Level of Fecal Calprotectin Correlates With Severity of Small Bowel Crohn's Disease, Measured by Balloon-assisted Enteroscopy and Computed Tomography Enterography

Efficient diagnosis for endoscopic remission in Crohn's diseases by the combination of three non-invasive markers

BACKGROUND

Serum C-reactive protein (CRP), leucine-rich alpha-2 glycoprotein (LRG), and fecal calprotectin (Fcal) are non-invasive markers used to assess Crohn's disease (CD) severity. However, the accuracy of these markers alone is often limited, and most previous reports have evaluated the efficacy of each marker individually. We aimed to improve the diagnostic performance of endoscopic remission (ER) of CD by combining these 3 markers.

METHODS

We tested the diagnostic ability of various combinations of these 3 markers for endoscopic severity in 230 consecutive patients with CD from September 2014 to July 2023. The modified Simple Endoscopic Score for Crohn's disease (mSES-CD) was used to determine endoscopic severity.

RESULTS

Each of the 3 markers was correlated with mSED-CD (LRG: r = 0.69, CRP: r = 0.60, and Fcal: r = 0.67). A combination of 2 of the 3 markers did not increase the diagnostic accuracy of ER. However, by combining all 3 markers, the diagnostic ability for ER was improved in comparison to the diagnostic ability of the 3 individual markers, assuming that ER was obtained if 2 or 3 markers were negative. The sensitivity, specificity, and accuracy were 89%, 83%, and 86%, respectively. Additionally, we established a 2-step method using Fcal values after evaluating the 2 serum markers. This method was most useful for reducing both the patient burden and costs.

CONCLUSIONS

The newly established 2-step method allowed for a higher accuracy in the non-invasive diagnosis of ER when the 3 markers were combined.

Evaluating the role of kynurenine/tryptophan ratio as an indicator of disease activity in Indian patients with inflammatory bowel disease. A case-control study

BACKGROUND

Tryptophan (T), an essential amino acid, is primarily metabolized (∼90%) to kynurenine (K) by indoleamine 2,3-dioxygenase 1 (IDO1) mainly in intestinal cells. In inflammatory bowel disease (IBD), there is an increase in IDO1 activity which would increase Kynurenine levels and Kynurenine/Tryptophan (K/T) ratio. We hypothesize that alteration in K/T may be an indicator of disease severity in IBD.

METHODS

55 healthy controls (HC), 55 Ulcerative colitis (UC) (35 active and 20 remission) and 30 Crohn's disease (CD) (20 active and 10 remission) were enrolled from November 2020 to March 2023. Plasma Kyn & Trp were simultaneously estimated using ultra-high-pressure liquid chromatography (UPLC). K/T ratio was correlated with disease activity and fecal calprotectin. In 25 patients follow-up samples were also collected with change in disease activity.

RESULTS

Median K/T ratio was significantly higher in patients with active disease as compared to those in remission and HC (p < .0001). A cut-off of ≤41 distinguished remission/healthy controls with a sensitivity of 92.73%, specificity of 76.36%, and an AUC of 0.9 (95% CI: 0.83-0.95, p < .001). The K/T ratio correlated with FC levels at a diagnostic cut-off of 250 µg/g. A significant reduction in K/T ratio with disease activity was noted in 80% of follow-up patients.

CONCLUSION

The K/T ratio with a cut-off of 41, correlated with the disease activity in 82% of patients, suggesting that the K/T ratio alters remarkably with disease activity in IBD patients. These findings can be further assessed for disease marker in a larger cohort of IBD patients.

Intricacy of Crohn's disease: Incongruity between diagnostic modalities and histopathologic assessment

Crohn's disease (CD) is a chronic and recurrent inflammatory condition. Histologic healing is associated with better outcomes in CD, while less is known regarding the assessment of histological condition. Recently, a study has examined the discordance between endoscopic and histopathologic assessment in ileal CD, revealing a poor correlation between endoscopic and histologic evaluations in assessing mucosal inflammation and disease activity. However, the involvement of CD can span the entire gastrointestinal tract, as well as numerous clinical manifestations and extraintestinal complications, and the patchy nature of transmural inflammation is a well-established characteristic of this disease. The diagnosis of CD relies on a comprehensive evaluation that includes clinical, biochemical, stool, endoscopic, cross-sectional imaging, and histological investigations due to the incomplete understanding of its etiology and pathogenesis. Upon diagnosis, complimentary investigations should focus on markers of disease activity. Since transmural inflammation can only be assessed in resections, therefore, we primarily focused on the evaluation value of clinical aspects, histological scoring systems, particular in vivo imaging evaluation such as computed tomography enterography, magnetic resonance elastography, scintigraphy, sonographically measurement, endoscopic ultrasonography, and advanced endoscopic imaging techniques.

Leucine-rich alpha-2 glycoprotein is useful in predicting clinical relapse in patients with Crohn's disease during biological remission

BACKGROUND/AIMS

Serum leucine-rich alpha-2 glycoprotein (LRG) is a potential biomarker of Crohn's disease (CD). This study aimed to evaluate the usefulness of LRG in predicting clinical relapse in patients in remission with CD.

METHODS

This retrospective observational study assessed the relationships among patient-reported outcome (PRO2), LRG, and other blood markers. The influence of LRG on clinical relapse was assessed in patients in remission with CD.

RESULTS

Data of 94 patients tested for LRG between January 2021 and May 2023 were collected. LRG level did not correlate with PRO2 score (ρ = 0.06); however, it strongly correlated with C-reactive protein (CRP) level (r=0.79) and serum albumin level (r=-0.70). Among 69 patients in clinical remission, relapse occurred in 22 patients (31.9%). In the context of predicting relapse, LRG showed the highest area under the curve, followed by CRP level, platelet count, and albumin level. Multivariate analysis revealed that only LRG (P= 0.02) was an independent factor for predicting clinical remission. The cumulative non-relapse rate was significantly higher in patients with LRG < 13.8 μg/mL than in patients in remission with LRG ≥ 13.8 μg/mL and normal CRP level (P= 0.002) or normal albumin level (P= 0.001). Cumulative non-relapse rate was also higher in patients with LRG < 13.8 μg/mL compared to those with LRG ≥ 13.8 μg/mL in patients with L3 or B2+B3 of Montreal calcification.

CONCLUSIONS

LRG is useful in predicting clinical relapse in patients with CD during biological remission. LRG is a useful biomarker for predicting prognosis, even in patients with intestinal stenosis, or previous/present fistulas.

Assessment of activity and severity of inflammatory bowel disease in cross-sectional imaging techniques: a systematic review

BACKGROUND AND AIMS

Cross-sectional imaging techniques, including intestinal ultrasonography (IUS), computed tomography enterography (CTE), magnetic resonance enterography (MRE), are increasingly used for the evaluation of inflammatory bowel diseases (IBD). We aimed to systematically review literature evidence on the assessment of disease activity, and/or severity through cross-sectional imaging in IBD patients, and to offer guidance on their most effective utilization.

METHODS

We performed a systematic review of PubMed, EMBASE, and Scopus to identify citations pertaining to the assessment of disease activity and/or severity at cross-sectional imaging techniques compared to a reference standard (ie, other radiological techniques, endoscopy, histopathology, and surgery) in IBD patients published until December 2023.

RESULTS

Overall, 179 papers published between 1990 and 2023 were included, with a total of 10 988 IBD patients (9304 Crohn's disease [84.7%], 1206 ulcerative colitis [11.0%], 38 IBD-U [0.3%], 440 unspecified [4.0%]). Of the 179 studies, 39 investigated IUS, 22/179 CTE, and 101/179 MRE. In the remaining papers, 2 techniques were addressed together. In 81.6% of the papers, endoscopy (with or without histopathology) was used as a reference standard. All studies included evaluated disease activity, while just over half (100/179, 55.8%) also evaluated disease severity of the addressed cross-sectional methodology. Pooled sensitivity, specificity, and overall accuracy of IUS, MRE, and CTE compared to the reference standard were 60%-99%, 60%-100%, and 70%-99%, respectively.

