Angiotensin II receptor blockers and gastrointestinal adverse events of resembling sprue-like enteropathy: a systematic review

Chronic diarrhoea, weight loss and a positive anti-tissue transglutaminase antibody: A case report of olmesartan-induced enteropathy

Olmesartan is an angiotensin II receptor blocker licensed for the treatment of hypertension. It can cause a sprue-like enteropathy (SLE), characterised by chronic diarrhoea, weight loss and villous atrophy. Transiently raised anti-tissue transglutaminase (ATTG) antibody has also been rarely reported in the literature.We describe the case of a woman in her mid-50s, who presented with a history of intermittent loose stools over 1 year, associated with significant weight loss. She had two marginally raised serum ATTG antibody tests during her work-up.After extensive investigations, she was diagnosed with olmesartan-induced enteropathy. On subsequent follow-up, her symptoms had resolved with cessation of her olmesartan therapy.This case adds to existing literature, highlighting the importance of considering olmesartan as a possible differential diagnosis for SLE. It also reports the presence of a raised ATTG antibody which is infrequently reported in this context.

Angiotensin Receptor Blocker-Related Sprue-like Enteropathy: Review of Food and Drug Administration Adverse Event Reporting System

BACKGROUND

Sprue-like enteropathy (SE) related to olmesartan use was first reported in 2012. In 2017, the manufacturer of Benicar paid $300 million for 2300 claims for olmesartan-related SE.

OBJECTIVE

A study in 2019 suggested that SE was related to olmesartan and with the possibility of angiotensin receptor blocker (ARB) class effect. To further characterize this condition, our group examined reports of ARB-related SE to Food and Drug Administration Adverse Event Reporting System (FAERS).

METHODS

All reports of ARB-related SE from January 2017 to December 2021 were downloaded from the FAERS database. Gastrointestinal adverse events including SE were reviewed. Reporter categories included physicians, pharmacists, other health care professionals, consumers, and attorneys.

RESULTS

A total of 106 590 reports of ARB-related adverse effects were analyzed. Sprue-like enteropathy was identified in 4337 cases (4.1% of total reports). Of these, 4240 cases (98.0%) of ARB-related SE were reported in patients using products with olmesartan, and 97 cases of SE were reported for all other ARBs (eprosartan, losartan, telmisartan, irbesartan, valsartan, and candesartan). Reports of olmesartan-related SE increased rapidly in 2017, continued at a high rate in 2018 and 2019, and essentially stopped in 2020 and 2021.

CONCLUSIONS AND RELEVANCE

Reports to FAERS for ARB-related SE are mostly related to olmesartan. There was a steep decline in reports of olmesartan-related SE following the lawsuit with potential of lawyer interference. There are reports of SE related to ARBs other than olmesartan, with increased physician awareness and the potential to discover a class effect with future studies.

An immunochromatographic strip sensor for rapid and sensitive detection of candesartan, olmesartan medoxomil, and irbesartan in herbal beverages

Sartans, as a class of antihypertensive drugs, pose a threat to human health when illegally added to herbal beverages. It is crucial to detect sartans in herbal beverages. We have developed a highly sensitive monoclonal antibody against candesartan (CAN), olmesartan medoxomil (OLM), and irbesartan (IRB), with 50% inhibitory concentrations (IC50) that were obtained via indirect enzyme-linked immunosorbent assay (ic-ELISA) as 0.178 ng mL-1, 0.185 ng mL-1, and 0.262 ng mL-1 against CAN, OLM, and IRB, respectively. Based on this monoclonal antibody, we developed a rapid screening method for CAN, OLM, and IRB in herbal beverage samples using an immunochromatographic assay (ICA) strip. Test for 15 minutes after simple and rapid sample pre-treatment and the results of this method can be obtained through naked eye observation. The detection limits (LODs) of the ICA strip for CAN, OLM, and IRB in herbal beverage samples are lower than 0.15 ng mL-1, and the results of the ICA strip and ic-ELISA are consistent in spiked samples and recovery experiments. Therefore, this method can quickly, efficiently, and reliably achieve high-throughput on-site rapid detection of illegally added CAN, OLM, and IRB in herbal beverages.

Markedly increased duodenal villous surface apoptosis in patients taking pre-exposure prophylaxis (PrEP) against human immunodeficiency virus

AIMS

Pre-exposure prophylaxis (PrEP) consists of combination antiretroviral therapy and is increasingly utilized to prevent human immunodeficiency virus (HIV) in high-risk populations. Two index cases noted during routine care showed markedly increased duodenal villous surface apoptosis in patients on PrEP. We sought to examine the prevalence of this finding and identify any clinicopathologic correlations.

