Pembrolizumab-induced Myasthenia Gravis and Myocarditis.

As the use of immune checkpoint inhibitors (ICPi) such as pembrolizumab is rapidly expanding in the field of immuno-oncology, it is crucial for healthcare providers to be aware of their immune-related adverse events (irAE) which are thought to be driven by augmented immune response of T-cells. While neurologic irAE are underrepresented in literature, their consequences could lead to fatal outcomes. In this report, we describe the case of a patient with excellent performance status prior to pembrolizumab therapy who subsequently suffered myasthenic crisis eventually requiring tracheostomy and long-term mechanical ventilation.

MTGR1 is required to maintain small intestinal stem cell populations.

Undifferentiated intestinal stem cells (ISCs) are crucial for maintaining homeostasis and resolving injury. Lgr5+ cells in the crypt base constantly divide, pushing daughter cells upward along the crypt axis where they differentiate into specialized cell types. Coordinated execution of complex transcriptional programs is necessary to allow for the maintenance of undifferentiated stem cells while permitting differentiation of the wide array of intestinal cells necessary for homeostasis. Previously, members of the myeloid translocation gene (MTG) family have been identified as transcriptional co-repressors that regulate stem cell maintenance and differentiation programs in multiple organ systems, including the intestine. One MTG family member, myeloid translocation gene related 1 (MTGR1), has been recognized as a crucial regulator of secretory cell differentiation and response to injury. However, whether MTGR1 contributes to the function of ISCs has not yet been examined. Here, using Mtgr1-/- mice, we have assessed the effects of MTGR1 loss specifically in ISC biology. Interestingly, loss of MTGR1 increased the total number of cells expressing Lgr5, the canonical marker of cycling ISCs, suggesting higher overall stem cell numbers. However, expanded transcriptomic and functional analyses revealed deficiencies in Mtgr1-null ISCs, including deregulated ISC-associated transcriptional programs. Ex vivo, intestinal organoids established from Mtgr1-null mice were unable to survive and expand due to aberrant differentiation and loss of stem and proliferative cells. Together, these results indicate that the role of MTGR1 in intestinal differentiation is likely stem cell intrinsic and identify a novel role for MTGR1 in maintaining ISC function.

Pseudomonas fluorescens 15 small RNA Pfs1 mediates transgenerational epigenetic inheritance of pathogen avoidance in C. elegans through the Ephrin receptor VAB-1.

C. elegans are exposed to a variety of pathogenic and non-pathogenic bacteria species in their natural environment. Correspondingly, C. elegans has evolved an ability to discern between nutritive and infectious bacterial food sources. Here we show that C. elegans can learn to avoid the pathogenic bacteria Pseudomonas fluorescens 15 (PF15), and that this learned avoidance behavior is passed on to progeny for four generations, as we previously demonstrated for Pseudomonas aeruginosa (PA14) and Pseudomonas vranovensis, using similar mechanisms, including the involvement of both the TGF-ß ligand DAF-7 and Cer1 retrotransposon-encoded virus-like particles. PF15 small RNAs are both necessary and sufficient to induce this transgenerational avoidance behavior. Unlike PA14 or P. vranovensis, PF15 does not use P11, Pv1, or a small RNA with maco-1 homology for this avoidance; instead, an unrelated PF15 small RNA, Pfs1, that targets the C. elegans vab-1 Ephrin receptor gene is necessary and sufficient for learned avoidance, suggesting the evolution of yet another bacterial sRNA/C. elegans gene target pair involved in transgenerational inheritance of pathogen avoidance. As VAB-2 Ephrin receptor ligand and MACO-1 knockdown also induce PF15 avoidance, we have begun to understand the genetic pathway involved in small RNA targeted pathogenic avoidance. Moreover, these data show that axon guidance pathway genes (VAB-1 and VAB-2) have previously unknown adult roles in regulating neuronal function. C. elegans may have evolved multiple bacterial specificity-encoded small RNA-dependent mechanisms to avoid different pathogenic bacteria species, thereby providing progeny with a survival advantage in a dynamic environment.

