Pathology of drug-associated gastrointestinal disease

Histology of IBD and related colitides in the elderly

Inflammatory bowel disease (IBD) are chronic relapsing diseases, affecting both children and adults with a life-long duration. An increased co-morbidity gives raise to fragility in the elderly. In this regard it should consider that several non-IBD colitides may mimic both ulcerative colitis and Crohn's disease. Moreover, chronic diseases represent a clinical challenge, mostly about treatment effectiveness. Finally, it is worth noting that patients with long-standing diseases - and elderly patients among them - have an increased malignancy risk when compared to general (non-IBD) population. Our paper aims to review the three main histological topics that play a role in the clinical management of IBD in the elderly, namely differential diagnosis, mucosal healing and IBD-associated dysplasia.

Colopathy Associated with Pentosan Polysulfate Use

Introduction

We describe a novel colopathy associated with pentosan polysulfate (PPS) use and measure the strength of the drug-disease association.

Methods

Two-part investigation. In the cohort study of individuals with a history of prior long-term PPS use, case histories were obtained and gastrointestinal disease course was followed with review of endoscopy records and histopathology specimens. Findings were summarized with descriptive statistics. In the cross-sectional study of individuals with interstitial cystitis, drug exposure and medical histories were obtained for patients seen at a single clinical center. Strength of association between PPS use and diagnoses of inflammatory bowel disease (IBD) and/or irritable bowel syndrome (IBS) was measured with multivariate logistic regression.

Results

In the cohort study of 13 participants, median PPS exposure was 2.04 kg (0.99-2.54). Eleven (84.6%) developed symptoms suggestive of IBD and/or IBS after initiation of PPS therapy. Of the 10 participants whose endoscopic and histopathologic findings we reviewed, six had abnormal-appearing colonic mucosa on endoscopy and all 10 had abnormal mucosal changes on histology. Clinical and histologic improvement was observed after PPS cessation. In the cross-sectional study of 219 subjects with interstitial cystitis, PPS use was a statistically significant predictor of both the IBD [adjusted odds ratio=3.3 (95% confidence interval, 1.2-8.8, p=0.02)] and the composite IBD+IBS [adjusted odds ratio=3.3 (95% confidence interval, 1.5-7.3, p=0.002)] outcomes.

Discussion

We describe a strong association between PPS use and a clinical diagnosis of IBD and/or IBS. Histopathologic findings suggest a novel drug-associated colopathy, with some subjects requiring colectomy for dysplasia.

Gut Barrier Damage and Gut Translocation of Pathogen Molecules in Lupus, an Impact of Innate Immunity (Macrophages and Neutrophils) in Autoimmune Disease

The gut barrier is a single cell layer that separates gut micro-organisms from the host, and gut permeability defects result in the translocation of microbial molecules from the gut into the blood. Despite the silent clinical manifestation, gut translocation of microbial molecules can induce systemic inflammation that might be an endogenous exacerbating factor of systemic lupus erythematosus. In contrast, circulatory immune-complex deposition and the effect of medications on the gut, an organ with an extremely large surface area, of patients with active lupus might cause gut translocation of microbial molecules, which worsens lupus severity. Likewise, the imbalance of gut microbiota may initiate lupus and/or interfere with gut integrity which results in microbial translocation and lupus exacerbation. Moreover, immune hyper-responsiveness of innate immune cells (macrophages and neutrophils) is demonstrated in a lupus model from the loss of inhibitory Fc gamma receptor IIb (FcgRIIb), which induces prominent responses through the cross-link between activating-FcgRs and innate immune receptors. The immune hyper-responsiveness can cause cell death, especially apoptosis and neutrophil extracellular traps (NETosis), which possibly exacerbates lupus, partly through the enhanced exposure of the self-antigens. Leaky gut monitoring and treatments (such as probiotics) might be beneficial in lupus. Here, we discuss the current information on leaky gut in lupus.

Hematochezia Due to Panitumumab-induced Colitis with Vitamin K Deficiency

Panitumumab, a fully human anti-epidermal growth factor receptor (EGFR) monoclonal antibody, has been shown to be useful in treating either advanced or recurrent KRAS/NRAS/BRAF wild-type colorectal cancer. We herein report the case of a 60-year-old man with short bowel syndrome who developed hematochezia due to panitumumab-induced colitis with vitamin K deficiency during third-line chemotherapy. The cause of vitamin K deficiency was the lack of intravenous vitamin K supplementation following a change from central venous nutrition to peripheral venous nutrition. We advise clinicians to carefully check for colitis and manage the infusions of chemotherapy patients with short bowel syndrome.

ECCO Topical Review on Clinicopathological Spectrum and Differential Diagnosis of Inflammatory Bowel Disease

INTRODUCTION

Many diseases can imitate inflammatory bowel disease [IBD] clinically and pathologically. This review outlines the differential diagnosis of IBD and discusses morphological pointers and ancillary techniques that assist with the distinction between IBD and its mimics.

METHODS

European Crohn's and Colitis Organisation [ECCO] Topical Reviews are the result of an expert consensus. For this review, ECCO announced an open call to its members and formed three working groups [WGs] to study clinical aspects, pathological considerations, and the value of ancillary techniques. All WGs performed a systematic literature search.

RESULTS

Each WG produced a draft text and drew up provisional Current Practice Position [CPP] statements that highlighted the most important conclusions. Discussions and a preliminary voting round took place, with subsequent revision of CPP statements and text and a further meeting to agree on final statements.

CONCLUSIONS

Clinicians and pathologists encounter a wide variety of mimics of IBD, including infection, drug-induced disease, vascular disorders, diverticular disease, diversion proctocolitis, radiation damage, and immune disorders. Reliable distinction requires a multidisciplinary approach.

Pathologist's approach to paediatric and neonatal eosinophilic gastrointestinal disorders

Children are not simply miniature adults. The evaluation of their gastrointestinal disorders is therefore different from that in full-grown adults and requires a particular clinical/pathologic approach.