METHODS

Gastrointestinal biopsy specimens from 23 male patients aged 18-40 years taking PrEP and 23 control patients were reviewed. Patients with HIV, inflammatory gastrointestinal diseases, and celiac disease were excluded. Apoptoses were counted on surface epithelium and deep crypts. The highest apoptotic body count per tissue fragment was recorded. Clusters were defined as groups of ≥5 apoptoses. Apoptotic counts between patients taking PrEP and controls were compared using t-tests.

RESULTS

In PrEP patients, the median age was 35 years (range 25-40) and 83% (19/23) were white. The control patients were demographically similar (median age: 32 years [range 23-40]; 70% [16/23] white). Duodenal apoptosis in villous surface epithelium was increased in PrEP patients, with 14/23 (60.9%) patients having ≥10 surface apoptoses compared to 2/23 (8.7%) controls (P = 2.1 × 10-3 ) and 14/23 (61%) having clusters compared to 3/23 (13%) controls (P = 2.0 × 10-3 ). There was no significant association between increased surface apoptosis or clusters and clinical symptoms or duration of PrEP use.

CONCLUSION

Markedly increased villous surface apoptosis, particularly in clusters, is often seen in the duodenum of patients taking PrEP. Although the mechanism and significance are unknown, knowledge of this peculiar finding may prevent unnecessary additional testing.

Capecitabine-induced Gastrointestinal Injury Shows a Graft-Versus-Host Disease (GVHD)-like Pattern

Capecitabine is a commonly used oral chemotherapeutic agent. Gastrointestinal (GI) side effects are clinically well-known, however, the histopathologic changes have not been comprehensively studied. This study describes the largest case series (8 patients) characterizing the histopathology of capecitabine-induced GI injury. All patients were adults (median age: 64.5 y, range: 61 to 76 y) and there was gender parity. Patients were receiving treatment for malignancies of the colorectum (n=5), breast (n=1), pancreas (n=1), and appendix (n=1). All had GI symptoms, including 7 with diarrhea and abdominal pain and 1 with melena. Five of 8 (63%) showed graft-versus-host disease (GVHD)-like histologic changes in small intestinal and/or colonic biopsies characterized by crypt disarray and dropout, crypt atrophy, dilated crypts lined by attenuated epithelium, and increased crypt apoptosis. Neuroendocrine cell aggregates were present in 4 of 5 cases. Four of 5 showed patchy prominence in lamina propria eosinophils. One patient receiving concomitant radiation therapy had a small intestinal biopsy showing regenerative changes. Two patients had histologically unremarkable biopsies. On follow-up, capecitabine was discontinued or dose-reduced in all patients. Three of 5 patients with a GVHD-like pattern had clinical improvement, whereas 2 died shortly after biopsy. One with regenerative changes also had radiation dose reduction and improved clinically. Two with unremarkable biopsies improved symptomatically. In summary, capecitabine-related GI injury shows a GVHD-like pattern. Knowledge of this is important to confirm the diagnosis as patients typically improve with dose reduction or discontinuation of the drug.

A Rare Case of Olmesartan-Associated Enteropathy Successfully Managed With Steroid Taper

Olmesartan is a commonly used antihypertensive medication belonging to the class of angiotensin II receptor blockers. Though generally well-tolerated, olmesartan can rarely cause olmesartan-associated enteropathy (OAE) with non-bloody diarrhea, weight loss, abdominal pain, and vomiting. Patients may develop enteropathy months to years after drug initiation. In severe cases, patients may develop complications that require hospitalization. Diagnosis is often delayed due to unfamiliarity of OAE, nonspecific presenting symptoms, and normal-appearing gross endoscopic findings. Esophagogastroduodenoscopy (EGD) with biopsy is essential to the diagnosis, showing sprue-like enteropathy with intestinal villous atrophy and mucosal inflammation. This report describes a case of a 70-year-old man who presented with three months of profuse watery diarrhea and 40-pound unintentional weight loss. After an extensive workup, including EGD with duodenal biopsies, the patient was diagnosed with OAE. The biopsies showed findings consistent with acute and chronic duodenitis, mucosal desquamation and ulceration, blunting of villi, and a sprue-like pattern with neutrophils. Celiac serologies and anti-enterocyte antibodies were negative, further supporting the diagnosis of OAE. Complete resolution of symptoms was achieved by discontinuing olmesartan and administering a steroid taper. Considering the frequent use of olmesartan, the increasing occurrence of OAE, and the wide range of associated symptoms, it is crucial for providers to recognize OAE and consider early discontinuation of olmesartan. This approach can help prevent further intestinal damage, protracted symptoms, unnecessary diagnostic tests, and financial burdens on both patients and the healthcare system.