TIGIT+Tfh show poor B-helper function and negatively correlate with SARS-CoV-2 antibody titre.

Circulating follicular helper T cells (cTfh) can show phenotypic alterations in disease settings, including in the context of tissue-damaging autoimmune or anti-viral responses. Using severe COVID-19 as a paradigm of immune dysregulation, we have explored how cTfh phenotype relates to the titre and quality of antibody responses. Severe disease was associated with higher titres of neutralising S1 IgG and evidence of increased T cell activation. ICOS, CD38 and HLA-DR expressing cTfh correlated with serum S1 IgG titres and neutralising strength, and interestingly expression of TIGIT by cTfh showed a negative correlation. TIGIT+cTfh expressed increased IFNγ and decreased IL-17 compared to their TIGIT-cTfh counterparts, and showed reduced capacity to help B cells in vitro. Additionally, TIGIT+cTfh expressed lower levels of CD40L than TIGIT-cTfh, providing a potential explanation for their poor B-helper function. These data identify phenotypic changes in polyclonal cTfh that correlate with specific antibody responses and reveal TIGIT as a marker of cTfh with altered function.

Patient Engagement with Conversational Agents in Health Applications 2016-2022: A Systematic Review and Meta-Analysis.

Clinicians and patients seeking electronic health applications face challenges in selecting effective solutions due to a high market failure rate. Conversational agent applications ("chatbots") show promise in increasing healthcare user engagement by creating bonds between the applications and users. It is unclear if chatbots improve patient adherence or if past trends to include chatbots in electronic health applications were due to technology hype dynamics and competitive pressure to innovate. We conducted a systematic literature review using Preferred Reporting Items for Systematic reviews and Meta-Analyses methodology on health chatbot randomized control trials. The goal of this review was to identify if user engagement indicators are published in eHealth chatbot studies. A meta-analysis examined patient clinical trial retention of chatbot apps. The results showed no chatbot arm patient retention effect. The small number of studies suggests a need for ongoing eHealth chatbot research, especially given the claims regarding their effectiveness made outside the scientific literatures.

Production benefits on encoding are modulated by language experience: Less experience may help.

Several lines of research have shown that performing movements while learning new information aids later retention of that information, compared to learning by perception alone. For instance, articulated words are more accurately remembered than words that are silently read (the production effect). A candidate mechanism for this movement-enhanced encoding, sensorimotor prediction, assumes that acquired sensorimotor associations enable movements to prime associated percepts and hence improve encoding. Yet it is still unknown how the extent of prior sensorimotor experience influences the benefits of movement on encoding. The current study addressed this question by examining whether the production effect is modified by prior language experience. Does the production effect reduce or persist in a second language (L2) compared to a first language (L1)? Two groups of unbalanced bilinguals, German (L1) - English (L2) bilinguals (Experiment 1) and English (L1) - German (L2) bilinguals (Experiment 2), learned lists of German and English words by reading the words silently or reading the words aloud, and they subsequently performed recognition tests. Both groups showed a pronounced production effect (higher recognition accuracy for spoken compared to silently read words) in the first and second languages. Surprisingly, the production effect was greater in the second languages compared to the first languages, across both bilingual groups. We discuss interpretations based on increased phonological encoding, increased effort or attention, or both, when reading aloud in a second language.

Histopathological findings from the investigation of paediatric acute hepatitis of unknown aetiology, United Kingdom 2022.

In 2022, there were global reports of increased numbers of acute hepatitis not explained by hepatitis A-E virus infection in children. This manuscript summarises histopathology results from 20 patients in the United Kingdom who underwent liver transplant or had a liver biopsy as part of aetiological investigations. All available histopathological samples were reviewed centrally as part of the outbreak investigation. A working group comprised of infection specialists, hepatologists and histopathologists met virtually to review the cases, presentation, investigations and histopathology. All 20 liver samples had evidence of inflammation without significant interface activity, and submassive confluent pan-lobular or multilobular hepatocellular necrosis. Overall, the predominant histopathological findings were of acute nonspecific hepatitis with submassive hepatic necrosis and central vein perivenulitis and endothelitis. Histopathological findings were a poor indicator of aetiology.

