The histologic examination of endoscopic biopsies or resection specimens remains a key step in the work-up of affected inflammatory bowel disease (IBD) patients and can be used for diagnosis and ...differential diagnosis, particularly in the differentiation of UC from CD and other non-IBD related colitides. The introduction of new treatment strategies in inflammatory bowel disease (IBD) interfering with the patients' immune system may result in mucosal healing, making the pathologists aware of the impact of treatment upon diagnostic features. The European Crohn's and Colitis Organisation (ECCO) and the European Society of Pathology (ESP) jointly elaborated a consensus to establish standards for histopathology diagnosis in IBD. The consensus endeavors to address: (i) procedures required for a proper diagnosis, (ii) features which can be used for the analysis of endoscopic biopsies, (iii) features which can be used for the analysis of surgical samples, (iv) criteria for diagnosis and differential diagnosis, and (v) special situations including those inherent to therapy. Questions that were addressed include: how many features should be present for a firm diagnosis? What is the role of histology in patient management, including search for dysplasia? Which features if any, can be used for assessment of disease activity? The statements and general recommendations of this consensus are based on the highest level of evidence available, but significant gaps remain in certain areas.
Abstract
Background
Histological assessment is becoming increasingly important in the management of Ulcerative Colitis (UC). The Nancy index (NI), a recently developed and validated score, has been ...shown to accurately represent histological inflammation and to correlate with prognosis. However, it is a composite score, involving the analysis of more than one histological feature, which may limit its applicability. Our aim was to evaluate if a single component of the NI could individually predict prognosis in limited UC (E1 and E2) patients.
Methods
Multi-centre retrospective cohort study of newly diagnosed, treatment-naïve proctitis and left-sided ulcerative colitis patients. Biopsies from inflamed rectal mucosa were reviewed by two pathologists. Histological features from the NI were selected for analysis, including presence of ulcers, acute inflammatory infiltrate (with separate evaluation of neutrophils in lamina propria and epithelium) and chronic inflammatory infiltrate. Mucin depletion and basal plasmacytosis were also evaluated. The primary outcome was a composite outcome intended to evaluate disease-related complications, including proximal disease extension, need for hospitalisation or colectomy. Survival analysis, including univariate and multivariate Cox-regression analysis was performed.
Results
A total of 91 patients were included (56.0% males, mean age 44±17 years, median follow-up 44 months 2–328). Overall, 64.8% of the patients had proctitis (E1) and 35.2% left-sided colitis (E2). The most frequent histological features were the presence of chronic inflammatory infiltrate (93.4%), mucin depletion (81.3%) and basal plasmacytosis (78.0%). During the follow-up, 22.0% presented a disease-related complication. The NI was not able to predict prognosis (HR 3.09, 95% CI 0.71–13.36, p=0.132). In univariate analysis, the presence of neutrophils in the epithelium in more than 50% of the crypts was marginally significant for the primary outcome (HR 2.51, 95% CI 0.99–6.36, p=0.05). In multivariate analysis, after adjusting for gender, age at diagnosis, disease extent (E1 vs E2), Mayo endoscopic score (< 2 vs ≥ 2) and clinical severity at diagnosis (mild vs moderate to severe UC) this single component of the score was associated with the primary outcome (aHR 3.36, 95% IC 1.21–9.31, p=0.02). No other histological feature was able to individually predict prognosis (p>0.05).
Conclusion
The presence of neutrophils in the epithelium in more than 50% of the crypts in endoscopically inflamed mucosa at diagnosis was associated with higher disease complications in limited UC patients. The evaluation of a single feature could facilitate the use of histology in the prediction of prognosis in UC. Our results need to be prospectively validated.
Abstract
Background
High quality histological examination of ileocolonic biopsies in inflammatory bowel disease (IBD) plays a critical role in optimising clinical management, investigative studies, ...and clinical trials. The correct assessment of histological features can confirm the diagnosis of IBD, assist with its subclassification (as ulcerative colitis or Crohn’s disease), facilitate the estimation of disease activity and disease extent, and aid the detection of mimics and complication.
