What is the role of C-reactive protein and fecal calprotectin in evaluating Crohn's disease activity?

The Relationship Between the Endoscopic Healing Index, Fecal Calprotectin, and Magnetic Resonance Enterography in Crohn's Disease

INTRODUCTION

The serum-based endoscopic healing index (EHI) test identifies endoscopic Crohn's disease (CD) activity. Data are lacking on the relationship between EHI with other endpoints. We assessed the relationship between EHI and the simplified Magnetic Resonance Index of Activity.

MATERIALS AND METHODS

Data were prospectively collected on patients with CD with either an EHI or fecal calprotectin (FCAL) within 90 days of magnetic resonance enterography (MRE). Diagnostic accuracy was assessed using area under the receiver operator characteristics. Proportions with any, severe, and terminal ileum MR inflammation were compared above/below identified thresholds for both EHI and FCAL.

RESULTS

A total of 241 MREs paired to either EHI or FCAL from 155 patients were included. Both EHI and FCAL had similar accuracy to diagnose inflammation (area under the receiver operator characteristics: EHI: 0.635 to 0.651, FCAL: 0.680 to 0.708). Optimal EHI values were 42 and 26 for inflammation on MRE and endoscopy, respectively. Patients with EHI ≥42 (100% vs. 63%, P =0.002), FCAL >50 µg/g (87% vs. 64%, P <0.001) and FCAL >250 µg/g (90% vs. 75%, P =0.02) had higher rates of simplified Magnetic Resonance Index of Activity ≥1 compared with lower values. EHI differentiated ileitis numerically more than FCAL (delta: 24% to 25% vs. 11% to 21%). Patients with FCAL ≥50 µg/g had higher rates of severe inflammation compared with FCAL <50 µg/g (75% vs. 47%, P <0.001), whereas smaller differentiation existed for EHI threshold of 42 (63% vs. 49%, P =0.35).

CONCLUSION

Both EHI and FCAL were specific in their confirmation of inflammation and disease activity on MRE in patients with CD. However, MRE-detected inflammation was frequently present in the presence of low EHI and FCAL in similar proportions.

Baseline TREM-1 Whole Blood Gene Expression Does Not Predict Response to Adalimumab Treatment in Patients with Ulcerative Colitis or Crohn's Disease in the SERENE Studies

BACKGROUND AND AIMS

This study assessed whether baseline triggering receptor expressed on myeloid cells [TREM-1] whole blood gene expression predicts response to anti-tumour necrosis factor [anti-TNF] therapy in patients with ulcerative colitis [UC] or Crohn's disease [CD].

METHODS

TREM-1 whole blood gene expression was analysed by RNA sequencing in patients with moderately to severely active UC or CD treated with adalimumab in the Phase 3 SERENE-UC and SERENE-CD clinical trials. The predictive value of baseline TREM-1 expression was evaluated and compared according to endoscopic and clinical response vs non-response, and remission vs non-remission, at Weeks 8 and 52 [SERENE-UC], and Weeks 12 and 56 [SERENE-CD].

RESULTS

TREM-1 expression was analysed in 95 and 106 patients with UC and CD, respectively, receiving standard-dose adalimumab induction treatment. In SERENE-UC, baseline TREM-1 expression was not predictive of endoscopic response [p = 0.48], endoscopic remission [p = 0.53], clinical response [p = 0.58], or clinical remission [p = 0.79] at Week 8, or clinical response [p = 0.60] at Week 52. However, an association was observed with endoscopic response [p = 0.01], endoscopic remission [p = 0.048], and clinical remission [p = 0.04997] at Week 52. For SERENE-CD, baseline TREM-1 expression was not predictive of endoscopic response [p = 0.56], endoscopic remission [p = 0.33], clinical response [p = 0.07], or clinical remission [p = 0.65] at Week 12, or endoscopic response [p = 0.61], endoscopic remission [p = 0.51], clinical response [p = 0.62], or clinical remission [p = 0.97] at Week 56.

CONCLUSIONS

Baseline TREM-1 gene expression did not uniformly predict adalimumab response in SERENE clinical trials. Further research is needed to identify potential blood-based biomarkers predictive of response to anti-TNF therapy in patients with inflammatory bowel disease.

CLINICALTRIALS.GOV IDENTIFIERS

NCT02065622; NCT02065570.

