Variability of Faecal Calprotectin in Inflammatory Bowel Disease Patients: An Observational Case-control Study

Delayed Ustekinumab and Adalimumab Responders Have Similar Outcomes as Early Responders in Biologic-Naïve Crohn's Disease

INTRODUCTION

Differences in 1-year outcomes among early and delayed responders have been demonstrated with some therapies in ulcerative colitis. However, it is unclear whether similar differences exist in patients with Crohn's disease (CD) treated with biologic therapies.

METHODS

This was a post hoc analysis of patient-level data from the SEAVUE clinical trial program. Ustekinumab-treated and adalimumab-treated patients with clinical response at week 8, defined as a reduction in Crohn's Disease Activity Index (CDAI) score of at least 100 points from baseline or CDAI score <150, were deemed early responders and their outcomes were compared with delayed responders (week 8 nonresponders who subsequently responded at week 16) and nonresponders (no response at week 8 or 16). The primary outcome assessed was clinical remission at week 56, defined as CDAI <150.

RESULTS

A total of 373 participants (187 treated with ustekinumab and 186 treated with adalimumab) were included in this analysis. The overall rate of delayed clinical response was low in the SEAVUE clinical trial program (13.1%). No differences were observed for week 56 clinical remission among early vs delayed responders to ustekinumab or adalimumab nor were there significant differences for secondary outcomes assessed. Delayed responders to ustekinumab and adalimumab had a significant decline in C-reactive protein by week 8 when compared with nonresponders.

DISCUSSION

Among patients with moderate-to-severe CD, early and delayed responders to adalimumab and ustekinumab have similar 1-year clinical outcomes. Biomarker decline can be observed through the initial 8 weeks of therapy in patients who will eventually be delayed responders, which may help differentiate from nonresponders.

Biomarkers in inflammatory bowel disease: a practical guide

Inflammatory bowel disease (IBD), comprising ulcerative colitis (UC) and Crohn's disease (CD), is a costly condition in terms of morbidity and healthcare utilization, with an increasing prevalence now approaching 1% in the Western world. Endoscopic assessment of IBD remains the gold standard for diagnosis, evaluation of treatment response and determination of post-operative recurrence, but is expensive and invasive. Biomarkers can facilitate non-invasive disease assessment, with C-reactive protein and faecal calprotectin as the most widely available biomarkers in current clinical practice. This narrative review summarizes the evidence for their use in both UC and CD and offers practical guidance for healthcare providers taking into account the limitations of biomarker interpretation. We present evidence for the future use of novel biomarkers in IBD and discuss how biomarker discovery could deliver the goal of precision medicine in IBD.

Composite Assessment Using Intestinal Ultrasound and Calprotectin Is Accurate in Predicting Histological Activity in Ulcerative Colitis: A Cohort Study

BACKGROUND

Beyond endoscopic remission, histological remission in ulcerative colitis (UC) is predictive of clinical outcomes. Intestinal ultrasound (IUS) may offer a noninvasive surrogate marker for histological activity; however, there are limited data correlating validated ultrasound and histological indices.

AIM

Our aim was to determine the correlation of IUS activity in UC with a validated histological activity index.

METHODS

Twenty-nine prospective, paired, same-day IUS/endoscopy/histology/fecal calprotectin (FC) cases were included. Intestinal ultrasound activity was determined using the Milan Ultrasound Criteria, histological activity using the Nancy Histological Index, endoscopic activity using Mayo endoscopic subscore and Ulcerative Colitis Endoscopic Index of Severity, and clinical activity using the Simple Clinical Colitis Activity Score.

RESULTS

Histological activity demonstrated a significant linear association with overall IUS activity (coefficient 0.14; 95% CI, 0.03-0.25; P = .011). Intestinal ultrasound activity was also significantly associated with endoscopic activity (0.32; 95% CI, 0.14-0.49; P < 0.001), total Mayo score (0.31; 95% CI, 0.02-0.60; P = .036) but not FC (0.10; 95% CI, -0.01 to 0.21; P = .064) or clinical disease activity (0.04; 95% CI, -0.21 to 0.28; P = .768). A composite of IUS and FC showed the greatest association (1.31; 95% CI, 0.43-2.18; P = .003) and accurately predicted histological activity in 88% of cases (P = .007), with sensitivity of 88%, specificity 80%, positive predictive value 95%, and negative predictive value 57%.

