Impact of revised International Staging System 2 risk stratification on outcomes of patients with multiple myeloma receiving autologous haematopoietic stem cell transplantation.

The second revision of the International Staging System (R2-ISS) is a simple tool to risk-stratify newly diagnosed multiple myeloma (NDMM) patients. Here, we completed a retrospective analysis to evaluate the utility of R2-ISS in NDMM patients who underwent up-front autologous haematopoietic stem cell transplantation (auto-HCT). A total of 1291 patients were included, with a median age of 62 years (range 29-83). The distribution of R2-ISS stages was: 123 (10%) stage I, 471 (36%) stage II, 566 (44%) stage III and 131 (10%) stage IV. With a median follow-up of 42.2 months (range 0.3-181.0), the median PFS was 73.0, 65.2, 44.0 and 24.8 months, (p < 0.001) and the median OS was 130.8, 128.5, 94.2 and 61.4 months (p < 0.001) for patients with R2-ISS stages I, II, III and IV respectively. On multivariable analysis (MVA) for PFS, using R2-ISS stage I as reference, R2-ISS stages III (hazard ratio [95% confidence interval], 1.55 [1.05-2.29]; p = 0.028) and IV (2.04 [1.24-3.36]; p = 0.005) were associated with significantly inferior PFS. In the MVA of OS, using R2-ISS stage I as reference, only R2-ISS stage IV was associated with significantly inferior OS (2.43 [1.18-5.01]; p = 0.017). Overall, we found that R2-ISS is a reliable prognostic tool for NDMM patients undergoing up-front auto-HCT.

Reliability of CT Enterography for Describing Fibrostenosing Crohn Disease.

Background Standardized methods to measure and describe Crohn disease strictures at CT enterography are needed to guide clinical decision making and for use in therapeutic studies. Purpose To assess the reliability of CT enterography features to describe Crohn disease strictures and their correlation with stricture severity. Materials and Methods A retrospective study was conducted in 43 adult patients with symptomatic terminal ileal Crohn disease strictures who underwent standard-of-care CT enterography at a tertiary care center at the Cleveland Clinic between January 2008 and August 2016. After training on standardized definitions, four abdominal radiologists blinded to all patient information assessed imaging features (seven continuous measurements and nine observations) of the most distal ileal stricture in two separate sessions (separated by ≥2 weeks) in random order. Features with an interrater intraclass correlation coefficient (ICC) of 0.41 or greater (ie, moderate reliability or better) were considered reliable. Univariable and multivariable linear regression analysis identified reliable features associated with a visual analog scale of overall stricture severity. Significant reliable features were assessed as components of a CT enterography-based model to quantitate stricture severity. Results Examinations in 43 patients (mean age, 52 years ± 16 [SD]; 23 female) were evaluated. Five continuous measurements and six observations demonstrated at least moderate interrater reliability (interrater ICC range, 0.42 [95% CI: 0.25, 0.57] to 0.80 [95% CI: 0.67, 0.88]). Of these, 10 were univariably associated with stricture severity, and three continuous measurements-stricture length (interrater ICC, 0.64 [95% CI: 0.42, 0.81]), maximal associated small bowel dilation (interrater ICC, 0.80 [95% CI: 0.67, 0.88]), and maximal stricture wall thickness (interrater ICC, 0.50 [95% CI: 0.34, 0.62])-were independently associated (P value range, <.001 to .003) with stricture severity in a multivariable model. These three measurements were used to derive a well-calibrated (optimism-adjusted calibration slope = 1.00) quantitative model of stricture severity. Conclusion Standardized CT enterography measurements and observations can reliably describe terminal ileal Crohn disease strictures. Stricture length, maximal associated small bowel dilation, and maximal stricture wall thickness are correlated with stricture severity. © RSNA, 2024 Supplemental material is available for this article. See also the article by Rieder et al in this issue. See also the editorial by Galgano and Summerlin in this issue.

Reliability of MR Enterography Features for Describing Fibrostenosing Crohn Disease.