CONCLUSIONS

All cross-sectional imaging techniques demonstrated moderate-to-good accuracy in assessing disease activity and severity of IBD. This finding highlights the potential, especially for MRE and IUS to be widely utilized in managing IBD in both clinical practice and clinical trials.

Fecal Calprotectin Diagnostic Level Gradient Along the Small Bowel in Patients With Crohn's Disease

BACKGROUND AND AIMS

Fecal calprotectin (FC) is known to be a sensitive biomarker of colonic inflammation but to a lesser degree of small bowel (SB) inflammation. Moreover, data on FC's diagnostic levels in different SB segments are scarce. We aimed to examine FC's diagnostic levels along the SB axis in CD.

METHODS

This was a post hoc aggregated analysis of 5 prospective studies of adult CD patients who underwent FC testing and SB video capsule endoscopy. Lewis score (LS) inflammation in different SB segments was tested for correlation with FC level after the exclusion of colonic disease. The diagnostic levels of FC for SB inflammatory topographical gradient were assessed using a receiver operating characteristic.

RESULTS

Two hundred and fourteen patients were included (age: 30 [24-43] year-old, males-57%). For a similar SB inflammatory activity (LS ≥ 135), FC levels incrementally increased from proximal to distal SB segments (63 [30-121] vs 190 [78-549], p = 0.005) and from distal SB segment to the colon (190 [78-549] vs 542 [185-1000], p = 0.010). The best FC cutoffs to identify isolated mild proximal/distal SB inflammation (LS ≥ 135) were 77 µg/g and 123 µg/g, respectively. A cutoff of 234 µg/g was best to detect more significant proximal inflammation (LS ≥ 350) when only mild distal SB inflammation was present. In sensitivity analyses, this proximal-to-distal FC gradient was maintained when LS ≥ 350 and LS ≥ 790 were used as the inflammatory reference values. Unlike FC, the magnitude of CRP elevation was unrelated to the topography of inflammation along the SB axis.

CONCLUSIONS

FC may serve as a topographical biomarker of CD-activity, with its sensitivity to identify mucosal inflammation increases from proximal to distal SB segments.

Fecal calprotectin and endoscopic scores: The cornerstones in clinical practice for evaluating mucosal healing in inflammatory bowel disease

Managing inflammatory bowel disease (IBD) is becoming increasingly complex and personalized, considering the advent of new advanced therapies with distinct mechanisms of action. Achieving mucosal healing (MH) is a pivotal therapeutic goal in IBD management and can prevent IBD progression and reduce flares, hospitalization, surgery, intestinal damage, and colorectal cancer. Employing proactive disease and therapy assessment is essential to achieve better control of intestinal inflammation, even if subclinical, to alter the natural course of IBD. Periodic monitoring of fecal calprotectin (FC) levels and interval endoscopic evaluations are cornerstones for evaluating response/remission to advanced therapies targeting IBD, assessing MH, and detecting subclinical recurrence. Here, we comment on the article by Ishida et al Moreover, this editorial aimed to review the role of FC and endoscopic scores in predicting MH in patients with IBD. Furthermore, we intend to present some evidence on the role of these markers in future targets, such as histological and transmural healing. Additional prospective multicenter studies with a stricter MH criterion, standardized endoscopic and histopathological analyses, and virtual chromoscopy, potentially including artificial intelligence and other biomarkers, are desired.

Exploring the relationship between urinary phthalate metabolites and Crohn's disease via oxidative stress, and the potential moderating role of gut microbiota: A conditional mediation model

OBJECTIVE

Interactions between phthalic acid esters (PAEs) exposure and Crohn's disease (CD) were unknown. This study aims to examine the association between exposure to PAEs and CD activity and to explore the roles of oxidative stress and microbiota.

METHODS

A cross-sectional study with 127 CD patients was conducted. The disease activity was evaluated based on symptoms (Harvey-Bradshaw index, HBI), endoscopy findings (Simple Endoscopic Score for CD, SES-CD), and computed tomography enterography (CTE-scores). Ten urinary PAEs metabolites (mPAEs), two urinary oxidative stress biomarkers, including 8-hydroxydeoxyguanosine (8-OHdG) and 8-iso-prostaglandin-F2α (8-iso-PGF2α), as well as 16S rRNA sequencing of stool samples were determined. Multiple linear regression models and Hayes's PROCESS macro for SPSS were used to evaluate the interplays between urinary PAEs metabolites, CD activities, oxidative stress, and microbiota diversity.

RESULTS

There were positive associations between most mPAEs and HBI. Oxidative stress mediated 20.69-89.29% of the indirect associations between low molecular weight (LMW) mPAEs and HBI, while the majority of the high molecular weight (HMW) mPAEs were directly associated with HBI. In addition, microbiota diversity moderated the indirect associations of LMW mPAEs on HBI.

CONCLUSIONS

PAEs exposure was related to CD activity, and the association could be mediated by oxidative stress and reversed or alleviated by rich gut microbiota.

Clinical value of fecal calprotectin for evaluating disease activity in patients with Crohn's disease

Objective: To explore the clinical value of fecal calprotectin (FC) for evaluating disease activity in patients with Crohn's disease (CD) and its relationship with disease location. Methods: Patients with CD were enrolled retrospectively, and clinical data, including FC levels, were collected. Clinical activity was assessed using the Crohn's disease activity index (CDAI). Endoscopic activity was assessed using a simple endoscopic score for Crohn's disease (SES-CD). The partial SES-CD (pSES-CD) was scored for the size of ulcers in each segment as defined by the SES-CD and was calculated as the sum of segmental ulcer scores. Results: This study included 273 CD patients. The FC level was significantly positively correlated with the CDAI and SES-CD, with correlation coefficients of 0.666 and 0.674, respectively. The median FC levels in patients with clinical remission and mildly active and moderately-severely active disease were 41.01, 164.20, and 444.45 μg/g. These values were 26.94, 66.77, and 327.22 μg/g during endoscopic remission and mildly and moderately-severely active stages, respectively. Compared with c-reactive protein (CRP), the erythrocyte sedimentation rate (ESR), and other biomarker parameters, FC was better at predicting disease activity for CD patients. For an FC <74.52 μg/g, the area under the curve (AUC) for predicting clinical remission was 0.86, with a sensitivity of 89.47% and a specificity of 71.70%. Moreover, endoscopic remission was predicted with a sensitivity of 68.02% and a specificity of 85.53%. The AUC was 0.83, and the cutoff value was 80.84 μg/g. In patients with ileal and (ileo) colonic CD, FC was significantly correlated with the CDAI, SES-CD, and pSES-CD. The correlation coefficients were 0.711 (CDAI), 0.473 (SES-CD), and 0.369 (pSES-CD) in patients with ileal CD and 0.687, 0.745, and 0.714 in patients with (ileo) colonic CD, respectively. For patients in remission, those in the active stage, and those with large or very large ulcers, differences in FC levels were not significant between patients with ileal and (ileo) colonic CD. Conclusion: FC is a reliable predictor of disease activity in patients with CD, including those with ileal CD. FC is thus recommended for the routine follow-up of patients with CD.

[68Ga]Ga-FAPI-04 PET/CT on assessing Crohn's disease intestinal lesions

BACKGROUND

Fibrosis and inflammation are major pathological changes of Crohn's disease (CD). Early detection and accurate severity evaluation of CD are critical for patient's prognosis. Endoscopy is widely used to evaluate CD progression. Herein, we evaluated the efficacy of [⁶⁸Ga]Ga-FAPI-04 PET/CT to identify lesions and assess the progression of CD.

