biopsies. The cumulative incidence of clinical relapse was evaluated during follow-up. RESULTS: At the second endoscopic re-evaluation, 59 (68.6%) patients achieved EH (MES ≤1). Of these patients, 39 (66%) achieved complete EH. 20 of the 39 patients who achieved complete EH attained complete HH. Patients who achieved partial and complete EH showed higher recurrence-free survival rates compared to those who did not (p < 0.01 and p < 0.01, respectively). Amongst patients with complete EH, those who achieved complete HH had lower recurrence rates when compared to patients who still showed microscopic inflammation (p = 0.049). CONCLUSION: Achievement of EH and HH is associated with fewer disease relapses, with patients achieving HH showing longer relapse-free survival rates.

Nutritional intervention with TGF-beta enriched food for special medical purposes (TGF-FSMP) is associated with a reduction of malnutrition, acute GVHD, pneumonia and may improve overall survival in patients undergoing allogeneic hematopoietic stem transplantation.

Malnutrition in allogeneic stem cell transplant (allo-SCT) is associated with poor outcomes. Supplementation with Foods for Special Medical Purposes may be a valid alternative to enteral nutrition or total parental nutrition to reduce malnutrition in allo-SCT. In this study, 133 patients consecutively allo-transplanted were assessed for nutritional status by Patient- Generated Subjective Global Assessment (PG-SGA) and supplemented with TGF-beta enriched Food for Special Medical Purposes (TGF-FSMP). PG-SGA, gold standard for nutritional assessment in oncologic patients, was assessed at admission and on day 0, +7, +14, +21, and + 28 from transplant and categorized as follows: A = good nutritional status; B = moderate malnutrition; C = severe malnutrition. TGF-FSMP (Modulen-IBD) is currently used in Inflammatory Bowel Diseases (IBD) as primary nutritional support and in this study the dose was calculated according to BMI and total daily energy expenditure (TDEE). The patients assuming ≥50% of the prescribed TGF-FSMP dose were classified in Group A; the patients who received < 50% were included in Group B per protocol. The primary endpoint of the study was the assessment of the malnourished patients in Group A and B at day+28 after transplantation, according to the criteria of PG-SGA C categorization. At day +28 after transplant: i) patients in Group A were significantly less severely malnourished than patients in the Group B (21/76,28% vs 42/53, 79% respectively, OR 2.86 - CI 1.94-4.23 -, p = 0.000); ii) the incidence of severe (MAGIC II-IV) aGVHD and of any grade gastrointestinal (GI) aGVHD was higher in Group B than in Group A, (43% vs 21% p = 0.003) and (34.5% vs 9.2% p = 0.001); iii) Pneumonia was more frequent in the malnourished patients of Group B than in well/moderate nourished patients of Group A (52.7% vs 27.6% p = 0.002). In group A parenteral nutrition was avoided more frequently than in group B (67.5% vs 33.3% p = 0.000) and a median hospital stay of 27 days in comparison to 32 was reported (p = 0.006). The estimated median overall survival (OS) of the population was 33 months in Group A and 25.1 months in group B (p = 0.03). By multivariate and ANN analysis, TGF-FSMP TR < 50% assumption was significantly correlated with malnutrition, severe and GI aGVHD, pneumonia and reduced OS.

Immunoglobulin light chain transcript detection by ultrasensitive RNA in situ hybridization for B-cell lymphoma diagnosis.

Evaluation of B-cell clonality can be challenging in the interpretation of lymphoid infiltrates on tissue sections. Clonality testing based on IG gene rearrangements analysis by PCR (IG-PCR) is the gold standard. Alternatively, B-cell clonality can be assessed by the recognition of immunoglobulin light chain (IgLC) restriction, by immunohistochemistry (IHC), chromogenic in situ hybridization (ISH) or flow cytometry (FC). IG-PCR requires molecular facilities, and FC requires cell suspensions, both not widely available in routine pathology units. This study evaluates the performance of B-cell clonality detection by IgLC-RNAscope® (RNAsc) in a group of 216 formalin-fixed, paraffin-embedded samples including 185 non-Hodgkin B-cell lymphomas, 11 Hodgkin lymphomas (HL) and 20 reactive samples. IgLC-RNAsc, performed in parallel with FC in 53 cases, demonstrated better performances (93% vs 83%), particularly in diffuse large B-cell lymphoma (98% vs 71%) and follicular lymphoma (93% vs 83%) diagnosis. IgLC-RNAsc was also superior to IHC and ISH especially in samples with limited tumor cell content, where IG-PCR was not informative. Performed for the first time on mediastinal lymphomas, IgLC-RNAsc identified monotypic IgLC transcripts in 69% of primary mediastinal large B-cell lymphoma (PMBCL) and 67% of mediastinal gray zone lymphomas (MGZL). IGK/L double-negative cells were detected in 1 PMBCL, 2 MGZL, and all classical HL, while monotypic IgLC expression appeared to be a hallmark in nodular lymphocyte-predominant HL. IgLC-RNAsc demonstrates to be a powerful tool in B-cell lymphoma diagnosis, above all in challenging cases with limited tumor cell content, ensuring in situ investigations on mechanisms of Ig regulation across lymphoma entities.

