Combined Use of Common Fecal and Blood Markers for Detection of Endoscopically Active Inflammatory Bowel Disease. Clin Transl Gastroenterol. 2020;11:e00138. [PMID: 32132451 PMCID: PMC7145039 DOI: 10.14309/ctg.0000000000000138]

The Diagnostic Utility of Biochemical Markers and Intestinal Ultrasound Compared with Endoscopy in Patients with Crohn's Disease and Ulcerative Colitis: A Systemic Review and Meta-Analysis

Background: Inflammatory bowel disease (IBD) consists of Crohn's disease (CD) and Ulcerative colitis (UC). The main goal of treatment is to obtain mucosal healing via endoscopy. More recently, intestinal ultrasounds, along with biochemical markers, have been increasingly popular as point-of-care testing to monitor treatment response. This systemic review and meta-analysis aimed to assess the diagnostic test performance of ultrasonography and biochemical markers (C-reactive protein and fecal calprotectin) compared with endoscopy for detecting inflammation in IBD. Methods: A comprehensive literature search was conducted using PubMed Medline, EMBASE, ScienceDirect, and CINAHL from 1 January 2018 to 1 January 2024. The included studies were prospective and retrospective observational studies, clinical trials, and cross-sectional studies investigating the diagnostic sensitivity and specificity of ultrasonography, biochemical markers, and endoscopy. Studies were selected based on the Preferred Reporting Items for Systematic Review and Meta-analysis Statement (PRISMA). Results: Of the 1035 studies retrieved, 16 met the inclusion criteria, and most of the included studies were prospective observational studies. Diagnostic test accuracy was conducted, and the pooled sensitivity and specificity of all the studies revealed that ultrasonography has the highest pooled sensitivity, at 85% (95% CI, 78 to 91%), and specificity, at 92% (95% CI, 86 to 96%), as compared with biochemical markers and endoscopy. More specifically, biochemical markers had a pooled sensitivity and specificity of 85% (95% CI, 81 to 87%) and 61% (95% CI, 58 to 64%), respectively, and endoscopy had 60% (95% CI, 52 to 68%) and 82% (95% CI, 76 to 87%), respectively. However, the results also show substantial heterogeneity in the studies because of various populations, protocols, and outcomes in the studies included. This was especially noted in the assessment of biochemical markers, in which a metaregression was performed showing a nonsignificant p-value of 0.8856 for the coefficient. Conclusions: IUS was found to have the highest pooled sensitivity and specificity of all the included studies for diagnosing inflammation in patients with CD and UC, and this, coupled with biochemical markers, can improve diagnostic utility.

Smart Capsule for Targeted Detection of Inflammation Levels Inside the GI Tract

Effective management of Inflammatory Bowel Disease (IBD) is contingent upon frequent monitoring of inflammation levels at targeted locations within the gastrointestinal (GI) tract. This is crucial for assessing disease progression and detecting potential relapses. To address this need, a novel single-use capsule technology has been devised that enables region-specific inflammation measurement, thereby facilitating repeatable monitoring within the GI tract. The capsule integrates a pH-responsive coating for location-specific activation, a chemiluminescent paper-based myeloperoxidase (MPO) sensor for inflammation detection, and a miniaturized photodetector, complemented by embedded electronics for real-time wireless data transmission. Demonstrating linear sensitivity within the physiological MPO concentration range, the sensor is capable of effectively identifying inflammation risk in the GI fluid. Luminescence emitted by the sensor, proportional to MPO concentration, is converted into an electrical signal by the photodetector, generating a quantifiable energy output with a sensitivity of 6.14 µJ/U.ml-1. The capsule was also tested with GI fluids collected from pig models simulating various inflammation states. Despite the physiological complexities, the capsule consistently activated in the intended region and accurately detected MPO levels with less than a 5% variation between readings in GI fluid and a PBS solution. This study heralds a significant step towards minimally invasive, in situ GI inflammation monitoring, potentially revolutionizing personalized IBD management and patient-specific therapeutic strategies.

Absolute monocyte counts could predict disease activity and secondary loss of response of patients with Crohn's disease treated with anti-TNF-α drug

BACKGROUND

Assessing Crohn's disease (CD) activity is critical for monitoring disease progression. In CD, monocytes could release TNF-α. Thus, it is extremely important to study its role in the disease activity and loss of response to anti-TNF-α biologics.