METHODS

All CD patients received computed tomography enterography (CTE), [⁶⁸Ga]Ga-FAPI-04 PET/CT examination, and ileocolonoscopy within 1 week. Two independent gastroenterologists computed the Crohn's disease activity index (CDAI) of all patients. Two radiology physicians assessed the CTE images separately, and the CTE scores were calculated. Lastly, two nuclear medicine physicians independently examined the [⁶⁸Ga]Ga-FAPI-04 PET/CT images. Once the FAPI uptake of the intestinal segment was equal or higher relative to the liver (considered FAPI-positive), the target-to-background ratio (TBR) and global FAPI PET/CT score were computed, representing the independent intestinal activity and activity of all intestinal segments, respectively. Levels of fecal calprotectin (FCP) and C-reactive protein (CRP) were determined before the endoscopy. The Crohn's disease endoscopy index of severity (CDEIS) and the simple endoscopic score for Crohn's disease (SES-CD) were calculated during the endoscopy. Finally, all data were obtained and analyzed.

RESULTS

There were 74 intestinal segments in 16 patients were assessed. [⁶⁸Ga]Ga-FAPI-04 PET/CT identified 42 of 45 endoscopically lesioned segments (endoscopic lesions detection sensitivity: 93.3%), while CTE identified 39 of them (endoscopic lesions detection sensitivity: 86.7%). According to the receiver operating characteristic (ROC) analysis, [⁶⁸Ga]Ga-FAPI-04 PET/CT showed better performance in the detection of endoscopic lesions compared with CTE (P < 0.05). The TBR was significantly associated with the CTE score (r = 0.81; (95% CI): 0.736-0.869; P < 0.0001) and SES-CD values (r = 0.86; (95% CI): 0.776-0.908; P < 0.0001). In addition, the global FAPI PET/CT score was significantly correlated with FCP (r = 0.52; 95% CI, 0.02-0.81; P = 0.039), CRP (r = 0.60; 95% CI, 0.13-0.85; P = 0.014), CDEIS (r = 0.55; 95% CI, 0.06-0.83; P = 0.028), and CDAI (r = 0.81; 95% CI, 0.50-0.93; P < 0.0001).

CONCLUSION

In summary, [⁶⁸Ga]Ga-FAPI-04 PET/CT correlated well with endoscopic, CTE, clinical, and biomarkers of CD. It was also highly sensitive in the detection of different classes of lesions in all intestinal segments, and unlike other examinations, this technique required no patient fasting or bowel preparation. Therefore, [⁶⁸Ga]Ga-FAPI-04 PET/CT may be a promising method for assessing the activity of CD.

What Do NAFLD, Liver Fibrosis, and Inflammatory Bowel Disease Have in Common? Review of the Current Literature

Liver disease is one of the most common extraintestinal manifestations of inflammatory bowel disease (IBD). Often the course of liver disease is associated with an exacerbation of the underlying disease (Crohn’s Disease/Ulcerative Colitis). Nonalcoholic steatohepatitis encompasses a wide spectrum of liver damage. The most common form is nonalcoholic fatty liver disease (NAFLD) (75–80%), and the less common but more dangerous form is nonalcoholic steatohepatitis (NASH). NAFLD is now the most common cause of chronic liver disease in developed countries and the leading indication for liver transplantation in the United States. Genetic, demographic, clinical, and environmental factors can play a role in the pathogenesis of NAFLD. The increasing prevalence of NAFLD is associated with a widespread obesity epidemic, metabolic complications, including hypertension, type 2 diabetes, and dyslipidaemia. Some of the most common manifestations of IBD are liver, biliary tract, and gallbladder diseases. The liver fibrosis process has a complex pathophysiology and is often dependent on exogenous factors such as the treatment used and endogenous factors such as the gut microbiome. However, the factors that link IBD and liver fibrosis are not yet clear. The main purpose of the review is to try to find links between IBD and selected liver diseases and to identify knowledge gaps that will inform further research.

The Evaluation of Transmural Healing by Low-dose Computed Tomography Enterography in Patients with Crohn's Disease

Objective Transmural healing (TH) has been attracting attention as a new therapeutic target for Crohn's disease, but there are few clinical data on TH in Japan. We introduced low-dose computed tomography enterography (CTE) as a monitoring method for Crohn's disease and retrospectively investigated the accuracy of evaluating TH by CTE. Methods Among Crohn's disease patients who underwent low-dose CTE at our hospital from January 2009 to March 2021, 122 patients who underwent colonoscopy or balloon endoscopy within 2 weeks were included. Results of radiological and endoscopic examinations were reviewed independently by radiologists and gastrointestinal endoscopists, respectively. The concordance rate of the diagnosis between CTE and endoscopy was evaluated. Results Twenty-six patients (21.3%) achieved TH, and the kappa index was 0.743. On comparing the TH and non-TH groups, the Crohn's disease activity index (p=0.02), endoscopic healing rate (p<0.001), serum albumin (p=0.043), and serum C-reactive protein level (p=0.018) showed significant differences. Among the 122 patients, 69 (56.5%) showed concordance between the diagnosis of CTE and endoscopy, and 22 (18.0%) achieved both TH and endoscopic healing. Conclusion This study provides real-world data on Crohn's disease evaluated with low-dose CTE in Japan. The TH criterion used in this study has a high kappa coefficient and can be used reproducibly in many institutions.

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.

Fecal calprotectin predicts endoscopic activity and mucosal healing of small bowel Crohn's disease evaluated by double-balloon endoscopy

PURPOSE

Fecal calprotectin (FC) levels can reflect the level of intestinal inflammation. Crohn's disease (CD), which affects the small bowel, has not been linked to FC levels. We determined if FC levels and endoscopic activity were related by performing double-balloon endoscopy (DBE).

METHODS

Herein, patients with small bowel CD diagnosed by DBE between January 2020 and January 2022 were prospectively observed. Feces and blood samples of patients were collected before performing DBE and checked for the levels of FC and serological biomarkers. The endoscopic activity and mucosal healing (MH) were evaluated using the partial simple endoscopic score (pSES-CD).

RESULTS

In all 254 CD patients, FC levels were correlated with pSES-CD (r = 0.775, P < 0.001). Even in patients with isolated small bowel CD, FC levels were strongly correlated with pSES-CD (r = 0.753, P < 0.001). In all patients, FC as an endoscopic remission indicator was found to have an area under the curve (AUC) of 0.872, with a cut-off value of 156.09 µg/g. In patients with isolated small bowel CD, FC yielded a high AUC of 0.865 for predicting endoscopic remission, with a cut-off value of 211.48 µg/g, sensitivity of 73.95%, and specificity of 91.30%. FC was optimally cut-off at 76.99 µg/g to predict MH in accordance with the AUC of 0.877.

CONCLUSIONS

Using DBE findings, FC was found to be significantly correlated with pSES-CD. Even in isolated small bowel CD, FC may be a more reliable marker of accurately predicting endoscopic remission and MH.

Serum leucine-rich alpha-2 glycoprotein as a predictive factor of endoscopic remission in Crohn's disease

BACKGROUND AND AIM

The usefulness of fecal calprotectin (FC) and serum leucine-rich alpha-2 glycoprotein (LRG) assessing the activity of Crohn's disease (CD) remains to be fully demonstrated in Asia. The present study aimed to elucidate whether FC and LRG could predict endoscopic remission (ER) in Japanese patients with CD.

METHODS

Between October 2018 and July 2021, we prospectively observed treatment courses of CD patients treated with biologic agents. The optimal cutoff values of Crohn's Disease Activity Index (CDAI), serum C-reactive protein (CRP), serum albumin (Alb), FC, and LRG levels for predicting ER at week 52 were calculated using receiver operating characteristic (ROC) curves. We also analyzed the correlations between the achievement of clinical remission (CR) or biomarker remission (BR) at week 12/24/52 and ER at week 52.