CONCLUSIONS

Intestinal ultrasound is an accurate noninvasive marker of histological disease activity in UC, the accuracy of which is further enhanced when used in composite with FC. This can reduce the need for colonoscopy in routine care by supporting accurate point-of-care decision-making in patients with UC.

Is a Lower Dose of More Bioavailable Iron (18-mg Ferrous Bisglycinate) Noninferior to 60-mg Ferrous Sulfate in Increasing Ferritin Concentrations While Reducing Gut Inflammation and Enteropathogen Detection in Cambodian Women? A Randomized Controlled Noninferiority Trial

BACKGROUND

Global guidelines recommend untargeted iron supplementation for women in regions of anemia prevalence ≥40%, such as Cambodia. However, the potential harms of untargeted iron on the gut have not been rigorously studied in women and likely vary depending on iron dose and form.

OBJECTIVES

We investigated if a lower dose of a highly bioavailable iron amino acid chelate was as effective as the standard dose of iron salts in increasing ferritin concentrations and whether any differences were observed in gut inflammation or enteropathogen detection.

METHODS

A double-blind, randomized placebo-controlled noninferiority trial was conducted in Cambodia. Nonpregnant women (n = 480, 18-45 y) were randomly assigned to 60-mg ferrous sulfate, 18-mg ferrous bisglycinate, or placebo for 12 wk. Nonfasting blood and stool specimens were collected at baseline and 12 wk. Ferritin and fecal calprotectin were measured with an ELISA. A molecular assay was used to detect 11 enteropathogens in a random subset of n = 100 women. Generalized linear mixed-effects models were used to estimate the adjusted mean difference in ferritin concentrations at 12 wk (primary outcome), as compared with our 'a priori' noninferiority margin of 20 μg/L.

RESULTS

Baseline anemia and iron deficiency prevalence was low (17% and 6%, respectively). The adjusted mean difference in ferritin concentrations between the iron groups was 14.6 (95% confidence interval [CI]: 7.6, 21.6) μg/L. Mean ferritin concentration at 12 wk was higher in the ferrous sulfate (99 [95% CI: 95, 103] μg/L, P < 0.001) than in ferrous bisglycinate (84 [95% CI: 80, 88] μg/L) and placebo groups (78 [95% CI: 74, 82] μg/L). No differences in fecal calprotectin concentrations or enteropathogen detection were observed across groups at 12 wk.

CONCLUSIONS

Ferrous bisglycinate (18-mg) was not as effective as ferrous sulfate (60-mg) in increasing ferritin concentrations and did not differentially influence biomarkers of gut health in this predominantly iron-replete population of Cambodian women. This trial was registered at clinicaltrials.gov registry as NCT04017598.

Fecal Calprotectin in Gastrointestinal Disease

BACKGROUND

Inflammatory bowel disease (IBD) comprises a group of chronic conditions characterized by relapsing and remitting inflammation of the gastrointestinal tract. The incidence is increasing worldwide, and the therapeutic options for management are expanding. Endoscopy is the gold standard investigation for diagnosis of IBD and for assessing mucosal healing, which is increasingly being used as a measure of disease control. However, it is an invasive procedure that is unpleasant for patients and expensive and time-consuming for hospitals. Fecal calprotectin has been shown to be an accurate surrogate marker of gastrointestinal inflammation in IBD.

CONTENT

Fecal calprotectin was initially used for the diagnosis of IBD but is now recognized as having a role in assisting in assessment of disease activity, prediction of relapse, and informing decisions around therapy and may help to minimize requirement for endoscopy. However, there are various preanalytical and analytical factors that can affect interpretation of the results; these need to be understood to optimize clinical care.

SUMMARY

Preanalytical and analytical factors that can potentially influence fecal calprotectin concentrations are examined, and an overview is provided of clinical situations in which fecal calprotectin is commonly measured.

The Reliability of Patient-Performed Fecal Calprotectin Testing in Inflammatory Bowel Disease

BACKGROUND

Home use of a buffer-containing extraction device for fecal calprotectin determination can bypass the labor-intensive extraction procedure and potentially prevent degradation at room temperature.