Interplay in galectin expression predicts patient outcomes in a spatially restricted manner in PDAC.

BACKGROUND: Galectins (Gal's) are a family of carbohydrate-binding proteins that are known to support the tumour microenvironment through their immunosuppressive activity and ability to promote metastasis. As such they are attractive therapeutic targets, but little is known about the cellular expression pattern of galectins within the tumour and its neighbouring stromal microenvironment. Here we investigated the cellular expression pattern of Gals within pancreatic ductal adenocarcinoma (PDAC). METHODS: Galectin gene and protein expression were analysed by scRNAseq (n=4) and immunofluorescence imaging (n=19) in fibroblasts and epithelial cells of pancreatic biopsies from PDAC patients. Galectin surface expression was also assessed on tumour adjacent normal fibroblasts and cancer associated primary fibroblasts from PDAC biopsies using flow cytometry. RESULTS: scRNAseq revealed higher Gal-1 expression in fibroblasts and higher Gal-3 and -4 expression in epithelial cells. Both podoplanin (PDPN+, stromal/fibroblast) cells and EpCAM+ epithelial cells expressed Gal-1 protein, with highest expression seen in the stromal compartment. By contrast, significantly more Gal-3 and -4 protein was expressed in ductal cells expressing either EpCAM or PDPN, when compared to the stroma. Ductal Gal-4 cellular expression negatively correlated with ductal Gal-1, but not Gal-3 expression. Higher ductal cellular expression of Gal-1 correlated with smaller tumour size and better patient survival. CONCLUSIONS: In summary, the intricate interplay and cell-specific expression patterns of galectins within the PDAC tissue, particularly the inverse correlation between Gal-1 and Gal-4 in ducts and its significant association with patient survival, highlights the complex molecular landscape underlying PDAC and provides valuable insights for future therapeutic interventions.

Risk of low energy availability and nutrition knowledge among female team sport athletes.

BACKGROUND: Nutrition knowledge influences adequate dietary intake in athletes. Inadequate dietary intakes can result in low energy availability (LEA) which can lead to relative energy deficiency in sport (RED-S). To date, there is little information on the relationship between nutrition knowledge and the risk of LEA in female team sport athletes. This study investigates if general and sports nutrition knowledge are associated with the risk of LEA in female team athletes. METHODS: A cross-sectional design was used. Female athletes (>16 years) who participate in team sports in New Zealand were asked to complete an online questionnaire. The LEA in Females Questionnaire and the Abridged Sport Nutrition Knowledge Questionnaire were included. LEA risk and general/sports nutrition knowledge were assessed. The relationship between LEA risk and knowledge was analyzed using the Kruskal-Wallis Test of independent variables and χ2 tests. RESULTS: Among 100 female athletes, 53% were at-risk for LEA, and 70% (N.=67) had poor nutrition knowledge. Athletes who were "at-risk" for LEA and those who were "not at-risk" for LEA did not differ statistically in terms of age (P=0.350) or BMI (P=0.576). Of those "not at risk" 54% had an A-NSK score between 50 and 60% (i.e., average knowledge), whereas 54% of the athletes who were "at risk" for LEA had poor nutrition knowledge. There was no statistical difference between the groups (P=0.273). CONCLUSIONS: The poor nutrition knowledge and the high rates of those "at risk" of LEA among team sports athletes indicates the need for more nutrition education in this population.

Evaluating whether Prostate Cancer UK's risk checker is a help or hindrance to prostate-specific antigen testing policy: a mixed-methods study.