Candesartan-Induced Enteropathy That Mimics Celiac Disease in a 90-Year-Old Patient

Sprue-like enteropathy (SLE) is a clinical syndrome similar to celiac disease and has been associated with the use of various angiotensin receptor blockers (ARBs), a class of medications frequently used in the management of hypertension. Currently, there has only been one documented case report which has observed this occurrence with the use of the ARB candesartan. A 90-year-old female patient presented with chronic diarrhea and weight loss of unclear etiology. Diagnostic esophagogastroduodenoscopy and ileocolonoscopy were macroscopically unremarkable, but histological samples revealed complete villous atrophy, chronic mucosal inflammation, and intraepithelial T-lymphocytic infiltration. However, serological studies could not confirm celiac disease as a cause for the patient’s symptoms of malabsorption. After exclusion of other intestinal inflammation etiologies with noted ongoing candesartan use, the diagnosis of SLE was made, and candesartan therapy was discontinued. Additionally, we decided to initiate a lactose-free diet. Clinical remission was achieved without any recurrences. Candesartan is a commonly prescribed therapeutic agent in the treatment of hypertension. Our case underlines the importance of considering it as a potential cause for unexplained symptoms of malabsorption.

Olmesartan-Induced Ischemic Enteritis Complicated With Bowel Perforation: A Case Report and Literature Review

Olmesartan is a relatively new angiotensin receptor blocker used widely to control hypertension. Cases have been reported previously of enteropathy induced by olmesartan. Here, the authors report a case of olmesartan-induced ischemic enteritis complicated by bowel perforation. A 52-year-old male patient, during the treatment with olmesartan, developed severe abdominal pain of five-day duration. He underwent exploratory laparotomy for bowel perforation and surgical resection of the ischemic bowel segment. On a two-month follow-up after the discontinuation of olmesartan and the emergency surgery, the patient was symptom-free and functioning well. This rare report focuses on ischemic enteritis associated with olmesartan, describes the symptoms, and records the progression of this side effect and the corresponding treatment. Our case aims to raise awareness amongst physicians about the possibility of this severe complication and to point out that more research is still needed on its pathophysiology to better understand this drug.

Assessment of risk factors and establishment of a nomogram model to predict early high-output ileostomy

OBJECTIVE

This study evaluated the prevalence and perioperative risk factors for early high-output ileostomy (EHOI) and developed a precise nomogram model to predict the occurrence of EHOI.

METHODS

140 patients who underwent ileostomy surgery at three hospitals in Wuhan, Hubei Province, between January 2022 and May 2022 were enrolled in this prospective cohort study. By using univariate and multifactorial logistic regression, independent risk variables for the development of EHOI were examined, and the nomogram model for predicting the risk of EHOI was created by using R software. The calibration curve and area under the receiver operating characteristic curve (ROC AUC) were used to evaluate the calibration and discrimination of the prediction model, Hosmer-Lemeshow to verify the fit of the model. Clinical impact curve (CIC) and decision curve analysis (DCA) were used to assess the model's clinical efficacy.

RESULTS

A total of 132 patients participated in the study, and the incidence of EHOI was 25.8% (34/132). The nomogram model incorporated 3 risk factors hypertension, drinking habits, and high white blood cell (WBC) count after surgery. The AUC was 0.742, and the nomogram showed great calibration and clinical validity by comparing the calibration curve, DCA, and CIC.

CONCLUSIONS

Hypertension, drinking, and high WBC was significantly correlated with EHOI. The nomogram model has great clinical value in predicting the EHOI.

[Lymphocytic "…itis", from esophagus to large bowel]

Intra-epithelial lymphocytosis is an elementary lesion frequently observed in the gastrointestinal tract, which can be found from the esophagus to the colon. Many conditions of a varied nature (dysimmunitary diseases, drugs, infections…) are associated with intra-epithelial lymphocytosis, and the etiological diagnosis most often requires an anatomo-clinical correlation. The pathologist will have to identify histological lesions associated with intra-epithelial lymphocytosis allowing the diagnosis to be oriented in order to propose appropriate treatment. In this review, the main entities associated with digestive intra-epithelial lymphocytosis will be presented, detailing the key elements allowing their diagnosis.