Background Clinical decision making and drug development for fibrostenosing Crohn disease is constrained by a lack of imaging definitions, scoring conventions, and validated end points. Purpose To assess the reliability of MR enterography features to describe Crohn disease strictures and determine correlation with stricture severity. Materials and Methods A retrospective study of patients with symptomatic terminal ileal Crohn disease strictures who underwent MR enterography at tertiary care centers (Cleveland Clinic: September 2013 to November 2020; Mayo Clinic: February 2008 to March 2019) was conducted by using convenience sampling. In the development phase, blinded and trained radiologists independently evaluated 26 MR enterography features from baseline and follow-up examinations performed more than 6 months apart, with no bowel resection performed between examinations. Follow-up examinations closest to 12 months after baseline were selected. Reliability was assessed using the intraclass correlation coefficient (ICC). In the validation phase, after five features were redefined, reliability was re-estimated in an independent convenience sample using baseline examinations. Multivariable linear regression analysis identified features with at least moderate interrater reliability (ICC ≥0.41) that were independently associated with stricture severity. Results Ninety-nine (mean age, 40 years ± 14 [SD]; 50 male) patients were included in the development group and 51 (mean age, 45 years ± 16 [SD]; 35 female) patients were included in the validation group. In the development group, nine features had at least moderate interrater reliability. One additional feature demonstrated moderate reliability in the validation group. Stricture length (ICC = 0.85 [95% CI: 0.75, 0.91] and 0.91 [95% CI: 0.75, 0.96] in development and validation phase, respectively) and maximal associated small bowel dilation (ICC = 0.74 [95% CI: 0.63, 0.80] and 0.73 [95% CI: 0.58, 0.87] in development and validation group, respectively) had the highest interrater reliability. Stricture length, maximal stricture wall thickness, and maximal associated small bowel dilation were independently (regression coefficients, 0.09-3.97; P < .001) associated with stricture severity. Conclusion MR enterography definitions and scoring conventions for reliably assessing features of Crohn disease strictures were developed and validated, and feature correlation with stricture severity was determined. © RSNA, 2024 Supplemental material is available for this article. See also the article by Rieder and Ma et al in this issue. See also the editorial by Galgano and Summerlin in this issue.

Higher Postinduction Infliximab Concentrations Are Associated With Favorable Clinical Outcomes in Pediatric Crohn's Disease: A Post Hoc Analysis of the REACH Trial.

INTRODUCTION: Exposure-outcome relationship data show that higher infliximab concentrations are associated with better outcomes in patients with Crohn's disease (CD). However, most of these data were derived from adult patients on maintenance therapy. We aimed to investigate the association of infliximab concentrations during and early after induction therapy of infliximab with short-term and long-term clinical outcomes in a pediatric CD population. METHODS: We conducted a post hoc analysis of the REACH trial which included pediatric patients with moderate-to-severe CD treated with infliximab (n = 103). The investigated outcomes were early clinical remission (CR) defined as a pediatric CD activity index score of ≤ 10, assessed at week 10, and long-term clinical response (LTCR) defined as a decrease from baseline in the pediatric CD activity index score of at least 15 points, with a total score of ≤ 30 and no need for drug discontinuation, assessed at weeks 30 and 54. RESULTS: Based on multivariable logistic regression analysis, higher week 10 infliximab concentrations were independently associated with CR at week 10 (odds ratio: 1.54; 95% confidence interval: 1.06-2.22; P = 0.022) and LTCR at week 30 (odds ratio: 1.62; 95% confidence interval: 1.12-2.36; P = 0.010). Receiver operating characteristic analysis identified week 10 infliximab concentration thresholds of ≥7.1 µg/mL and ≥6.5 µg/mL to be associated with CR at week 10 and LTCR at week 30, respectively. DISCUSSION: Higher postinduction infliximab concentrations are associated with both short-term and long-term favorable clinical outcomes in pediatric patients with CD. Tailoring dosing during induction to achieve higher infliximab exposure may lead to better outcomes in pediatric patients with CD.

Re-evaluating Methods for Assessing Differences in Response in Ileal vs. Colonic Crohn's Disease: A Post-hoc Analysis of the FITZROY Trial.