However, there are surprisingly few universal definitions of each histological abnormalities and the existing definitions are often inconsistent. The main practical concern is that histological scoring schemes, or guidelines on histological diagnosis, include detailed features, and many of these features have, paradoxically, no, or vague definitions. Furthermore, interobserver variability for many histological features in IBD is significantly high, possibly reflecting lack of precision.
The aim of this paper is to review and assess any existing histologcal definitions and criteria, selecting the most appropriate where possible, and modifying them or writing new definitions where necessary.
Methods
The European Crohn's and Colitis Organisation (ECCO) and the project leaders formed a panel of experts in the IBD field, composed of pathologists and gastroenterologists to explore inconsistencies in the definitions of histological abnormalities using the best resources and evidence available. The panel examined existing definitions, peer reviews publications, scoring schemes, guidelines and textbooks. An important contribution was also given by their professional experience and knowledge.
Results
The literature review process confirmed that most current existing definitions often have no evidence base and vary between sources.
The panel of experts developed 40 statements on histological definitions in IBD with accompanying supporting text for each statement.
Conclusion
The statements represent expert consensus with the support of evidence where available. Further possible development of this process will include attempts to grade histological changes, aiming to improve the consistency of pathological diagnosis, a reduction in currently high rates of interobserver variability, more precision in clinical trial work and research, and to facilitate development of new guidelines and scoring schemes for IBD.
Abstract
Background
Several studies have reported that the presence of histological inflammation in patients with ulcerative colitis affects prognosis and important UC-related outcomes. However, the ...prognostic value of histological inflammation at the time of diagnosis is not well characterised, and histology is not currently used to assess prognosis in UC patients. Our aim was to review the microscopic features at the time of UC diagnosis, and to assess its prognostic value during follow-up.
Methods
Multi-centre restrospective study. Biopsies obtained from the rectum in newly-diagnosed, treatment-naïve patients with proctitis (E1) and left-sided colitis (E2) were obtained. Pathology slides were reviewed by two independent pathologists and classified according to the Nancy score, grading from 0 (mild chronic inflammation) to 4 (ulcers). The impact of the severity of inflammation at diagnosis on a composite outcome (need for hospitalisation, steroids, and therapy escalation, acute severe UC or proximal disease extension) was evaluated using chi-square analysis. Wilcoxon test was performed to evaluate the performance of Nancy score in time to an adverse outcome.
Results
Forty patients were included (56.3% men, median age at diagnosis 47 years 17–66, median follow-up 1389 days 67–9836). 64.6% were classified as proctitis (E1) and 35.4% as left-sided colitis (E2). Histological features found in inflamed rectal mucosa were marked chronic inflammation in 75%, moderate-to-severe basal plasmocytosis in 70.9%, moderate to severe neutrophils invasion in lamina propria in 60.5%, moderate-to-severe mucin depletion in 79.2% and ulcers in 27.1%. During the follow-up, 13/48 cases had an adverse outcome: 7/48 needed steroids, 2/48 were hospitalised, 1/48 had an acute episode of severe UC, 4/48 had proximal endoscopic extension and 9/48 escalated therapy. Moderate to severe histological features were more frequent in patients who were hospitalised (2/2), had disease extension (4/4) and needed steroids (basal plasmocytosis (6/7), neutrophils in lamina propria (5/7) and mucin depletion (6/7). In a composite endpoint no significant association was found with basal plasmocytosis (p = 0.18), mucin depletion (p = 0.17) and neutrophils invasion in lamina propria (p = 0.60). In the subgroup of patient developing an adverse outcome during follow-up, the median time to an adverse event was lower in Nancy scores ≥3 (781 vs. 1567 days, p < 0.001).
Conclusions
In our cohort of newly diagnosed patients severe histological inflammation at the time of diagnosis, as assessed by the Nancy score, was associated with a lower median time to an adverse outcome, suggesting that histological information should also be incorporated to guide prognosis assessment and therapeutic choices.
Abstract
Background
A wide variety of intestinal and non-intestinal diseases can resemble chronic idiopathic inflammatory bowel disease (IBD) clinically and/or pathologically. The aim of the current ...Topical Review was to explore the differential diagnosis of IBD and to discuss clinical, histomorphological features and ancillary techniques that help distinguish between IBD and its mimics.