Collagenous sprue: a rare cause of watery diarrhea and villous atrophy - case report

Collagenous sprue is a rare and unrecognized cause of diarrhea and weight loss, mainly affecting the duodenum and small bowel. The clinical picture often resembles that of coeliac sprue, the main differential diagnosis, albeit, being refractory to a gluten-free diet. The histological features are fundamentally characterized by the deposition of collagen beneath the basement membrane of gut mucosa. Treatment should be initiated as soon as the diagnosis is established, so as to prevent the progression of fibrosis. We will describe the case of a 76-year-old woman with collagenous sprue, her diagnostic workup, histopathological examination, and response to treatment.

The histological spectrum of ARB-induced gastritis

AIMS

Olmesartan, an angiotensin receptor blocker (ARB) used for hypertension management, is known to cause a sprue-like enteropathy in a subset of patients. Rare cases of gastritis occurring with ARB use have also been reported, but the histological features of ARB-induced gastritis and the response to drug cessation have not been examined in a dedicated case-series.

METHODS AND RESULTS

Cases of suspected ARB-induced gastritis were identified from the pathology archives of four institutions. Haematoxylin and eosin (H&E) slides from gastric biopsies were reviewed. Fifteen patients (14 female, one male) were identified. The most common presenting symptoms were diarrhoea (10) and weight loss (six). Gastric biopsies commonly showed a full-thickness active chronic gastritis with surface epithelial injury involving the antrum and body. Glandular atrophy, intra-epithelial lymphocytosis and/or subepithelial collagen thickening were also present in some cases. Duodenal involvement, including villous atrophy, intra-epithelial lymphocytosis and/or collagenous sprue, was identified in 11 of 13 cases with concurrent duodenal biopsies. Following drug cessation, symptomatic improvement occurred in all 11 cases for which follow-up data were available. Histological resolution occurred in five of eight cases with follow-up gastric biopsies, with improvement seen in the remaining three biopsies.

CONCLUSION

ARB-induced gastritis typically presents as active chronic gastritis, frequently with associated surface epithelial injury. Glandular atrophy, intra-epithelial lymphocytosis and/or subepithelial collagen thickening may also be present. These gastric changes can be seen without associated duodenal injury in rare cases, and they should alert the pathologist to the possibility of ARB-induced injury. Drug cessation results in marked symptomatic and histological improvement.

Angiotensin II receptor blockers (ARBs) and manufacturing contamination: A retrospective National Register Study into suspected associated adverse drug reactions

AIMS

The aim of this study was to determine if any suspected adverse drug reactions (ADRs) observed with the use of angiotensin II receptor blockers (ARBs) could be linked to either (a) their unique respective physicochemical and pharmacological profiles and (b) the recently disclosed suspected carcinogenic manufacturing contaminants found in certain sartan drug class batches.

METHODS

The pharmacology profiles of ARBs were data-mined from the Chemical Database of bioactive molecules with drug-like properties, European Molecular Biology Laboratory (ChEMBL). Suspected ADR data (from 01/2016-10/2022, inclusive) and prescribing rates of ARBs over a 5-year prescribing window (from 09/2016 to 08/2021, inclusive) were obtained via analysis of the United Kingdom Medicines and Healthcare products Regulatory Authority (MHRA) Yellow Card drug analysis profile and Open prescribing databases, respectively.

RESULTS

The overall suspected ADRs and fatalities per 100 000 prescriptions identified across the ARBs studied were found to be different between the sartan drug class members (chi-squared test, P < .05). There is a greater relative rate of reports for valsartan across all investigated organ classes of ADRs, than other ARBs, despite valsartan's more limited pharmacological profile and similar physicochemical properties to other sartans. The disparity in ADR reporting rates with valsartan vs other ARBs could be due to the dissimilarity in formulation excipients, patient factors and publicity surrounding batch contaminations, amongst others. Cancer-related ADRs and fatalities per 100 000 prescriptions identified across the ARBs studied are not statistically significant (chi-squared test, P > .05) based on the datasets used over the 5-year period.

CONCLUSION

No connection between ARB pharmacology and their suspected ADRs could be found. No conclusion between sartan batch contaminations and increased suspected cancer-related ADRs was found.

Mimics of Crohn's Disease

Crohn's disease is a chronic inflammatory disease that can affect any portion of the gastrointestinal tract. Associated symptoms can vary based on the severity of disease, extent of involvement, presence of extraintestinal manifestations, and development of complications. Diagnosis is based on a constellation of findings. Many diseases can mimic Crohn's disease and lead to diagnostic conundrums. These include entities associated with the gastrointestinal luminal tract, vascular disease, autoimmune processes, various infections, malignancies and complications, drug- or treatment-induced conditions, and genetic diseases. Careful consideration of possible causes is necessary to establish the correct diagnosis.