Plasminogen Activator Inhibitor 1 Is a Novel Faecal Biomarker for Monitoring Disease Activity and Therapeutic Response in Inflammatory Bowel Diseases

BACKGROUND AND AIMS

Crohn's disease [CD] and ulcerative colitis [UC] require lifelong treatment and patient monitoring. Current biomarkers have several limitations; therefore, there is an unmet need to identify novel biomarkers in inflammatory bowel disease [IBD]. Previously, the role of plasminogen activator inhibitor 1 [PAI-1] was established in the pathogenesis of IBD and suggested as a potential biomarker. Therefore, we aimed to comprehensively analyse the selectivity of PAI-1 in IBD, its correlation with disease activity, and its potential to predict therapeutic response.

METHODS

Blood, colon biopsy, organoid cultures [OC], and faecal samples were used from active and inactive IBD patients and control subjects. Serpin E1 gene expressions and PAI-1 protein levels and localisation in serum, biopsy, and faecal samples were evaluated by qRT-PCR, ELISA, and immunostaining, respectively.

RESULTS

The study population comprised 132 IBD patients [56 CD and 76 UC] and 40 non-IBD patients. We demonstrated that the serum, mucosal, and faecal PAI-1 concentrations are elevated in IBD patients, showing clinical and endoscopic activity. In responders [decrease of eMayo ≥3 in UC; or SES-CD  50% in CD], the initial PAI-1 level decreased significantly upon successful therapy. OCs derived from active IBD patients produced higher concentrations of PAI-1 than the controls, suggesting that epithelial cells could be a source of PAI-1. Moreover, faecal PAI-1 selectively increases in active IBD but not in other organic gastrointestinal diseases.

CONCLUSIONS

The serum, mucosal, and faecal PAI-1 concentration correlates with disease activity and therapeutic response in IBD, suggesting that PAI-1 could be used as a novel, non-invasive, disease-specific, faecal biomarker in patient follow-up.

Longitudinal Measurements of Blood Biomarkers in Patients with Crohn's Disease or Ulcerative Colitis Treated with Infliximab: Only the Latest Values in the Induction Period Predict Treatment Failure

Background: Few studies have incorporated longitudinal assessments or used combinations of blood biomarkers as predictors of loss of response to biologic therapy for patients with Crohn's disease (CD) or ulcerative colitis (UC). Methods: This is a population-based cohort study comprising Danish patients with CD or UC from 2008 to 2018. We used logistic regression to analyze whether levels and changes in levels of C-reactive protein (CRP), serum albumin, and hemoglobin, routinely measured during a 14-week infliximab induction period, predicted a change to another biologic medication or cessation of biologic therapy. Results: During the induction period, 2883 (1626 CD, 1257 UC) patients had 12,730, 12,040, and 13,538 specimens with CRP, serum albumin, and hemoglobin, respectively. In all, 284 patients (9.9%) switched to another biologic medication, and 139 (4.8%) ceased biologic therapy in the follow-up period. Only the most recent CRP and hemoglobin levels predicted the efficacy of infliximab treatment at approximately 14 weeks, a time point when the clinician often determines whether to continue treatment. Conclusion: Measurement of blood biomarkers prior to the clinical assessment does not predict the effectiveness of infliximab.

Unveiling Distinct Proteomic Signatures in Complicated Crohn's Disease That Could Predict the Disease Course

Crohn's disease (CD) is characterized by a chronic, progressive inflammation of the gastrointestinal tract often leading to complications, such as strictures and fistulae. Currently, there are no validated tools anticipating short- and long-term outcomes at an early stage. This investigation aims to elucidate variations in protein abundance across distinct CD phenotypes with the objective of uncovering potential biomarkers implicated in disease advancement. Serum samples collected from 30 CD patients and 15 healthy age-matched controls (HC) were subjected to depletion of highly abundant proteins and to a label-free mass spectrometry analysis. Twenty-four proteins were shown to be significantly different when comparing CD with HC. Of these, WD repeat-containing protein 31 (WDR31), and proteins involved in the acute inflammatory response, leucine-rich alpha-2-glycoprotein (LRG1) and serum amyloid A1 (SAA1), were more abundant in the aggressive subgroup. Against standard biomarkers, a positive correlation between SAA1 and WDR31 and C-reactive protein (CRP) was found. In this study, a unique serum biomarker panel for aggressive CD was identified, which could aid in predicting the disease course.