Different studies have tried to assess the normal eosinophil distribution in the gastrointestinal tract in adults while very few studies have investigated the paediatric population, consequently complicating the pathologist’s ability in identifying an abnormal number of eosinophils in this setting of patients.

When evaluating gastrointestinal tract biopsies with eosinophilia, eosinophilic count must be considered along with other histological features like eosinophil distribution in the gastrointestinal wall, their degranulation, cryptitis and crypt abscesses, other accompanying inflammatory cells, apoptotic bodies, foreign material or microorganisms; these findings, although rarely specific, may be a useful aid for diagnosis.

Reports should not include a diagnosis of primary eosinophilic gastrointestinal disorders (EoGID) if clinical data and test results do not rule out other forms of gastrointestinal eosinophilia. A more descriptive definition like “with eosinophilic pattern” should be favoured over a specific diagnosis of “eosinophilic disorder” in order to avoid potential confusion between different entities.

Differential diagnosis and management of immune checkpoint inhibitor-induced colitis: A comprehensive review

Immune checkpoint inhibitors (ICIs) are a new class of cancer pharmacotherapy consisting of antibodies that block inhibitory immune regulators such as cytotoxic T lymphocyte antigen 4, programmed cell death 1 and programmed death-ligand 1. Checkpoint blockade by ICIs reactivates a tumor-specific T cell response. Immune-related adverse events can occur in various organs including skin, liver, and gastrointestinal tract. Mild to severe colitis is the most common side effect with some experiencing rapid progression to more serious complications including bowel perforation and even death. Prompt diagnosis and management of ICI-induced colitis is crucial for optimal outcome. Unfortunately, its clinical, endoscopic and histopathologic presentations are non-specific and overlap with those of colitis caused by other etiologies, such as infection, medication, graft-versus-host disease and inflammatory bowel disease. Thus, a definitive diagnosis can only be rendered after these other possible etiologies are excluded. Sometimes an extensive clinical, laboratory and radiologic workup is required, making it challenging to arrive at a prompt diagnosis. Most patients experience full resolution of symptoms with corticosteroids and/or infliximab. For ICI-induced colitis that is treatment-refractory, small scale studies offer alternative strategies, such as vedolizumab and fecal microbiota transplantation. In this review, we focus on the clinical features, differential diagnosis, and management of ICI-induced colitis with special attention to emerging treatment options for treatment-refractory ICI-induced colitis.

Next-Generation Intestinal Toxicity Model of Human Embryonic Stem Cell-Derived Enterocyte-Like Cells

The gastrointestinal tract is the most common exposure route of xenobiotics, and intestinal toxicity can result in systemic toxicity in most cases. It is important to develop intestinal toxicity assays mimicking the human system; thus, stem cells are rapidly being developed as new paradigms of toxicity assessment. In this study, we established human embryonic stem cell (hESC)-derived enterocyte-like cells (ELCs) and compared them to existing in vivo and in vitro models. We found that hESC-ELCs and the in vivo model showed transcriptomically similar expression patterns of a total of 10,020 genes than the commercialized cell lines. Besides, we treated the hESC-ELCs, in vivo rats, Caco-2 cells, and Hutu-80 cells with quarter log units of lethal dose 50 or lethal concentration 50 of eight drugs—chloramphenicol, cycloheximide, cytarabine, diclofenac, fluorouracil, indomethacin, methotrexate, and oxytetracycline—and then subsequently analyzed the biomolecular markers and morphological changes. While the four models showed similar tendencies in general toxicological reaction, hESC-ELCs showed a stronger correlation with the in vivo model than the immortalized cell lines. These results indicate that hESC-ELCs can serve as a next-generation intestinal toxicity model.

Histopathology of non-IBD colitis practical recommendations from pathologists of IG-IBD Group

Pathologists are often called upon to diagnose colitides that differ from the two main forms of inflammatory bowel disease (IBD). These non-IBD colitides include infectious colitis, microscopic colitis, ischemic colitis, eosinophilic colitis, autoimmune enterocolitis, segmental colitis associated with diverticulosis, drug-induced colitis, radiation colitis and diversion colitis. The diagnosis of these different disease entities relies on the histopathological examination of endoscopic biopsies of the gastrointestinal tract. This paper reviews the main histomorphological characteristics of the various Non-IBD colitides.

Histopathological Mimics of Inflammatory Bowel Disease

This review article discusses the challenges of making a firm histopathological diagnosis of inflammatory bowel disease (IBD) on biopsy and resection material and the importance of its distinction from a range of other inflammatory and infective conditions that may closely mimic IBD. In many cases, the diagnosis of ulcerative colitis or Crohn's disease is straightforward, especially when patients have a typical presentation and characteristic histopathological features. Knowledge of the full clinical history is very important, particularly past and recent medical history, drug history, foreign travel, or known contact with individuals with specific infection. Discussion of all cases of suspected IBD within a multidisciplinary team meeting is required to ensure that clinical, radiological, and pathological features can be correlated. Mimics of IBD can be divided into 4 categories: 1) those due to specific infection, 2) those due to a specific localized inflammatory process, 3) those due to iatrogenic causes, and 4) other rarer causes. Accurate diagnosis of IBD and exclusion of these mimics are crucial for patient management. Once a diagnosis of IBD has been proffered by a pathologist, it is very difficult to "undiagnose" the condition when an alternative diagnosis or "mimic" has been subsequently identified. The histological diagnosis of each of these IBD mimics is discussed in detail, with guidance on how to avoid the pitfall of missing these sometimes very subtle and "difficult to diagnose" conditions.

Deep learning algorithms for automated detection of Crohn's disease ulcers by video capsule endoscopy

BACKGROUND AND AIMS

The aim of our study was to develop and evaluate a deep learning algorithm for the automated detection of small-bowel ulcers in Crohn's disease (CD) on capsule endoscopy (CE) images of individual patients.