Olmesartan-associated Enteropathy with Acute Kidney Injury

Olmesartan, a recently introduced angiotensin II receptor blocker for hypertension, has been reported to cause drug-induced small bowel enteropathy. The diagnosis of olmesartan-associated enteropathy (OAE) needs clinical suspicion and the exclusion of coeliac disease, as it mimics coeliac sprue. Once diagnosed, it can be completely cured with the discontinuation of olmesartan. However, due to the extremely low incidence of OAE in Korea, clinical suspicion and diagnosis may be a challenge. The authors report the first case of OAE presenting with chronic diarrhea and acute kidney injury in Korea.

Diarrhea and angiotensin II receptor blockers: Is there any difference between the different drugs?

Diarrhea is an adverse drug reaction (ADR) widely reported with olmesartan, an angiotensin II receptor blocker (ARB). Isolated case reports described this ADR with other ARBs. The present study was performed to investigate if, among the different ARBs, some drugs are more at risk of diarrhea than others. Using VigiBase®, the WHO pharmacovigilance database, we performed a disproportionality analysis (case/noncase study). Cases were reports with the MedDRA PT term « diarrhea » and noncases all other reports registered during the same period in Vigibase® from April 6, 1995 to December 31, 2020. After comparison of ARBs and angiotensin converting enzyme inhibitors (ACEIs), the main analysis was a comparison of the diarrhea reporting risk between each ARB and the seven other ARBs. Results are reported as reporting odds ratio (ROR) adjusted on age, gender, exposure to antihypertensive, and antidiabetic drugs with their 95% confidence interval. Among the 22,429,334 deduplicated reports registered in VigiBase® during the study period, 73,507 involved ARBs, including 2119 diarrhea. The reporting risk of diarrhea was higher with ARBs than with ACEIs (ROR = 2.06 (1.55-2.17)). Diarrhea with ARBs mainly occurred in females with a mean age of 65 years. After exclusion of olmesartan (to minimize a notoriety bias), two ARBs were significantly associated with diarrhea: eprosartan (ROR = 1.93 (1.32-2.72) and telmisartan (ROR = 1.41 (1.23-1.62) but not the six others. The present study found first that diarrhea is more frequently reported with ARBs than with ACEIs and second that the risk of diarrhea differs according to the different ARBs. Diarrhea with ARBs is not a class effect.

Shuttling of cellular proteins between the plasma membrane and nucleus (Review)

Recently accumulated evidence has indicated that the nucleomembrane shuttling of cellular proteins is common, which provides new insight into the subcellular translocation and biological functions of proteins synthesized in the cytoplasm. The present study aimed to clarify the trafficking of proteins between the plasma membrane and nucleus. These proteins primarily consist of transmembrane receptors, membrane adaptor proteins, adhesive proteins, signal proteins and nuclear proteins, which contribute to proliferation, apoptosis, chemoresistance, adhesion, migration and gene expression. The proteins frequently undergo cross-talk, such as the interaction of transmembrane proteins with signal proteins. The transmembrane proteins undergo endocytosis, infusion into organelles or proteolysis into soluble forms for import into the nucleus, while nuclear proteins interact with membrane proteins or act as receptors. The nucleocytosolic translocation involves export or import through nuclear membrane pores by importin or exportin. Nuclear proteins generally interact with other transcription factors, and then binding to the promoter for gene expression, while membrane proteins are responsible for signal initiation by binding to other membrane and/or adaptor proteins. Protein translocation occurs in a cell-specific manner and is closely linked to cellular biological events. The present review aimed to improve understanding of cytosolic protein shuttling between the plasma membrane and nucleus and the associated signaling pathways.

Duodenal Histological Findings and Risk of Coeliac Disease in Subjects with Autoimmune Atrophic Gastritis: A Retrospective Evaluation

BACKGROUND AND AIM

Autoimmune atrophic gastritis (AAG) is characterized by a variable spectrum of gastric and extra-gastric symptoms and has been associated with other autoimmune diseases. It is still unknown whether AAG patients have a higher risk of coeliac disease (CeD) or of any other particular duodenal histological damage. Our study aimed at evaluating the duodenal histological findings and the risk of CeD in patients with AAG, with and without other concurrent autoimmune diseases.