RESULTS

Among 53 patients who completed 52 weeks of observation, 20 (37.7%) achieved ER at week 52. Using the calculated cutoff values, patients who achieved CR (CDAI ≤ 112) or BR (CRP ≤ 0.42 mg/dL, Alb ≥ 3.8 g/dL, FC ≤ 287 μg/g, or LRG ≤ 13.6 μg/mL) at week 12/24/52 had a higher ER rate at week 52. FC-BR at week 12/24 showed low sensitivity (0.58/0.60) but high specificity (0.78/0.74) for predicting ER; LRG-BR at week 12/24 also showed low sensitivity (0.68/0.74) but high specificity (0.87/0.78). However, FC-BR and LRG-BR at week 52 had improved sensitivity (0.80/0.84) while specificity remained (0.79/0.85).

CONCLUSIONS

From the early phase of biologic treatment, both FC and LRG had high specificity for predicting ER at week 52. LRG showed higher sensitivity than FC.

Both fecal calprotectin and fecal immunochemical tests are useful in children with inflammatory bowel disease

BACKGROUND

Noninvasive biomarkers of intestinal inflammation can reduce the number of endoscopies in children with inflammatory bowel disease (IBD). This study aimed to prospectively investigate the usefulness of fecal calprotectin (FCP) and fecal immunochemical test (FIT) in pediatric IBD.

METHODS

Patients aged 6-17 years who underwent ileocolonoscopy for established or suspected IBD were eligible for this study. Fecal samples for FCP and FIT were collected before colonoscopy.

RESULTS

A total of 251 samples were analyzed: 88 from ulcerative colitis (UC), 74 from Crohn's disease (CD), 75 from healthy controls (HC), and 14 from children with functional gastrointestinal disorders and normal colonoscopy (NC). At IBD diagnosis, both FCP and FIT were significantly higher in the newly diagnosed UC/CD group than in the HC/NC group (P < 0.001). The optimal cutoffs of FCP and FIT to predict IBD diagnosis were 217 mg/kg and 87 ng/mL, respectively. Patients without mucosal healing (MH) showed higher FCP and FIT than those with MH in both UC and CD (P < 0.001). The FCP increased exponentially as the endoscopic activity score increased. The optimal cutoff values of FCP and FIT for predicting MH were 161 mg/kg and 106 ng/mL for UC and 367 mg/kg and 57 ng/mL for CD, respectively. FCP showed better specificity than the FIT. Patients with CD and normal ileocolonoscopy had elevated FCP during active small intestinal inflammation.

CONCLUSIONS

Both FCP and FIT correlate well with endoscopic activity in pediatric patients with IBD. The FCP is a superior marker for predicting MH.

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.

Association of Fecal Calprotectin With Endoscopic and Histologic Activity in Pediatric Inflammatory Bowel Disease

Fecal calprotectin (FC) is a noninvasive marker of intestinal inflammation used for screening and ongoing monitoring of inflammatory bowel disease (IBD); it is unclear the association of specific FC values with disease activity. The aim of our study was to examine the association of FC values with endoscopic and histologic severity.

Methods

We performed a retrospective chart review of patients who had FC done between 30 days and 1 day before colonoscopy at our institution. IBD patients were graded using the simple endoscopic score for Crohn's disease or Mayo endoscopic score for ulcerative colitis. Histologic slides were graded using the Geboes method.

Results

Three-hundred thirty-one patients were included in the study and 107 had IBD. For endoscopy, median FC was lowest for all IBD patients with no disease (181 μg/g) and highest in severe disease (921 μg/g), with significant difference between no disease and moderate and severe disease (P = 0.019, 0.003), and between mild and severe disease (P = 0.012). For histology, median FC was lowest with no disease (328 μg/g) and highest in severe disease (895 μg/g), with significant difference between no disease and moderate and severe disease (P = 0.021, 0.018). The control population had a significantly lower median FC than the IBD population in endoscopic remission (35.5 versus 181 μg/g; P = 0.018).

Conclusions

There was a linear increase in FC values associated with increasing disease severity in the undifferentiated IBD cohort. Values for IBD patients in endoscopic remission were significantly different from our control population. FC may be a useful noninvasive marker to assess disease severity.

Optimal Range of Fecal Calprotectin for Predicting Mucosal Healing in Patients with Inflammatory Bowel Disease: A Systematic Review and Meta-Analysis

OBJECTIVE

Fecal calprotectin (FC) is a promising marker for assessment of inflammatory bowel disease (IBD) activity. However, the utility of FC for predicting mucosal healing (MH) of IBD patients has yet to be clearly demonstrated. The objective of our study was to perform a meta-analysis evaluating the diagnostic accuracy of FC in predicting MH of IBD patients.

METHODS

We systematically searched the databases for studies from inception to April 2020 that evaluated MH in IBD. The methodological quality of each study was assessed according to the Quality Assessment of Diagnostic Accuracy Studies checklist. The extracted data were pooled using a summary receiver operating characteristic curve model. Random-effects model was used to summarize the diagnostic odds ratio, sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio.

RESULTS

Sixteen studies comprising 1,682 ulcerative colitis (UC) patients and 4 studies comprising 221 Crohn's disease (CD) patients were included. The best performance of FC for predicting MH in UC was at cut-off range of 60-75 μg/g with area under the curve (AUC) of 0.88 and pooled sensitivity and specificity of 0.87 and 0.79, respectively. The pooled sensitivity and specificity values of cutoff range 180-250 μg/g for predicting MH in CD were 0.67 and 0.76, respectively. The AUC of 0.79 also revealed improved discrimination for identifying MH in CD with FC concentration.

CONCLUSION

Our meta-analysis has found that FC is a simple, reliable noninvasive marker for predicting MH in IBD patients. FC cutoff range 60-75 μg/g appears to have the best overall accuracy in UC patients.

Leucine-rich alpha-2 glycoprotein is a potential biomarker to monitor disease activity in inflammatory bowel disease receiving adalimumab: PLANET study

BACKGROUND

This multicenter prospective study (UMIN000019958) aimed to evaluate the usefulness of serum leucin-rich alpha-2 glycoprotein (LRG) levels in monitoring disease activity in inflammatory bowel disease (IBD).

METHODS

Patients with moderate-to-severe IBD initiated on adalimumab therapy were enrolled herein. Serum LRG, C-reactive protein (CRP), and fecal calprotectin (fCal) levels were measured at week 0, 12, 24, and 52. Colonoscopy was performed at week 0, 12, and 52 for ulcerative colitis (UC), and at week 0, 24, and 52 for Crohn's disease (CD). Endoscopic activity was assessed using the Simple Endoscopic Score for Crohn's Disease (SES-CD) for CD and the Mayo endoscopic subscore (MES) for UC.

RESULTS

A total of 81 patients was enrolled. Serum LRG levels decreased along with improvements in clinical and endoscopic outcomes upon adalimumab treatment (27.4 ± 12.6 μg/ml at week 0, 15.5 ± 7.7 μg/ml at week 12, 15.7 ± 9.6 μg/ml at week 24, and 14.5 ± 6.8 μg/ml at week 52), being correlated with endoscopic activity at each time point (SES-CD: r = 0.391 at week 0, r = 0.563 at week 24, r = 0.697 at week 52; MES: r = 0.534 at week 0, r = 0.429 at week 12, r = 0.335 at week 52). Endoscopic activity better correlated with LRG compared to CRP and fCal on pooled analysis at all time points (SES-CD: LRG: r = 0.636, CRP: r = 0.402, fCal: r = 0.435; MES: LRG: r = 0.568, CRP: 0.389, fCal: r = 0.426).

CONCLUSIONS

Serum LRG is a useful biomarker of endoscopic activity both in CD and UC during the adalimumab treatment.