METHODS

We retrospectively collected CE images of known CD patients and control subjects. Each image was labeled by an expert gastroenterologist as either normal mucosa or containing mucosal ulcers. A convolutional neural network was trained to classify images into either normal mucosa or mucosal ulcers. First, we trained the network on 5-fold randomly split images (each fold with 80% training images and 20% images testing). We then conducted 10 experiments in which images from n - 1 patients were used to train a network and images from a different individual patient were used to test the network. Results of the networks were compared for randomly split images and for individual patients. Area under the curves (AUCs) and accuracies were computed for each individual network.

RESULTS

Overall, our dataset included 17,640 CE images from 49 patients: 7391 images with mucosal ulcers and 10,249 images of normal mucosa. For randomly split images results were excellent, with AUCs of .99 and accuracies ranging from 95.4% to 96.7%. For individual patient-level experiments, the AUCs were also excellent (.94-.99).

CONCLUSIONS

Deep learning technology provides accurate and fast automated detection of mucosal ulcers on CE images. Individual patient-level analysis provided high and consistent diagnostic accuracy with shortened reading time; in the future, deep learning algorithms may augment and facilitate CE reading.

Histopathologic Patterns of Colitis in Patients With Impaired Renal Function

OBJECTIVES

To characterize the histopathologic features of colitis in patients with impaired renal function.

METHODS

We retrospectively identified 413 patients who underwent colonoscopic evaluation for colitis between 2011 and 2015. Patients were divided into four groups based on estimated glomerular filtrate rates. Patients with impaired renal function were compared to overall and age-matched patients with normal renal function.

RESULTS

Compared to a preponderance of inflammatory bowel disease (33%) and lymphocytic colitis (9.6%) in patients with normal renal function, ischemic colitis (58%) was the predominant histopathologic pattern in the patients with impaired renal function. Infectious colitis was the second most common pattern (20.8%), with Clostridium difficile and cytomegalovirus infections being more frequent. Medication-induced injury was the third most common pattern, with crystal-associated injury being the exclusive pattern found in this study.

CONCLUSIONS

Colitis in patients with impaired renal function is etiologically distinct from that seen in patients with normal renal function.

GLM, a novel luteolin derivative, attenuates inflammatory responses in dendritic cells: Therapeutic potential against ulcerative colitis

GLM, a luteolin derivative, shows anti-melanogenic effect via regulation of various signal molecules; however, it is unclear whether it also exerts anti-inflammatory effect. This study investigated the mechanisms of the anti-inflammatory effect of GLM on activated dendritic cells (DCs) to elucidate its therapeutic potential for ulcerative colitis. The anti-inflammatory effect of GLM was firstly investigated based on its effect on DCs maturation and T cells proliferation/activation. GLM treatment downregulated pro-inflammatory cytokine productions, surface molecule expression, and antigen-presenting ability for MHC-II complex in LPS-activated DCs. Importantly, anti-inflammatory effect induced by GLM treatment were independent of MAPK/NF-κB signaling pathways. Furthermore, DCs that were co-treated with LPS and GLM impaired the proliferation and activation of naïve CD4⁺ T cells. Interestingly, GLM exerted in vivo protective effect in DSS-induced colitis models by decreasing Th1, Th2, and Th17 cells and myeloperoxidase (MPO) levels, as well as restoring body weight, disease activity, and DSS-induced pathology. Based on these results, GLM was shown to be a potential candidate treatment for ulcerative colitis.

Phenotype of histologically suspected drug-induced colitis; results of a comparative, retrospective cohort study

Background/aims: Drug-induced colitis (DiC) is a rarely reported form of colonopathy and data about the clinical and endoscopic characteristics are scarce. The aim was to investigate the phenotype of DiC. Methods: Patients in a retrospective case control study were assigned to either DiC or one of two age- and gender-matched control groups (non-inflammatory controls and inflammatory colitis from other causes) based on histopathological findings. Patients' basic characteristics, symptoms, biochemical results and endoscopic appearance were collected. Statistical analysis included ANOVA, the chi-squared test and two-tailed t-test. Results: A total of 211 patients with DiC were included (97 males, age 62.1 ± 16.1 years, BMI 25.9 ± 6.1 kg m^-2). In comparison to both control groups, DiC patients presented higher ASA and ECOG-scores and more particularly atherosclerotic comorbidities. The most abundant symptoms were abdominal pain (51.8%), diarrhoea (50.7%) and haematochezia (24.3%). The red blood cell count demarcated anaemia (12.7 ± 2.3 mg/dl) and C-reactive protein was slightly elevated (2.7 ± 5.2 mg/dl). The endoscopic features included erythema (46.9%), oedema (29.9%), erosions (29.9%) and ulcers (14.7%). The inflammation affected the rectum rarely (2.4%) but affected the rest of the colon without predilection in a segmental manner (p<.05). The severity of DiC was mostly mild (85.7%). Conclusions: The phenotype of DiC differs slightly from that of colitis from other causes. Taking the clinical features into account might help to confirm drug-induced aetiology once the pathologist has raised the suspicion.

Triggers of histologically suspected drug-induced colitis

BACKGROUND

Drug toxicity is a common and even serious problem in the gastrointestinal tract that is thought to be caused by a broad spectrum of agents. Although withdrawal of the causative agent would cure the disease knowledge is scarce and mostly derives from case reports and series.

AIM

To investigate potential triggers of drug-induced colitis (DiC).

METHODS

We conducted a retrospective, observational case control study. Patients were assigned to DiC or one of two age- and gender-matched control groups (non-inflammatory controls and inflammatory colitis of another cause) based on histopathological findings. Histopathology was reassessed in a subset of patients (28 DiC with atherosclerosis, DiC without atherosclerosis and ischaemic colitis each) for validation purposes. Medical history was collected from the electronic database and patient records. Statistical analysis included chi-squared test, t-test, logistic and multivariate regression models.