BACKGROUND: The UK has an informed choice testing policy for prostate cancer. The prostate-specific antigen (PSA) blood test is available for free to any man aged ≥50 years who requests it and has been informed of the harms and benefits. This policy leads to differences in PSA testing rates, which can exacerbate health inequalities. AIM: To assess whether Prostate Cancer UK's risk checker helps men at risk of prostate cancer make an informed choice about the PSA test. DESIGN & SETTING: Mixed-methods study in the UK. METHOD: In total, 1181 men at risk, their partners, and clinical experts participated in surveys, focus groups, and one-to-one interviews. Data on risk checker completions by sociodemographic factors were analysed over time. Data from general practices that sent the risk checker to their patients were collected and analysed for service monitoring purposes. RESULTS: There was a strong assumption that testing must be good, and therefore a need to emphasise the pros and cons of the test and that having it was the patient's decision. Men believed their GP would invite them for PSA testing. On the impact of the risk checker, 79.6% of men who completed it had at least one prostate cancer risk factor; the average time they interacted with the information in the tool was 9 minutes 28 seconds; and 75.7% felt the tool had equipped them to make an informed choice. CONCLUSION: Online decision-making tools, such as the risk checker, can help reach men at high risk of prostate cancer and support them in making an informed choice about the PSA test.

Real-world efficacy of single-agent belantamab mafodotin in relapsed systemic AL amyloidosis.

Systemic light chain (AL) amyloidosis is a relapsing plasma cell disorder. Therapy is limited, particularly for triple-class refractory disease. We report the use of belantamab mafodotin, a BCMA-directed drug-antibody conjugate, for relapsed AL amyloidosis, including patients traditionally excluded from clinical trials. Thirty-one patients were reviewed, with a median of three prior lines of therapy. The median follow-up was 12 months (95% CI 4-19), and a median of five doses were delivered. The best haematological overall response rate was 71%, and the complete/very good partial response was 58%. Sixty-eight percent had keratopathy and improved in all. Belantamab mafodotin has high efficacy and good tolerability in patients with relapsed AL amyloidosis.

Adapting an equity-focused implementation process framework with a focus on ethnic health inequities in the Aotearoa New Zealand context.

BACKGROUND: Health intervention implementation in Aotearoa New Zealand (NZ), as in many countries globally, usually varies by ethnicity. Maori (the Indigenous peoples of Aotearoa) and Pacific peoples are less likely to receive interventions than other ethnic groups, despite experiencing persistent health inequities. This study aimed to develop an equity-focused implementation framework, appropriate for the Aotearoa NZ context, to support the planning and delivery of equitable implementation pathways for health interventions, with the intention of achieving equitable outcomes for Maori, as well as people originating from the Pacific Islands. METHODS: A scoping review of the literature to identify existing equity-focused implementation theories, models and frameworks was undertaken. One of these, the Equity-based framework for Implementation Research (EquIR), was selected for adaptation. The adaptation process was undertaken in collaboration with the project's Maori and consumer advisory groups and informed by the expertise of local health equity researchers and stakeholders, as well as the international implementation science literature. RESULTS: The adapted framework's foundation is the principles of Te Tiriti o Waitangi (the written agreement between Maori rangatira (chiefs) and the British Crown), and its focus is whanau (extended family)-centred implementation that meets the health and wellbeing aspirations, priorities and needs of whanau. The implementation pathway comprises four main steps: implementation planning, pathway design, monitoring, and outcomes and evaluation, all with an equity focus. The pathway is underpinned by the core constructs of equitable implementation in Aotearoa NZ: collaborative design, anti-racism, Maori and priority population expertise, cultural safety and values-based. Additionally, the contextual factors impacting implementation, i.e. the social, economic, commercial and political determinants of health, are included. CONCLUSIONS: The framework presented in this study is the first equity-focused process-type implementation framework to be adapted for the Aotearoa NZ context. This framework is intended to support and facilitate equity-focused implementation research and health intervention implementation by mainstream health services.