METHODS

In this prospective cross-sectional observational study, 2 CALiaGold tubes (extraction device) and one native tube were filled from the same bowel movement by patients with inflammatory bowel disease. Afterwards patients completed a questionnaire including whether they preferred the extraction device or the normal sampling method. All tubes were sent to the laboratory and when they arrived, 2 more CALiaGold tubes were filled at the laboratory from the native sample. The fecal calprotectin concentrations in all tubes were measured by a particle-enhanced turbidimetric immunoassay.

RESULTS

Fifty-three patients were included in the study. Fecal calprotectin levels were significantly higher in samples extracted by the patient compared to the analyst-performed extractions. When patients were divided into 3 groups (i.e., fecal calprotectin levels <50 ug/g, 50 to 200 µg/g, and >200 µg/g) a substantial concordance was found (Cohen kappa 0.654). Patients sampling imprecision was higher (P < 0.018, median CV 16%) compared to the analyst. Most patients preferred this extraction device.

CONCLUSIONS

Patient-performed fecal calprotectin extraction seems a realistic alternative sampling method and is preferred by most patients.

Endoscopic Postoperative Recurrence in Crohn's Disease After Curative Ileocecal Resection with Early Prophylaxis by Anti-TNF, Vedolizumab or Ustekinumab: A Real-World Multicentre European Study

BACKGROUND

Endoscopic-post-operative-recurrence [ePOR] in Crohn's disease [CD] after ileocecal resection [ICR] is a major concern. We aimed to evaluate the effectiveness of early prophylaxis with biologics and to compare anti-tumour necrosis factor [anti-TNF] therapy to vedolizumab [VDZ] and ustekinumab [UST] in a real-world setting.

METHODS

A retrospective multicentre study of CD-adults after curative ICR on early prophylaxis was undertaken. ePOR was defined as a Rutgeerts score [RS] ≥ i2 or colonic-segmental-SES-CD ≥ 6. Multivariable logistic regression was used to evaluate risk factors, and inverse probability treatment weighting [IPTW] was applied to compare the effectiveness between agents.

RESULTS

The study included 297 patients (53.9% males, age at diagnosis 24 years [19-32], age at ICR 34 years [26-43], 18.5% smokers, 27.6% biologic-naïve, 65.7% anti-TNF experienced, 28.6% two or more biologics and 17.2% previous surgery). Overall, 224, 39 and 34 patients received anti-TNF, VDZ or UST, respectively. Patients treated with VDZ and UST were more biologic experienced with higher rates of previous surgery. ePOR rates within 1 year were 41.8%. ePOR rates by treatment groups were: anti-TNF 40.2%, VDZ 33% and UST 61.8%. Risk factors for ePOR at 1 year were: past-infliximab (adjusted odds ratio [adj.OR] = 1.73 [95% confidence interval, CI: 1.01-2.97]), past-adalimumab [adj.OR = 2.32 [95% CI: 1.35-4.01] and surgical aspects. After IPTW, the risk of ePOR within 1 year of VDZ vs anti-TNF or UST vs anti-TNF was comparable (OR = 0.55 [95% CI: 0.25-1.19], OR = 1.86 [95% CI: 0.79-4.38]), respectively.

CONCLUSION

Prevention of ePOR within 1 year after surgery was successful in ~60% of patients. Patients treated with VDZ or UST consisted of a more refractory group. After controlling for confounders, no differences in ePOR risk were seen between anti-TNF prophylaxis and other groups.

Polyphenols and Ulcerative Colitis: An Exploratory Study of the Effects of Red Wine Consumption on Gut and Oral Microbiome in Active-Phase Patients

SCOPE

This paper explores the effects of moderate red wine consumption on the clinical status and symptomatology of patients with ulcerative colitis (UC), including the study of the oral and intestinal microbiome.