Development of a multimodal machine-learning fusion model to non-invasively assess ileal Crohn's disease endoscopic activity

BACKGROUND AND OBJECTIVE

Recurrent attentive non-invasive observation of intestinal inflammation is essential for the proper management of Crohn's disease (CD). The goal of this study was to develop and evaluate a multi-modal machine-learning (ML) model to assess ileal CD endoscopic activity by integrating information from Magnetic Resonance Enterography (MRE) and biochemical biomarkers.

METHODS

We obtained MRE, biochemical and ileocolonoscopy data from the multi-center ImageKids study database. We developed an optimized multimodal fusion ML model to non-invasively assess terminal ileum (TI) endoscopic disease activity in CD from MRE data. We determined the most informative features for model development using a permutation feature importance technique. We assessed model performance in comparison to the clinically recommended linear-regression MRE model in an experimental setup that consisted of stratified 2-fold validation, repeated 50 times, with the ileocolonoscopy-based Simple Endoscopic Score for CD at the TI (TI SES-CD) as a reference. We used the predictions' mean-squared-error (MSE) and the receiver operation characteristics (ROC) area under curve (AUC) for active disease classification (TI SEC-CD≥3) as performance metrics.

RESULTS

121 subjects out of the 240 subjects in the ImageKids study cohort had all required information (Non-active CD: 62 [51%], active CD: 59 [49%]). Length of disease segment and normalized biochemical biomarkers were the most informative features. The optimized fusion model performed better than the clinically recommended model determined by both a better median test MSE distribution (7.73 vs. 8.8, Wilcoxon test, p<1e-5) and a better aggregated AUC over the folds (0.84 vs. 0.8, DeLong's test, p<1e-9).

CONCLUSIONS

Optimized ML models for ileal CD endoscopic activity assessment have the potential to enable accurate and non-invasive attentive observation of intestinal inflammation in CD patients. The presented model is available at https://tcml-bme.github.io/ML_SESCD.html.

Fecal Calprotectin for Small Bowel Crohn's Disease: Is It a Cutoff Issue?

(1) Background: Fecal calprotectin (FC) correlates well with colonic inflammatory activity of Crohn’s disease (CD); data about relation of FC and small bowel (SB) lesions are still contradictory. The main aim was to analyze the relationship between FC levels and SB inflammatory activity in patients with established or suspected Crohn’s disease, assessed by small bowel capsule endoscopy (SBCE) or magnetic resonance enterography (MRE). (2) Methods: Two cohorts of patients were included: 1. Prospective data were collected from patients with established or suspected CD who underwent SBCE and FC (Cohort A); 2. A retrospective cohort of patients who underwent MRE and FC determination (Cohort B). Different cutoffs for FC were tested in both cohorts. (3) Results: 83 patients were included and 66 were finally analyzed. A total of 69.6% had SB lesions seen by SBCE (n = 25) or MRE (n = 21). FC mean levels were 605.74 + 607.07 μg/g (IQ range: 99.00−878.75), being significantly higher in patients with SB lesions compared to patients without lesions (735.91 + 639.70 μg/g (IQ range: 107.75−1366.25) vs. 306.35 + 395.26 μg/g (IQ range: 78.25−411.0), p < 0.005). For cohort A, 25 out of 35 patients had SB lesions and a significant correlation between Lewis Score and FC levels was achieved (R2: 0.34; p = 0.04). FC sensitivity (S), specificity (E), positive predictive value (PPV), and negative predictive values (NPV) for predicting SB lesions were 80%, 50%, 80%, and 50%, respectively, for FC > 100 µg/g. For cohort B, inflammatory SB activity, measured by MaRIA score, was detected in 21 out of 31 patients (67.7%). Patients with positive findings in MRE had significantly higher values of FC than those with no lesions (944.9 + 672.1 µg/g vs. 221 + 212.2 µg/g, p < 0.05). S, E, PPV, and NPV of FC were 89%, 50%, 77.2%, and 71.4% for FC levels > 100 µg/g. The higher sensitivity and specificity of the FC levels for the detection of SB lesions with SBCE and MRE was obtained for an FC cutoff >265 μg/g and >430 μg/g, respectively. (4) Conclusions: FC has a good correlation with the presence of SB lesions, assessed by SBCE and MRE, in patients with established or suspected Crohn’s disease. However, the ideal cutoff is here proven to be higher than previously reported. Multicenter and large prospective studies are needed in order to establish definitive FC cutoff levels.