METHODS

In this study, we collected CD patients treated with biologics from January 2017 to May 2022. Indicators associated with disease activity were evaluated by Spearman correlation analysis and Mann-Whitney U test. Specifically, logistic analyses were used to explore the predictors of primary nonresponse (PNR) and secondary loss of response (SLOR) within 1 year of anti-TNF-α agents. In addition, a nomogram was developed for therapeutic effect prediction.

RESULTS

283 patients with CD were identified. Disease activity group, defined as CDAI equal to or greater than 150, had significant elevated absolute monocyte counts than disease remission group based on CDAI score (p = 0.019, Z = -2.354). Logistic analyses showed that absolute monocyte counts could be an independent predictor of 1-year SLOR of anti-TNF-α agents in CD patients (p = 0.013). A nomogram established based on gender, absolute monocyte counts, and hemoglobin could predict SLOR within 1 year of anti-TNF-α agents reliably.

CONCLUSION

The results of this study support the utility of absolute monocyte counts detecting disease activity and anti-TNF-α therapy effect in patients with CD.

The synergy of dual faecal immunochemical and faecal calprotectin testing for accurate assessment of endoscopic and histological activity in inflammatory bowel disease

Background

Faecal biomarkers are increasingly utilized for disease assessment in inflammatory bowel disease (IBD).

Objectives

To characterize the relative and combined accuracy of faecal calprotectin (FC) and faecal immunochemical testing (FIT) for detecting endoscopic and histologically active disease in Crohn's disease (CD) and ulcerative colitis (UC), subdivided by disease location.

Design

A prospective cohort study.

Methods

Patients with confirmed IBD undergoing routine ileocolonoscopy for activity assessment were prospectively recruited and performed both FC and FIT ±30 days of ileocolonoscopy. Endoscopic activity was assessed via the simplified endoscopic score for CD, Mayo endoscopic score for UC and histological activity graded as nil/mild/moderate. Receiver-operator curve analyses were utilized to assess the performance of FC and FIT per disease subtype and location.

Results

In all, 137 (79 CD, 57 UC) patients were recruited. FC was more sensitive than FIT in detecting active endoscopic (CD: 91% versus 69%, UC: 94% versus 82%) and histological (CD: 86% versus 55%, UC 88% versus 56%) disease. However, FIT was more specific than FC in detecting active endoscopic (CD: 94% versus 56%, UC: 85% versus 69%) and histological (CD: 93% versus 55%, UC: 96% versus 70%) diseases. FIT was more sensitive and specific than FC in detecting active colonic CD (endoscopic activity: 94% versus 93%, histological activity: 92% versus 77%, respectively); however, it was poorly sensitive for active ileal CD (43% versus 89%).

Conclusion

FC demonstrated higher sensitivity and FIT higher specificity for active IBD. Hence, dual testing was synergistic, displaying excellent performance characteristics across most IBD locations and subtypes, holding promise for future clinical application.

Trial registration

Not applicable.

Clinical Value of Detecting Fecal Calprotectin by Using Colloidal Gold Assay in Screening or Diagnosing Crohn's Disease

Background

Crohn's disease (CD) is a chronic inflammatory disease, and its incidence is gradually increasing. Thus, the use of a simple and convenient examination method to detect CD in the natural population as early as possible is crucial. This study is aimed at using the colloidal gold semiquantitative assay to detect fecal calprotectin (FCP) and determine whether it is helpful in screening or diagnosing CD.

Methods

Using a prospectively maintained database, 59 patients with CD were analyzed using FCP measurement. Subsequently, 76 patients and 89 healthy individuals were assigned to the gastrointestinal dysfunction and control groups, respectively. To aid in the screening or diagnosis of CD, the receiver operating characteristic curve was used to determine the diagnostic efficacy of FCP thresholds. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were presented with 95% confidence intervals (CIs).

Results

Patients with CD showed significantly higher FCP levels. Compared with the healthy population, when the FCP level cut-off was 15 μg/g and 60 μg/g, the sensitivity, specificity, PPV, and NPV for CD diagnosis were 98.3% (CI, 95.0%-100%) and 78.0% (CI, 67.4-88.6%), 84.3% (CI, 76.7%-91.8%) and 98.9% (CI, 96.7%-100%), 80.6% (CI, 71.5%-89.7%) and 97.9% (CI, 93.7%-100%), and 98.7% (CI, 96.2%-100%) and 87.1% (CI, 80.6%-93.6%), respectively. The AUCs were 0.969 (CI, 0.941-0.997). Compared with the gastrointestinal dysfunction group, using the same FCP level cut-off, the sensitivity, specificity, PPV, and NPV for CD diagnosis were 98.3% (CI, 95.0%-100%) and 78.0% (CI, 67.4%-88.6%), 71.1% (CI, 60.9%-81.3%) and 89.5% (CI, 82.3%-96.7%), 72.5% (CI, 62.7%-82.3%) and 85.2% (CI, 75.7%-94.7%), and 98.1% (CI, 94.5%-100%) and 84.0% (CI, 76.0%-92.0%), respectively. The AUCs were 0.908 (CI, 0.856-0.960).