BACKGROUND AND AIMS: The ileum is the most commonly affected segment of the gastrointestinal tract in Crohn's disease (CD). We aimed to determine whether disease location affects response to filgotinib, a Janus kinase (JAK) inhibitor, in patients with moderate-to-severely active Crohn's disease (CD) and applying appropriate methods to account for differences in measuring disease activity in the ileum compared to the colon. METHODS: This post-hoc analysis of data from the FITZROY phase 2 trial (NCT02048618) compared changes in the Crohn's Disease Activity Index (CDAI) and Simple Endoscopic Score for Crohn's Disease (SES-CD) amongst patients with ileal-dominant and isolated colonic CD treated with 10 weeks of filgotinib 200 mg daily or placebo. A mixed effects model for repeated measures was used to test whether ileal disease responded differently than colonic disease, by evaluating for effect modification using the interaction term of treatment assignment-by-disease location. RESULTS: Numerically greater proportions of patients with isolated colonic disease compared to ileal-dominant CD achieved clinical remission (CDAI <150, 75.9% vs. 41.6%) and endoscopic response (SES-CD reduction by 50%, 52.5% vs. 15.5%) at Week 10. However, after adjusting for baseline disease activity by disease location and within-patient clustering effects, there was no significant difference in treatment response by disease location (mean difference in ΔCDAI between ileal-dominant vs. isolated colonic disease +9.24 [95% CI: -87.19, +105.67], p=0.85; mean difference in ΔSES-CD -1.93 [95% CI: -7.03, +3.44], p=0.48). CONCLUSIONS: Filgotinib demonstrated similar efficacy in ileal-dominant and isolated colonic CD when controlling for baseline disease activity and clustering effects.

Identification of immune cell markers associated with ulcerative colitis histological disease activity in colonic biopsies.

AIMS: Accurate determination of histological activity in ulcerative colitis (UC) is essential given its diagnostic and prognostic importance. Data on the relationship between histology and immune cell markers are limited. We aimed to evaluate the association between histological disease activity and immune cell marker concentration in colonic biopsies from patients with UC. METHODS: Sigmoid colon biopsies from 20 patients with UC were retrospectively assessed using the Robarts Histopathology Index (RHI). Targeted mass spectrometry determined the concentration of 18 immune cell markers (cluster of differentiation (CD) 4, CD8, CD19, CD20, CD40, CD56, CD68, CD103, forkhead box p3 (FOXP3), human leucocyte antigen, DR alpha chain (HLA-DRA), interleukin 10 (IL-10), IL-23 subunit alpha (IL-23A), IL-23 receptor (IL-23R), IL-2 receptor alpha chain (IL-2RA), Ki67, lymphocyte-activation gene 3 (LAG-3), programmed cell death protein 1 (PD-1) and PD ligand 1 (PD-L1)). The association between RHI score and immune cell marker concentration was quantified using Spearman's rank correlation coefficient (ρ) and related 95% CIs. RESULTS: Fourteen of the 18 immune cell marker proteins were detected, with tissue concentration ranging from 0.003 to 11.53 fmol/µg. The overall RHI score was positively correlated with CD19, CD20, CD40, FOXP3, LAG-3, PD-1 and PD-L1 concentration (ρ=0.596-0.799) and negatively correlated with CD56 concentration (ρ=-0.460). There was no significant association between RHI score and CD4, CD8, CD68, CD103, HLA-DRA or Ki67 concentration. CONCLUSIONS: This study provides insight into the correlation between immune cell marker expression and histological disease activity and the possible molecular and immunological determinants underlying microscopic disease activity in UC.

Multiple myeloma patients with a long remission after autologous hematopoietic stem cell transplantation.

Autologous stem cell transplantation (autoHCT) is considered standard of care for newly diagnosed multiple myeloma (MM). Although most patients eventually progress after autoHCT, a small proportion achieve a durable response. In this retrospective study we included 1576 patients, 244 (15%) of whom were long-term responders (LTR), defined as having a progression-free survival (PFS) of ≥8 years after transplant. Patients in the LTR group were younger than the non-LTR group (median age 58.4 vs. 59.5 years; p = 0.012), less likely to have high-risk cytogenetics (4% vs. 14%; p < 0.001), more often had <50% bone marrow plasma cells (67% vs. 58%; p = 0.018) and R-ISS stage I disease (43% vs. 34%). More patients in the LTR group received post-transplant maintenance (63% vs. 52%; p = 0.002). Patients in the LTR group had higher rates of complete response (CR) at day100 (41% vs. 27%; p < 0.001) and at best post-transplant response (70% vs. 37%; p < 0.001), compared to the non-LTR group. Patients in the LTR groups had a median PFS of 169.3 months and the median overall survival (OS) had not been reached. The leading cause of death in the LTR was disease progression. In conclusion, 15% of patients in the cohort were LTR after upfront autoHCT, with distinct characteristics and a median PFS of more than 14 years.