A synthesis and subgroup analysis of the eosinophilic esophagitis tissue transcriptome.

BACKGROUND: Eosinophilic esophagitis (EoE) is a chronic immune mediated inflammatory disorder of the esophagus. It is still unknown why children and adults present differently, and there is little evidence about why it is more common in men than women. OBJECTIVE: Our aim was to synthesize published and unpublished esophageal bulk RNA-sequencing (RNA-seq) data to gain novel insights into the pathobiology of EoE and examine the differences in EoE transcriptome by sex and age group. METHODS: Esophageal bulk RNA-seq data from 5 published and 2 unpublished studies resulting in 137 subjects (EoE: N = 76; controls: N = 61) were analyzed. For overall analysis, combined RNA-seq data of patients with EoE were compared with those of controls and subgroup analysis was conducted in patients with EoE by age of the patient (children [<18 years] vs adults [≥18 years]) and sex (female vs male). Gene-set enrichment analysis, ingenuity pathway analysis (IPA), cell-type analysis, immunohistochemistry, and T-cell or B-cell receptor analysis were performed. RESULTS: Overall analysis identified dysregulation of new genes in EoE compared with controls. IPA revealed that EoE is characterized by a mixed inflammatory response compared with controls. Cell-type analysis showed that cell composition varied with age: children had more mast cells, whereas adults had more macrophages. Finally, gene-set enrichment analysis and IPA revealed pathways that were differentially regulated in adults versus children and male versus female patients with EoE. CONCLUSIONS: Using a unique approach to analyze bulk RNA-seq data, we found that EoE is characterized by a mixed inflammatory response, and the EoE transcriptome may be influenced by age and sex. These findings enhance insights into the molecular mechanisms of EoE.

Developing and Validating a Multivariable Prognostic-Predictive Classifier for Treatment Escalation of Oropharyngeal Squamous Cell Carcinoma: The PREDICTR-OPC Study.

PURPOSE: While there are several prognostic classifiers, to date, there are no validated predictive models that inform treatment selection for oropharyngeal squamous cell carcinoma (OPSCC).Our aim was to develop clinical and/or biomarker predictive models for patient outcome and treatment escalation for OPSCC. EXPERIMENTAL DESIGN: We retrospectively collated clinical data and samples from a consecutive cohort of OPSCC cases treated with curative intent at ten secondary care centers in United Kingdom and Poland between 1999 and 2012. We constructed tissue microarrays, which were stained and scored for 10 biomarkers. We then undertook multivariable regression of eight clinical parameters and 10 biomarkers on a development cohort of 600 patients. Models were validated on an independent, retrospectively collected, 385-patient cohort. RESULTS: A total of 985 subjects (median follow-up 5.03 years, range: 4.73-5.21 years) were included. The final biomarker classifier, comprising p16 and survivin immunohistochemistry, high-risk human papillomavirus (HPV) DNA in situ hybridization, and tumor-infiltrating lymphocytes, predicted benefit from combined surgery + adjuvant chemo/radiotherapy over primary chemoradiotherapy in the high-risk group [3-year overall survival (OS) 63.1% vs. 41.1%, respectively, HR = 0.32; 95% confidence interval (CI), 0.16-0.65; P = 0.002], but not in the low-risk group (HR = 0.4; 95% CI, 0.14-1.24; P = 0.114). On further adjustment by propensity scores, the adjusted HR in the high-risk group was 0.34, 95% CI = 0.17-0.67, P = 0.002, and in the low-risk group HR was 0.5, 95% CI = 0.1-2.38, P = 0.384. The concordance index was 0.73. CONCLUSIONS: We have developed a prognostic classifier, which also appears to demonstrate moderate predictive ability. External validation in a prospective setting is now underway to confirm this and prepare for clinical adoption.

What Can You Learn About Psychiatry Programs from Their Website? A Content Evaluation for Potential Applicants.

