Development and validation of a novel therapeutic drug monitoring-based nomogram for prediction of primary endoscopic response to anti-TNF therapy in active Crohn's disease.

Background: Anti-tumor necrosis factor (TNF) monoclonal antibodies, especially infliximab (IFX) and adalimumab (ADA), are considered the first-line treatment for active Crohn's disease (CD). However, the predictive role of therapeutic drug monitoring (TDM) of serum anti-TNF in monitoring the treatment of inflammatory bowel disease (IBD) remains controversial. Objectives: To explore the correlation between serum anti-TNF levels and early endoscopic response in active CD using a TDM-based nomogram. Design: Cross-sectional study. Methods: The simplified endoscopic activity score for CD (SES-CD), Crohn's disease activity index (CDAI), laboratory parameters, and the serum trough levels of IFX and ADA were assessed. Results: The trough levels of IFX or ADA were significantly higher in patients with endoscopic response compared to non-responders in the development cohort (p < 0.001). The IFX and ADA levels showed a weak but significantly negative correlation with SES-CD (p < 0.001), CDAI (p < 0.001), and C-reactive protein (CRP) (p < 0.001) at week 14 post-IFX therapy in the development cohort. Furthermore, the receiver operating characteristic curve revealed that an optimal level of IFX (4.80 µg/mL) and ADA (8.80 µg/mL) exhibited the best performance in predicting endoscopic response. Concomitantly, we developed a novel nomogram prediction model based on the results of multivariate logistic regression analysis, which consisted of CRP, albumin (Alb), and anti-TNF trough levels at week 14. The nomogram showed significant discrimination and calibration for both IFX and ADA in the development cohort and performed well in the external validation cohort. Conclusion: This study demonstrates a robust association between serum concentrations of IFX, ADA, Alb, and CRP and primary endoscopic response in active CD patients. Importantly, the TDM- and laboratory marker-based nomogram may be used to evaluate the primary endoscopic response to anti-TNF therapy, especially for optimizing treatment strategies and switching therapy in CD patients.

Therapeutic drug monitoring-based nomogram predicts primary endoscopic response in Crohn's disease The present study established a therapeutic drug monitoring-based nomogram, which exhibits an exceptional predictive value, remarkable accuracy, and discrimination. This algorithmic nomogram holds the potential to enhance clinicians' comprehension of the underlying mechanisms contributing to individual patients' failure in achieving expected efficacy. Such approach is crucial for optimizing therapy options and facilitating biologic switching in refractory Crohn's disease.

Distinct alterations of fecal microbiota refer to the efficacy of adalimumab in Crohn's disease.

Background and Aims: Anti-tumor necrosis factor mAb (i.e., adalimumab, ADA) is currently used in the treatment of patients with Crohn's disease (CD). However, its regulation on fecal microbiota is still not fully understood. Methods: A retrospective analysis was conducted on 115 patients with CD who received treatment with ADA for 12 weeks at the Inflammatory Bowel Disease Center in Shanghai Tenth People's Hospital and Department of Gastroenterology in Shanghai General Hospital. The Crohn's disease activity index (CDAI) evaluation was applied to patients before ADA therapy at week 0, 4, 8, and 12. Clinical remission (CR) was defined as the CDAI < 150. All patients underwent ileocolonoscopy or enteroscopy at baseline (week 0) and week 12. Crohn's Disease Endoscopic Index of Severity (CDEIS) scores were calculated by two experienced physicians to assess endoscopic activity. Mucosal healing (MH) was assigned a CDEIS score between 0 and 3. Fecal samples were collected from eight CD patients at baseline and week 12, and the microbiota was analyzed by using 16S RNA sequencing. Results: At week 12, CR was achieved in 70.6% (72/102) of the patients with active CD. A total of 47.1% (48/102) of the patients with active CD attained MH, among which, 56.6% (30/53) of the patients with mildly active CD (3 ≤ CDEIS <9) and 48.0% (12/25) of the moderately active CD patients (9 ≤ CDEIS <12) attained MH, but only 25.0% (6/24) achieved MH in severely active CD patients (CDEIS ≥12). The efficacy of ADA was not associated with lesion locations (χ 2 = 0.409, p = 0.815). Unexpectedly, we found an increase in protective microbiota at the genus level (e.g., Barnesiella, Anaerostipes, Tyzzerella, Lachnoclostridium, and Lachnospiraceae_unclassified) but a decrease in pathogenic bacteria (Escherichia-Shigella) in fecal samples of the ADA-responsive group (ADA-R) when compared with those in the ADA-nonresponsive group (ADA-NR). Notably, the gene bglX coding ß-glucosidase and gph encoding phosphoglycolate phosphatase were enriched in fecal samples of ADA-R. Conversely, the abundance of genes coding ATP-binding cassette (ABC) transporter system proteins was significantly enriched in fecal samples of ADA-NR when compared with that of the ADA-R. Conclusion: This study reveals that ADA markedly improves clinical remission and induces MH in mildly to moderately active CD patients and that distinct changes in the gut microbiota can be used to predict the efficacy of ADA.