Determining the optimal treatment target in patients with ulcerative colitis: rationale, design, protocol and interim analysis for the randomised controlled VERDICT trial.

INTRODUCTION: Symptoms, endoscopy and histology have been proposed as therapeutic targets in ulcerative colitis (UC). Observational studies suggest that the achievement of histologic remission may be associated with a lower risk of complications, compared with the achievement of endoscopic remission alone. The actiVE ulcerative colitis, a RanDomIsed Controlled Trial (VERDICT) aims to determine the optimal treatment target in patients with UC. METHODS AND ANALYSIS: In this multicentre, prospective randomised study, 660 patients with moderate to severe UC (Mayo rectal bleeding subscore [RBS] ≥1; Mayo endoscopic score [MES] ≥2) are randomly assigned to three treatment targets: corticosteroid-free symptomatic remission (Mayo RBS=0) (group 1); corticosteroid-free endoscopic remission (MES ≤1) and symptomatic remission (group 2); or corticosteroid-free histologic remission (Geboes score <2B.0), endoscopic remission and symptomatic remission (group 3). Treatment is escalated using vedolizumab according to a treatment algorithm that is dependent on the patient's baseline UC therapy until the target is achieved at weeks 16, 32 or 48. The primary outcome, the time from target achievement to a UC-related complication, will be compared between groups 1 and 3 using a Cox proportional hazards model. ETHICS AND DISSEMINATION: The study was approved by ethics committees at the country level or at individual sites as per individual country requirements. A full list of ethics committees is available on request. Study results will be disseminated in peer-reviewed journals and at scientific meetings. TRIAL REGISTRATION NUMBER: EudraCT: 2019-002485-12; NCT04259138.

Ribosomal DNA integrating rAAV-rDNA vectors allow for stable transgene expression.

Although recombinant adeno-associated virus (rAAV) vectors are proving to be efficacious in clinical trials, the episomal character of the delivered transgene restricts their effectiveness to use in quiescent tissues, and may not provide lifelong expression. In contrast, integrating vectors enhance the risk of insertional mutagenesis. In an attempt to overcome both of these limitations, we created new rAAV-rDNA vectors, with an expression cassette flanked by ribosomal DNA (rDNA) sequences capable of homologous recombination into genomic rDNA. We show that after in vivo delivery the rAAV-rDNA vectors integrated into the genomic rDNA locus 8-13 times more frequently than control vectors, providing an estimate that 23-39% of the integrations were specific to the rDNA locus. Moreover, a rAAV-rDNA vector containing a human factor IX (hFIX) expression cassette resulted in sustained therapeutic levels of serum hFIX even after repeated manipulations to induce liver regeneration. Because of the relative safety of integration in the rDNA locus, these vectors expand the usage of rAAV for therapeutics requiring long-term gene transfer into dividing cells.

AAV vectors containing rDNA homology display increased chromosomal integration and transgene persistence.

Although recombinant adeno-associated viral (rAAV) vectors are promising tools for gene therapy of genetic disorders, they remain mostly episomal and hence are lost during cell replication. For this reason, rAAV vectors capable of chromosomal integration would be desirable. Ribosomal DNA (rDNA) repeat sequences are overrepresented during random integration of rAAV. We therefore sought to enhance AAV integration frequency by including 28S rDNA homology arms into our vector design. A vector containing ~1 kb of homology on each side of a cDNA expression cassette for human fumarylacetoacetate hydrolase (FAH) was constructed. rAAV of serotypes 2 and 8 were injected into Fah-deficient mice, a model for human tyrosinemia type 1. Integrated FAH transgenes are positively selected in this model and rDNA-containing AAV vectors had a ~30× higher integration frequency than controls. Integration by homologous recombination (HR) into the 28S rDNA locus was seen in multiple tissues. Furthermore, rDNA-containing AAV vectors for human factor IX (hFIX) demonstrated increased transgene persistence after liver regeneration. We conclude that rDNA containing AAV vectors may be superior to conventional vector design for the treatment of genetic diseases, especially those associated with increased hepatocyte replication.