METHODS AND RESULTS

A case control intervention study in UC patients is designed. Intervention patients (n = 5) consume red wine (250 mL day^-1 ) for 4 weeks whereas control patients (n = 5) do not. Moderate wine consumption significantly (p < 0.05) improves some clinical parameters related to serum iron, and alleviates intestinal symptoms as evaluated by the IBDQ-32 questionnaire. 16S rRNA gene sequencing indicate a non-significant (p > 0.05) increase in bacterial alpha diversity after wine intervention in both saliva and fecal microbiota. Additional comparison of taxonomic data between UC patients (n = 10) and healthy subjects (n = 8) confirm intestinal dysbiosis for the UC patients. Finally, analysis of fecal metabolites (i.e., phenolic acids and SCFAs) indicates a non-significant increase (p > 0.05) for the UC patients that consumed wine.

CONCLUSIONS

Moderate and regular red wine intake seems to improve the clinical status and symptoms of UC patients in the active phase of the disease. However, studies with a greater sample size are required to achieve conclusive results.

New Faecal Calprotectin Assay by IDS: Validation and Comparison to DiaSorin Method

Background: The faecal calprotectin (FC) measurement is used for inflammatory bowel disease (IBD) diagnosis and follow-up. The aim of this study was to validate for the first time the new IDS FC extraction device and immunoassay kit, and to compare it with the DiaSorin test in patients with and without IBD. Methods: First, the precision of the IDS assay and its stability were assessed. Then, 379 stool extracts were analysed with the IDS kit on iSYS and compared with a DiaSorin Liaison XL assay. Results: The intra- and inter-assay CVs did not exceed 5%. The stool samples were stable up to 4 weeks at −20 °C. Lot-to-lot comparison showed a good correlation (Lot1 = 1.06 × Lot2 + 0.60; p > 0.05). The Passing and Bablok regression showed no significant deviation from linearity between the two methods (IDS = 1.06 × DiaSorin − 0.6; p > 0.05; concordance correlation coefficient = 0.93). According to the recommended cut-offs, the IDS assay identified more IBD and irritable bowel syndrome patients than DiaSorin, which had more borderline results (16 vs. 20%, respectively). Conclusions: The IDS faecal calprotectin had good analytical validation parameters. Compared to the DiaSorin method, it showed comparable results, but slightly outperformed it in the identification of more IBD patients and active disease.

Intestinal Ultrasound Early on in Treatment Follow-up Predicts Endoscopic Response to Anti-TNFα Treatment in Crohn's Disease

BACKGROUND

To assess treatment response, objective measures are superior to clinical improvement in Crohn's disease [CD]. Intestinal ultrasound [IUS] is an attractive, non-invasive alternative to endoscopy, demonstrating early transmural changes after treatment initiation. Therefore, we investigated IUS and contrast-enhanced ultrasound [CEUS] to predict [early] endoscopic treatment response.

METHODS

Consecutive patients with endoscopically active CD, starting anti-TNFα therapy, were included. Clinical, biochemical, IUS, and CEUS parameters at baseline [T0], after 4-8 weeks [T1] and 12-34 weeks [T2] were collected. The most severely inflamed segment at endoscopy (highest segmental Simplified Endoscopic Score for Crohn's Disease [SES-CD]) and IUS (highest segmental bowel wall thickness [BWT]) was identified. At T2, endoscopic response [decrease in SES-CD ≥ 50%] and remission [SES-CD = 0] were scored.

RESULTS

A total of 40 patients were included: 14 reached endoscopic remission and 17 endoscopic response. At T1 (3.1 mm [1.9-4.2] vs 5.3 mm [3.8-6.9], p = 0.005) and T2 (2.0 mm [1.8-3.1] vs 5.1 [3.0-6.3] mm, p = 0.002) BWT was lower in patients with endoscopic remission. At T1 and T2, 18% (area under the receiver operating curve [AUROC]: 0.77; odds ratio [OR]: 10.80, p = 0.012) and 29% [AUROC: 0.833; OR: 37.50, p = 0.006] BWT decrease predicted endoscopic response, respectively. To determine endoscopic remission, BWT 3.2 mm was most accurate [AUROC: 0.94; OR: 39.42, p < 0.0001] at T2. In addition, absence of colour Doppler signal [OR: 13.76, p = 0.03] and the CEUS parameter wash-out rate [OR: 0.76, p = 0.019] improved the prediction model.