METHODS

We retrospectively collected all the histological findings of the adult patients undergoing upper gastrointestinal endoscopy with concurrent duodenal and gastric biopsies at our gastroenterology unit between 2015 and 2018 and who were regularly followed up at our centre. Date of endoscopy evaluation, endoscopy indication, data on previous CeD diagnosis and on other autoimmune-associated diseases, and a description of histological diagnosis were recorded.

RESULTS

Of the 2,423 evaluated endoscopies, 209 patients had an AAG diagnosis (8.6%). One hundred thirty-nine patients, aged 57.4 (standard deviation 13.2) years, were regularly followed up at our centre and were included. Of them, 4 subjects had a previous diagnosis of CeD and one had CeD diagnosis at index endoscopy. Additionally, 8 patients had an isolated increase of intraepithelial lymphocytes (IELs, 6%) and 2 villous atrophy with a normal IEL count. The risk of CeD in AAG was not modulated by the presence of other concurrent autoimmune diseases.

CONCLUSIONS

We support the screening of all AAG patients with CeD autoantibodies. Findings of isolated IEL or villous atrophy are not exclusively related to CeD.

Approach to the adult patient with chronic diarrhea: A literature review

Chronic diarrhea is defined by symptoms lasting longer than 4 weeks. It is a common problem that affects up to 5% of the adult population. Different pathophysiologic mechanisms involve numerous causes, including drug side effects, postoperative anatomic and physiologic alterations, intestinal and colonic wall abnormalities, inflammatory or malabsorption causes, pancreatobiliary diseases, and functional or gut-brain axis disorders associated with dysbiosis or gastrointestinal motility alterations. Due to such a broad differential diagnosis, it is important to categorize chronic diarrhea into five main groups: drug side effect, postoperative, postinfectious, malabsorptive, inflammatory, and functional. The present review is a narrative analysis of the diagnostic approach, emphasizing key aspects of the clinical history, the utility of biomarkers (in breath, stool, urine, and serology) and malabsorption and motility tests, the role of radiologic and endoscopic studies, and the most common histologic findings. A diagnostic algorithm aimed at determining etiology and personalizing therapy is also proposed.

Cutaneous ulcers in association with sprue-like enteropathy secondary to Losartan

Losartan is an angiotensin II receptor blocker (ARB) which may cause severe sprue-like enteropathy (SLE) with skin manifestation. Clinicians should be informed of this side effect and its reversibility after cessation of the drug.

Coeliac disease enteropathy and symptoms may be aggravated by angiotensin receptor blockers in patients on a gluten-free diet

Background

Angiotensin receptor blocker‐associated enteropathy (ARB‐e) is an increasingly recognised clinical entity with symptoms and histological findings identical to coeliac disease (CD). There is evidence to suggest immune‐mediated mucosal injury in ARB‐e with a high prevalence of DQ2/DQ8; however, as IgA anti‐tissue transglutaminase (anti‐TTG) is usually negative, an insult other than TTG‐mediated injury is suspected. The impact of ARBs on disease activity in patients with CD is not known.

Objective

To assess the effect of ARB exposure on patients with established CD.

Methods

A patient record search of 1142 individual patients attending a dedicated coeliac clinic from 2010 to the present identified 59 patients treated with ARB. Those with CD confirmed by serology (TTG + ve/EMA + ve) and histopathology (Marsh criteria) were included (n = 40, 0.52%). Data collected included disease duration, compliance with gluten‐free diet (GFD), reported symptoms (diarrhoea, weight loss and abdominal pain), surrogate markers of absorption (Vitamin D, Iron, Calcium and Haemoglobin), in addition to anti‐TTG titre and histological grade at last follow up. Patients were age and sex‐matched in a 1:2 ratio with CD patients not taking ARBs (controls), with comparable rates of disease duration and compliance with GFD.

Results

The ARB and control groups were matched in terms of age (mean 66.2 years) and gender (female 63%). Strict compliance with GFD was reported in 55% and 56%, respectively. Persistent symptoms were reported in 10/40 (25%) of the ARB group compared with 7/82 (9%) of controls (p = 0.0181). There were lower rates of mucosal healing (Marsh grade 0) in the ARB group (36% n = 11) compared to controls (55%, n = 33). There was no significant difference in anti‐TTG titres. Surrogate markers of absorption were comparable across the groups, except for Vitamin D which was lower in those taking olmesartan (p = 0.0015).

Conclusions

ARBs may aggravate the enteropathy and lead to increased symptoms in patients with bone fide diagnosed CD following a GFD.