OBJECTIVE: This project aimed to assess the information contained on general psychiatry program websites and identify common themes that may be useful and informative for residency applicants. METHODS: A survey study design was used to evaluate all US general psychiatry program websites as listed in the FREIDA database. The evaluation form included 44 binary (yes or no) items. Two reviewers rated each item on all program websites between September 2021 and January 2022. Item discrepancies were settled by a third reviewer. Fisher's exact tests evaluated differences between geographic regions and program types. Multidimensional scaling and Rasch modeling were conducted to examine clustering and the probability of items reported on program websites. RESULTS: A total of 285 websites were identified; 13 were excluded. Internal consistency was high among reviewers, Cronbach's Alpha = 0.927; κ = 0.863. Websites varied considerably in quality. Significant inconsistent reporting was observed by region for current residents' photos and alumni careers (fellowship/jobs); p<0.001. Program types varied regarding information about program faculty, which included significant differences for faculty photo, faculty research interest, and faculty research publications; p<0.001. CONCLUSIONS: While inter-rater reliability was high, considerable variation among websites was observed. Residency programs could be improved by consistently reporting resident and faculty information. Results show that applicants may encounter issues finding pertinent information, as programs' FREIDA link did not direct the user to the residency program website two-thirds of the time.

Investigating misdiagnosis of suspected cancer among patients undergoing pancreatoduodenectomy: three decades of experience.

BACKGROUND: Diagnostic error can result in pancreatoduodenectomy (PD) being mistakenly performed for benign disease. The aims of this study were to observe the error rate in PD over three decades and identify characteristics of benign disease that can mimic malignancy. METHODS: Patients with a benign histological diagnosis after having PD performed for suspected malignancy between 1988 and 2019 were selected for review. Preoperative clinical features, imaging and pathological samples were reviewed alongside resection specimens to identify features that may have led to misdiagnosis. RESULTS: Over the study period, 1812 patients underwent PD for suspected malignancy and 97 (5.2 %) of these had a final benign diagnosis. The rate of benign cases reduced across the study period. Some 62 patients proceeded to surgery without a preoperative tissue diagnosis; the decision to operate was made upon clinical and radiologic features alone. There were six patients who had a preoperative pathological sample suspicious for malignancy, of which two had autoimmune pancreatitis in the postoperative histology specimen. DISCUSSION: Benign conditions, notably autoimmune and chronic pancreatitis, can mimic malignancy even with the use of EUS-FNA. The results of all available diagnostic modalities should be interpreted by a multidisciplinary team and honest discussions with the patient should follow.

METTL3 alters capping enzyme expression and its activity on ribosomal proteins.

The 5' cap, catalyzed by RNA guanylyltransferase and 5'-phosphatase (RNGTT), is a vital mRNA modification for the functionality of mRNAs. mRNA capping occurs in the nucleus for the maturation of the functional mRNA and in the cytoplasm for fine-tuning gene expression. Given the fundamental importance of RNGTT in mRNA maturation and expression there is a need to further investigate the regulation of RNGTT. N6-methyladenosine (m6A) is one of the most abundant RNA modifications involved in the regulation of protein translation, mRNA stability, splicing, and export. We sought to investigate whether m6A could regulate the expression and activity of RNGTT. A motif for the m6A writer methyltransferase 3 (METTL3) in the 3'UTR of RNGTT mRNA was identified. Knockdown of METTL3 resulted in destabilizing RNGTT mRNA, and reduced protein expression. Sequencing of capped mRNAs identified an underrepresentation of ribosomal protein mRNA overlapping with 5' terminal oligopyrimidine (TOP) mRNAs and genes are dysregulated when cytoplasmic capping is inhibited. Pathway analysis identified disruptions in the mTOR and p70S6K pathways. A reduction in RPS6 mRNA capping, protein expression, and phosphorylation was detected with METTL3 knockdown.