Endoscopic features with associated histological and molecular alterations in serrated polyps with dysplasia: Retrospective analysis of a tertiary case series.

BACKGROUND: Serrated polyps are incompletely understood lesions and include serrated sessile lesion (SSL) without or with dysplasia and traditional serrated adenoma (TSA). AIMS: We investigated prevalence and characteristics of serrated lesions, especially SSL with dysplasia (mixed polyps). METHODS: This retrospective study analyzed data from consecutive patients referred for colonoscopy at a tertiary care center. Endoscopic and histopathological characteristics of identified lesions were studied. SSLs with dysplasia were molecularly analyzed for mutations and microsatellite instability. RESULTS: Among 1147 patients, a total of 436 polyps were found, including 288 adenomas (66.1 %) and 114 serrated lesions (SLDR 26.2 %). PDR was 34.5 % and ADR was of 30.2 %. Serrated lesions included 75 hyperplastic polyps (17.2 %), 24 SSLs without dysplasia (5.5 %), 6 SSLs with dysplasia (mixed polyps) (1.4 %) and 9 TSA (2.1 %). The mixed polyps were evaluated molecularly: these analyses found no KRAS mutation, a single NRAS mutation in one lesion, the Val600Glu BRAF mutation in four lesions in both their serrated non-dysplastic and dysplastic areas, and microsatellite instability in four lesions, limited to the dysplastic areas. CONCLUSION: Our single-center experience confirms the high prevalence of serrated lesions, a part of which are SSL with dysplasia. These lesions seem to carry specific molecular alterations.

Serum anti-tissue transglutaminase IgA and prediction of duodenal villous atrophy in adults with suspected coeliac disease without IgA deficiency (Bi.A.CeD): a multicentre, prospective cohort study.