Leucine-rich alpha-2 glycoprotein as a marker of mucosal healing in inflammatory bowel disease

Leucine-rich alpha-2 glycoprotein (LRG) may be a novel serum biomarker for patients with inflammatory bowel disease. The association of LRG with the endoscopic activity and predictability of mucosal healing (MH) was determined and compared with those of C-reactive protein (CRP) and fecal markers (fecal immunochemical test [FIT] and fecal calprotectin [Fcal]) in 166 ulcerative colitis (UC) and 56 Crohn's disease (CD) patients. In UC, LRG was correlated with the endoscopic activity and could predict MH, but the performance was not superior to that of fecal markers (areas under the curve [AUCs] for predicting MH: LRG: 0.61, CRP: 0.59, FIT: 0.75, and Fcal: 0.72). In CD, the performance of LRG was equivalent to that of CRP and Fcal (AUCs for predicting MH: LRG: 0.82, CRP: 0.82, FIT: 0.70, and Fcal: 0.88). LRG was able to discriminate patients with MH from those with endoscopic activity among UC and CD patients with normal CRP levels. LRG was associated with endoscopic activity and could predict MH in both UC and CD patients. It may be particularly useful in CD.

Patient knowledge of fecal calprotectin in inflammatory bowel disease (IBD): An observational study in Mexico

Background: Fecal calprotectin (FC) can be a valuable tool to optimize health care for patients with inflammatory bowel disease (IBD). The objective of this observational study was to determine the level of knowledge of the FC test in Mexican patients with IBD. Methods: A self-report questionnaire was distributed via Facebook to patients with IBD. The survey consisted of 15 questions in two categories: the first category assessed knowledge of IBD diagnosis, and the second category assessed knowledge of the FC test. Results: In total, 460 patients with IBD participated, of which 83.9% (386) had ulcerative colitis (UC) and 16.0% (74) had Crohn's disease (CD). Regarding IBD diagnosis, 41.9% of participants stated that they did not know of a non-invasive test for fecal matter to identify inflammation of the colon. Regarding the FC test, 57.5% (UC) and 58.1% (CD) stated that they did not know about the test. Additionally, 65.8% (UC) and 51.3% (CD) of participants stated that they had never received the FC test and 82.6% (UC) and 77.0% (CD) recognized that the FC test was difficult to access in their medical practice. Furthermore, 66% (UC) and 52.7% (CD) of participants noted that their specialist doctor had never suggested the FC test to them, yet 89.1% (UC) and 87.8% (CD) stated that they would prefer FC analysis for their IBD follow-up assessments. Conclusions: There is little knowledge of the FC biomarker among Mexican patients with IBD. This suggests the need for greater dissemination of its use and scope as a biomarker in IBD.

Patient knowledge of fecal calprotectin in inflammatory bowel disease (IBD): An observational study in Mexico

Background: Fecal calprotectin (FC) can be a valuable tool to optimize health care for patients with inflammatory bowel disease (IBD). The objective of this observational study was to determine the level of knowledge of the FC test in Mexican patients with IBD. Methods: A self-report questionnaire was distributed via Facebook to patients with IBD. The survey consisted of 15 questions in two categories: the first category assessed knowledge of IBD diagnosis, and the second category assessed knowledge of the FC test. Results: In total, 460 patients with IBD participated, of which 83.9% (386) had ulcerative colitis (UC) and 16.0% (74) had Crohn's disease (CD). Regarding IBD diagnosis, 41.9% of participants stated that they did not know of a non-invasive test for fecal matter to identify inflammation of the colon. Regarding the FC test, 57.5% (UC) and 58.1% (CD) stated that they did not know about the test. Additionally, 65.8% (UC) and 51.3% (CD) of participants stated that they had never received the FC test and 82.6% (UC) and 77.0% (CD) recognized that the FC test was difficult to access in their medical practice. Furthermore, 66% (UC) and 52.7% (CD) of participants noted that their specialist doctor had never suggested the FC test to them, yet 89.1% (UC) and 87.8% (CD) stated that they would prefer FC analysis for their IBD follow-up assessments. Conclusions: There is little knowledge of the FC biomarker among Mexican patients with IBD. This suggests the need for greater dissemination of its use and scope as a biomarker in IBD.

A Conceptual Framework for Rescheduling Elective Pediatric Gastroenterology Procedures Following COVID-19 Pandemic Lockdown

Elective surgical and endoscopic procedures were suspended nationwide during the March 2020 COVID-19 pandemic to minimize exposure and healthcare resource utilization. This resulted in an unprecedented backlog of procedures in most clinical practices including pediatrics. Our group developed an internal process toward the rational development of an algorithm prioritizing elective procedures. This was based on patient disease severity defined by the presence of alert symptoms, symptom severity for dysphagia and abdominal pain, and diagnostic investigation findings. The underlying rationale is to prioritize patients in whom suspected disease course would be greatest impacted by endoscopy. We developed a nurse phone call-based process utilizing REDCap®, identifying relevant symptoms categorized by severity, and a validated functional impairment questionnaire for abdominal pain. We abstracted key laboratory and radiological findings also categorized by severity. The order of priority of procedures was established on the basis of a 4-tiered system factoring both presence and severity of symptoms or prior diagnostic testing results. We present the framework that we have adopted toward prioritizing procedures with the assumption that it offers an objective methodology and that can be efficiently and more broadly applied to other similar practice scenarios. Our tool may have wide-ranging implications both in the current COVID-19 pandemic and in other scenarios of limited resource allocation and deserves further investigation.

The Course of SARS-COV2 Infection Was Not Severe in a Crohn's Patient Who Administered Maintenance Anti-TNF Therapy Overlapping the Early Pre-Symptomatic Period of Infection

The Inflammatory Bowel Disease (IBD) population, which may require treatment with immunosuppressive medications, may be uniquely vulnerable to COVID-19 infection. In fact, there is some evidence these medications may inhibit the cytokine storm that is theorized to cause a rapid decline seen in COVID-19. In addition, the digestive symptoms of COVID-19 can be difficult to distinguish from the activation of IBD. We present an interesting case of a Crohn's patient inadvertently administering anti-cytokine therapy during the pre-symptomatic period of COVID-19 infection. Immune suppression during early infection with SARS-COV2 risks a poor immune response to the virus and could theoretically result in a more severe course of infection.

Biochemical Biomarkers of Mucosal Healing for Inflammatory Bowel Disease in Adults

Mucosal healing (MH) is the key therapeutic target of inflammatory bowel disease (IBD). The evaluation of MH remains challenging, with endoscopy being the golden standard. We performed a comprehensive overview of the performance of fecal-, serum-, and urine-based biochemical markers in colonic IBD to find out whether we are ready to replace endoscopy with a non-invasive but equally accurate instrument. A Pubmed, Web of Knowledge, and Scopus search of original articles as potential MH markers in adults, published between January 2009 and March 2020, was conducted. Finally, 84 eligible studies were identified. The most frequently studied fecal marker was calprotectin (44 studies), with areas under the curves (AUCs) ranging from 0.70 to 0.99 in ulcerative colitis (UC) and from 0.70 to 0.94 in Crohn`s disease (CD), followed by lactoferrin (4 studies), matrix metalloproteinase-9 (3 studies), and lipocalin-2 (3 studies). The most frequently studied serum marker was C-reactive protein (30 studies), with AUCs ranging from 0.60 to 0.96 in UC and from 0.64 to 0.93 in CD. Fecal calprotectin is an accurate MH marker in IBD in adults; however, it cannot replace endoscopy and the application of calprotectin is hampered by the lack of standardization concerning the cut-off value. Other markers are either not sufficiently accurate or have not been studied extensively enough.