Conclusion

Detecting FCP by using the colloidal gold semiquantitative assay can be effective in screening and adjunct diagnosing of CD.

Emergency colectomy for massive rectal bleeding in a patient with well-controlled ulcerative colitis receiving Vedolizumab

Ulcerative colitis (UC) is a chronic inflammatory condition, with a relapsing-remitting course. The case presented poses some valid questions regarding short-term and long-term management of patients with UC, and if the outcome (colectomy) could have been delayed or even prevented. Rectal bleeding is a cardinal symptom in patients with UC and it occurs among all patients during active disease. Massive rectal bleeding is an uncommon, but serious, complication of UC accounting for 0.1-1.4% of admissions. It is, nonetheless, noteworthy that instances of acute significant lower gastrointestinal bleeding accompanied by hemodynamic instability are infrequent. The rate of colectomy appears to be positively impacted by biological treatment. However, a refractory condition is still the primary reason for surgery, indicating a pressing need for new treatment approaches. Here we present the case of a young male patient who developed massive rectal bleeding and underwent emergent colectomy with ileostomy while having clinical and biological remission (normal calprotectin levels) at week 10 of Vedolizumab treatment.

New score models for assessing disease activity in Crohn's disease based on bowel ultrasound and biomarkers: Ideal surrogates for endoscopy or imaging

Disease activity evaluation is important in Crohn's disease (CD). We aimed to establish new disease activity indices for CD based on noninvasive parameters. The data of 110 patients with CD were retrospectively analyzed. Parameters from bowel ultrasound and biomarkers were measured to select the variables included in the models by univariate analysis. Logistic regression analysis was performed to predict mucosal and transmural activities defined by ileocolonoscopy or computed tomography enterography, respectively. The models' performance was measured by the area under the receiver operating characteristic (ROC) curve (AUC). Leave-one-out cross validation (LOOCV) was applied to adjust for overconfidence in the newly established score models. To predict mucosal activity, erythrocyte sedimentation rate (ESR) and (LimG × BWT)-SUM (the sum of the product of Limberg grade [LimG] and bowel wall thickness [BWT] of each bowel segment) were selected for model A, and the equation was A = 2 × ESR + 9.3 × (LimG × BWT)-SUM. The AUC of ROC, sensitivity, and specificity were 0.927%, 89.8%, and 86.4%, respectively. The AUC of the ROC curve verified by LOOCV was 0.913. To predict transmural activity, albumin (ALB) and LimG-SUM (the sum of the LimG of all the bowel segments) were selected for model B, which was established as B = -1.3 × ALB +1.7 × LimG-SUM. The AUC of ROC, sensitivity, and specificity were 0.851%, 78.0%, and 84.2%, respectively. The AUC of the ROC curve verified by LOOCV was 0.833. Nomograms were developed for two score models. New score models based on noninvasive parameters established in this study showed good abilities in detecting active disease and performed well in the validation phase.

Under the Umbrella of Clinical Pharmacology: Inflammatory Bowel Disease, Infliximab and Adalimumab, and a Bridge to an Era of Biosimilars

Monoclonal antibodies (MAbs) have revolutionized the treatment of many chronic inflammatory diseases, including inflammatory bowel disease (IBD). IBD is a term that comprises two quite similar, yet distinctive, disorders—Crohn’s disease (CD) and ulcerative colitis (UC). Two blockbuster MAbs, infliximab (IFX) and adalimumab (ADL), transformed the pharmacological approach of treating CD and UC. However, due to the complex interplay of pharmacology and immunology, MAbs face challenges related to their immunogenicity, effectiveness, and safety. To ease the burden of IBD and other severe diseases, biosimilars have emerged as a cost-effective alternative to an originator product. According to the current knowledge, biosimilars of IFX and ADL in IBD patients are shown to be as safe and effective as their originators. The future of biosimilars, in general, is promising due to the potential of making the health care system more sustainable. However, their use is accompanied by misconceptions regarding their effectiveness and safety, as well as by controversy regarding their interchangeability. Hence, until a scientific consensus is achieved, scientific data on the long-term effectiveness and safety of biosimilars are needed.