CONCLUSIONS

Reduction in BWT, already after 4-8 weeks of follow-up, predicted endoscopic response and remission. CEUS parameters were of limited value. Furthermore, we have provided accurate cut-offs for BWT reflecting endoscopic response and remission at different time points.

Measurement of Serum IgG Anti-Integrin αvβ6 Autoantibodies Is a Promising Tool in the Diagnosis of Ulcerative Colitis

IgG anti-integrin αvβ6 autoantibodies (IgG anti-αvβ6) have been described as highly sensitive and specific markers of ulcerative colitis (UC) in the sera of Japanese inflammatory bowel disease (IBD) patients. We aimed to evaluate the diagnostic performance of IgG anti-αvβ6 as a biomarker in Swedish patients with IBD or irritable bowel syndrome (IBS). The study included adult UC (n = 59), Crohn’s disease (CD, n = 38), and IBS patients (n = 100). Partial Mayo score and Harvey−Bradshaw index were used to assess disease severity for UC and CD, respectively. Serum levels of IgG anti-αvβ6, reported as absorbance units (AU), were measured using an in-house ELISA where the 95th percentile of 76 healthy controls defined positivity. Faecal calprotectin (fCP) was measured using a commercial assay. The majority of the IBD patients were on medical treatment, and many were in remission (UC: 40.7%; CD: 47.4%). Seventy-one percent of the UC patients, 74.2% of CD patients, and 23.1% of the IBS patients had fCP test results >50 mg/kg. The UC group had significantly higher IgG anti-αvβ6 levels (median: 1.76 AU) than the CD and IBS groups (0.34 and 0.31 AU, both p < 0.0001). The diagnostic sensitivity of IgG anti-αvβ6 in UC was 76.3%, and the specificities were 79.0% (vs. CD) and 96.0% (vs. IBS). The IgG anti-αvβ6 levels related to disease severity of the UC patients (p < 0.01−0.05). Our study shows that IgG anti-αvβ6 is associated with UC in Swedish IBD patients and that the levels of the autoantibodies reflect disease severity. IgG anti-αvβ6 could be an attractive complement to fCP in the diagnostic work up of IBD patients.

Elevated Serum D-Dimer May Reflect the Presence of Gut Inflammation in Spondyloarthritis

Background

To investigate the association of D-dimer with gut inflammation in spondyloarthritis (SpA).

Methods

Sixty-five patients with SpA and 70 healthy controls were included. Demographic, clinical, and laboratory parameters were collected. The differences of clinical and laboratory parameters were compared between patients with SpA and healthy controls, and between patients with SpA, with and without gut inflammation. The associations of D-dimer with laboratory data were analyzed. The predictive value of D-dimer was obtained by a receiver operator characteristic (ROC) curve analysis. The independent risk factors for gut inflammation in SpA were investigated by binary logistic regression analysis.

Results

Patients with SpA had higher D-dimer than healthy controls (P = 0.016). D-dimer was positively correlated with platelet (PLT), erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP), and negatively correlated with hemoglobin (Hb). Besides, significant differences were observed in D-dimer between SpA patients with and without gut inflammation (P < 0.001). Furthermore, SpA patients with gut inflammation were more likely to have peripheral joint involvement than those without gut inflammation (P < 0.001). The AUC of D-dimer was 0.865 at cut-off value of 0.29 mg/L, with a sensitivity of 82.6%, and a specificity of 81%. Elevated D-dimer (OR = 15.451, 95% CI: 3.030–78.780, P = 0.001) was independently associated with gut inflammation in SpA.

Conclusion

D-dimer may be a potential biomarker for identifying SpA patients with gut inflammation.

A Computational Platform Integrating a Mechanistic Model of Crohn's Disease for Predicting Temporal Progression of Mucosal Damage and Healing

INTRODUCTION

Physicians are often required to make treatment decisions for patients with Crohn's disease on the basis of limited objective information about the state of the patient's gastrointestinal tissue while aiming to achieve mucosal healing. Tools to predict changes in mucosal health with treatment are needed. We evaluated a computational approach integrating a mechanistic model of Crohn's disease with a responder classifier to predict temporal changes in mucosal health.