Summarise the estabished knowledge on this subject

Angiotensin receptor blocker‐associated enteropathy (ARB‐e) is an increasingly recognised clinical entity with symptoms and histological findings identical to coeliac disease (CD).

The exact cause of mucosal injury in ARB‐e is unknown however there is evidence to suggest immune‐mediated mucosal injury in ARB‐e with a high prevalence of DQ2/DQ8, however as anti‐tissue transglutaminase (TTG) is usually negative, an insult other than TTG‐mediated injury is suspected. The impact of ARBs on disease activity in patients with CD is not known.

What are the significance and/or new findins of this study?

Coeliac patients who take ARBs are more likely to have persistent symptoms and lower rates of mucosal healing than their age‐matched coeliac controls. This observation appears to be independent of TTG mediated injury, akin to that reported in non‐coeliac populations.

ARB use in patients with established coeliac disease may confound the interpretation of clinical and histological response to a gluten‐free diet.

Approach to the adult patient with chronic diarrhea: a literature review

Chronic diarrhea is defined by symptoms lasting longer than 4 weeks. It is a common problem that affects up to 5% of the adult population. Different pathophysiologic mechanisms involve numerous causes, including drug side effects, postoperative anatomic and physiologic alterations, intestinal and colonic wall abnormalities, inflammatory or malabsorption causes, pancreatobiliary diseases, and functional or gut-brain axis disorders associated with dysbiosis or gastrointestinal motility alterations. Due to such a broad differential diagnosis, it is important to categorize chronic diarrhea into five main groups: drug side effect, postoperative, postinfectious, malabsorptive, inflammatory, and functional. The present review is a narrative analysis of the diagnostic approach, emphasizing key aspects of the clinical history, the utility of biomarkers (in breath, stool, urine, and serology) and malabsorption and motility tests, the role of radiologic and endoscopic studies, and the most common histologic findings. A diagnostic algorithm aimed at determining etiology and personalizing therapy is also proposed.

The role of histopathology in the diagnosis and management of coeliac disease and other malabsorptive conditions

Most absorption of nutrients takes place in the proximal small intestine, and the most common disorders leading to malabsorption are associated with a morphological abnormality in the duodenal mucosa that is appreciable in histological sections of biopsy specimens. Coeliac disease is the most well-known example, causing intraepithelial lymphocytosis, inflammation and villous atrophy in the duodenum. Remarkably similar inflammatory changes can be induced by other processes, including medications, e.g. angiotensin II receptor blockers and immune checkpoint inhibitors, immune dysregulation disorders, e.g. common variable immunodeficiency and autoimmune enteropathy, infections, collagenous sprue, and tropical sprue. However, there are often subtle histological differences from coeliac disease in the type of inflammatory infiltrate, the presence of crypt apoptosis, and the extent and type of inflammation beyond the duodenum. The clinical setting and serological investigation usually allow diagnostic separation, but some cases remain challenging. Histopathology is also important in assessing the response to treatment, such as the change in villous architecture caused by a gluten-free diet, or the response to cessation of a potentially causative medication. This review examines the practical role that histopathology of duodenal biopsy specimens plays in the assessment and management of inflammatory malabsorptive processes of the proximal small intestine, with a particular emphasis on coeliac disease.

Severe Sprue-Like Enteropathy and Colitis due to Olmesartan: Lessons Learned From a Rare Entity

Olmesartan is an angiotensin II receptor blocker (ARB) drug approved in 2002 for the treatment of hypertension. Since 2012, there have been reports of a rare adverse effect suspected to be related to its use. The author presents a case of a 63-year-old female with refractory gastrointestinal (GI) symptoms including diarrhea with associated weight loss and severe electrolyte abnormalities necessitating hospitalization. An extensive inpatient evaluation ensued and was initially unremarkable. Esophagogastroduodenoscopy (EGD) discovered an endoscopically normal duodenum that was biopsied and notably revealed villous atrophy and intraepithelial lymphocytosis. Colonoscopy was normal appearing though biopsy findings were significant for nonspecific colitis. The endoscopy findings in the setting of the clinical presentation confirmed the diagnosis of olmesartan-associated enteropathy (OAE). Clinical improvement was noted after cessation of olmesartan and histological resolution was confirmed with repeat EGD post-discharge.