Effect of storage time on peripheral blood mononuclear cell isolation from blood collected in vacutainer CPT™ tubes.

BACKGROUND: Clinical trials of novel therapies for the treatment of ulcerative colitis (UC) may benefit from immune cell profiling, however implementation of this methodology is limited in the multicenter trial setting by necessity of timely (within 6 to 8 h) isolation and processing of peripheral blood mononuclear cells (PBMC) from whole blood samples. Becton Dickinson Vacutainer CPT™ Cell Preparation Tubes (CPT™) limit required processing prior to shipping to a central lab to an initial centrifugation step within 24 h of sample collection. As shipping may delay final processing beyond 24 h, we analyzed cell viability and T cell composition in whole blood stored in CPT™ to determine if their use may accommodate processing delays typical for multicenter clinical trials. METHODS: Whole blood samples from 3 patients with UC were collected in CPT™ (15 tubes/patient) and PBMC were processed at various timepoints (24-96 h). Cell viability and T cell composition (26 types) were evaluated by flow cytometry. Variability between technical and biological replicates was evaluated in the context of cell-type abundance, delayed processing time, and data normalization. RESULTS: Total cell viability was <50% when processing was delayed to 48 h after collection and was further reduced at later processing timepoints. The effect of delayed processing on cell abundance varied widely across cell types, with CD4+, CD8+, naïve effector CD8+, and Tcm CD4 + T cells displaying the least variability in abundance with delayed processing. Normalization of cell counts to cell types other than total T cells corrected for the effect of delayed processing for several cell types, particularly Th17. CONCLUSIONS: Based on these data, processing of PBMC in CPT™ should ideally be performed within 48 h. Delayed processing of PBMC in CPT™ may be considered for cell types that are robust to these conditions. Normalization of cell abundance to different parental cell-types may reduce variability in quantitation and should be used in conjunction with the expected effect size to meet the experimental goals of a multicenter clinical trial.

Mixed nuts with high nutrient density improve insulin resistance in mice by gut microbiota remodeling.

The consumption of mixed nuts is a healthy dietary strategy to reduce the risk of cardiovascular disease and has a prebiotic effect on the gut microbiota. However, there is a lack of basic research based on mixed nut formulation. This study established a new method for optimizing mixed nut formulations using the Nutrient Rich Food (NRF) index model. Nutrient indices were adjusted by combining 10 and 8 encouraging nutrients and 3 limiting nutrients of nuts and dried fruits, respectively. The optimized mixed nut formulation had the highest total NRF and the lowest energy, which was achieved by applying linear programming. The effect of an optimized mixed nut formulation on insulin resistance and gut microbiota was investigated in an animal model of metabolic disorders caused by a high-fat diet. Male C57BL/6J mice (n = 12 per group) were fed a low-fat diet, a high-fat diet (HFD), HFD with a supplemented classical randomized controlled trial mixed nut formula (MN1), a commercially available mixed nut formula (MN2), a high-nutrient density mixed nut formula (MN3), or ellagic acid (positive control). MN3 treatment decreased total plasma cholesterol, homeostasis model assessment-insulin resistance index, high sensitivity C-reactive protein, and zonulin levels, strengthened the intestinal barrier, and significantly altered the ß-diversity of the intestinal microbiota as compared to the HFD group. These effects of MN3 were superior to MN1 and MN2. In conclusion, MN3 had the highest nutrient density and improved insulin resistance in low-grade inflammation via gut microbiota remodeling.

A Clinical Prediction Model to Determine Probability of Response to Certolizumab Pegol for Crohn's Disease.