METHODS

A hybrid mechanistic-statistical platform was developed to predict biomarker and tissue health time courses in patients with Crohn's disease. Eligible patients from the VERSIFY study (n = 69) were classified into archetypical response cohorts using a decision tree based on early treatment data and baseline characteristics. A virtual patient matching algorithm assigned a digital twin to each patient from their corresponding response cohort. The digital twin was used to forecast response to treatment using the mechanistic model.

RESULTS

The responder classifier predicted endoscopic remission and mucosal healing for treatment with vedolizumab over 26 weeks, with overall sensitivities of 80% and 75% and overall specificities of 69% and 70%, respectively. Predictions for changes in tissue damage over time in the validation set (n = 31), a measure of the overall performance of the platform, were considered good (at least 70% of data points matched), fair (at least 50%), and poor (less than 50%) for 71%, 23%, and 6% of patients, respectively.

CONCLUSION

Hybrid computational tools including mechanistic components represent a promising form of decision support that can predict outcomes and patient progress in Crohn's disease.

Role of Biomarkers in the Diagnosis and Treatment of Inflammatory Bowel Disease

The number of patients with inflammatory bowel disease (IBD) is increasing worldwide. Endoscopy is the gold standard to assess the condition of IBD. The problem with this procedure is that the burden and cost on the patient are high. Therefore, the identification of a reliable biomarker to replace endoscopy is desired. Biomarkers are used in various situations such as diagnosis of IBD, evaluation of disease activity, prediction of therapeutic effect, and prediction of relapse. C-reactive protein and fecal calprotectin have a lot of evidence as objective biomarkers of disease activity in IBD. The usefulness of the fecal immunochemical test, serum leucine-rich glycoprotein, and urinary prostaglandin E major metabolite have also been reported. Herein, we comprehensively review the usefulness and limitations of biomarkers that can be used in daily clinical practice regarding IBD. To date, no biomarker is sufficiently accurate to replace endoscopy; however, it is important to understand the characteristics of each biomarker and use the appropriate biomarker at the right time in daily clinical practice.

International consensus on methodological issues in standardization of fecal calprotectin measurement in inflammatory bowel diseases

BACKGROUND

Fecal calprotectin (FC) is a non-invasive marker of gut inflammation which is frequently used to guide therapeutic decisions in patients with inflammatory bowel diseases (IBD). Each step of FC measurement can influence the results, leading to misinterpretations and potentially impacting the management of IBD patients. To date, there is high heterogeneity between FC measurements and no current method is universally accepted as a standard.

AIMS

Our aim was to provide clear position statementsabout the pre-analytical and the analytical phases of FC measurement to homogenize FC levels and to minimize variability and risk of misinterpretation through aninternational consensus.

MATERIALS & METHODS

Fourteen physicians with expertise in the field of IBD and FC from 11 countries attended a virtual international consensus meeting on July 17th, 2020. A systematic literature was conducted and the literature evidence was shared and discussedamong the participants. Statements were formulated, discussed, and voted. Statements were considered approved if all participants agreed.

RESULTS

Nine statements were formulated and approved. Based on the available evidence, quantitative tests should be preferred for measuring FC. Furthermore, FC measurement, if possible, should always be performed with the same method and factors influencing FC levels should be taken into account when interpreting the results.

DISCUSSION

FC has an increasingly important role in the management of patients with IBD. However, large multicenter studies should be conducted to define the reproducibility and to confirm the diagnostic accuracy of the available FC tests.

CONCLUSION

FC concentrations guide clinicians' treatment decisions. Our statements have a relevant impact in daily practice and could be applied in clinical trials to standardize FC measurement.

Moderate-to-severe Endoscopic Inflammation is Frequent After Clinical Remission in Pediatric Ulcerative Colitis

OBJECTIVES

Pediatric ulcerative colitis (UC) is characterized by low sustained remission rates and frequent extension of disease even if clinical remission is obtained with therapy. Moderate-to-severe endoscopic activity is a risk factor for relapse while prospective evidence regarding early mucosal healing or persistence of inflammation after remission in children is not available. Our aim was to evaluate if significant inflammation is common after clinical remission and could explain the high relapse rate in pediatric UC.