Intestinal ultrasonography and fecal calprotectin for monitoring inflammation of ileal Crohn's disease: two complementary tests

Background/Aims

Tight control of inflammation and adjustment of treatment if activity persists is the current strategy for the management of Crohn’s disease (CD). The usefulness of fecal calprotectin (FC) in isolated involvement of the small intestine in CD is controversial. To assess the usefulness of FC to determine the inflammatory activity detected by intestinal ultrasonography (IUS) in ileal CD.

Methods

Patients with exclusively ileal involvement CD who underwent IUS and an FC were prospectively included. Simple ultrasound index was used to determine inflammatory activity. The usual statistical tests for comparison of diagnostic techniques were used.

Results

One hundred and five patients were included, IUS showed inflammatory activity in 59% of patients and complications in 18.1%. FC showed a significant correlation with IUS in the weak range (Spearman coefficient r=0.502; P<0.001); the area under the receiver operating characteristic curve was 0.79 (95% confidence interval, 0.70–0.88; P<0.001). The FC value that best reflected the activity in IUS was 100 μg/g with sensitivity, specificity, and positive and negative predictive values of 73.0%, 71.4%, 79.3% and 63.8%, respectively. There were no differences in FC concentration between patients with or without transmural complications. The addition of serum C-reactive protein to FC did not improve the ability to assess IUS activity.

Conclusions

FC has a significant correlation with IUS to monitor ileal CD activity. This correlation is weak and it does not allow assessing the presence of CD complications. Both tests should be used in conjunction for tight control of ileal CD. More studies on noninvasive tests in this location are needed.

Fecal Calprotectin in Parkinson's Disease and Multiple System Atrophy

Objective

Converging evidence suggests that intestinal inflammation is involved in the pathogenesis of neurodegenerative diseases. Previous studies on fecal calprotectin in Parkinson’s disease (PD) were limited by small sample sizes, and literature regarding intestinal inflammation in multiple system atrophy (MSA) is very scarce. We investigated the levels of fecal calprotectin, a marker of intestinal inflammation, in PD and MSA.

Methods

We recruited 169 subjects (71 PD, 38 MSA, and 60 age-similar nonneurological controls). Clinico-demographic data were collected. PD and MSA were subtyped and the severity assessed using the MDS-UPDRS and UMSARS, respectively. Fecal calprotectin and blood immune markers were analyzed.

Results

Compared to controls (median: 35.7 [IQR: 114.2] μg/g), fecal calprotectin was significantly elevated in PD (median: 95.6 [IQR: 162.1] μg/g, p = 0.003) and even higher in MSA (median: 129.5 [IQR: 373.8] μg/g, p = 0.002). A significant interaction effect with age was observed; between-group differences were significant only in older subjects (i.e., ≥ 61 years) and became more apparent with increasing age. A total of 28.9% of MSA and 18.3% of PD patients had highly abnormal fecal calprotectin levels (≥ 250 μg/g); however, this difference was only significant for MSA compared to controls. Fecal calprotectin correlated moderately with selected blood immune markers in PD, but not with clinical features of PD or MSA.

Conclusions

Elevated fecal calprotectin suggests a role for intestinal inflammation in PD and MSA. A more complete understanding of gut immune alterations could open up new avenues of research and treatment for these debilitating diseases.

Combined Use of Fecal Biomarkers in Inflammatory Bowel Diseases: Oncostatin M and Calprotectin

Background

Fecal biomarkers have emerged as one of the most useful tools for clinical management of inflammatory bowel disease (IBD). Oncostatin M (OSM), like fecal calprotectin (FC), is highly expressed in the inflamed intestinal mucosa which may have potential usefulness. We aimed to evaluate the additional utility of these two fecal biomarkers for IBD diagnosis, activity, and prediction of infliximab response over FC alone.

Methods

In group 1, 236 IBD patients (145 Crohn’s disease, 91 ulcerative colitis), 50 disease controls, and 32 healthy controls were recruited for IBD diagnosis and activity. In group 2, baseline stool samples were collected from 62 patients to predict infliximab response at week 28 and 52. The performance of fecal biomarkers for IBD management was assessed by the area under the receiver operating characteristic curve (AUC).