BACKGROUND: Certolizumab pegol (CZP) is effective for moderately to severely active Crohn's disease (CD). Higher plasma concentrations are associated with better outcomes and increased drug clearance is the driver of subtherapeutic CZP concentrations. OBJECTIVE: We aimed to develop a prediction model incorporating predicted CZP clearance and patient variables to allow estimation of the probability for remission prior to initiating therapy. METHODS: A population pharmacokinetic model estimated baseline CZP clearance in patients with CD from nine phase II and III trials. Multivariable prediction models were developed and validated using the PRECiSE 1 and PRECiSE 2 datasets to identify candidate predictors for a composite remission outcome (Crohn's Disease Activity Index ≤ 150 and fecal calprotectin concentration ≤ 250 µg/g) at Weeks 6 or 26. An online clinical decision support tool (CDST) was developed. RESULTS: Baseline predicted CZP clearance ≥ 0.5 L/day was associated with subtherapeutic Week 6 CZP plasma concentrations. Baseline weight (odds ratio [OR] 1.04; 95% confidence interval [CI] 1.02-1.07), calculated CZP clearance (OR 0.92; 95% CI 0.87-0.96), hematocrit (OR 2.55; 95% CI 1.43-4.54), and fecal calprotectin (OR 0.66; 95% CI 0.54-0.80) were associated with Week 6 remission (p ≤ 0.0015 for all predictors). Baseline weight (OR 1.04; 95% CI 1.02-1.07), calculated CZP clearance (OR 0.93; 95% CI 0.88-0.97), and Patient-Reported Outcome-2 (PRO2) (OR 0.93; 95% CI 0.87-0.99) were associated with Week 26 remission (p ≤ 0.033 for all predictors). CONCLUSIONS: Patients who are predicted to have accelerated baseline CZP clearance are at risk of subtherapeutic CZP concentrations. Patient-level probabilities for a composite remission outcome can be predicted for patients with CD by entering commonly available patient- and disease-related factors into an online CDST ( https://premedibd.com ) incorporating predicted CZP clearance.

Loss of perivascular aquaporin-4 localization impairs glymphatic exchange and promotes amyloid ß plaque formation in mice.

BACKGROUND: Slowed clearance of amyloid ß (Aß) is believed to underlie the development of Aß plaques that characterize Alzheimer's disease (AD). Aß is cleared in part by the glymphatic system, a brain-wide network of perivascular pathways that supports the exchange of cerebrospinal and brain interstitial fluid. Glymphatic clearance, or perivascular CSF-interstitial fluid exchange, is dependent on the astroglial water channel aquaporin-4 (AQP4) as deletion of Aqp4 in mice slows perivascular exchange, impairs Aß clearance, and promotes Aß plaque formation. METHODS: To define the role of AQP4 in human AD, we evaluated AQP4 expression and localization in a human post mortem case series. We then used the α-syntrophin (Snta1) knockout mouse model which lacks perivascular AQP4 localization to evaluate the effect that loss of perivascular AQP4 localization has on glymphatic CSF tracer distribution. Lastly, we crossed this line into a mouse model of amyloidosis (Tg2576 mice) to evaluate the effect of AQP4 localization on amyloid ß levels. RESULTS: In the post mortem case series, we observed that the perivascular localization of AQP4 is reduced in frontal cortical gray matter of subjects with AD compared to cognitively intact subjects. This decline in perivascular AQP4 localization was associated with increasing Aß and neurofibrillary pathological burden, and with cognitive decline prior to dementia onset. In rodent studies, Snta1 gene deletion slowed CSF tracer influx and interstitial tracer efflux from the mouse brain and increased amyloid ß levels. CONCLUSIONS: These findings suggest that the loss of perivascular AQP4 localization may contribute to the development of AD pathology in human populations.

Adeno-associated virus gene repair corrects a mouse model of hereditary tyrosinemia in vivo.

UNLABELLED: Adeno-associated virus (AAV) vectors are ideal for performing gene repair due to their ability to target multiple different genomic loci, low immunogenicity, capability to achieve targeted and stable expression through integration, and low mutagenic and oncogenic potential. However, many handicaps to gene repair therapy remain. Most notable is the low frequency of correction in vivo. To date, this frequency is too low to be of therapeutic value for any disease. To address this, a point-mutation-based mouse model of the metabolic disease hereditary tyrosinemia type I was used to test whether targeted AAV integration by homologous recombination could achieve high-level stable gene repair in vivo. Both neonatal and adult mice were treated with AAV serotypes 2 and 8 carrying a wild-type genomic sequence for repairing the mutated Fah (fumarylacetoacetate hydrolase) gene. Hepatic gene repair was quantified by immunohistochemistry and supported with reverse transcription polymerase chain reaction and serology for functional correction parameters. Successful gene repair was observed with both serotypes but was more efficient with AAV8. Correction frequencies of up to 10(-3) were achieved and highly reproducible within typical dose ranges. In this model, repaired hepatocytes have a selective growth advantage and are thus able to proliferate to efficiently repopulate mutant livers and cure the underlying metabolic disease. CONCLUSION: AAV-mediated gene repair is feasible in vivo and can functionally correct an appropriate selection-based metabolic liver disease in both adults and neonates.