METHODS

Pediatric UC patients with clinical remission, defined as pediatric UC activity index (PUCAI) scores <10, were prospectively assessed for mucosal healing by endoscopy 3 to 5 months after remission was documented. Mayo score was assessed for each segment by a blinded adult gastroenterologist using central reading. Symptomatic patients before sigmoidoscopy were excluded. Sustained remission was assessed retrospectively at 18 months follow-up.

RESULTS

Forty-two children were screened, 28 children in continuous clinical remission at time of sigmoidoscopy were included. Mayo 0 was present in 12/28 (42.86%), Mayo 1 in 2/28 (7.1%) and Mayo 2 to 3 in 14/28 (50.0%) endoscopies. Among 23 patients with follow-up through 18 months, remission was sustained in 6/12 (50.0%) with Mayo score 0 to 1 versus 2/11 (18.18%) of patients with Mayo 2 and 3.

CONCLUSIONS

Over 50% of children assessed for mucosal healing 3 to 5 months after clinical remission is obtained, have endoscopic disease, primarily moderate-to-severe Mayo 2 to 3 inflammation, which was associated with lower sustained remission.

A Practical Guide for Faecal Calprotectin Measurement: Myths and Realities

BACKGROUND AND AIMS

Faecal calprotectin [FC] is a valid and non-invasive marker of mucosal inflammation. It is widely used both in clinical trials and in daily clinical practice for patients with inflammatory bowel diseases, but currently no accepted standardization for FC testing is available. Our primary aim here was to provide a clinician's guide containing all the practical information on FC measurement in order to avoid any confounding factors, to minimize intra- and inter-individual variability in dosage, and to ensure a better and adequate interpretation of the results.

METHODS

We conducted a detailed search of the scientific literature in the PubMed/MEDLINE, EMBASE and Cochrane databases up to January 2020 to find all relevant and available articles on pre-analytical and analytical phases of FC measurement.

RESULTS

FC testing is a multi-step procedure consisting of a pre-analytical phase aimed to collect and process the stool sample and a subsequent analytical phase of FC measurement. Several factors can influence test results determining false positives or false negatives. Importantly, this faecal marker is mostly used for patient follow-up and as a predictor of treatment response. For this reason, any altered data may affect the physicians' decisions, negatively impacting on patient management.

CONCLUSIONS

This review provides for the first time practical advice to minimize dosage variability, although further dedicated studies are needed to compare commercially available tests and identify the best tools for the most precise and accurate FC measurement.

Repeated prolonged moderate-intensity walking exercise does not appear to have harmful effects on inflammatory markers in patients with inflammatory bowel disease

BACKGROUND AND OBJECTIVES

The role of exercise in the management of inflammatory bowel disease (IBD) is inconclusive as most research focused on short or low-intensity exercise bouts and subjective outcomes. We assessed the effects of repeated prolonged moderate-intensity exercise on objective inflammatory markers in IBD patients.

METHODS

In this study, IBD patients (IBD walkers, n = 18), and a control group (non-IBD walkers, n = 19), completed a 30, 40 or 50 km walking exercise on four consecutive days. Blood samples were taken at baseline and every day post-exercise to test for the effect of disease on exercise-induced changes in cytokine concentrations. A second control group of IBD patients who did not take part in the exercise, IBD non-walkers (n = 19), was used to test for the effect of exercise on faecal calprotectin. Both IBD groups also completed a clinical disease activity questionnaire.

RESULTS

Changes in cytokine concentrations were similar for IBD walkers and non-IBD walkers (IL-6 p = .95; IL-8 p = .07; IL-10 p = .40; IL-1β p = .28; TNF-α p = .45), with a temporary significant increase in IL-6 (p < .001) and IL-10 (p = .006) from baseline to post-exercise day 1. Faecal calprotectin was not affected by exercise (p = .48). Clinical disease activity did not change in the IBD walkers with ulcerative colitis (p = .92), but did increase in the IBD walkers with Crohn's disease (p = .024).

CONCLUSION

Repeated prolonged moderate-intensity walking exercise led to similar cytokine responses in participants with or without IBD, and it did not affect faecal calprotectin concentrations, suggesting that IBD patients can safely perform this type of exercise.

