Inflammatory bowel disease symptoms at the time of anal fistula lead to the diagnosis of Crohn's disease

Surface-enhanced Raman spectroscopy analysis reveals biochemical difference in urine of patients with perianal fistula

BACKGROUND & AIMS

Perianal fistulising Crohn's disease (PFCD) is different from the characteristics and outcomes of traditional non-inflammatory bowel disease (IBD) anal fistulas. The presence of perianal disease was a poor prognostic indicator for Crohn's disease (CD) patients and PFCD patients were more likely to bear an increased risk of recurrence. However, the effective and accurate diagnosis methods to early distinguish PFCD from simple perianal fistula were still scarce. The purpose of this study is to develop a non-invasive detecting approach to predict CD in patients with perianal fistulas.

METHODS

Data on patients with anal fistulizing disease were collected from July 2020 to September 2020 in two IBD centers. Urine samples from PFCD and simple perianal fistula patients were investigated by surface-enhanced Raman spectroscopy (SERS). Principal component analysis (PCA)-support vector machine (SVM) was utilized to establish classification models to distinguish PFCD from simple perianal fistula.

RESULTS

After a case-matched 1:1 selection by age and gender, 110 patients were included in the study. By analyzing the average SERS spectra of PFCD and simple perianal fistula patients, it revealed that there were significant differences in intensities at 11 Raman peaks. The established PCA-SVM model distinguished PFCD from simple perianal fistula with a sensitivity of 71.43%, specificity 80.00% and accuracy 75.71% in the leave-one-patient-out cross-validation. The accuracy of the model in validation cohort was 77.5%.

CONCLUSIONS

Investigation of urine samples by SERS helps clinicians to predict Crohn's disease from perianal fistulas, which make patients achieve benefit from a more individualized treatment strategy.

Systematic review with meta-analysis: Time to diagnosis and the impact of delayed diagnosis on clinical outcomes in inflammatory bowel disease

BACKGROUND

The impact of diagnostic delay on the clinical course of inflammatory bowel disease (IBD) remains uncertain.

AIM

To perform a systematic review of time to diagnosis and the impact of delayed diagnosis on clinical outcomes in Crohn's disease (CD) and ulcerative colitis (UC).

METHODS

We searched EMBASE and Medline from inception to 30th November 2022 for studies reporting diagnostic interval, from symptom onset to IBD diagnosis. We calculated the median, interquartile range (IQR) and pooled weighted median, of median diagnostic intervals of eligible studies. We defined delayed diagnosis as individuals above the 75th centile of longest time to diagnosis in each study. Using random effects meta-analysis, we pooled odds ratios (ORs) with 95% confidence intervals (CI) for studies reporting clinical outcomes, according to delayed diagnosis.

RESULTS

One hundred and one studies representing 112,194 patients with IBD (CD = 59,359; UC = 52,835) met inclusion criteria. The median of median times to diagnosis was 8.0 (IQR: 5.0-15.2) and 3.7 months (IQR: 2.0-6.7) in CD and UC, respectively. In high-income countries, this was 6.2 (IQR: 5.0-12.3) and 3.2 months (IQR: 2.2-5.3), compared with 11.7 (IQR: 8.3-18.0) and 7.8 months (IQR: 5.2-21.8) in low-middle-income, countries, for CD and UC respectively. The pooled weighted median was 7.0 (95% CI: 3.0-26.4) and 4.6 (95% CI: 1.0-96.0) months, for CD and UC respectively. Eleven studies, representing 6164 patients (CD = 4858; UC = 1306), were included in the meta-analysis that examined the impact of diagnostic delay on clinical outcomes. In CD, delayed diagnosis was associated with higher odds of stricturing (OR = 1.88; CI: 1.35-2.62), penetrating disease (OR = 1.64; CI: 1.21-2.20) and intestinal surgery (OR = 2.24; CI: 1.57-3.19). In UC, delayed diagnosis was associated with higher odds of colectomy (OR = 4.13; CI: 1.04-16.40).

CONCLUSION

Delayed diagnosis is associated with disease progression in CD, and intestinal surgery in both CD and UC. Strategies are needed to achieve earlier diagnosis of IBD.

Strategies to Distinguish Perianal Fistulas Related to Crohn's Disease From Cryptoglandular Disease: Systematic Review With Meta-Analysis

BACKGROUND

Management of perianal fistulas differs based on fistula type. We aimed to assess the ability of diagnostic strategies to differentiate between Crohn's disease (CD) and cryptoglandular disease (CGD) in patients with perianal fistulas.

METHODS

We performed a diagnostic accuracy systematic review and meta-analysis. A systematic search of electronic databases was performed from inception through February 2021 for studies assessing a diagnostic test's ability to distinguish fistula types. We calculated weighted summary estimates with 95% confidence intervals for sensitivity and specificity by bivariate analysis, using fixed effects models when data were available from 2 or more studies. The Quality Assessment of Diagnostic Accuracy Studies tool was used to assess study quality.

RESULTS

Twenty-one studies were identified and included clinical symptoms (2 studies; n=154), magnetic resonance imaging (MRI) characteristics (3 studies; n=296), ultrasound characteristics (7 studies; n=1003), video capsule endoscopy (2 studies; n=44), fecal calprotectin (1 study; n=56), and various biomarkers (8 studies; n=440). MRI and ultrasound characteristics had the most robust data. Rectal inflammation, multiple-branched fistula tracts, and abscesses on pelvic MRI and the Crohn's ultrasound fistula sign, fistula debris, and bifurcated fistulas on pelvic ultrasonography had high specificity (range, 80%-95% vs 89%-96%) but poor sensitivity (range, 17%-37% vs 31%-63%), respectively. Fourteen of 21 studies had risk of bias on at least 1 of the Quality Assessment of Diagnostic Accuracy Studies domains.

CONCLUSIONS

Limited high-quality evidence suggest that imaging characteristics may help discriminate CD from CGD in patients with perianal fistulas. Larger, prospective studies are needed to confirm these findings and to evaluate if combining multiple diagnostic tests can improve diagnostic sensitivity.

Bachu Mushroom Polysaccharide Alleviates Colonic Injury by Modulating the Gut Microbiota

Objective

This study was to define the protective effect of purified Helvella leucopus polysaccharide (p-HLP) against dextran sulfate sodium- (DSS-) induced colitis.

Methods

The novel p-HLP was isolated from Bachu mushroom through hot water extraction, ethanol precipitation, and column chromatography. Then, we evaluated the potential effects of p-HLP on colonic histopathology, inflammation, and microbiota composition in DSS-induced colitis mice.

Results

p-HLP was a homopolysaccharide with an average molecular weight of 39.14 × 10⁸ Da. Functionally, p-HLP significantly attenuated DSS-induced body weight loss and colon shortening. The histological score of the colon lesion was significantly decreased upon p-HLP treatment. Also, p-HLP treatment led to decreased expression of proinflammatory cytokines and mediators (IL-6, IL-1β and TNF-α, and COX-2 and iNOS) and increased expression of anti-inflammatory cytokine (IL-10) in the colon tissues. Illumina MiSeq sequencing revealed that p-HLP modulated the composition of the gut microbiota.

Conclusion

p-HLP is a potent regulator that protects the lesions from DSS-induced colitis.