Exploring the concept of deep remission in Crohn's disease: correlation between transmural healing and biomarkers

Inflammatory Bowel Diseases and Nephropathies: Exploring the Gut-Kidney Axis

Inflammatory bowel disease (IBD) can extend beyond the gastrointestinal tract, affecting extraintestinal organs and significantly increasing morbidity and mortality. Despite early studies revealing kidney involvement in nearly a quarter of patients with IBD, renal manifestations have been notably overlooked. Among these manifestations, nephrolithiasis, obstructive uropathy, and fistula formation between the bowel and urinary tract are the most reported occurrences. Additionally, renal parenchymal involvement in IBD, including glomerulonephritis (GN), tubulointerstitial nephritis, and amyloidosis, has been documented. GN is particularly noteworthy, as a significant proportion of patients progress to end-stage kidney disease (ESKD). Although GN has long been recognized as a potential extraintestinal manifestation (EIM) of IBD, it has often been dismissed as an anecdotal association. Recently, several studies highlighted the clinical correlation between GN and IBD, suggesting a pathogenic interplay involving gut inflammation, dysbiosis, and intrinsic glomerular processes. Thus, our objective is to elucidate the basis of IBD-related nephropathies, with a specific focus on IgA nephropathy (IgAN) and the gut-kidney axis.

Optimal timeframe for achieving biochemical remission in Crohn's disease patients treated with first-line biologics: A retrospective multicenter study

Predicting treatment response in Crohn's disease (CD) patients initiating biological therapy is crucial. The first step involves considering symptom control and normalization of C-reactive protein (CRP). However, data on the actual rates of achieving CRP normalization and the appropriate timeframe are lacking. Therefore, we aim to investigate the rate of attaining CRP normalization and identify its optimal timeframe in CD patients initiating biological therapy. In this retrospective multi-center study, we analyzed moderate to severe CD patients initiating biological therapy from January 2012 to July 2023. The primary outcome was the rate and timeframe for achieving CRP normalization. Secondary outcomes included clinical outcomes in patients who achieved CRP normalization and factors associated with early CRP normalization. Of 183 patients, 123 (67.2%) achieved CRP normalization, with a median duration of 3.8 months (interquartile range 1.4 to 7.4 months). The duration and value difference for CRP normalization between anti-tumor necrosis factor agents, ustekinumab, and vedolizumab were statistically insignificant. Cumulative rates of CD-related hospitalization, intestinal resection, and drug discontinuation over 8 years were 11.4%, 2.4%, and 12.2%, respectively. The duration of CRP normalization correlates with drug discontinuation (area under the curve: 0.64). Treatment with 5-aminosalicylic acid (HR 2.77; 95% confidence interval [CI] 1.26-6.11) and high albumin level (HR 1.64, 95% CI 1.04-2.61) favored early CRP normalization, whereas structuring behavior less likely than inflammatory behavior (HR 0.43, 95% CI 0.19-0.96). We have provided the actual rate of achieving CRP normalization and its appropriate timeframe as an initial target in CD treatment.

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.

Tight control using fecal calprotectin and early disease intervention increase the rates of transmural remission in Crohn's disease

BACKGROUND

Increasing evidence supports the use of transmural remission as a treatment target in Crohn's disease (CD), but it is seldom achieved in clinical practice. Tight monitoring of inflammation using fecal calprotectin with reactive treatment escalation may potentially improve these results.

AIMS

To evaluate if treatment escalation based on fecal calprotectin can improve the rates of transmural remission in CD. The influence of the timing of intervention on this strategy was also evaluated.

METHODS

Retrospective cohort study including 256 CD patients with 2 consecutive assessments by MRI-enterography and colonoscopy and with regular monitoring using fecal calprotectin. For each occurrence of an elevated fecal calprotectin (≥250 μg/g), we evaluated whether a reactive adjustment of medical treatment was performed. The ratio of treatment escalation/elevated fecal calprotectin was correlated with the chances of reaching transmural remission. Early disease was defined as disease duration <18 months without previous exposure to immunomodulators and biologics.

RESULTS

After a median follow-up of 2 years (IQR 1-4), 61 patients (23.8%) reached transmural remission. Ratios of escalation ≥50% resulted in higher rates of transmural remission (34.2% vs. 15.1%, p < 0.001). The effect was more pronounced in patients with early disease (50.0% vs. 12.0%, p = 0.003). In multivariate analysis, a treatment escalation ratio ≥50% (OR 3.46, 95% CI 1.67-7.17, p = 0.001) and early disease intervention (OR 3.24, 95% CI 1.12-9.34, p = 0.030) were independent predictors of achieving transmural remission.

CONCLUSION

Tight-monitoring and reactive treatment escalation increase the rates of transmural remission in CD. Intervention in early disease further improves these results.

Effectiveness of Partial Enteral Nutrition as Add-On to Biologics in Patients With Refractory and Difficult-to-Treat Crohn's Disease: A Pilot Study

BACKGROUND

Partial enteral nutrition (PEN) is a well-established treatment for children with Crohn's disease (CD). However, its efficacy in adults with CD remains uncertain. We aimed to assess the effectiveness of PEN as an add-on to escalated biological therapy in adults with CD who have lost response to biologics.

METHODS

We conducted a retrospective observational study including patients who had lost response to biologics and received PEN in combination with escalated treatment, compared to those treated only with escalated therapy. The primary endpoint was steroid-free clinical remission (CR) at 24 weeks. Secondary endpoints included transmural healing (TH) and response (TR) rates along with selected clinical outcomes.