BACKGROUND: Whether coeliac disease in adults can be diagnosed with serology alone remains controversial. We aimed to evaluate the accuracy of serum anti-tissue transglutaminase IgA (tTG-IgA) in the diagnosis of coeliac disease. METHODS: In this multicentre, prospective cohort study, adult participants (aged ≥18 years) with suspected coeliac disease without IgA deficiency who were not on a gluten-free diet and who had a local serum tTG-IgA measurement, were enrolled from Feb 27, 2018, to Dec 24, 2020, by 14 tertiary referral centres (ten from Europe, two from Asia, one from Oceania, and one from South America) to undergo local endoscopic duodenal biopsy. Local serum tTG-IgA was measured with 14 different test brands and concentration expressed as a multiple of each test's upper limit of normal (ULN), and defined as positive when greater than 1 times the ULN. The main study outcome was the reliability of serum tests for the diagnosis of coeliac disease, as defined by duodenal villous atrophy (Marsh type 3 or Corazza-Villanacci grade B). Histology was evaluated by the local pathologist, with discordant cases (positive tTG-IgA without duodenal villous atrophy or negative tTG-IgA with duodenal villous atrophy) re-evaluated by a central pathologist. The reliability of serum tests for the prediction of duodenal villous atrophy was evaluated according to sensitivity, specificity, positive predictive value, negative predictive value, and the area under the receiver operating characteristic curve (AUC) for categorical and continuous data. FINDINGS: We enrolled 436 participants with complete local data on serum tTG-IgA and duodenal histology (296 [68%] women and 140 [32%] men; mean age 40 years [SD 15]). Positive serum tTG-IgA was detected in 363 (83%) participants and negative serum tTG-IgA in 73 (17%). Of the 363 participants with positive serum tTG-IgA, 341 had positive histology (true positives) and 22 had negative histology (false positives) after local review. Of the 73 participants with negative serum tTG-IgA, seven had positive histology (false negatives) and 66 had negative histology (true negatives) after local review. The positive predictive value was 93·9% (95% CI 89·2-98·6), the negative predictive value was 90·4% (85·5-95·3), sensitivity was 98·0% (95·3-100·0), and specificity was 75·0% (66·6-83·4). After central re-evaluation of duodenal histology in 29 discordant cases, there were 348 true positive cases, 15 false positive cases, 66 true negative cases, and seven false negative cases, resulting in a positive predictive value of 95·9% (92·0-99·8), a negative predictive value of 90·4% (85·5-95·3), a sensitivity of 98·0% (95·3-100·0), and a specificity of 81·5% (73·9-89·1). Either using the local or central definition of duodenal histology, the positive predictive value of local serum tTG-IgA increased when the serological threshold was defined at increasing multiples of the ULN (p<0·0001). The AUC for serum tTG-IgA for the prediction of duodenal villous atrophy was 0·87 (95% CI 0·81-0·92) when applying the categorical definition of serum tTG-IgA (positive [>1 × ULN] vs negative [≤1 × ULN]), and 0·93 (0·89-0·96) when applying the numerical definition of serum tTG-IgA (multiples of the ULN). Additional endoscopic findings included peptic gastritis (nine patients), autoimmune atrophic gastritis (three), reflux oesophagitis (31), gastric or duodenal ulcer (three), and Barrett's oesophagus (one). In the 1-year follow-up, a midgut ileum lymphoma was diagnosed in a woman on a gluten-free diet. INTERPRETATION: Our data showed that biopsy could be reasonably avoided in the diagnosis of coeliac disease in adults with reliable suspicion of coeliac disease and high serum tTG-IgA. FUNDING: None.

Misinterpreting Diarrhea-Predominant Irritable Bowel Syndrome and Functional Diarrhea: Pathophysiological Highlights.

Irritable bowel syndrome with predominant diarrhea (IBS-D) and functional diarrhea (FD) are disorders of gut-brain interaction characterized by recurring symptoms which have a serious impact on the patient's quality of life. Their pathophysiology is far from being completely understood. In IBS-D growing evidence suggests that bile acid malabsorption (BAM) could be present in up to 30% of patients. Microscopic colitis (MC) is a well-known cause of watery diarrhea and some patients, at first, can be diagnosed as IBS-D or FD. Both BAM and MC are often responsible for the lack of response to conventional treatments in patients labelled as "refractory". Moreover, because BAM and MC are not mutually exclusive, and can be found in the same patient, they should always be considered in the diagnostic workout when a specific treatment for BAM or MC is unsatisfactory. In the present review the possible shared pathogenetic mechanisms between BAM and MC are discussed highlighting how MC can induce a secondary BAM. Moreover, a brief overview of the current literature regarding the prevalence of their association is provided.

What does not look like celiac disease and instead it is.

The celiac disease (CD) diagnosis sometimes is challenging and diagnostic process cannot always follow a simple algorithm but it requires a close collaboration between histo-pathologists, clinicians, laboratory and genetic experts. The genetic predisposition for CD is related to HLA-DQ2 and/or DQ8 but other HLA haplotypes and non-HLA genes may be involved in genetic predisposition. In particular DQ7 may represent an additive and independent CD risk associated haplotype. We describe an unusual case of a female 42 year old with a previous diagnosis of Hodgkin lymphoma, who has a clinical presentation suggestive for CD with negativity for anti-transglutaminase and anti-endomysium antibodies and HLA-DQ7 positivity.

Celiac disease: experience of general practitioners in Brianza Area- Monza- Milan-Italy.