Biomarkers of disease activity and other factors as predictors of adalimumab pharmacokinetics in inflammatory bowel disease

Inflammatory bowel disease (IBD) is commonly treated with adalimumab. The main objective of the study was to develop a population pharmacokinetic model of adalimumab in IBD patients evaluating the potential biomarkers of disease activity and other factors and its implications in adalimumab dosing. A prospective observational study was performed in adult patients diagnosed with Crohn's disease and ulcerative colitis treated with adalimumab and following a proactive therapeutic drug monitoring of serum concentrations. Adalimumab serum concentrations (ASC) were quantified mainly prior the administration using an enzyme-linked immunosorbent assay (ELISA). A population pharmacokinetic model was developed based on 303 ASC data of 104 IBD patients using non-linear mixed effect modelling approach. Sixty-five ASC from 20 additional patients were randomly selected as an external validation group. A one-compartment model with first order absorption and elimination best describe the ASC time course. Body mass index (BMI), faecal calprotectin (FCP), unexplained decline in ASC and the specific administration pen device exhibited significant influence on apparent clearance (p-value < 0.001). FCP was the inflammatory activity biomarker showing the most relevant impact on adalimumab exposure, higher than C-reactive protein and albumin, and may be useful for adalimumab dosing adjustment. The population-based pharmacokinetic model developed adequately characterized adalimumab exposure in IBD patients. The unexplained decline in ASC, FCP, BMI and the specific administration pen device were identified as meaningful variables significantly influencing adalimumab pharmacokinetics.

Is fecal calprotectin an accurate marker in the management of Crohn's disease?

Although lacking validated cutoff values, fecal calprotectin (FC), besides C-reactive protein, is considered the standard test for assessing disease activity in Crohn's disease (CD). The aim of the present review is to provide a general overview of the literature addressing the role of FC in the clinical and endoscopic assessment of disease activity in CD, seeking correlations with capsule endoscopy, response to therapy, prediction of relapse, and postoperative recurrence. A systematic search of the literature up to September 2019 was performed using Medline, Embase, and the Cochrane Library. Only papers written in English concerning FC in adult patients affected by CD were included. Pediatric studies, in vitro studies, animal studies, studies on blood/serum samples, and studies analyzing FC in ulcerative colitis or in both CD and ulcerative colitis were excluded. Out of 713 citations, 65 eligible studies were identified. FC showed high accuracy in the assessment of intestinal inflammation and response to therapy, in particular in colonic disease, thus proving a good surrogate marker for these aims. FC is useful in identifying patients at high risk for endoscopic relapse or postoperative recurrence, for optimizing or downstage therapy. Unfortunately, FC performs less well in small bowel CD. FC is an effective fecal marker in the management of CD patients, optimizing the use of endoscopic procedures. Owing to its diagnostic accuracy, FC may represent a cornerstone of the "treat-to-target" management strategy of CD patients.

Objective evaluation for treat to target in Crohn's disease

BACKGROUND

Crohn's disease (CD) is a chronic and destructive bowel disease; continued disease activity can lead to penetrating complications. With the recent advent of effective medications, the importance of using a treat-to-target approach to guide therapy is becoming important.

METHODS

In this review, we reviewed the previous evidence for evaluating CD lesions.

RESULTS

We describe ileocolonoscopy's role in assessing disease activity, as well as recent progress in modalities, such as balloon-assisted endoscopy, capsule endoscopy, magnetic resonance enterography, computed tomography enterography, and ultrasonography. Advances in modalities have changed CD assessment, with small-bowel involvement becoming more important.

CONCLUSIONS

Proper optimization is necessary in clinical practice.

Magnetic resonance enterography, colonoscopy, and fecal calprotectin correlate in colonic Crohn's disease

Background

Fecal calprotectin (FCP), magnetic resonance enterography (MRE), and colonoscopy are complementary biometric tests that are used to assess patients with Crohn’s Disease (CD). While prior studies have evaluated the association between combinations of these tests, no study has established a correlation between all three: FCP, MRE, and colonoscopy. We prospectively investigated if there is correlation between these three tests, which may result in improved clinical outcomes that can then be used to streamline patient monitoring and treatment modification.

Methods

One hundred fifty-six patients with colonic CD were prospectively examined between March 2017 and December 2018. FCP levels, MRE, and colonoscopy were assessed in parallel on all 156 patients. Clinical CD activity was measured with the Crohn’s Disease Activity Index (CDAI). CD activity with FCP was measured with a quantitative immunoassay. CD activity on MRE was measured with the Magnetic Resonance Index of Activity (MaRIA). CD activity on colonoscopy was measured with the Crohn’s Disease Endoscopic Index of Severity (CDEIS).

Results

One hundred twelve patients (72%) had active disease (Crohn’s Disease Activity Index > 150) and 44 patients (28%) were in clinical remission disease (Crohn’s Disease Activity Index < 150). FCP levels, MaRIA, and CDEIS are highly correlated with positive and significant Pearson and Spearman coefficients, respectively (P < 0.0001), in univariate analyses. Regression analysis (multivariate analyses) demonstrates significant, positive correlation between FCP and MaRIA (r = 1.07, P < 0.0001) and between FCP and CDEIS (r = 0.71, P = 0.03), and between.

MaRIA and CDEIS (r = 0.63, P = 0.01).

Conclusions

FCP levels significantly correlate with the degree of active inflammation in patients with colonic Crohn’s Disease. Improved clinical results may be achieved by using a biometric strategy that incorporates FCP, colonoscopy, and MRE together. This strategy may in-turn be used in the future to streamline monitoring disease activity and adjustment of therapy to improve long term patient outcomes.

Should We Divide Crohn's Disease Into Ileum-Dominant and Isolated Colonic Diseases?

Crohn's disease (CD) is an inflammatory bowel disease that can involve any region of the gastrointestinal tract. First described in 1932 as terminal ileitis or regional enteritis, it predominately involves the ileum with or without colonic involvement. Isolated colonic CD was first described in 1960 and since then the phenotypic classification of CD has evolved to stratify patients into isolated ileal, ileocolonic, or isolated colonic involvement. In the current review we evaluate the published literature regarding differences in epidemiology, natural history, pathogenesis, response to therapy, and disease monitoring, when stratified by disease location. Based on the available evidence consideration could be given to a new classification for CD, which splits it into ileum dominant (isolated ileal and ileocolonic) and isolated colonic disease. This may allow for a more optimized approach to clinical care and scientific research for CD.

Faecal calprotectin delivers on convenience, cost reduction and clinical decision-making in inflammatory bowel disease: a real-world cohort study

BACKGROUND

Faecal calprotectin (FC) is an accurate biomarker of disease activity in inflammatory bowel disease (IBD), yet the cost/resource implications of incorporating FC into 'real-world' practice remain uncertain.

AIM

To evaluate the utility of FC in clinical decision-making and on healthcare costs in IBD.

METHODS

Retrospective data, including colonoscopy/other investigations, medication, admission and surgical data, were collected from hospital records and compared between two groups: pre-FC historical cohort (2005-2009) where colonoscopy was used to assess IBD activity versus the cohort where FC was used first instead (2010-2014). Post-test costs were also compared.

RESULTS

A total of 357 FC tests (246 patients, 2010-2014) and 450 colonoscopies (268 patients, 2005-2009) were performed. On subsequent review, both FC and colonoscopy (in their respective cohorts) were associated with changes in management in 50.7 versus 56.2% (P = 0.14), respectively, with similar proportions of subsequent IBD-related investigations within 6 months (21.8 vs 21.9%, P = 1.0). Prior to FC availability (2005-2009), a colonoscopy for disease reassessment cost AU$606 578 (cost per patient-year $1887.34) versus AU$282 048 (cost per patient-year $968.60) when FC ± colonoscopy was used (2010-2014). Within the FC cohort, 73.6% did not proceed to colonoscopy within 6 months post-FC, and 60.6% had not undergone colonoscopy post-FC by the end of follow up (median 1.8 years (0.1, 4.6) post-FC). Those with FC ≥ 250 were scoped earlier than those with FC < 100 μg/mL (median 0.49 vs 1.0 years, P = 0.03).