Methods
An open ECCO call led to the selection of 12 participants who formed three working groups (WG) to study the mimics of IBD. WG 1 comprised gastroenterologists, who explored mainly the clinical features. WG 2 consisted of histopathologists, who focused on macroscopic and microscopic pathological aspects. WG 3 was a mixed group of pathologists and clinicians who studied the value of additional investigative techniques such as imaging, serology and molecular markers. A systematic literature search allowed exploration of these topics and the identification of the most helpful and relevant distinguishing features. The process led to the development of Current Practice Position (CPP) statements and supporting text. Consensus meetings with voting by all participants facilitated modification and finalisation of CPP statements.
Results
The project highlighted several points. Firstly, there is a wide and sometimes overwhelming variety of potential mimics of new and established IBD, both in adults and in children.
Secondly, some mimics are more important clinically and others pathologically, meaning that the emphasis on the mimics of IBD is different for clinicians and pathologists. Thirdly, close attention to all clinical features, pathological findings and other evidence optimises accuracy. Finally, newer techniques sometimes have a role, e.g., in distinguishing monogenic IBD-like disorders from IBD in young children, and the value of many novel techniques is as yet uncertain. A practical message is that constant awareness by clinicians and pathologists of the possibility of mimics is particularly important.
Conclusion
Discussions between pathologists and clinicians were particularly useful during this process and were a reminder of the importance of clinicopathological correlation. There is a wide variety of mimics of IBD, including infections, diverticular disease, drug effect, radiation damage, immune disorders, vascular disorders and diversion proctocolitis. An important, relatively new, and sometimes very close mimic of IBD is immune checkpoint inhibitor colitis. In turn, reliable distinction between IBD and other entities requires a multidisciplinary approach with a full clinical history (including duration of disease), and with appropriate investigations that may include endoscopy, pathology, imaging, microbiological tests, serology, and newer molecular tests.
Simultaneous isolation of nucleic acids and proteins from a single biological sample facilitates meaningful data interpretation and reduces time, cost and sampling errors. This is particularly ...relevant for rare human and animal specimens, often scarce, and/or irreplaceable. TRIzol(®) and TRIzol(®)LS are suitable for simultaneous isolation of RNA, DNA and proteins from the same biological sample. These reagents are widely used for RNA and/or DNA isolation, while reports on their use for protein extraction are limited, attributable to technical difficulties in protein solubilisation.
TRIzol(®)LS was used for RNA isolation from 284 human colon cancer samples, including normal colon mucosa, tubulovillous adenomas, and colon carcinomas with proficient and deficient mismatch repair system. TRIzol(®) was used for RNA isolation from human colon cancer cells, from brains of transgenic Alzheimer's disease mice model, and from cultured mouse cortical neurons. Following RNA extraction, the TRIzol(®)-chloroform fractions from human colon cancer samples and from mouse hippocampus and frontal cortex were stored for 2 years and 3 months, respectively, at -80°C until used for protein isolation.Simple modifications to the TRIzol(®) manufacturer's protocol, including Urea:SDS solubilization and sonication, allowed improved protein recovery yield compared to the TRIzol(®) manufacturer's protocol. Following SDS-PAGE and Ponceau and Coomassie staining, recovered proteins displayed wide molecular weight range and staining pattern comparable to those obtainable with commonly used protein extraction protocols. We also show that nuclear and cytosolic proteins can be easily extracted and detected by immunoblotting, and that posttranslational modifications, such as protein phosphorylation, are detectable in proteins recovered from TRIzol(®)-chloroform fractions stored for up to 2 years at -80°C.
We provide a novel approach to improve protein recovery from samples processed for nucleic acid extraction with TRIzol(®) and TRIzol(®)LS compared to the manufacturer`s protocol, allowing downstream immunoblotting and evaluation of steady-state relative protein expression levels. The method was validated in large sets of samples from multiple sources, including human colon cancer and brains of transgenic Alzheimer's disease mice model, stored in TRIzol(®)-chloroform for up to two years. Collectively, we provide a faster and cheaper alternative to the TRIzol(®) manufacturer`s protein extraction protocol, illustrating the high relevance, and wide applicability, of the present protein isolation method for the immunoblot evaluation of steady-state relative protein expression levels in samples from multiple sources, and following prolonged storage.
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