Aim: The purpose of the study was to better investigate the degree of knowledge and the diagnostic approach concerning celiac disease and its extra-intestinal manifestations by general practitioners in Italy. Background: Celiac Disease is a common chronic disease, but often goes undiagnosed because of atypical symptoms or silent disease. Currently there are non-definitive data about the disease management approach concerning celiac disease by general practitioners. Methods: To better investigate the degree of knowledge and the diagnostic approach concerning celiac disease and its extra-intestinal manifestations, questionnaire was used to assess the daily practice of diagnosis, treatment, and follow-up of this condition by general practitioners in two densely populated area in Italy: Monza-Brianza Area and Milan City. The questionnaire was composed of 18 questions that explored 3 precise domains: diagnosis criteria, correct management of celiac disease and availability for training. The frequencies of the domains explored were analyzed, analyzes were carried out to identify differences between the groups of general practitioners interviewed. Results: Analysis of the questionnaires showed a degree of knowledge and preparation comparable to that of other countries, even though not sufficient to guarantee access to early diagnosis for all patients with celiac disease. The knowledge was not influenced by the years of experience or specific curriculum of health professionals. General practitioners under 40 were much more in favor of continuous training and were aware of its importance (OR=10.55; CI95%: 1.62-445.39), although this need was a high priority in the whole group interviewed (84.7%). Conclusion: Continuous specific training aimed at primary care physicians and general practitioners is the first tool to improve early diagnosis. A second opportunity is represented by the continuous dialogue between general practitioners and tertiary level hospitals and universities.

The correct methodological approach to the diagnosis of celiac disease: the point of view of the pathologist.

The diagnosis of celiac disease relies on the assessment of serological data and the presence of histological alterations in the duodenal mucosa. The duodenal biopsy is pivotal in adults, and in some circumstances in children, to confirm the clinical suspicion of celiac disease. The correct interpretation of duodenal biopsies is influenced by numerous variables. The aim of this overview is to describe the correct methodological approach including the procedures of biopsy sampling, orientation, processing, staining and histopathological classification in order to avoid or minimize the errors and the variability in duodenal biopsy interpretation. Multiple biopsies taken from different sites of the duodenum during endoscopy maximize the diagnostic yield of duodenal histological sampling. Proper orientation of the biopsy samples is of the utmost importance to assess histological features of pathological duodenal mucosa and to avoid artifacts that may lead even an experienced pathologist to a wrong histological interpretation with subsequent misdiagnosis of celiac disease. An immunohistochemical stain for CD3 can be invaluable to aid the pathologist in obtaining a more accurate intra-epithelial T lymphocytes count. A simplified histological classification facilitates the clinician's work and improves the communication between pathologist and clinician. An integrated clinical and pathological approach is required for a correct diagnosis of celiac disease since a relatively large number of conditions may cause duodenal damage with a histological appearance similar to that of celiac disease.

Neutrophil-only Histological Assessment of Ulcerative Colitis Correlates with Endoscopic Activity and Predicts Long-term Outcomes in a Multicentre Study.

BACKGROUNDS AND AIMS: Absence of neutrophils is the minimum standard to consider histological remission of ulcerative colitis [UC]. The PICaSSO Histological Remission Index [PHRI] is a new simple index for UC, based only on the detection of neutrophils. We evaluate PHRI's correlation with endoscopy and its prognostic value compared with other established indices. METHODS: Consecutive patients with UC underwent colonoscopy at two referral centres [Birmingham, UK, and Milan, Italy,] and were followed up for 2 years. Correlation between histology (PHRI, Nancy [NHI], and Robarts [RHI] indexes) and endoscopy (Mayo Endoscopic Score [MES], Ulcerative Colitis Endoscopic Index of Severity [UCEIS], and PICaSSO index) was calculated as Spearman coefficients. Diagnostic performance of endoscopy was assessed with receiver operating characteristic [ROC] curves and outcome stratification with Kaplan-Meier curves. RESULTS: A total of 192 patients with UC was enrolled, representing all grades of endoscopic severity. Correlation between histology and endoscopy did not differ significantly when using PHRI instead of NHI or RHI. In particular, PHRI's correlation with MES, UCEIS, and PICaSSO was 0.745, 0.718, and 0.694, respectively. Endoscopically-assessed remission reflected the absence of neutrophils [PHRI = 0] with areas under the ROC curve of 0.905, 0.906, and 0.877 for MES, UCEIS, and PICaSSO, respectively. The hazard ratio for disease flare between patients in histological activity/remission was statistically similar [p >0.05] across indexes [2.752, 2.706, and 2.871 for RHI, NHI, and PHRI, respectively]. CONCLUSION: PHRI correlates with endoscopy and stratifies risk of relapse similarly to RHI and NHI. Neutrophil-only assessment of UC is a simple yet viable alternative to established histological scores.