RESULTS

Drug-induced colitis was detected in 211 endoscopically sampled biopsy specimens of the colon mucosa (7% of all screened colonoscopic biopsy samples); a total of 633 patients were included equally matched throughout the three groups (291 males, mean age: 62.1 ± 16.1 years). In the univariate analysis, DiC was associated with diuretics, dihydropyridines, glycosides, ASS, platelet aggregation inhibitors, nonsteroidal anti-inflammatory drugs (NSAIDs), statins and fibrates, and with atherosclerosis, particularly coronary heart disease, and hyperlipoproteinaemia. Echocardiographic parameters did not show substantial differences. In the multivariate analysis only fibrates [odds ratio (OR) = 9.1], NSAIDs (OR = 6.7) and atherosclerosis (OR = 2.1) proved to be associated with DiC. Both DiC reassessment groups presented milder inflammation than ischaemic colitis. The DiC patients with atherosclerosis exhibited histological features from both DiC without atherosclerosis and ischaemic colitis.

CONCLUSION

Several drugs indicated for the treatment of cardiovascular and related diseases are associated with DiC. Atherosclerosis and microcirculatory disturbances seem to play an important pathogenetic role.

Review article: the pharmacological causes of colon ischaemia

BACKGROUND

Colon ischaemia is the most common ischaemic disorder of the gastrointestinal system, can affect any segment of the colon, and may present with a range of symptoms. Diagnosis can be challenging due to symptom overlap with other conditions, varied aetiology, and often rapid and self-resolving course.

AIM

To review comprehensively the literature regarding the pharmacological aetiologies of colonic ischaemia to enhance the understanding of the various mechanisms of disease, presentations, distribution, and outcomes.

METHODS

A PubMed search for "colon ischaemia" and "ischaemic colitis" alone as well as in combination with various known pharmacologic causes was performed. Only the highest quality and relevant literature was included in this review. The quality of the literature for each association was rated by the authors and a consensus was made when discrepancies were encountered. Only associations that were deemed "moderate" or "strong" were included.

RESULTS

The literature considering pharmacologically associated colonic ischaemia is diverse, lacks codification and is characterised by numerous case reports and case series. Constipation-inducing drugs, digoxin, hormonal therapies, illicit drugs, immunomodulators, laxatives, and NSAIDs were strongly associated with colonic ischaemia. Antimicrobials, appetite suppressants, chemotherapies, decongestants, diuretics, ergot alkaloids, serotonin agents, statins, and vasopressor agents were moderately associated.

CONCLUSIONS

Patients presenting with abdominal pain, diarrhoea, or bloody stool need to be evaluated for the possibility of this condition and treated accordingly. Timely diagnosis is necessary to improve patient outcomes. This review aims to increase awareness among clinicians regarding the presentation of pharmacologically induced colonic ischaemia.

Causality and preventability assessment of adverse drug reactions and adverse drug events of antibiotics among hospitalized patients: A multicenter, cross-sectional study in Lahore, Pakistan

Background and objectives

Adverse drug events (ADEs) are the fifth leading cause of death and thus responsible for a large number of hospital admissions in all over the globe. This study was aimed to assess the antibiotics associated preventability of ADEs and causality of adverse drug reactions (ADRs) among hospitalized patients.

Methods

A prospective, cross-sectional, observational study was conducted in four tertiary care public sector hospitals of Lahore, Pakistan. Study population consisted of hospitalized patients who were prescribed with one or more antibiotics. Data were collected between 1^st January, 2017 and 31^st June, 2017 from 1,249 patients (384 patients aged ≤ 18 years and 865 patients aged >18 years). Schumock and Thornton scale was used to assess the preventability of the ADEs. Medication errors (MEs) that caused preventable ADEs were assessed by MEs tracking form while Naranjo score was used to evaluate the causal relation of ADRs with the antibiotics. Statistical Package for the Social Sciences (IBM SPSS Statistics for Windows, Version 21.0. Armonk, NY: IBM Corp.) and Microsoft Excel (MS Office, 2010) were used for data analysis.

Results

2,686 antibiotics were prescribed to 1,249 patients. Among them, fluoroquinolones (11.8%), macrolides (11.6%) and cephalosporins (10.9%) were the most frequently prescribed antibiotics. The most affected organ system by antibiotics associated ADEs was gastrointestinal tract. A total of 486 ADEs were found. The preventability assessment revealed that most of the ADEs (58.4%) were preventable (43.6% of the ADEs were definitely preventable while 14.8% were probably preventable) and caused by MEs including wrong drug (40.1%) and monitoring errors (25.0%), during the stage of physician ordering (22.2%) and patient monitoring (21.1%). The errors were caused due to non-adherence of policies (38.4%) and lack of information about antibiotics (32%). Most of the non-preventable ADEs or ADRs among adults and children were “probable” (35.5%) and “possible” (35.8%), respectively. Logistic regression analysis revealed that ADEs were significantly less among females (OR = 0.047, 95%CI = 0.018–0.121, p-value = <0.001), patients aged 18–52 years (OR = 0.041, 95%CI = 0.013–0.130, p-value = <0.001), tuberculosis patients (OR = 0.304, 95%CI = 0.186–0.497, p-value = <0.001), patients with acute respiratory tract infections (OR = 0.004, 95%CI = 0.01−0.019, p-value = <0.001) and among the patients prescribed with 2 antibiotics per prescription (OR = 0.455, 95%CI = 0.319–0.650, p-value = <0.001).

Conclusion

According to preventability assessment most of the ADEs were definitely preventable and caused by MEs due to non-adherence of policies and lack of information about antibiotics. The causality assessment of non-preventable ADEs showed that most of the ADRs were probable and possible.

