Comparative proteomic analysis of supportive and unsupportive extracellular matrix substrates for human embryonic stem cell maintenance.

Human embryonic stem cells (hESCs) are pluripotent cells that have indefinite replicative potential and the ability to differentiate into derivatives of all three germ layers. hESCs are conventionally grown on mitotically inactivated mouse embryonic fibroblasts (MEFs) or feeder cells of human origin. In addition, feeder-free culture systems can be used to support hESCs, in which the adhesive substrate plays a key role in the regulation of stem cell self-renewal or differentiation. Extracellular matrix (ECM) components define the microenvironment of the niche for many types of stem cells, but their role in the maintenance of hESCs remains poorly understood. We used a proteomic approach to characterize in detail the composition and interaction networks of ECMs that support the growth of self-renewing hESCs. Whereas many ECM components were produced by supportive and unsupportive MEF and human placental stromal fibroblast feeder cells, some proteins were only expressed in supportive ECM, suggestive of a role in the maintenance of pluripotency. We show that identified candidate molecules can support attachment and self-renewal of hESCs alone (fibrillin-1) or in combination with fibronectin (perlecan, fibulin-2), in the absence of feeder cells. Together, these data highlight the importance of specific ECM interactions in the regulation of hESC phenotype and provide a resource for future studies of hESC self-renewal.

A propensity score-matched, real-world comparison of ustekinumab vs vedolizumab as a second-line treatment for Crohn's disease. The Cross Pennine study II.

BACKGROUND: The optimal choice of biological agents after failure of anti-tumour-necrosis-factor-(TNF)α agent in Crohn's disease (CD) is yet to be defined. AIMS: To assess the effectiveness and safety of ustekinumab compared to vedolizumab as second-line treatment in CD patients who failed anti-TNFα therapy. METHODS: Retrospective analysis of clinical response and remission at 14 and 52 weeks to ustekinumab by physician global assessment (PGA). A propensity score-matched analysis with a cohort treated with vedolizumab was performed. RESULTS: Of 282 patients (mean age 40 ± 15, F:M ratio 1.7:1) treated with ustekinumab, clinical response or remission was reached by 200/282 patients (70.9%) at 14 weeks, and 162/259 patients (62.5%) at 52 weeks. Overall, 74 adverse events occurred, of which 26 were labelled as serious (8.3 per 100 person-year). After exclusion of patients without prior anti-TNFα exposure and patients previously exposed to vedolizumab or ustekinumab, we analysed 275/282 patients (97.5%) on ustekinumab and 118/135 patients (87.4%) on vedolizumab. Propensity score analysis revealed that at 14 weeks, patients treated with ustekinumab were 38% (95% CI 25%-50%; P < 0.001) more likely to achieve clinical remission, while at 52 weeks, the difference of 9% (95% CI -15% to 33%; P = 0.462) was not significant. CONCLUSIONS: Ustekinumab was effective and well tolerated in this real-world cohort. While ustekinumab proved more effective at 14-weeks, we found no statistically significant differences at 52 weeks compared to vedolizumab.

Implications for sequencing of biologic therapy and choice of second anti-TNF in patients with inflammatory bowel disease: results from the IMmunogenicity to Second Anti-TNF therapy (IMSAT) therapeutic drug monitoring study.

BACKGROUND: Anti-drug antibodies are associated with treatment failure to anti-TNF agents in patients with inflammatory bowel disease (IBD). AIM: To assess whether immunogenicity to a patient's first anti-TNF agent would be associated with immunogenicity to the second, irrespective of drug sequence METHODS: We conducted a UK-wide, multicentre, retrospective cohort study to report rates of immunogenicity and treatment failure of second anti-TNF therapies in 1058 patients with IBD who underwent therapeutic drug monitoring for both infliximab and adalimumab. The primary outcome was immunogenicity to the second anti-TNF agent, defined at any timepoint as an anti-TNF antibody concentration ≥9 AU/ml for infliximab and ≥6 AU/ml for adalimumab. RESULTS: In patients treated with infliximab and then adalimumab, those who developed antibodies to infliximab were more likely to develop antibodies to adalimumab, than patients who did not develop antibodies to infliximab (OR 1.99, 95%CI 1.27-3.20, p = 0.002). Similarly, in patients treated with adalimumab and then infliximab, immunogenicity to adalimumab was associated with subsequent immunogenicity to infliximab (OR 2.63, 95%CI 1.46-4.80, p < 0.001). For each 10-fold increase in anti-infliximab and anti-adalimumab antibody concentration, the odds of subsequently developing antibodies to adalimumab and infliximab increased by 1.73 (95% CI 1.38-2.17, p < 0.001) and 1.99 (95%CI 1.34-2.99, p < 0.001), respectively. Patients who developed immunogenicity with undetectable drug levels to infliximab were more likely to develop immunogenicity with undetectable drug levels to adalimumab (OR 2.37, 95% CI 1.39-4.19, p < 0.001). Commencing an immunomodulator at the time of switching to the second anti-TNF was associated with improved drug persistence in patients with immunogenic, but not pharmacodynamic failure. CONCLUSION: Irrespective of drug sequence, immunogenicity to the first anti-TNF agent was associated with immunogenicity to the second, which was mitigated by the introduction of an immunomodulator in patients with immunogenic, but not pharmacodynamic treatment failure.

Precision medicine in inflammatory bowel disease: concept, progress and challenges.

Crohn's disease and ulcerative colitis are increasingly prevalent, relapsing and remitting inflammatory bowel diseases (IBDs) with variable disease courses and complications. Their aetiology remains unclear but current evidence shows an increasingly complex pathophysiology broadly centring on the genome, exposome, microbiome and immunome. Our increased understanding of disease pathogenesis is providing an ever-expanding arsenal of therapeutic options, but these can be expensive and patients can lose response or never respond to certain therapies. Therefore, there is now a growing need to personalise therapies on the basis of the underlying disease biology and a desire to shift our approach from "reactive" management driven by disease complications to "proactive" care with an aim to prevent disease sequelae. Precision medicine is the tailoring of medical treatment to the individual patient, encompassing a multitude of data-driven (and multi-omic) approaches to foster accurate clinical decision-making. In IBD, precision medicine would have significant benefits, enabling timely therapy that is both effective and appropriate for the individual. In this review, we summarise some of the key areas of progress towards precision medicine, including predicting disease susceptibility and its course, personalising therapies in IBD and monitoring response to therapy. We also highlight some of the challenges to be overcome in order to deliver this approach.

Posterior Reversible Encephalopathy Syndrome and Fatal Cryptococcal Meningitis After Immunosuppression in a Patient With Elderly Onset Inflammatory Bowel Disease.

Advanced age and associated comorbidities are-recognized predictors of life-threatening adverse outcomes, such as opportunistic infection following immunosuppressive therapy. We describe the case of an elderly patient with stricturing colonic Crohn's disease and significant clinical comorbidities, initially controlled with corticosteroid induction followed by infliximab, whose course was complicated by fatal disseminated cryptococcal infection and posterior reversible encephalopathy syndrome. Our patient's case highlights rare, but serious, complications of immunosuppression. In applying modern treatment paradigms to the elderly, the clinician must consider the potential for more pronounced adverse effects in this potentially vulnerable group, maximizing benefit and minimizing harm.