Systematic Review and Meta-analysis: The Association Between Serum Ustekinumab Trough Concentrations and Treatment Response in Inflammatory Bowel Disease.

BACKGROUND: Optimizing therapy and monitoring response are integral aspects of inflammatory bowel disease treatment. We conducted a systematic review and meta-analysis to determine whether serum ustekinumab trough concentrations during maintenance therapy were associated with ustekinumab treatment response in patients with inflammatory bowel disease. METHODS: A systematic review was performed to March 21, 2022, to identify studies using MEDLINE, EMBASE, and the Cochrane library. We included studies that reported the association between serum ustekinumab trough concentrations with clinical or endoscopic remission. Outcome measures were combined across studies using the random-effects model with an odds ratio (OR) for binary outcomes of endoscopic and clinical remission. RESULTS: We identified 14 observational studies that were included in the analysis for clinical remission (919 patients, 63% with Crohn's disease) or endoscopic remission (290 patients, all with Crohn's disease). Median ustekinumab trough concentrations were higher amongst individuals achieving clinical remission compared with those not achieving remission (mean difference, 1.6 ug/mL; 95% confidence interval [CI], 0.21-3.01 ug/mL). Furthermore, individuals with median serum trough concentration in the fourth quartile were significantly more likely to achieve clinical (OR, 3.61; 95% CI, 2.11-6.20) but not endoscopic remission (OR, 4.67; 95% CI, 0.86-25.19) compared with those with first quartile median trough concentrations. CONCLUSION: Based on the results of this meta-analysis primarily relating to patients with Crohn's disease on maintenance ustekinumab treatment, it appears that there is an association between higher ustekinumab trough concentration and clinical outcomes. Prospective studies are required to determine whether proactive dose adjustments of ustekinumab therapy provides additional clinical benefit.

This meta-analysis of 14 observational studies found an association between better clinical outcomes and higher trough ustekinumab levels for maintenance treatment in inflammatory bowel disease.

Volvulus of the ileal pouch-anal anastomosis: a meta-narrative systematic review of frequency, diagnosis, and treatment outcomes.

BACKGROUND: Proctocolectomy with ileal pouch-anal anastomosis (IPAA) is the surgical procedure of choice for medically refractory ulcerative colitis and familial adenomatous polyposis. While rare, a pouch volvulus can occur. We aimed to determine the frequency, presentation, and management approach of pouch volvulus in patients with IPAA. METHODS: A systematic search of published literature was performed by a medical reference librarian on 10 August 2018 and two independent reviewers identified relevant publications, extracted data, and assessed the methodological quality based on a validated tool. A retrospective review of the Mayo Clinic electronic medical records identified one case of pouch volvulus between January 2008 and August 2018. RESULTS: The frequency of pouch volvulus from one large published study reporting long-term outcomes of IPAA was 0.18% (3/1,700). A total of 22 patients (18 ulcerative colitis) were included (median age 32 years, 73% females). Median time to volvulus after IPAA was 36 months while median interval to volvulus diagnosis from symptom onset was 24 hours. Abdominal pain was the most commonly reported symptom (76%). The diagnosis was made primarily by abdominal computed tomography (13/17 patients, 76%). Endoscopic treatment was successful in 1 of 11 patients (9%). Surgery was performed in 20 patients and pouch-pexy and pouch excision were the most frequent surgical operations. A redo IPAA was performed in five patients (25%). CONCLUSION: Pouch volvulus is a rare but serious complication of IPAA and should be suspected even in the absence of obstruction symptoms. Endoscopic treatment often fails and surgery is effective when performed early.

Clinical Response and Complications are not Associated with Drug Levels in Patients with Severe Ulcerative Colitis on IV Cyclosporine Induction Therapy.

Background: IV ciclosporin therapy is effective in steroid-refractory ulcerative colitis. The optimal drug level to achieve response and minimize complications during induction therapy is not known. Aim: The primary aim was to evaluate if serum ciclosporin drug levels are associated with increased risk of colectomy within 90 days of hospitalization. Secondary aims were to determine if ciclosporin levels are associated with avoidance of colectomy at 7 and 30 days, if ciclosporin levels are associated with drug-related and postoperative complications, and if patient-specific factors are associated with response to ciclosporin. Methods: We conducted a retrospective analysis of 81 hospitalized patients with steroid-refractory ulcerative colitis treated with ciclosporin. Risk factors for colectomy within 7, 30, and 90 days, medication-specific and postoperative complications were compared by first, mean, and peak ciclosporin level during IV induction therapy. Results: There were 47 patients (58%) who underwent surgery. There were no differences between initial, mean, and peak ciclosporin levels among responders and nonresponders and treatment-related or postoperative complications. Responders within 90 days had lower C-reactive-protein levels (20mg/L vs. 38mg/L, P = 0.01), lower serum albumin concentrations (3.4g/dL vs. 3.7g/dL, P = 0.03), and higher rates of kidney injury (50% vs 17%, P = 0.002). Conclusion: Initial, mean, and peak serum levels of ciclosporin did not correlate with response or toxicity. However, C-reactive-protein levels levels and kidney injury may be helpful in predicting clinical response to ciclosporin.

Early Transcriptomic Changes in the Ileal Pouch Provide Insight into the Molecular Pathogenesis of Pouchitis and Ulcerative Colitis.