CONCLUSION

Introduction of FC into routine IBD care aided changes in clinical management in a similar proportion, yet at potentially half the total cost, compared to a historical colonoscopy-only cohort at the same centre.

Targeting mucosal healing in Crohn's disease: what the clinician needs to know

In recent years, mucosal healing has emerged as a key therapeutic goal in the clinical management of patients with Crohn's disease, as it has been associated with improved long-term clinical outcomes. With the vast improvements in endoscopic imaging techniques and the increase in available treatment options, which reportedly are able to induce mucosal healing, the practising physician is left to wonder: how is endoscopic mucosal healing exactly defined in Crohn's disease, and how can it effectively be achieved and monitored in daily clinical practice? Within this review, we will give an overview of the ongoing debate about the definition of mucosal healing and the modalities to monitor inflammation, and finally present available therapies with the capacity to induce mucosal healing.

The role of small bowel endoscopy for Crohn's disease

PURPOSE OF REVIEW

The review discusses the roles of small bowel capsule endoscopy and deep enteroscopy in patients with Crohn's disease. It highlights recent advances in the field and identifies areas where evidence is lacking.

RECENT FINDINGS

Small bowel capsule endoscopy has an important role in the follow-up of patients with Crohn's disease after escalation of therapy and in the postoperative assessment period following surgical resection. Device-assisted enteroscopy offers the therapeutic advantage of small bowel dilatation, which may result in a reduction in the number of surgical resections required, thus avoiding long-term complications, such as short bowel syndrome and malabsorption.

SUMMARY

Capsule endoscopy has an established role in the diagnosis and management of small bowel Crohn's disease. It is used in the setting of suspected Crohn's disease when ileocolonoscopy is negative and for the assessment of extent of small bowel disease in established Crohn's disease. It is relatively well tolerated because of the provision of patency capsule endoscopy to minimize the risk of inadvertent capsule retention. Device-assisted enteroscopy aids with the diagnosis of Crohn's disease as it enables histology to be taken from inflamed areas within the small bowel. Therapeutic procedures can be carried out during device-assisted enteroscopy including dilatation of Crohn's disease-related strictures and retrieval of retained capsules.

Update on C-reactive protein and fecal calprotectin: are they accurate measures of disease activity in Crohn's disease?

'Treat-to-target' paradigms in Crohn's disease (CD) directed at suppressing intestinal inflammation require accurate and reliable measures of disease activity. Although endoscopy has traditionally been considered a gold standard, cost, complexity, resource limitations, and invasiveness are important limitations. Hence, substantial interest exists for non-invasive serum and fecal biomarkers, namely C-reactive protein (CRP) and fecal calprotectin (FC), in the diagnosis, monitoring, and treatment of CD. Areas covered: We review the evidence for using serum CRP and FC in distinguishing patients with CD from those with irritable bowel syndrome, categorizing disease activity among patients with an established diagnosis of CD, predicting the likelihood of treatment response, identifying asymptomatic patients in medically or surgically induced remission who are at risk for disease relapse, and as treatment targets. Expert commentary: Accurate interpretation of CRP and FC is dependent on several factors including the clinical context, the performance characteristics of the assay, the specified test cut-offs, and the pre-test probability of disease. Emerging evidence indicates that CRP and FC are valuable adjuncts for the management of CD in specific circumstances described in this review.

Prediction of disease activity of Crohn's disease through fecal calprotectin evaluated by balloon-assisted endoscopy

BACKGROUND AND AIM

Fecal calprotectin (FC) is a useful marker for assessing the activity of intestinal inflammation. However, most studies have used ileocolonoscopy to evaluate the association of FC with intestinal inflammation, and it is not clear whether FC is useful for the evaluation of small-bowel Crohn's disease (CD). This study aimed to determine the usefulness of FC for predicting intestinal inflammation evaluated by balloon-assisted endoscopy (BAE), which can visualize the deep small intestine.

METHODS

This was a cross-sectional, observational study involving 69 CD patients, 39 of whom had only small-bowel disease. The extended simplified endoscopic activity score for Crohn's disease (eSES-CD) was calculated based on the findings of BAE. Mucosal healing was defined as an eSES-CD of 0.

RESULTS

In all CD patients, FC levels were correlated with the eSES-CD (r = 0.663, P < 0.001). The cutoff value to predict mucosal healing was 92 mg/kg, with a sensitivity of 94%, specificity of 88%, positive predictive value of 98%, negative predictive value of 64%, and the area under the curve of 0.91. Even in small-bowel CD patients, FC levels were correlated with the eSES-CD (r = 0.607, P < 0.001). The cutoff value was 92 mg/kg, with a sensitivity of 87%, specificity of 88%, positive predictive value of 96%, negative predictive value of 64%, and area under the curve of 0.85.

CONCLUSIONS

Fecal calprotectin showed a significant correlation with the intestinal inflammation evaluated with BAE even in patients with only small intestinal disease. FC is useful for the evaluation of CD including both the small and large intestines.

Serum amyloid A level correlated with endoscopic findings in patients with Crohn's disease-Possible biomarker for evaluating mucosal healing

BACKGROUND

Mucosal healing (MH) has been proposed as an essential therapeutic goal for treatment of Crohn's disease (CD) patients. The utility of serum amyloid A (SAA) for prediction of MH in CD patients is lacking.

AIMS

This study was conducted to evaluate the correlation of SAA with CD-related endoscopic disease activity.

METHODS

SAA levels in serum samples obtained from CD patients as well as endoscopic findings based on a simple endoscopic score for CD (SES-CD) were assessed in relation to CD activity index (CDAI). The diagnostic ability of MH in correlation with SAA level was evaluated using receiver operating characteristic (ROC) curve analysis.

RESULTS

Fifty-five patients with CD were enrolled. Mean SAA level was significantly higher in clinical and endoscopic active phases as compared to an inactive phase. SAA level was also significantly correlated with SES-CD (r = 0.64, p < 0.01) and CDAI (r = 0.42, p < 0.01). The area under the ROC curve for SAA level was 0.77 and the optimal cut-off value for SAA to predict MH was 5.9 μg/dl. SAA level was shown to be associated with MH, with a sensitivity of 68% and specificity of 83%.

CONCLUSIONS

SAA may be a possible biomarker for evaluating MH in CD patients.

[Monitoring Disease Activity: How and When?]

Inflammatory bowel disease (IBD) is a chronic, idiopathic inflammatory disease of gastrointestinal tract with waxing and waning clinical course, which may lead to irreversible bowel damage and a loss of bowel function. Cumulative intestinal damage results in complications such as stricture or fistulae, and eventually a large number of IBD patients undergo surgery. Notably, even during remission period (no clinical symptoms), subclinical inflammation often persists and the disease continues to progress. Therefore, the therapeutic target of IBD has been evolving from symptomatic control to mucosal healing to prevent structural intestinal damage. To achieve therapeutic goals in IBD, it is important to optimize therapy according to disease severity and response to treatment. Therefore, monitoring disease activity is recommended throughout the disease course of IBD. Especially strategies to monitor disease beyond symptoms through endoscopy, laboratory markers, and imaging is required.

Fecal Calprotectin More Accurately Predicts Endoscopic Remission of Crohn's Disease than Serological Biomarkers Evaluated Using Balloon-assisted Enteroscopy

BACKGROUND

Fecal calprotectin (FC) has emerged as a reliable surrogate marker of endoscopic remission in Crohn's disease (CD), which has been mainly evaluated using ileocolonoscopy. We conducted this study to clarify the predictability of FC level for predicting endoscopic remission using balloon-assisted enteroscopy (BAE) findings in patients with CD and compare with that of conventional serological biomarkers.

METHODS

Patients with CD scheduled to undergo BAE were prospectively enrolled, and fecal and blood samples collected before the procedures. We used a modified simple endoscopic score for CD, in which the parameter "presence of narrowing" was removed from conventional simple endoscopic score for CD. Endoscopic remission was defined as modified simple endoscopic score for CD 0 to 2.