Real-world use of endoscopic and histological indices in ulcerative colitis: Results of a global survey.

BACKGROUND: Treatment targets of ulcerative colitis (UC) have evolved to include not only endoscopic but also histologic remission. However, the concept of histological activity is still in its early days. We aimed to capture the attitudes toward UC histology and the uptake of standardized reporting of endoscopy and histology of UC in daily practice. METHODS: We conducted a cross-sectional survey of physicians involved in the care of inflammatory bowel disease worldwide. The survey included 21 questions divided into three sections. The first recorded demographics, specialty, and level of experience of participants; the second covered clinical practices and attitudes toward the use and reporting of endoscopy; and the third covered histology. RESULTS: In total, 359 participants from 60 countries and all levels of experience completed the survey. UC histology was used by nearly all respondents (90.5%) for initial diagnosis, by 72% to monitor disease course, by 62.4% to determine the microscopic extension, by 59.9% to confirm deep remission when considering to stop treatment, and 42.3% to increase/optimize treatment. Nevertheless 77.2% of participants reported that no standard histological index was available in their daily practice. Instead, endoscopy reports included the Mayo Endoscopic score in 90% of cases. The majority of respondents welcomed as useful or very useful an artificial intelligence system to automate scoring of endoscopy (69%) or histology (73%). CONCLUSION: UC histology reports are less standard than endoscopy reports, although most physicians consider histological activity useful when managing UC and would welcome artificial intelligence systems to automate endoscopic and histological scoring.

Immuno-Contexture and Immune Checkpoint Molecule Expression in Mismatch Repair Proficient Colorectal Carcinoma.

Colorectal carcinoma (CRC) represents a lethal disease with heterogeneous outcomes. Only patients with mismatch repair (MMR) deficient CRC showing microsatellite instability and hyper-mutated tumors can obtain clinical benefits from current immune checkpoint blockades; on the other hand, immune- or target-based therapeutic strategies are very limited for subjects with mismatch repair proficient CRC (CRCpMMR). Here, we report a comprehensive typing of immune infiltrating cells in CRCpMMR. We also tested the expression and interferon-γ-modulation of PD-L1/CD274. Relevant findings were subsequently validated by immunohistochemistry on fixed materials. CRCpMMR contain a significantly increased fraction of CD163+ macrophages (TAMs) expressing TREM2 and CD66+ neutrophils (TANs) together with decrease in CD4-CD8-CD3+ double negative T lymphocytes (DNTs); no differences were revealed by the analysis of conventional and plasmacytoid dendritic cell populations. A fraction of tumor-infiltrating T-cells displays an exhausted phenotype, co-expressing PD-1 and TIM-3. Remarkably, expression of PD-L1 on fresh tumor cells and TAMs was undetectable even after in vitro stimulation with interferon-γ. These findings confirm the immune suppressive microenvironment of CRCpMMR characterized by dense infiltration of TAMs, occurrence of TANs, lack of DNTs, T-cell exhaustion, and interferon-γ unresponsiveness by host and tumor cells. Appropriate bypass strategies should consider these combinations of immune escape mechanisms in CRCpMMR.

Inflammatory Bowel Diseases: Does One Histological Score Fit All?

Mucosal healing (MH) is the main treatment target in ulcerative colitis (UC) and Crohn's disease, and it is defined by the combination of complete endoscopic and histologic remission. The complete resolution of mucosal inflammation should be confirmed by histology but its assessment is not always univocal. Neutrophil infiltration represents the unique histological marker in discriminating the active vs. quiescent phases of the disease, together with crypt injuries (cryptitis and crypt abscesses), erosions, and ulcerations. On the contrary, basal plasmacytosis is not indicative of activity or the remission of inflammatory bowel diseases (IBDs) but instead represents a diagnostic clue, mostly at the onset. Several histological scoring systems have been developed to assess grade severity, particularly for UC. However, most are complex and/or subjective. The aim of this review was to summarize available scores, their characteristics and limitations, and to present the advantages of a simplified mucosa healing scheme (SHMHS) based on neutrophils and their distribution in the gut mucosa. Finally, we overview future developments including artificial intelligence models for standardization of disease assessments and novel molecular markers of inflammation with potential application in diagnostic practice.