BACKGROUND: Ulcerative colitis (UC) only involves the colonic mucosa. Yet, nearly 50% of patients with UC who undergo total proctocolectomy with ileal pouch anal anastomosis develop UC-like inflammation of the ileal pouch (pouchitis). By contrast, patients with familial adenomatous polyposis (FAP) with ileal pouch anal anastomosis develop pouchitis far less frequently. We hypothesized that pathogenic events associated with the development of UC are recapitulated by colonic-metaplastic transcriptomic reprogramming of the UC pouch. METHODS: We prospectively sampled pouch and prepouch ileum mucosal biopsies in patients with UC with ileal pouch anal anastomosis 4, 8, and 12 months after their pouch was in continuity. Mucosal samples were also obtained from patients with FAP. Transcriptional profiles of the UC and FAP pouch and prepouch ileum were investigated via RNA sequencing and compared with data from a previously published microarray study. RESULTS: Unlike patients with FAP, subjects with UC exhibited a large set of differentially expressed genes between the pouch and prepouch ileum as early as 4 months after pouch functionalization. Functional pathway analysis of differentially expressed genes in the UC pouch revealed an enhanced state of immune/inflammatory response and extracellular matrix remodeling. Moreover, >70% of differentially expressed genes mapped to published inflammatory bowel diseases microarray data sets displayed directional changes consistent with active UC but not with Crohn's disease. CONCLUSIONS: The UC pouch, well before histologic inflammation, already displays a systems-level gain of colon-associated genes and loss of ileum-associated genes. Patients with UC exhibit a unique transcriptomic response to ileal pouch creation that can be observed well before disease and may in part explain their susceptibility to the development of pouchitis.

Patient-Specific Bacteroides Genome Variants in Pouchitis.

A 2-year longitudinal microbiome study of 22 patients who underwent colectomy with an ileal pouch anal anastomosis detected significant increases in distinct populations of Bacteroides during 9 of 11 patient visits that coincided with inflammation (pouchitis). Oligotyping and metagenomic short-read annotation identified Bacteroides populations that occurred in early samples, bloomed during inflammation, and reappeared after antibiotic treatment. Targeted cultivation of Bacteroides isolates from the same individual at multiple time points and from several patients detected subtle genomic changes, including the identification of rapidly evolving genomic elements that differentiate isogenic strains of Bacteroides fragilis from the mucosa versus lumen. Each patient harbored Bacteroides spp. that are closely related to commonly occurring clinical isolates, including Bacteroides ovatus, B. thetaiotaomicron, B. vulgatus, and B. fragilis, which contained unique loci in different patients for synthesis of capsular polysaccharides. The presence of unique Bacteroides capsular polysaccharide loci within different hosts and between the lumen and mucosa may represent adaptations to stimulate, suppress, and evade host-specific immune responses at different microsites of the ileal pouch. IMPORTANCE: This longitudinal study provides an opportunity to describe shifts in the microbiomes of individual patients who suffer from ulcerative colitis (UC) prior to and following inflammation. Pouchitis serves as a model for UC with a predictable incidence of disease onset and enables prospective longitudinal investigations of UC etiology prior to inflammation. Because of insufficient criteria for predicting which patients will develop UC or pouchitis, the interpretation of cross-sectional study designs suffers from lack of information about the microbiome structure and host gene expression patterns that directly correlate with the onset of disease. Our unique longitudinal study design allows each patient to serve as their own control, providing information about the state of the microbiome and host prior to and during the course of disease. Of significance to the broader community, this study identifies microbial strains that may have genetic elements that trigger the onset of disease in susceptible hosts.

Multiphasic analysis of the temporal development of the distal gut microbiota in patients following ileal pouch anal anastomosis.

BACKGROUND: The indigenous gut microbiota are thought to play a crucial role in the development and maintenance of the abnormal inflammatory responses that are the hallmark of inflammatory bowel disease. Direct tests of the role of the gut microbiome in these disorders are typically limited by the fact that sampling of the microbiota generally occurs once disease has become manifest. This limitation could potentially be circumvented by studying patients who undergo total proctocolectomy with ileal pouch anal anastomosis (IPAA) for the definitive treatment of ulcerative colitis. A subset of patients who undergo IPAA develops an inflammatory condition known as pouchitis, which is thought to mirror the pathogenesis of ulcerative colitis. Following the development of the microbiome of the pouch would allow characterization of the microbial community that predates the development of overt disease. RESULTS: We monitored the development of the pouch microbiota in four patients who underwent IPAA. Mucosal and luminal samples were obtained prior to takedown of the diverting ileostomy and compared to samples obtained 2, 4 and 8 weeks after intestinal continuity had been restored. Through the combined analysis of 16S rRNA-encoding gene amplicons, targeted 16S amplification and microbial cultivation, we observed major changes in structure and function of the pouch microbiota following ileostomy. There is a relative increase in anaerobic microorganisms with the capacity for fermentation of complex carbohydrates, which corresponds to the physical stasis of intestinal contents in the ileal pouch. Compared to the microbiome structure encountered in the colonic mucosa of healthy individuals, the pouch microbial community in three of the four individuals was quite distinct. In the fourth patient, a community that was much like that seen in a healthy colon was established, and this patient also had the most benign clinical course of the four patients, without the development of pouchitis 2 years after IPAA. CONCLUSIONS: The microbiota that inhabit the ileal-anal pouch of patients who undergo IPAA for treatment of ulcerative colitis demonstrate significant structural and functional changes related to the restoration of fecal flow. Our preliminary results suggest once the pouch has assumed the physiologic role previously played by the intact colon, the precise structure and function of the pouch microbiome, relative to a normal colonic microbiota, will determine if there is establishment of a stable, healthy mucosal environment or the reinitiation of the pathogenic cascade that results in intestinal inflammation.