Drug-induced enterocolitis: Prevention and management in primary care

Drug-induced enterocolitis is a condition diagnosed with increasing frequency. It includes a variety of morphological and functional alterations of the small and large intestine as a consequence of exposure to pharmacological active compounds. A number of factors play a key role in this condition or participate in the onset of enterocolitis, which is the result of an interplay between the effect of the drug molecule and the tolerance of the bowel to damaging insults. The patient's age, gender, dose of drug, time of exposure, pharmaceutical preparation, drug-drug and drug-food interactions, gut barrier integrity, underlying intestinal conditions, and gut microbiota composition are all involved in the occurrence and extent of the injury. This review approaches the topic from the viewpoint of primary care, and focuses on epidemiology, mechanisms of damage, protective systems and diagnostic tools. Although the first-line therapeutic measure is the discontinuation of the drug, some options for prevention and treatment are discussed.

In Vitro Intestinal and Liver Models for Toxicity Testing

The human body is exposed to hundreds of chemicals every day. Many of these toxicants have unknown effects on the body that can be deleterious. Furthermore, chemicals can have a synergistic effect, resulting in toxic responses of cocktails at relatively low individual exposure levels. The gastrointestinal (GI) tract and the liver are the first organs to be exposed to ingested pharmaceuticals and environmental chemicals. As a result, these organs often experience extensive damage from xenobiotics and their metabolites. In vitro models offer a promising method for testing toxic effects. Many advanced in vitro models have been developed for GI and liver toxicity. These models strive to recapitulate the in vivo organ architecture to more accurately model chemical toxicity. In this review, we discuss many of these advances, in addition to recent efforts to integrate the GI and the liver in vitro for a more holistic toxicity model.

Outcome of emergency surgery for severe neuroleptic-induced colitis: results of a prospective cohort

AIM

The study evaluated the outcome of severe acute antipsychotic (neuroleptic) drug related colitis requiring emergency surgery.

METHOD

From 2009 to 2014, 20 patients underwent emergency surgery for acute and severe neuroleptic-related ischaemic colitis. Neuroleptic-induced colitis was defined as another cause besides inflammatory, infectious or ischaemic colitis with a relationship to treatment by antipsychotic drugs.

RESULTS

The main drugs involved were cyamemazine (n = 9, 45%), loxapine (n = 5, 25%), haloperidol (n = 4, 20%) and alimemazine (n = 4, 20%). Most (n = 14, 70%) patients presented with haemodynamic instability requiring massive resuscitation and vasopressive drugs. CT signs of digestive impairment were found in 13 (65%) patients having emergency surgery. The lesions were pancolonic in 40%; transparietal necrosis was found in 45% and 15% had colonic perforation. Twelve (60%) patients had total or subtotal colectomy and eight (40%) a segmental colectomy with colostomy or ileostomy in all cases. The postoperative mortality was 15% and morbidity was 70%, necessitating surgical reintervention in two (10%) patients. Of the 17 surviving patients, 11 (64.7%) had restoration of intestinal continuity after a median delay of 103 days, with a postoperative morbidity rate of 36.3%. In the intent-to-treat population, the permanent stoma rate was 30%.

CONCLUSION

The morbidity and mortality of surgery for neuroleptic-drug-induced colitis is higher than for colitis due to other causes. A better knowledge of this condition should lead to early diagnosis.

The First Endoscopy in Suspected Inflammatory Bowel Disease

In a patient presenting with suspected inflammatory bowel disease, the initial endoscopic evaluation is a valuable tool for determining the correct disease diagnosis and the extent and severity of disease. A full colonoscopy and ileoscopy should be performed when possible, with systematic biopsies from each segment. When a diagnosis of inflammatory bowel disease is established, it is possible to distinguish between Crohn disease and ulcerative colitis, and specific endoscopic features may assist in this categorization. Because patchy healing can occur with treatment, it is important to obtain a thorough and accurate assessment of disease characteristics and distribution before initiating therapy.

Iatrogenic pathology of the intestines

Many drugs and chemical agents can cause enteritis and colitis, producing clinical gastrointestinal side effects, the most common of which are diarrhoea, constipation, nausea and vomiting. Significant histological overlap exists between some patterns of medication or chemical injury and various disease entities. A particular medication may cause multiple patterns of injury and may mimic common entities such as coeliac disease, Crohn's disease, infectious enteritis and colitis. Thus, given the common absence of specific histopathological features, the diagnosis often relies upon thorough clinicopathological correlation. This review concentrates on selected examples of medication-induced injury of the intestinal tract in which the pathology can be recognized, particularly on biopsies, with a focus on newly described medication-induced gastrointestinal effects.

Histological spectrum of mycophenolate mofetil-related colitis: association with apoptosis

AIMS

The main purpose of this study was to define diagnostic histological characteristics of mycophenolate mofetil (MMF)-related colitis in association with crypt epithelial cell turnover.

METHODS AND RESULTS

The examined material included 43 colonic biopsies from renal transplant recipients with MMF administration and persistent diarrhoea. Thirty-three cases showed MMF-related colitis, while 10 showed no significant changes. The histological findings were scored and correlated with the apoptotic index (AI) and with the proliferation rate (PR) of the crypt epithelium examined by TUNEL assay and Ki-67 immunoexpression. Ten cases of Crohn disease and 10 of ulcerative colitis were used as comparative groups. Crypt distortion and loss as well as increased apoptosis constituted the main features, their degree and combination leading either to an inflammatory bowel disease (IBD)-like (82%) or to a graft-versus-host disease-like pattern (18%). A high AI was associated more frequently with moderate and severe crypt distortion, while the values were significantly higher compared with the control groups (P < 0.01). High PR was noted in 18 of 29 (62.1%) of the cases.

CONCLUSIONS

The diagnostic hallmark of MMF-related colitis is an IBD-like histological pattern in association with increased epithelial apoptosis, while apoptotic cell death seems to be a potential pathogenetic factor of mucosa injury.