Results

Fecal OSM and FC levels were increased in IBD patients and were positively correlated with clinical and endoscopic activity. Their combination showed a better ability for disease diagnosis (AUC = 0.93) and slightly improved the capability to identify mucosal healing (AUC = 0.923). Baseline OSM and FC levels were elevated in non-responders at week 28 and 52. The AUCs of OSM, FC, and their combination to predict therapeutic response were 0.763, 0.834, and 0.859 at week 28, 0.638, 0.661, and 0.704 at week 52, respectively. Combined use of fecal and blood biomarkers improved predictive accuracy with an AUC of 0.919 at week 28 and 0.887 at week 52.

Conclusion

In addition to FC, OSM is a novel fecal biomarker, and their combination is more beneficial for disease diagnosis and prediction of infliximab response but not for disease activity in IBD patients. Further larger-scale studies are required to confirm our findings.

Serum oncostatin M is a potential biomarker of disease activity and infliximab response in inflammatory bowel disease measured by chemiluminescence immunoassay

BACKGROUND

Although endoscopy is the gold standard to assess disease activity and infliximab efficacy in inflammatory bowel disease (IBD), the invasive, costly, and time-consuming procedure limits its routine applications. We aimed to investigate the clinical value of serum oncostatin M (OSM) as a surrogate biomarker.

METHODS

Fifty healthy controls, 34 non-IBD patients, and 189 IBD patients who were pre-infliximab treatment (n = 122) or in infliximab maintenance (n = 67) were enrolled. A chemiluminescence immunoassay (CLIA) was constructed to quantify serum OSM concentrations. Receiver operator characteristic (ROC) curve analysis was used to evaluate the performance of blood biomarkers for IBD management.

RESULTS

The methodology of CLIA exhibited great analytical performance with a wide linear range of 31.25-25000 pg/mL, a low detection limit of 23.2 pg/mL, acceptable precision, and applicable accuracy. Patients with IBD (121.5 [43.3-249.4] pg/mL, p < 0.001) and non-IBD (72.4 [51.4-129.6] pg/mL, p = 0.005) had higher serum OSM levels than healthy controls (35.8 [23.2-56.4] pg/mL). In the analysis of clinical and endoscopic activity, serum OSM levels were elevated in moderate and severe patients compared to those in remission. IBD patients without mucosal healing had higher serum OSM levels than those with mucosal healing (AUC = 0.843). Besides, serum OSM levels were increased in clinical non-responders (287.3 [127.9-438] pg/mL) compared to responders (24.1 [23.2-53.4] pg/mL, p < 0.001), and showed great recognition ability with an AUC of 0.898.

CONCLUSIONS

The newly developed methodology of CLIA had great potential for use in the clinic. Elevated serum OSM expression was a promising biomarker of severe disease and infliximab non-response in IBD patients.

Prostaglandin E-Major Urinary Metabolite Predicts Relapse in Patients With Ulcerative Colitis in Clinical Remission

INTRODUCTION:

Prostaglandin E-major urinary metabolite (PGE-MUM) is a novel biomarker reflecting endoscopic activity in ulcerative colitis (UC). However, there are no studies investigating the efficacy of PGE-MUM as a biomarker for predicting relapse. We investigated whether PGE-MUM can predict clinical relapse of UC.

METHODS:

The measurement of PGE-MUM and endoscopic evaluation were performed in 70 patients with UC in clinical remission. The optimal cutoff values predicting relapse and relapse-free rate were analyzed.

RESULTS:

Sixteen patients (22.9%) relapsed during the 12-month follow-up. The median PGE-MUM value of relapsed patients at entry was significantly higher than that of patients in clinical remission (P = 0.008). The cutoff value of PGE-MUM predicting future relapse was 25.2 μg/g Cr by receiver-operating characteristic (ROC) analysis, and the area under the ROC curve was 0.721 (95% confidence interval: 0.556–0.886). The relapse-free rate of patients with PGE-MUM ≥25.2 μg/g Cr was significantly lower than that in patients with PGE-MUM <25.2 μg/g Cr (log-rank test: P < 0.001). The ROC analysis of UC patients with disease duration more than 1–8 years showed that duration of more than 5 years had the largest area under the ROC curve 0.821 (95% confidence interval: 0.583–1.000) and that the optimal cutoff value was 26.3 μg/g Cr.

DISCUSSION:

PGE-MUM is a reliable biomarker for predicting future relapse, particularly in UC patients with long-disease duration.