Evaluating the optimum number of biopsies to assess histological inflammation in ulcerative colitis: a retrospective cohort study.

BACKGROUND: The optimal ulcerative colitis biopsy protocol is unclear. AIM: To evaluate the number of biopsies required to accurately assess microscopic disease activity in ulcerative colitis METHODS: Biopsies from patients with ≥4 rectosigmoid samples, and clinical and endoscopic data, were retrospectively obtained from a prospective biobank. Histology and endoscopic videos were read blindly. A 4-biopsy Robarts Histopathology Index (RHI) reference score, consisting of the worst item-level ratings from four biopsies, was compared to 1-, 2- and 3-biopsy estimates. Agreement was determined using bivariate errors-in-variable regression analysis (acceptance interval: ±8.25). Endoscopic activity and disease location subgroup analyses were also performed. RESULTS: Forty-six patients had ≥4 rectosigmoid biopsies available (N = 287). The 2-biopsy (tolerance interval: -7.66, 4.79) and 3-biopsy (tolerance interval: -4.86, 3.46) RHI scores demonstrated acceptable agreement with 4-biopsy scores. One-biopsy scores demonstrated unacceptable agreement (tolerance interval: -13.99, 7.78). Mean RHI scores using the 2-, 3- and 4-biopsy approaches were similar (6.1 ± 9.6 P = 0.36; 6.8 ± 10.5, P = 0.7; 7.5 ± 11.2), whereas the 1-biopsy estimate was lower (4.4 ± 8.1, P = 0.06). Histological remission rates were identical for the 2-, 3- and 4-biopsy methods (65.2%, P = 1.0). Subgroup analysis demonstrated that three biopsies were required in patients with endoscopically active disease. Sampling additional colonic locations yielded lower histological remission rates compared to rectosigmoid sampling alone (33.3% vs 61.9%, P = 0.1). CONCLUSIONS: A minimum of two - conservatively, three - biopsies are required to reliably assess disease activity in a single colonic segment using the RHI. Further studies are needed of endoscopically active patients and sampling locations. These results have implications for biopsy strategies in clinical trials and practice.

Connexin 43-Mediated Astroglial Metabolic Networks Contribute to the Regulation of the Sleep-Wake Cycle.

Astrocytes produce and supply metabolic substrates to neurons through gap junction-mediated astroglial networks. However, the role of astroglial metabolic networks in behavior is unclear. Here, we demonstrate that perturbation of astroglial networks impairs the sleep-wake cycle. Using a conditional Cre-Lox system in mice, we show that knockout of the gap junction subunit connexin 43 in astrocytes throughout the brain causes excessive sleepiness and fragmented wakefulness during the nocturnal active phase. This astrocyte-specific genetic manipulation silenced the wake-promoting orexin neurons located in the lateral hypothalamic area (LHA) by impairing glucose and lactate trafficking through astrocytic networks. This global wakefulness instability was mimicked with viral delivery of Cre recombinase to astrocytes in the LHA and rescued by in vivo injections of lactate. Our findings propose a novel regulatory mechanism critical for maintaining normal daily cycle of wakefulness and involving astrocyte-neuron metabolic interactions.

Loss of p21 permits carcinogenesis from chronically damaged liver and kidney epithelial cells despite unchecked apoptosis.

Accumulation of toxic metabolites in hereditary tyrosinemia type I (HT1) patients leads to chronic DNA damage and the highest risk for hepatocellular carcinomas (HCCs) of any human disease. Here we show that hepatocytes of HT1 mice exhibit a profound cell-cycle arrest that, despite concomitant apoptosis resistance, causes mortality from impaired liver regeneration. However, additional loss of p21 in HT1 mice restores the proliferative capabilities of hepatocytes and renal proximal tubular cells. This growth response compensates cell loss due to uninhibited apoptosis and enables animal survival but rapidly leads to HCCs, renal cysts, and renal carcinomas. Thus, p21's antiproliferative function is indispensable for the suppression of carcinogenesis from chronically injured liver and renal epithelial cells and cannot be compensated by apoptosis.