Combination of serological biomarkers and clinical features to predict mucosal healing in Crohn's disease: a multicenter cohort study

PURPOSE

Mucosal healing (MH) has become the treatment goal of patients with Crohn's disease (CD). This study aims to develop a noninvasive and reliable clinical tool for individual evaluation of mucosal healing in patients with Crohn's disease.

METHODS

A multicenter retrospective cohort was established. Clinical and serological variables were collected. Separate risk factors were incorporated into a binary logistic regression model. A primary model and a simple model were established, respectively. The model performance was evaluated with C-index, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy. Internal validation was performed in patients with small intestinal lesions.

RESULTS

A total of 348 consecutive patients diagnosed with CD who underwent endoscopic examination and review after treatment from January 2010 to June 2021 were composed in the derivation cohort, and 112 patients with small intestinal lesions were included in the validation cohort. The following variables were independently associated with the MH and were subsequently included into the primary prediction model: PLR (platelet to lymphocyte ratio), CAR (C-reactive protein to albumin ratio), ESR (erythrocyte sedimentation rate), HBI (Harvey-Bradshaw Index) score and infliximab treatment. The simple model only included factors of PLR, CAR and ESR. The primary model performed better than the simple one in C-index (87.5% vs. 83.0%, p = 0.004). There was no statistical significance between these two models in sensitivity (70.43% vs. 62.61%, p = 0.467), specificity (87.12% vs. 80.69%, p = 0.448), PPV (72.97% vs. 61.54%, p = 0.292), NPV (85.65% vs. 81.39%, p = 0.614), and accuracy (81.61% vs. 74.71%, p = 0.303). The primary model had good calibration and high levels of explained variation and discrimination in validation cohort.

CONCLUSIONS

This model can be used to predict MH in post-treatment patients with CD. It can also be used as an indication of endoscopic surveillance to evaluate mucosal healing in patients with CD after treatment.

LncRNA LUCAT1 as a Plasma Biomarker for Assessing Disease Activity in Adult Patients with Crohn's Disease

Aim

To explore the expression of long noncoding RNA (LncRNA) LUCAT1 in adult patients with Crohn's disease (CD) and evaluate the relationship between LncRNA LUCAT1 and the disease activity in Chinese patients with CD.

Methods

Patients with CD and healthy participants (≥18 years old) were enrolled in this study between January 2018 and December 2019. The expression of LncRNA LUCAT1 in plasma samples was evaluated by quantitative reverse transcription-polymerase chain reaction. Basic characteristics of patients with CD were collected, including gender, age, clinical stage, disease behavior, disease location, C-reactive protein (CRP), platelet (PLT), erythrocyte sedimentation rate (ESR), fecal calprotectin (FC), Crohn's disease activity index (CDAI) score, and simplified Crohn's disease endoscopic score (SES-CD).

Results

In total, 168 patients with CD and 65 healthy participants (≥18 years old) were enrolled in this study. Among them, ninety patients with clinically active CD, seventy-eight patients with CD in clinical remission, forty-eight patients with endoscopically active CD, thirty patients with endoscopically inactive CD, and sixty-five healthy participants. LncRNA LUCAT1 was increased in plasma of patients with CD compared with the control group. The plasma LncRNA LUCAT1 level of patients with CD both in the clinical and endoscopic active phase was higher than that of both the clinical and endoscopic remission phase. The plasma level of LncRNA LUCAT1 in patients with CD was positively correlated with ESR, CRP, FC, CDAI, and SES-CD. There was no significant correlation between the level of LUCAT1 and platelets. The plasma LncRNA LUCAT1 level in patients with CD had significant differences between severe active patients and mild/moderate active patients.

Conclusion

The plasma LncRNA LUCAT1 is positively associated with the disease activity in patients with CD, and it may act as a noninvasive biomarker to identify the degree of disease activity.

A Novel Model Based on Serum Biomarkers to Predict Primary Non-Response to Infliximab in Crohn's Disease

Background

Infliximab is effective in inducing and maintaining remission in patients with Crohn's disease (CD), but primary non-response (PNR) occurs in 10-30% of cases. We investigated whether serum biomarkers are effective in predicting PNR in patients with CD.