Histopathological Changes in the Gastrointestinal Tract Due to Drugs

Abnormalities of the gastrointestinal (GI) tract due to drugs (AGIDs) are numerous and have significant impact. The aim of this narrative review is to help the practicing surgical pathologist recognize selected AGIDs. The adverse drug effects presented were chosen with an emphasis on recent and significant pathological and clinical contributions. The selection was based on a thorough review of the PUBMED-based literature and on the authors’ opinions and experience. In the first part of the review, diagnostic abnormalities due to crystals (eg, iron, biphosphonates, nonsystemic drugs), mitosis arresting drugs (colchicine, taxanes), and biological agents, especially ipilimumab, are discussed. Some AGIDs’ histopathologic features can be easily recognized. It is however the clinical correlation that in many cases of AGIDs will provide the necessary support for a drug effect diagnosis. The identification of AGIDs requires heightened awareness of the medical team in which close collaboration of pathologists and clinicians cannot be overemphasized.

Drug-induced, factitious, & idiopathic diarrhoea

The aetiology of diarrhoea can often be simple to identify, but in some cases may pose a challenge. The diagnosis of drug-induced diarrhoea can easily be sorted based on timing of the symptom with onset of a new drug. Treatment can vary from simply monitoring and eventual resolution with continuation of the drug, to discontinuation of the offending agent. In cases where a drug cannot always be stopped, additional medications can help control the symptom. Factitious diarrhoea can present a diagnostic challenge if the evaluating physician does not suspect its possibility. Typically a careful history, and in some cases, stool testing can provide clues. The diagnosis of idiopathic diarrhoea is often made when exhaustive testing provides no definite aetiology and the goal of management is supportive care and symptomatic treatment.

Histopathologic diagnosis of eosinophilic conditions in the gastrointestinal tract

Eosinophils, a constitutive component of the columnar-lined gastrointestinal tract, play an essential role in allergic responses and parasitic infections. The tissue density of these cells also increases in a variety of conditions of uncertain etiology. With the exception of the esophageal squamous epithelium, in which no eosinophils are normally present, the population of normal eosinophils in the remainder of the luminal gut is poorly defined. Therefore, histopathologists must rely on their subjective judgment to determine when a diagnosis of eosinophilic gastritis, enteritis, or colitis should be rendered. Eosinophilic esophagitis is currently the best defined and most studied eosinophilic condition of the digestive tract; therefore, the confidence in accurate diagnosis is increasing. In contrast, the characteristic clinicopathologic features of eosinophilic conditions affecting other parts of the digestive tract remain somewhat elusive. This review was designed to present pathologists with simple and practical information for the biopsy-based histopathologic diagnosis of eosinophilic esophagitis, gastritis, enteritis, and colitis. It was prepared by critically reviewing more than 200 articles on the topic, along with incorporating evidence accumulated through our own collective experience. We anticipate that by increasing pathologists' confidence in reporting these abnormal but often nameless eosinophilic infiltrates, we can help better define and characterize their significance.

The spectrum of drug-related colitides: important entities, though frequently overlooked

BACKGROUND

There is at present a relative lack of knowledge concerning drug-related colitides, although these may be not infrequent entities in clinical practice.

AIMS

To assess the frequency and the clinical-pathological subtypes of drug-related colitides in a gastrointestinal pathology referral centre.

METHODS

All charts of endoscopic biopsy samples referred for colitis in a eight-year period were reviewed. To be classified as drug related colitis, patients' charts should report the use of any drug in a two month period before colonoscopy and no other obvious cases of colitis be present. For analysis, we considered only patients taking one drug in this period.

RESULTS

We found 122 cases of drug-related colitis out of 3877 charts reviewed (3% of the overall colitis group). These cases were represented by microscopic colitis (50%), eosinophil rich infiltrate of the left colon (34%), ischemic colitis (11%), pseudomembranous colitis (3%), apoptotic colopathy (2%). The drugs most frequently associated with these colitides were represented by non-steroidal anti-inflammatory drugs.

CONCLUSION

It is important to raise awareness concerning drug-related colitides, to avoid diagnostic errors and provide a better therapeutic approach to patients with these conditions.

Undisclosed use of nonsteroidal anti-inflammatory drugs may underlie small-bowel injury observed by capsule endoscopy

BACKGROUND & AIMS

Findings from capsule endoscopies (CEs) of patients with enteropathy from nonsteroidal anti-inflammatory drugs (NSAIDs) may be indistinguishable from those with Crohn's disease, making medication history crucial to image interpretation. Undeclared NSAID use has been proposed to cause unexplained peptic ulcers; we investigated whether it is also an issue among patients referred for small-bowel CE.

METHODS

We collected demographic data, indications for CE, and medication history prospectively. A salicylate spot test and gas chromatography-mass spectrometry were performed for NSAID metabolites in urine samples of patients undergoing routine CE. Videos were analyzed by a gastroenterologist who was blinded to the urinalysis results.

RESULTS

Seventy-six patients (52 women; mean age, 50 y) underwent CE for suspected small-bowel pathology. Urinalysis was positive in 13.6% of patients (salicylates, n = 3; ibuprofen, n = 6; and ibuprofen and diclofenac, n = 1) although only 1 of these patients declared use of an NSAID (aspirin). Although 2 patients had normal CE results, 80% had positive results, including the presence of erosions (n = 5), ulceration (n = 2), and ulcers with early stricturing (n = 1, diagnosed with Crohn's disease). A patient with small-bowel ulceration underwent surgery and was found to have NSAID-associated enteropathy, based on histologic analysis.

CONCLUSIONS

Of patients who undergo CE, 13.6% took NSAIDs or aspirin, but most did not declare using these medications. Small-bowel inflammation was common in this cohort and could be mistaken for Crohn's disease. Patients should be questioned about use of over-the-counter medications, and routine urinalysis for NSAID metabolites may be helpful before interpretation of CE findings.

Drug-induced Injury of the Gastrointestinal Tract

The effects of drugs on the gastrointestinal tract are diverse and depend on numerous factors. Diagnosis is centered on histologic findings, with mostly nonspecific patterns of injury that must be interpreted in the correct clinical context. Nonsteroidal antiinflammatory drugs are a common cause of drug-induced gastrointestinal injury, with effects primarily in the gastric mucosa but also throughout the gastrointestinal tract. Another common class of drugs causing a variety of pathologic findings in the gut is chemotherapeutic agents. This article discusses the differential diagnosis of the various patterns of injury, including ischemic damage, and the histologic findings specific for certain drugs.