RESULTS

Seventy BAE procedures were performed in 53 patients with CD and evaluated. The area under the curve in receiver operating characteristic curve analysis of FC to predict endoscopic remission was 0.93, with an optimal cut-off value of 252.9 μg/g, and 96% sensitivity and 83% specificity, which was higher than that for C-reactive protein, albumin, white blood cell count, and platelet count (0.76, 0.66, 0.39, and 0.65, respectively). The area under the curve of FC for predicting endoscopic remission was high in patients with ileal and ileocolonic disease location (0.86 and 0.96, cut-off values 204.2 and 253.7 μg/g, respectively), and also higher than the area under the curve values of serological markers.

CONCLUSIONS

BAE findings showed that FC was more accurate for predicting endoscopic remission in CD than C-reactive protein, albumin, white blood cell count, and platelet count. Even in small-bowel CD, FC may be a more reliable surrogate marker of endoscopic remission than serological biomarkers.

Monitoring and detection of disease recurrence after resection for Crohn's disease: the role of non-invasive fecal biomarkers

Ileocolonoscopy is the gold standard for the diagnosis and assessment of postoperative recurrence in Crohn's disease (CD). Nevertheless, endoscopy is time-consuming and invasive. A minimally invasive and simple screening test would improve patient adherence to examination and provide greater clinical benefit. A number of fecal biomarkers have been evaluated for their utility for the diagnosis and monitoring of inflammatory bowel disease as alternative tests to endoscopy. Area covered: In this review, we focused on the utility of fecal biomarkers in the management of postoperative CD. Our major endeavor was to present an evidence-based assessment of the results of clinical trials on the available data. A literature search was conducted using the Medline. Expert commentary: Calprotectin and lactoferrin, both neutrophil-derived proteins, are the two most frequently used fecal biomarkers in clinical trials and practice. Several studies evaluated the role of these fecal biomarkers in patients with postoperative CD. These studies suggest that fecal calprotectin, and to a lesser degree lactoferrin, are useful in assessing endoscopic severity and in predicting future clinical recurrence after resection for CD. However, large scale, well-designed studies are necessary to rigorously evaluate the role of fecal biomarkers in postoperative CD.

Faecal biomarkers for screening small bowel inflammation in patients with Crohn's disease: a prospective study

BACKGROUND

The value of faecal biomarkers for screening small bowel inflammation in patients with Crohn's disease (CD) remains to be elucidated. This prospective study was to evaluate the utility of faecal biomarkers for detecting small intestinal inflammation.

METHODS

A total of 122 consecutive patients with a diagnosis of CD in the small intestine were screened for eligibility. Computed tomography enterography (CTE) was undertaken to evaluate small bowel inflammation followed by colonoscopy to confirm no large bowel involvement. Seventy eligible patients with inflammation confined to the small intestine were included. Faecal samples were collected for assaying calprotectin, lactoferrin and haemoglobin. For assessing the degree of small bowel inflammation, a semi-quantitative scoring system (CTE0, normal; CTE1, mild; CTE2, moderate; CTE3, severe) was applied.

RESULTS

The median calprotectin, lactoferrin and haemoglobin levels were significantly higher in patients with small bowel inflammation, CTE scores 1-3 (n = 42) versus 0 (n = 28): calprotectin, 330 versus 40 ng/ml, p < 0.0001; lactoferrin, 14 versus 3 ng/ml, p < 0.0001; haemoglobin, 29.5 versus 6.5 ng/ml, p = 0.005. There was a strong positive relationship between the faecal biomarkers and CTE score: calprotectin, p < 0.0001; lactoferrin, p < 0.0001; haemoglobin, p = 0.0004. A cutoff value of 140 ng/ml for calprotectin had a sensitivity of 69% and a specificity of 82% with an area under the receiver operating characteristic curve (AUC) of 0.82 to detect small bowel inflammation (CTE scores 1-3), while lactoferrin 6 ng/ml had a sensitivity of 69% and a specificity of 79% with an AUC of 0.83, and haemoglobin 9 ng/ml showed a sensitivity of 71% and a specificity of 39% with an AUC of 0.70.

CONCLUSIONS

Faecal calprotectin, lactoferrin, and to a lesser degree haemoglobin are relevant biomarkers for screening small bowel inflammation in CD patients without large bowel involvement. Further well-designed large-scale studies in this clinical setting should strengthen our findings.

Levels of Faecal Calprotectin and Magnetic Resonance Enterocolonography Correlate with Severity of Small Bowel Crohn's Disease: A Retrospective Cohort Study

Few studies have evaluated the usefulness of fecal calprotectin (FC) or magnetic resonance enterography (MRE) in diagnosing active Crohn's disease (CD) of the small bowel. In the study, we investigated the reliability of FC and MRE in assessing the activity of ileal CD and further explored the relationship between levels of FC and MRE scores. A total of 221 patients were diagnosed with ileal or ileo-colitis CD in our department between July 2012 and October 2016. The global magnetic resonance index of activity (MaRIA) correlated with the simple endoscopic score for CD (SES-CD) (r = 0.527, P = 0.005). When analysed segment-by-segment, a significant correlation was still observed (r = 0.590, P < 0.001). The SES-CD correlated closest with FC (r = 0.503), followed by CRP (r = 0.461), ESR (0.377) and the CDAI (r = 0.320). In receiver operating characteristic (ROC) analyses, the FC cut-off value of mucosal healing was 213.1 μg/g, with 76.1% sensitivity and 66.7% specificity. As for MaRIA, a cut-off value of 6.8 for each segment provided a sensitivity of 100% and a specificity of 79.2%. No agreement between MaRIA and FC levels was found. In conclusion, a combination of FC levels and MaRIA could be effective in monitoring mucosal activity in patients with small bowel CD.

Inter- and intraobserver agreement in computed tomography enterography in inflammatory bowel disease

AIM

To evaluate intra- and interobserver agreement in imaging features in inflammatory bowel disease and comparison with fecal calprotectin (FC) levels.

METHODS

Our institutional computed tomography enterography (CTE) database was retrospectively queried to identify patients who underwent CTE from January 2014 to June 2015. Patient inclusion criteria were confirmed inflammatory bowel disease (IBD) and FC collected < 4 mo after CTE without any change in clinical treatment or surgical treatment during this interval. The exclusion criterion was poor image quality. Two blinded abdominal radiologists, with 12 and 3 years of experience analyzed the CTE regarding localization (small bowel, colonic, both, or no disease detected); type of IBD (inflammatory, stenosing, fistulizing, > 1 pattern, or normal); and signs of active disease (present or absent). In 42 of 44 patients evaluated, routine CTE reports were made by one of the readers who re-evaluated the CTEs ≥ 6 mo later, to determine the intraobserver agreement. FC was considered a sign of disease activity when it was higher than 250 μg/g.

RESULTS

Forty-four patients with IBD (38 with Crohn's disease and 6 with ulcerative colitis) were included. There was a moderate interobserver agreement regarding localization of IBD (κ = 0.540), type of disease (κ = 0.410) and the presence of active signs in CTE (κ = 0.419). There was almost perfect intraobserver agreement regarding localization, type and signs of active disease in IBD. The κ values were 0.902, 0.937 and 0.830, respectively. After a consensus between both radiologists regarding inflammatory activity in CTE, we found that 24 (85.7%) of 28 patients who were classified with active disease had elevated FC, and six (37.5%) of 16 patients without inflammatory activity in CTE had elevated FC (P = 0.003). The correlation between elevated FC and the presence of active disease in CTE was significant (κ = 0.495, P = 0.001).

CONCLUSION

We found almost perfect intraobserver and moderate interobserver agreement in the signs of active disease in CTE with concurrence of high FC levels.