Methods

From January 2016 to April 2020, a total of 260 patients were recruited to this prospective and retrospective cohort study. Serum samples were collected at baseline and week 2 of infliximab treatment. Serum levels of 35 cytokines were assessed in 18 patients from the discovery cohort and were further evaluated in the 60-patient cohort 1. Then, candidate cytokines and other serological biomarkers were used to construct a predictive model by logistic regression in a 182-patient cohort 2. PNR was defined based on the change of CD activity index or clinical symptoms.

Results

Among the 35 cytokines, matrix metalloproteinase 3(MMP3) and C-C motif ligand 2 (CCL2) were two effective serum biomarkers associated with PNR in both the discovery cohort and cohort 1. In cohort 2, serum level of MMP3, CCL2 and C-reactive protein (CRP) at 2 weeks after infliximab injection were independent predictors of PNR, with odds ratios (95% confidence interval) of 1.108(1.059-1.159), 0.940(0.920-0.965) and 1.102(1.031-1.117), respectively. A PNR classifier combining these three indicators had a large area under the curve [0.896(95% CI:0.895-0.897)] and negative predictive value [0.918(95%CI:0.917-0.919)] to predict PNR to infliximab.

Conclusions

MMP3, CCL2, and CRP are promising biomarkers in prediction of PNR to infliximab, and PNR classifier could accurately predict PNR and may be useful in clinical practice for therapy selection.

Postoperative Ratio of C-Reactive Protein to Albumin as a Predictive Marker in Patients with Crohn's Disease Undergoing Bowel Resection

Background

The ratio of C-reactive protein (CRP) to albumin (CAR) has a significant correlation with postoperative complications and acts as a predictor in patients with pancreatic cancer and colorectal cancer. However, whether the CAR can be used to predict complications in Crohn's disease (CD) patients after surgery has not yet been reported.

Methods

A total of 534 CD patients undergoing surgery between 2016 and 2020 were enrolled. The risk factors of postoperative complications were assessed by univariate and multivariate analyses. The cutoff values and the accuracy of diagnosis for the CAR and postoperative CRP levels were examined with receiver operating characteristic (ROC) curves.

Results

The rate of postoperative complications was 32.2%. The postoperative CAR (OR 13.200; 95% CI 6.501-26.803; P < 0.001) was a significant independent risk factor for complications. Compared with the CRP level on postoperative day 3, the CAR more accurately indicated postoperative complications in CD patients (AUC: 0.699 vs. 0.771; Youden index: 0.361 vs. 0.599). ROC curves showed that the cutoff value for the CAR was 3.25. Patients with a CAR ≥ 3.25 had more complications (P < 0.001), a longer postoperative stay (15.5 ± 0.6 d vs. 9.0 ± 0.2 d, P < 0.001), and more surgical site infections (48.2% vs. 5.7%, P < 0.001) than those with a CAR < 3.25.

Conclusions

Compared to the CRP level, the CAR can more accurately predict postoperative complications and can act as a predictive marker in CD patients after surgery.

Treat-to-Target in Pediatric Inflammatory Bowel Disease: What Does the Evidence Say?

The traditional management of inflammatory bowel disease, based on treatment intensification guided by clinical activity alone, has been revised in the last 10 years and a treat-to-target approach has been proposed and is currently under evaluation as a disease-modifying strategy. Treat-to-target focuses on objective and scheduled measures to monitor intestinal damage, with consequent therapeutic adjustments in case of failure to achieve pre-defined targets. Identification of targets has been set out by the Selecting Therapeutic Targets in Inflammatory Bowel Disease (STRIDE) committee in 2015. Mucosal healing is universally accepted as the main target both in Crohn's disease and ulcerative colitis, given its proven association with better long-term outcomes than clinical remission alone. Equally important is to ensure patients' clinical remission and improve patient-reported outcomes. Transmural healing (for Crohn's disease) and histological remission (for ulcerative colitis), listed as adjunctive targets, are likely to become primary targets in the near future. The ultimate goal of this approach is to modify the natural history of inflammatory bowel diseases by trying to block bowel damage progression, with interventions in the pre-clinical stage. In this review, we will discuss the current recommended therapeutic targets, as well as those that are considered adjunctive targets, with a focus on the limited pediatric literature available. Prospective long-term trials are warranted in order to identify the most appropriate target for the pediatric population and its specific issues. Identification of reliable predictors of disease course, outcome, and response to treatment will help to individually adapt each step of this monitoring algorithm and consequent therapeutic decision.