RESULTS

Forty-two patients were screened; 12 (28.6%) were excluded for complicated disease and 30 (71.4%) were included in the final analysis. Fourteen (46.7%) patients completed PEN treatment at 8 weeks, while 16 patients (53.3%) discontinued treatment due to intolerance and continued with escalation of biologic (BT group). At 24 weeks, 9 patients (64.3%) in the PEN group achieved CR, compared to 4 patients (25%) in the BT group (P = .03). The TR rate was 64.9% in the PEN group and 25% in the BT group (P = .03). Patients receiving PEN exhibited an increase in albumin levels compared to those in the BT group (Δ = 0.5; P = .02). A higher rate of therapy changes (68.7%) was observed in the BT group compared to 14.2% in the PEN group (P = .004). Prior failure to 2 lines of biological therapy was associated with adherence to PEN (OR = 1.583; CI = 1.06-2.36; P = .01).

CONCLUSIONS

In patients who had lost response to biologics, PEN in combination with escalated biologics was associated with CR and TR and improved nutritional status. Hence, the addition of PEN should be considered for patients with difficult-to-treat CD.

The Utility of Faecal Calprotectin, Lactoferrin and Other Faecal Biomarkers in Discriminating Endoscopic Activity in Crohn's Disease: A Systematic Review and Meta-Analysis

INTRODUCTION

Currently, faecal calprotectin (FC) is the predominate faecal biomarker utilised in clinical practice to monitor Crohn's disease (CD) activity. However, there are several potential faecal biomarkers described in the literature. We performed a meta-analysis to determine the accuracy of faecal biomarkers in discriminating endoscopic activity and mucosal healing in CD.

METHODS

We searched the medical literature using MEDLINE, EMBASE, and PubMed from 1978 to 8 August 2022. Descriptive statistics, including sensitivity, specificity of the primary studies, their positive and negative likelihood ratios, and their diagnostic odds ratio (DOR), were calculated. The methodological quality of the included studies was evaluated using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS) criteria.

RESULTS

The search found 2382 studies, of which 33 were included for analysis after screening. FC was found to have a pooled sensitivity and specificity, DOR, and negative predictive value (NPV) in discriminating active endoscopic disease (versus inactive) of 81%, 74%, 13.93, and 0.27, respectively. Faecal lactoferrin (FL) had a pooled sensitivity and specificity, DOR, and NPV in discriminating active endoscopic disease of 75%, 80%, 13.41, and 0.34, respectively. FC demonstrated a pooled sensitivity and specificity, DOR, and NPV of 88%, 72%, 18.17, and 0.19 in predicting mucosal healing.

CONCLUSION

FC remains an accurate faecal biomarker. Further evaluation of the utility of novel faecal biomarkers is needed.

Use of biologics for the management of Crohn's disease: IG-IBD clinical guidelines based on the GRADE methodology

A cure for Crohn's disease (CD), a chronic inflammatory disease of the gastrointestinal tract of unknown etiology, is not available, so patients require lifelong management to keep inflammation under control. The therapeutic armamentarium has expanded with approval of several biological drugs, including infliximab, adalimumab, vedolizumab and ustekinumab - monoclonal antibodies that target different inflammatory pathways - and darvadstrocel, a suspension of expanded human allogeneic, adipose-derived, mesenchymal stromal cells for the treatment of refractory complex perianal fistula. Notwithstanding existing practice guidelines on medical therapy for CD, the Italian Group for the Study of Inflammatory Bowel Disease felt the need to issue new guidelines focused on the use of biologics for managing the intestinal manifestations of CD and based on the GRADE methodology. This document presents recommendations regarding six clinical settings, from the induction to the maintenance of clinical remission, and from optimization and de-escalation of treatments to dealing with perianal CD and post-operative recurrence. The 19 evidence-based statements are supported by information on the quality of the evidence, agreement rate among panel members, and panel comments mainly based on evidence from real world studies.

Serum Leucine-Rich α2 Glycoprotein: A Novel Biomarker for Transmural Inflammation in Crohn's Disease

INTRODUCTION

Leucine-rich alpha-2 glycoprotein (LRG) is a newly studied biomarker for inflammatory diseases. This study aimed to investigate whether LRG can be used for evaluating transmural activity in patients with Crohn's disease (CD).

METHODS

We performed magnetic resonance enterography (MRE) in 227 consecutive CD patients from June 2020 to August 2021. We prospectively compared MRE findings with clinical and laboratory data including LRG. MRE was evaluated using 2 validated scoring systems, and transmural inflammation was defined as having a maximum simplified magnetic resonance index of activity (sMaRIA) score of ≥4 and a 5-point classification score of ≥9, respectively.

RESULTS

The correlation between LRG and the total MRE score showed a positive correlation ( r = 0.576 for sMaRIA score, P < 0.01 and r = 0.633 for 5-point score, P < 0.01). Serum concentrations of LRG significantly increased as MRE scores increased ( P < 0.01). The area under the curve of LRG for sMaRIA score of ≥4 and 5-point score of ≥9 was 0.845 and 0.869, respectively, which was significantly higher than that of CDAI ( P < 0.01) or C-reactive protein ( P < 0.01). LRG levels of ≥14 μg/mL had a 67% sensitivity and a 90% specificity for sMaRIA score of ≥4, and 73% sensitivity and 89% specificity for 5-point score of ≥9. Patients with high LRG levels were also strongly associated with CD-related hospitalization, surgery, and clinical relapse compared to those with low LRG levels ( P < 0.01 for all).

DISCUSSION

LRG is a highly accurate serum biomarker for detecting transmural activity in CD patients. Results need to be validated in further multicenter studies.