Dyspepsia as an adverse effect of drugs

Drugs are frequently implicated as a possible cause in new onset dyspeptic symptoms and few drugs are free of this suspicion. Nausea, anorexia, abdominal pain and dyspepsia make up between one-tenth and one-third of reported adverse reactions but they are all so common, both in the background population and among patients, that they are frequently attributed to an illness rather than to medications. No symptom or clinical sign is pathognomonic for adverse drug effects, maybe with the exception of vomiting. Dyspepsia is a common reporting in placebo-arms of treatment trials. Owing to the high background incidence of dyspepsia, it is difficult to discern between spontaneous and true drug-related dyspepsia. The mechanisms by which a drug causes dyspepsia are often unknown even though some drugs are known to cause direct mucosal injury. Non-steroidal anti-inflammatory drugs and antibiotics are common causes of drug-related dyspepsia.

Lymphocytic disorders of the gastrointestinal tract: a review for the practicing pathologist

Increased numbers of intraepithelial lymphocytes (lymphocytosis) can be found in the esophagus, stomach, small intestine, and colon in a variety of clinical circumstances. This review, directed at practicing pathologists, portrays the normal resident lymphocyte population in the mucosa of each segment of the digestive tract and discusses the different situations that may result in quantitative or qualitative alterations of intraepithelial lymphocytes. Esophageal lymphocytosis has not been fully characterized and its clinical significance, if any, awaits definition. Thus, this diagnosis is presently discouraged. In the stomach, it is particularly important to exclude Helicobacter pylori infection and celiac sprue before diagnosing lymphocytic gastritis. Duodenal lymphocytic infiltrates, inextricably tied with alterations of the villous architecture of the mucosa, are often caused by gluten sensitivity. However, similar morphologic changes may be caused by a vast array of other conditions that must be carefully considered and excluded. Lymphocytic and collagenous colitis are most often unexplained, but their frequent association with autoimmune conditions or certain medications deserve a thorough investigation in each case. Using a combination of histologic and clinical clues, a cause for the intraepithelial lymphocytic infiltration can be identified in many instances. As some of the associated conditions are amenable to effective treatment, the importance of diligently seeking such associations before resorting to a diagnosis of primary lymphocytosis is emphasized.

Colonic left-side increase of eosinophils: a clue to drug-related colitis in adults

BACKGROUND

The colon shows frequent eosinophilic infiltration in allergic proctocolitis of infants, whereas in adults, eosinophilic infiltration of the colon is less defined and may be found in different conditions including drug-induced colitis, even though the pathological findings are often inconsistent.

AIM

To quantify eosinophils in the mucosa of normal controls and to compare them with those of patients with abdominal symptoms related to 'drug colitis'.

METHODS

Mucosal biopsies were obtained during colonoscopy in 15 controls and in 27 patients with abdominal symptoms, a history of probable 'drug-related colitis' and without obvious causes of eosinophilia.

RESULTS

The drugs related to the patient symptoms were nonsteroidal anti-inflammatory drugs (70%), antiplatelet agents (19%) and oestroprogestinic agents (11%). Colonoscopy was normal in 30% of patients and abnormal in 70%. Histology showed low content of inflammatory cells and normal crypt architecture in-patients with endoscopy similar to inflammatory bowel diseases. The eosinophil score was significantly higher in the left side of the colon in the patient group compared with controls.

CONCLUSIONS

The finding of an increased eosinophil count limited to the left (descending and sigmoid) colon is an important clue towards a diagnosis of drug-related colitis.

The prevalence of diarrhea and its association with drug use in elderly outpatients: a multicenter study

OBJECTIVES

To evaluate the prevalence of diarrhea and its association with drug use in elderly outpatients.

METHODS

The study was carried out by 133 general practitioners (GPs) who referred to 24 geriatric units in Italy. The demographic data, disability, gastrointestinal symptoms, and current medications were evaluated using a structured interview, including the evaluation of the activities of daily living (ADL), the instrumental activities of daily living (IADL), and the gastrointestinal symptoms rating scale (GSRS).

RESULTS

The study included 5,387 elderly subjects who regularly completed the structured interview. In total, 488 patients (9.1% of the whole population, 210 men and 278 women, mean age 75.6 +/- 6.2 yr, range 65-100 yr) reported diarrhea, that is, items 11 and 12 of the GSRS, during the 7-day period before the interview. The prevalence of diarrhea significantly increased with older age (P = 0.025), the severity of ADL (P < 0.0001) and IADL disability (P < 0.0001), and the number of drugs taken (P = 0.0002). A multivariate analysis demonstrated that the presence of diarrhea was significantly associated with the use of antibiotics (odds ratio [OR] 4.58, 95% confidence interval [CI] 1.95-10.73), proton pump inhibitors (OR 2.97, 95% CI 2.03-4.35), allopurinol (OR 2.19, 95% CI 1.26-3.81), psycholeptics (OR 1.82, 95% CI 1.26-2.61), selective serotonin reuptake inhibitors (OR 1.71, 95% CI 1.01-2.89), and angiotensin II receptor blockers (OR 1.46, 95% CI 1.08-1.99), also accounting for sex, age, and the use of antidiarrheal agents and drugs for functional gastrointestinal disorders.

CONCLUSION

Diarrhea is a common problem in elderly outpatients. Its prevalence increases with old age, the severity of disability, and the number of drugs. Monitoring the presence of diarrhea and its complications in elderly patients who need treatments with drugs significantly associated with diarrhea may be clinically useful.