Olmesartan-Induced Spruelike Enteropathy: An Emerging Cause of Small Bowel Injury

Olmesartan-induced spruelike enteropathy is a rare clinical entity that is characterized by unexplained chronic diarrhea and weight loss. Prompt recognition of this adverse event may be challenging due to clinical and histologic similarities with other small intestinal pathologies. We hereby delineate the case of an elderly female with a 14-month clinical history of non-bloody diarrhea and weight loss. After extensive diagnostic workup and exclusion of probable etiologies, the patient was diagnosed with olmesartan-associated enteropathy. A dramatic clinical and histologic recuperation was achieved after discontinuation of olmesartan. This paper illustrates the overarching need for a detailed clinical history focusing on medication review in patients presenting with chronic diarrhea with no obvious cause. The spruelike enteropathy associated with olmesartan is an emerging cause of small bowel injury. Clinicians should maintain a high index of suspicion for this adverse drug reaction. Early and correct diagnosis carries paramount importance in sparing these patients from unnecessary diagnostic investigations and therapeutic delays.

Losartan improves visceral sensation and gut barrier in a rat model of irritable bowel syndrome

BACKGROUND

Lipopolysaccharide (LPS) or repeated water avoidance stress (WAS) induces visceral allodynia and colonic hyperpermeability via corticotropin-releasing factor (CRF) and proinflammatory cytokines, which is considered to be a rat irritable bowel syndrome (IBS) model. As losartan is known to inhibit proinflammatory cytokine release, we hypothesized that it improves these visceral changes.

METHODS

The threshold of visceromotor response (VMR), that is, abdominal muscle contractions induced by colonic balloon distention was electrophysiologically measured in rats. Colonic permeability was determined in vivo by quantifying the absorbed Evans blue in colonic tissue for 15 minutes spectrophotometrically.

KEY RESULTS

Lipopolysaccharide (1 mg kg^-1 ) subcutaneously (s.c.) reduced the threshold of VMR and increased colonic permeability. Losartan (5-25 mg kg^-1  s.c.) for 3 days inhibited these changes in a dose-dependent manner. Moreover, repeated WAS (1 hour daily for 3 days) or intraperitoneal injection of CRF (50 µg kg^-1 ) induced the similar visceral changes as LPS, which were also eliminated by losartan. These effects by losartan in LPS model were reversed by GW9662 (a peroxisome proliferator-activated receptor-γ [PPAR-γ] antagonist), N^G -nitro-L-arginine methyl ester (a nitric oxide [NO] synthesis inhibitor), or naloxone (an opioid receptor antagonist). Moreover, it also inhibited by sulpiride (a dopamine D₂ receptor antagonist) or domperidone (a peripheral dopamine D₂ antagonist).

CONCLUSION & INFERENCES

Losartan prevented visceral allodynia and colonic hyperpermeability in rat IBS models. These actions may be PPAR-γ-dependent and also mediated by the NO, opioid, and dopamine D₂ pathways. Losartan may be useful for IBS treatment.

Olmesartan Associated Enteropathy: Usefulness of Video Capsule Endoscopy in a Case With Doubtful Upper Endoscopic/Histological Picture

BACKGROUND

Olmesartan, an antihypertensive drug, may be associated with a severe "sprue-like enteropathy".

OBJECTIVES

To report a case of Olmesartan enteropathy demonstrated by video capsule endoscopy distally from the second duodenum along with the whole small bowel before and after drug withdrawal.

CASE PRESENTATION

A 81-years-old man was referred for asthenia, chronic watery diarrhea and anasarca (ascites, pleural effusion and edemas of superior and inferior limb). The only comorbidity was hypertension treated with Olmesartan. All causes of infective and inflammatory chronic diarrhea were investigated and excluded. Upper endoscopy was normal; histological examination of the second portion of the duodenum showed moderate and patchy infiltration of lymphocytes at mucosal and intra-epithelial level with intermittent partial villous atrophy. The possibility of adverse drug reaction, estimated by Naranjo scale, showed a score of 7, indicating a strong probability. Olmesartan was then withdrawn. However, because of severe clinical general condition, we preferred to corroborate our diagnostic work-up by a non-invasive investigation, i.e. video capsule endoscopy, which showed jejunal and ileal mucosal alterations (mosaic pattern, diffuse hyperemia, severe edema, consequent apparent reduced lumen, diffuse thickening of intestinal folds, multiple erosions, patchy lymphangectasia). After 14 days, the resolution of anasarcatic state and hydroelectrolytic imbalances was observed. Nine months later, small-bowel video-capsule demonstrated mild mucosal hyperaemia and mosaic pattern.

CONCLUSION

Our case could give new insights in the field of Olmesartan associated enteropathy by highlighting the possibility of distally main lesion location and, therefore, the usefulness of video capsule endoscopy in the presence of doubtful diagnostic features.