Vein Wall Invasion Is a More Reliable Predictor of Oncological Outcomes than Vein-Related Margins after Pancreaticoduodenectomy for Early Stages of Pancreatic Ductal Adenocarcinoma.

Pancreaticoduodenectomy (PD) with vein resection is the only potentially curative option for patients with pancreatic ductal adenocarcinoma (PDAC) with venous involvement. The aim of our study was to assess the oncological prognostic significance of the different variables of venous involvement in patients undergoing PD for resectable and borderline-resectable with venous-only involvement (BR-V) PDAC. We performed a retrospective analysis of prospectively acquired data over a 10-year period. Of the 372 patients included, 105 (28%) required vein resection and vein wall involvement was identified in 37% of those. A multivariable analysis failed to identify the vein-related resection margins as independent predictors for OS, DFS or LR. Vein wall tumour involvement was an independent predictor of OS (risk x1.7-2) and DFS (risk x1.9-2.2) in all models, while it replaced overall surgical margin positivity as the only parameter independently predicting LR during an analysis of separate resection margins (risk x2.4). Vein wall tumour invasion may be a more reliable predictor of oncological outcomes compared to traditionally reported parameters. Future studies should focus on possible pre-operative investigations that could identify these cases and management pathways that could yield a survival benefit, such as the use of neoadjuvant treatments.

Periportal necrosis and successful liver transplantation following Lamotrigine drug-induced liver injury in a child.

Lamotrigine is one of the most prescribed antiepileptics in children and a well-known cause of drug-induced liver injury (DILI). The typical presentation usually includes a drug rash with eosinophilia and systemic symptoms (DRESS syndrome). Cases are typically mild and self-limiting, requiring supportive care only. We report a severe Lamotrigine-induced DILI with a non-typical presentation with hyperammonaemia and rapid clinical deterioration. We present a literature review exploring contributing factors, transplant considerations and liver histology. Histology showed periportal necrosis, which is recognised as a pattern of DILI but has not been previously described with Lamotrigine. Our patient proceeded to transplant and is the first reported liver transplant for Lamotrigine DILI in a child. A directed and rapid diagnostic approach is crucial to avoid delays and rule out multisystemic metabolic and genetic conditions that preclude liver transplantation.

MTGR1 is required to maintain small intestinal stem cell populations.

Undifferentiated intestinal stem cells (ISCs), particularly those marked by Lgr5, are crucial for maintaining homeostasis and resolving injury. Lgr5+ cells in the crypt base constantly divide, pushing daughter cells upward along the crypt axis, where they differentiate into a variety of specialized cell types. This process requires coordinated execution of complex transcriptional programs, which allow for the maintenance of undifferentiated stem cells while permitting differentiation of the wide array of intestinal cells necessary for homeostasis. Thus, disrupting these programs may negatively impact homeostasis and response to injury. Previously, members of the myeloid translocation gene (MTG) family have been identified as transcriptional co-repressors that regulate stem cell maintenance and differentiation programs in multiple organ systems, including the intestine. One MTG family member, myeloid translocation gene related 1 (MTGR1), has been recognized as a crucial regulator of secretory cell differentiation and response to injury. However, whether MTGR1 contributes to the function of ISCs has not yet been examined. Here, using Mtgr1-/- mice, we have assessed the effects of MTGR1 loss on ISC biology and differentiation programs. Interestingly, loss of MTGR1 increased the total number of cells expressing Lgr5, the canonical marker of cycling ISCs, suggesting higher overall stem cell numbers. However, expanded transcriptomic analyses revealed MTGR1 loss may instead promote stem cell differentiation into transit-amplifying cells at the expense of cycling ISC populations. Furthermore, ex vivo intestinal organoids established from Mtgr1 null were found nearly completely unable to survive and expand, likely due to aberrant ISC differentiation, suggesting that Mtgr1 null ISCs were functionally deficient as compared to WT ISCs. Together, these results identify a novel role for MTGR1 in ISC function and suggest that MTGR1 is required to maintain the undifferentiated state.