Drug-induced side effects affecting the gastrointestinal tract

With the ever-growing armamentarium of pharmacological agents, the gastrointestinal drug-induced side effects of dyspepsia, nausea, vomiting, diarrhoea and constipation are increasingly seen. They are often self-limiting and without serious sequelae, but of greater concern is drug-induced mucosal ulceration that can manifest as gastrointestinal haemorrhage, stricture and perforation. These complications are mainly attributable to NSAIDs and aspirin, which can injure the mucosa anywhere along the gastrointestinal tract. These iatrogenic serious side effects can be reduced with co-prescription of a proton pump inhibitor, substitution of a COX-2 inhibitor and eradication of Helicobacter pylori when the bacterium is present. Other recognised gastrointestinal complications include small intestinal diaphragm, microscopic colitis, a range of hepatotoxic effects and pancreatitis. The introduction of new classes of drugs has resulted in new adverse effects that require consideration in patients presenting with gastroenterological symptoms. These include pill oesophagitis from bisphosphonates and ischaemic colitis relating to serotonin antagonists. Here, the authors review the literature on drug-induced complications of the gastrointestinal tract and present the pertinent management issues relevant to clinical practice.

Significance of intraepithelial lymphocytes in appendix

The aim of this study was to investigate the importance of the increase in intraepithelial lymphocytes (IELs) in the mucosa of the appendix. One hundred and four retrospective appendectomy specimens were examined to evaluate the IELs. Intraepithelial lymphocytosis was identified in 11.5% (12 cases) of the specimens. Of these 12 cases, 6 cases with intraepithelial lymphocytosis were associated with parasitic infection. No increase in IELs was found in the 36 appendices that were removed in other primary operations. A wide range of immunologic stimuli can raise IELs in the gastrointestinal system. However, in appendectomies with clinical signs of acute appendicitis, an increase in IELs is more likely to be related to parasitic infection. This increase should be considered for the diagnosis of parasitic infections.

Pathological effects of drugs on the gastrointestinal tract: a review

Drug-induced injury of the gastrointestinal (GI) tract is increasingly common but generally under-recognized. Although there is an overwhelming number of drugs that are associated with adverse GI effects, there is a limited number of characteristic injury patterns that should prompt consideration of drug-induced GI pathology. These include the following: erosions, ulcers, and strictures; crystal deposition; parietal cell changes; reactive gastropathy; pseudodysplastic changes; microscopic colitis; infectious or necrotizing enterocolitis; ischemic colitis; focal active colitis; and increased epithelial apoptosis. This article reviews morphological and pathophysiological features of some of the more common and pathologically recognizable drug-related injury patterns and provides a practical guide for the recognition and diagnosis of drug-induced pathology in the upper and lower GI tract.

Differential diagnosis of reactive gastropathy

Reactive or chemical gastropathy is the constellation of endoscopic and histological changes caused by chemical injury to the gastric mucosa. Its diagnosis rests on the histopathological demonstration of nonspecific elementary lesions that may occur simultaneously or separately in different degrees and various proportions. These lesions include foveolar hyperplasia, interfoveolar smooth muscle fibers, erosions, edema, and hyperemia, in the absence of significant inflammation. Their respective occurrence in a set of gastric biopsies can be placed on a spectrum of diagnostic certainty that is never absolute because each of such changes can and does occur in other conditions. Although a correlation between histological evidence of chemical gastropathy and clinical manifestations, particularly risk of bleeding, is yet to be documented, reporting the suspicion of drug-induced gastric damage may help clinicians to identify patients that might benefit from change, reduction, or discontinuation of certain medications.

Histopathological diagnosis of microscopic colitis

A typical symptom of microscopic colitis (MC) is chronic watery diarrhea with normal endoscopic findings and characteristic inflammatory changes in histopathology. Treatment of the disease is mainly empiric. MC has two main subtypes: lymphocytic colitis and collagenous colitis. There are also untypical histopathological forms of MC: MC with giant cells, MC not otherwise specified (NOS) and cryptal lymphocytic coloproctitis. Some other histopathological changes in MC have been observed, especially Paneth cell hyperplasia or epithelial degeneration. Eosinophilic colitis, acute colitis, amyloidosis, ulcerative colitis and Crohn's disease should be taken into consideration in differential diagnosis. The most reliable biopsy material for histopathological examination are samples obtained from transverse colon. Some studies proved that treatment of MC makes it possible to reduce not only clinical, but also histopathological, manifestations.

Double-blind pilot study of mesalamine vs. placebo for treatment of chronic diarrhea and nonspecific colitis in immunocompetent HIV patients

Chronic diarrhea and colitis are common in patients positive for human immunodeficiency virus (HIV) under highly active antiretroviral treatment (HAART). This prospective double-blind study explores the effect of mesalamine vs. placebo in HIV-positive patients. Thirteen HIV-infected patients with noninfectious chronic diarrhea and > 250 CD4+ cells/mm(3) were randomized to mesalamine (2.4 g/day; n = 9) or placebo (n = 4) for 6 weeks. Colonoscopy was performed at baseline and week 6, and biopsies were obtained to calculate the Biopsy Activity Index (BAI). Diarrhea was assessed at baseline and end of treatment using the Disease Activity Index (DAI). Patients and clinicians completed Patient Global Improvement index (PGI) and Clinical Global Improvement index (CGI) at weeks 2 and 6. Comparisons at week 6 were statistically significant between mesalamine and placebo groups for BAI (P = 0.03), DAI (P = 0.007), PGI (P = 0.008), and CGI (P = 0.008). Furthermore, major improvements were documented in the mesalamine group at week 6 compared to baseline for all variables, whereas the placebo group did not have any. Mesalamine was effective for treatment of chronic diarrhea and moderate nonspecific colitis in HIV patients.

Diaphragm disease of the ileum

Diaphragm disease is a condition wherein the bowel lumen is divided into a series of short compartments by circular membranes of mucosa and submucosa, leading to a pinhole lumen and subsequent obstruction. It is a very rare condition commonly attributed to non-steroidal anti-inflammatory drugs (NSAIDs) usage. We present two cases of obstruction secondary to diaphragm disease of the ileum diagnosed on histology of the resected specimen. One patient had no history of chronic NSAID intake.