Serum biomarkers confirming stable remission in inflammatory bowel disease

Crohn's disease (CD) and ulcerative colitis (UC) have a chronic-remittent course. Optimal management of inflammatory bowel diseases (IBD) relies on early intervention, treat-to-target strategies and a tight disease control. However, it is challenging to assess the risk of relapses in individual patients. We investigated blood-based biomarkers for the confirmation of disease remission in patients with IBD. We retrospectively analyzed samples of 40 IBD patients (30 UC, 10 CD) enrolled in a tight-control follow-up study. Half of the patients had a flare during follow up. Serum was analyzed for S100A12 as well as S100A8/A9 and for 50 further biomarkers in a bead-based multiplex assay. The concentrations of 9 cytokines/chemokines and S100A8/A9 significantly differed in IBD patients with unstable remission (before flares) when compared to IBD patients with stable remission. Although the number of patients was small, ROC curve analyses revealed a number of biomarkers (IL-1β, IL-1RA, IL-8, IL13, IL-15, IL-21, IL-25, IFN-β, CXCL9, CXCL10, CXCL11, Galectin-1, G-CSF and S100A8/A9) that were elevated in patients with later occurring relapses. While earlier studies on peripheral biomarkers in IBD are limited to only few analytes, our study using a broad screening approach identified serum biomarkers with the potential to indicate unstable disease control in IBD, which may help to steer individual therapies to maintain remission.

Serum inflammatory markers in the diagnosis and assessment of Crohn's disease activity

INTRODUCTION

The aim of our study was to evaluate the diagnostic characteristics of selected inflammatory markers and the results of multiplication of their concentrations in the diagnosis and assessment of Crohn's disease (CD) activity.

METHODS

We studied 49 patients with CD and 31 healthy controls. The CD patients were assigned to subgroups with active and inactive disease based on the Crohn's Disease Activity Index score. Serum interleukins and C-reactive protein (CRP) were measured using immunoassays.

RESULTS

Serum CRP and interleukins: IL-6, IL-17A, IL-23 were significantly higher in the CD group than in controls, with the best diagnostic performance for IL-23. Only serum IL-6 and CRP were significantly higher in active than in inactive disease, with the better performance of CRP. Multiplication results did not perform better than individual multipliers.

CONCLUSIONS

Serum CRP may be useful in the assessment of CD activity and there is a need for introduction of IL-23 for the CD diagnosis.

Post-transplant colitis after kidney transplantation: clinical, endoscopic and histological features

Chronic immunosuppression may increase the risk of post-transplant infection and medication-related injury and may also be responsible for the increased risk of gastrointestinal complications in kidney transplant recipients. Differentiating the various forms of post-transplant colitis is challenging, since most have similar clinical and histological features. This study evaluated the incidence of post-transplant gastrointestinal complications during screening colonoscopy. Kidney transplant recipients undergoing a colonoscopy for any reasons in the period 2014-2018 were included. Among the 134 patients completing the colonoscopy, 74 patients (56%) had an abnormal finding: an adenoma was found in 25 patients (18.6%), while 19 patients (14.1%) had colitis. Mycophenolic acid/related colitis was the most common colitis (6%), while 7 patients (5.2%) developed a de novo inflammatory bowel disease. Patients with post-transplant colitis were younger and with shorter time from transplant compared to patients without colitis. In conclusions, immunosuppression may predispose kidney transplant recipients to an increased risk of post-transplant colitis. Diagnostic colonoscopy should be encouraged in all transplant patients with refractory diarrhea and gastrointestinal symptoms to allow a prompt diagnosis and a timely treatment, finally improving the quality of life and long-term outcomes of affected patients.

Gastrointestinal complications after kidney transplantation

Gastrointestinal complications are common after renal transplantation, and they have a wide clinical spectrum, varying from diarrhoea to post-transplant inflammatory bowel disease (IBD). Chronic immunosuppression may increase the risk of post-transplant infection and medication-related injury and may also be responsible for IBD in kidney transplant re-cipients despite immunosuppression. Differentiating the various forms of post-transplant colitis is challenging, since most have similar clinical and histological features. Drug-related colitis are the most frequently encountered colitis after kidney transplantation, particularly those related to the chronic use of mycophenolate mofetil, while de novo IBDs are quite rare. This review will explore colitis after kidney transplantation, with a particular focus on different clinical and histological features, attempting to clearly identify the right treatment, thereby improving the final outcome of patients.