Genetic Predictors of Long-term Response to Antitumor Necrosis Factor Agents in Pediatric Inflammatory Bowel Disease

OBJECTIVES

Inflammatory bowel disease (IBD) is more complex in children and they will have to live with the disease for much longer. For this reason, it is necessary to optimize treatment. The polymorphisms associated with the response to anti-tumor necrosis factor (TNF) drugs in adults with IBD have not been analyzed in children. The aim of the study was to identify genetic variants associated with the long-term response to anti-TNF drugs in children with IBD.

METHODS

An observational, longitudinal, ambispective cohort's study was conducted. We recruited 209 anti-TNF-treated children diagnosed with IBD and genotyped 21 polymorphisms previously studied in adults with Crohn disease (CD) using real-time PCR. The association between single-nucleotide polymorphisms (SNPs) and time-to-failure was analyzed using the log-rank test.

RESULTS

After multivariate analysis, 3 SNPs in IL10, IL17A and IL6 were significantly associated with response to anti-TNF treatment among patients diagnosed with CD (rs1800872-HR, 4.749 (95% confidence interval [CI] 1.156-19.517), P value < 0.05; rs2275913-HR, 0.320 [95% CI 0.111-0.920], P value  < 0.05; and rs10499563-HR, 0.210 [95% CI 0.047-0.947], P value 0.05, respectively). None of these SNPs were associated with response to infliximab in adults diagnosed with CD. Among patients diagnosed with ulcerative colitis (UC), 1 SNP in LY96 was significantly associated with response to anti-TNF treatment (rs-11465996-HR, 10.220 [95% CI 1.849-56.504] P value < 0.05).

CONCLUSIONS

Genotyping of these DNA variants before starting treatment may help to identify children who are long-term responders to anti-TNF drugs, and thus tailor treatment of pediatric IBD.

Gene Signatures of Early Response to Anti-TNF Drugs in Pediatric Inflammatory Bowel Disease

Around a 20–30% of inflammatory bowel disease (IBD) patients are diagnosed before they are 18 years old. Anti-TNF drugs can induce and maintain remission in IBD, however, up to 30% of patients do not respond. The aim of the work was to identify markers that would predict an early response to anti-TNF drugs in pediatric patients with IBD. The study population included 43 patients aged <18 years with IBD who started treatment with infliximab or adalimumab. Patients were classified into primary responders (n = 27) and non-responders to anti-TNF therapy (n = 6). Response to treatment could not be analyzed in 10 patients. Response was defined as a decrease in over 15 points in the disease activity indexes from week 0 to week 10 of infliximab treatment or from week 0 to week 26 of adalimumab treatment. The expression profiles of nine genes in total RNA isolated from the whole-blood of pediatric IBD patients taken before biologic administration and after 2 weeks were analyzed using qPCR and the 2^−∆∆Ct method. Before initiation and after 2 weeks of treatment the expression of SMAD7 was decreased in patients who were considered as non-responders (p value < 0.05). Changes in expression were also observed for TLR2 at T0 and T2, although that did not reach the level of statistical significance. In addition, the expression of DEFA5 decreased 1.75-fold during the first 2 weeks of anti-TNF treatment in responders, whereas no changes were observed in non-responders. Expression of the SMAD7 gene is a pharmacogenomic biomarker of early response to anti-TNF agents in pediatric IBD. TLR2 and DEFA5 need to be validated in larger studies.

Fecal Calprotectin, CRP and Leucocytes in IBD Patients: Comparison of Biomarkers With Biopsy Results

Background

This study aimed to compare fecal calprotectin (FC) levels with other commonly used parameters as part of patient care during evaluation for inflammatory bowel disease (IBD).

Methods

We recruited adult IBD patients with ulcerative colitis (UC) and Crohn's disease (CD) and compared the results of the patient's biopsy results (i.e., inflamed versus noninflamed) for six sites (i.e., ileum, ascending colon, transverse colon, descending colon, sigmoid colon, rectum) with concentrations of C-reactive protein (CRP), total leucocytes and fecal calprotectin (FC).

Results

We found that FC was significantly elevated in a concentration-dependent manner that correlated with the number of active inflammation sites reported in biopsy. Although CRP and leucocyte measurements trended upwards in line with inflammation reported from biopsy, the results were highly variable and highlighted poor reliability of these biomarkers for indicating IBD inflammation.

Conclusions

These results strongly suggest that FC correlates best with biopsy reports and is a superior marker than CRP and leucocytes.