Platelet-to-lymphocyte percentage ratio index: a simple non-invasive index to monitor the endoscopic activity in Crohn's disease

BACKGROUND

Recent evidence has shown that the complete blood count (CBC) is abnormal in patients with Crohn's disease (CD). We aimed to investigate an effective CBC parameter and explore its impact on disease activity in a large CD cohort.

METHODS

We performed a retrospective analysis of patients with established CD who underwent clinically indicated endoscopy at four tertiary centres in China between 2016 and 2020. Individual variables of the Simple Endoscopic Score for CD, CBC parameters, C-reactive protein (CRP) levels, erythrocyte sedimentation rate, and faecal calprotectin (FC) were independently reviewed by different investigators. The hold-out method was used to verify the predictive power of the established model.

RESULTS

Data from a total of 1388 endoscopic procedures performed for 882 eligible CD patients were available with routine blood parameters and related indicators. The model using platelet-to-lymphocyte percentage ratio (PLpR) had high accuracy for identifying patients in endoscopic remission (ER), with an area under the curve (AUC) of 0.785 [95% confidence interval (CI): 0.784-0.787], which was comparable with that for CRP (AUC: 0.775, 95% CI: 0.774-0.777). Notably, the AUC of PLpR was significantly higher than that of CRP in patients with colonic disease and with a history of surgery. Moreover, after combining the FC with PLpR, the AUC value of FC + PLpR increased up to 0.892 (95% CI: 0.890-0.894) for identifying ER.

CONCLUSIONS

We explored an index (PLpR) to identify CD patients in ER based on platelet and lymphocyte percentage from the CBC. PLpR helped evaluate the degree of disease activity and monitor the therapeutic response.

Bacterial Taxa and Functions Are Predictive of Sustained Remission Following Exclusive Enteral Nutrition in Pediatric Crohn's Disease

BACKGROUND

The gut microbiome is extensively involved in induction of remission in pediatric Crohn's disease (CD) patients by exclusive enteral nutrition (EEN). In this follow-up study of pediatric CD patients undergoing treatment with EEN, we employ machine learning models trained on baseline gut microbiome data to distinguish patients who achieved and sustained remission (SR) from those who did not achieve remission nor relapse (non-SR) by 24 weeks.

METHODS

A total of 139 fecal samples were obtained from 22 patients (8-15 years of age) for up to 96 weeks. Gut microbiome taxonomy was assessed by 16S rRNA gene sequencing, and functional capacity was assessed by metagenomic sequencing. We used standard metrics of diversity and taxonomy to quantify differences between SR and non-SR patients and to associate gut microbial shifts with fecal calprotectin (FCP), and disease severity as defined by weighted Pediatric Crohn's Disease Activity Index. We used microbial data sets in addition to clinical metadata in random forests (RFs) models to classify treatment response and predict FCP levels.

RESULTS

Microbial diversity did not change after EEN, but species richness was lower in low-FCP samples (<250 µg/g). An RF model using microbial abundances, species richness, and Paris disease classification was the best at classifying treatment response (area under the curve [AUC] = 0.9). KEGG Pathways also significantly classified treatment response with the addition of the same clinical data (AUC = 0.8). Top features of the RF model are consistent with previously identified IBD taxa, such as Ruminococcaceae and Ruminococcus gnavus.

CONCLUSIONS

Our machine learning approach is able to distinguish SR and non-SR samples using baseline microbiome and clinical data.

Soluble Blood Markers of Mucosal Healing in Inflammatory Bowel Disease: The Future of Noninvasive Monitoring

The traditional management of inflammatory bowel disease (IBD) based on symptom control is not considered valid anymore by most specialists in this field, and a new paradigm called "treat to target" has been introduced. This is based on the assessment of disease activity using objective measures. The identification of noninvasive biomarkers is crucial to diagnosis and monitor IBD because frequent endoscopic examinations are costly and uncomfortable for the patient. In this review, we focus on blood markers that may be able to assess mucosal healing (MH) in IBD and recent advances in this area. Introduction of commercial panel to predict MH opens the way for further developments so that colonoscopy or fecal markers may be avoided in some patients. This may also permit frequent monitoring for therapeutic response and achieve MH. It is a challenging area of research to identify a panel of biomarkers that may reflect inflammation and healing to serve as a surrogate of MH.