Distinct myeloid progenitor-differentiation pathways identified through single-cell RNA sequencing.

According to current models of hematopoiesis, lymphoid-primed multi-potent progenitors (LMPPs) (Lin(-)Sca-1(+)c-Kit(+)CD34(+)Flt3(hi)) and common myeloid progenitors (CMPs) (Lin(-)Sca-1(+)c-Kit(+)CD34(+)CD41(hi)) establish an early branch point for separate lineage-commitment pathways from hematopoietic stem cells, with the notable exception that both pathways are proposed to generate all myeloid innate immune cell types through the same myeloid-restricted pre-granulocyte-macrophage progenitor (pre-GM) (Lin(-)Sca-1(-)c-Kit(+)CD41(-)FcγRII/III(-)CD150(-)CD105(-)). By single-cell transcriptome profiling of pre-GMs, we identified distinct myeloid differentiation pathways: a pathway expressing the gene encoding the transcription factor GATA-1 generated mast cells, eosinophils, megakaryocytes and erythroid cells, and a pathway lacking expression of that gene generated monocytes, neutrophils and lymphocytes. These results identify an early hematopoietic-lineage bifurcation that separates the myeloid lineages before their segregation from other hematopoietic-lineage potential.

Pancreatic Enzyme Use Reduces Pancreatitis Frequency in Children With Acute Recurrent or Chronic Pancreatitis: A Report From INSPPIRE.

INTRODUCTION: Among children who suffer from acute recurrent pancreatitis (ARP) or chronic pancreatitis (CP), acute pancreatitis (AP) episodes are painful, often require hospitalization, and contribute to disease complications and progression. Despite this recognition, there are currently no interventions to prevent AP episodes. In this retrospective cohort study, we assessed the impact of pancreatic enzyme therapy (PERT) use on clinical outcomes among children with pancreatic-sufficient ARP or CP. METHODS: Children with pancreatic-sufficient ARP or CP in the INSPPIRE-2 cohort were included. Clinical outcomes were compared for those receiving vs not receiving PERT, as well as frequency of AP before and after PERT. Logistic regression was used to study the association between development of AP episodes after starting PERT and response predictors. RESULTS: Among 356 pancreatic-sufficient participants, 270 (76%) had ARP, and 60 (17%) received PERT. Among those on PERT, 42% did not have a subsequent AP episode, during a mean 2.1 years of follow-up. Children with a SPINK1 mutation ( P = 0.005) and those with ARP (compared with CP, P = 0.008) were less likely to have an AP episode after starting PERT. After initiation of PERT, the mean AP annual incidence rate decreased from 3.14 down to 0.71 ( P < 0.001). DISCUSSION: In a retrospective analysis, use of PERT was associated with a reduction in the incidence rate of AP among children with pancreatic-sufficient ARP or CP. These results support the need for a clinical trial to evaluate the efficacy of PERT to improve clinical outcomes among children with ARP or CP.

Hierarchically related lineage-restricted fates of multipotent haematopoietic stem cells.

Rare multipotent haematopoietic stem cells (HSCs) in adult bone marrow with extensive self-renewal potential can efficiently replenish all myeloid and lymphoid blood cells, securing long-term multilineage reconstitution after physiological and clinical challenges such as chemotherapy and haematopoietic transplantations. HSC transplantation remains the only curative treatment for many haematological malignancies, but inefficient blood-lineage replenishment remains a major cause of morbidity and mortality. Single-cell transplantation has uncovered considerable heterogeneity among reconstituting HSCs, a finding that is supported by studies of unperturbed haematopoiesis and may reflect different propensities for lineage-fate decisions by distinct myeloid-, lymphoid- and platelet-biased HSCs. Other studies suggested that such lineage bias might reflect generation of unipotent or oligopotent self-renewing progenitors within the phenotypic HSC compartment, and implicated uncoupling of the defining HSC properties of self-renewal and multipotency. Here we use highly sensitive tracking of progenitors and mature cells of the megakaryocyte/platelet, erythroid, myeloid and B and T cell lineages, produced from singly transplanted HSCs, to reveal a highly organized, predictable and stable framework for lineage-restricted fates of long-term self-renewing HSCs. Most notably, a distinct class of HSCs adopts a fate towards effective and stable replenishment of a megakaryocyte/platelet-lineage tree but not of other blood cell lineages, despite sustained multipotency. No HSCs contribute exclusively to any other single blood-cell lineage. Single multipotent HSCs can also fully restrict towards simultaneous replenishment of megakaryocyte, erythroid and myeloid lineages without executing their sustained lymphoid lineage potential. Genetic lineage-tracing analysis also provides evidence for an important role of platelet-biased HSCs in unperturbed adult haematopoiesis. These findings uncover a limited repertoire of distinct HSC subsets, defined by a predictable and hierarchical propensity to adopt a fate towards replenishment of a restricted set of blood lineages, before loss of self-renewal and multipotency.

Pancreatitis-Associated Medication Use in Hospitalized Pediatric and Young Adult Patients With Acute Pancreatitis.

OBJECTIVE: The objective of this study is (1) to describe the prevalence of pancreatitis-associated medication (PAM) use at admission and discharge in pediatric and young adult patients hospitalized with acute pancreatitis (AP) and (2) to describe the prevalence of PAM use at admission in patients classified as having idiopathic AP. STUDY DESIGN: A single-center retrospective study of patients <21 years who were hospitalized with AP or acute recurrent pancreatitis from March 2015 to July 2017 was performed. Charts were reviewed for demographic data, etiology of pancreatitis, comorbidities, and use of PAMs at admission and discharge. PAMs were defined and scored based on an evidence-based classification system, with class I PAMs having strongest evidence for causation. Standard descriptive statistics were used to report prevalence data. RESULTS: Our cohort was comprised of 119 patients; 50% of patients were using a PAM at admission and 67% were taking a PAM at discharge, reflecting a significant change (P = 0.0009); 44% of patients classified as having idiopathic pancreatitis were taking a PAM on admission, reflecting a possibly missed role of medication in their presentation. Comorbidities significantly associated with PAM use included seizure disorder (P = 0.005) and oncologic disease (P = 0.005). The most commonly used class I PAMs were omeprazole, trimethoprim-sulfamethazole, valproic acid, and 6-mercaptopurine. The increase in prevalence of PAM use at discharge compared to admission was partially driven by addition of omeprazole to the outpatient medication regimen during the hospital stay (P = 0.07). CONCLUSION: Medications likely play an under-recognized role in pediatric AP. The practice of using proton pump inhibitors in management of AP warrants further study.

Impact of Trainee Involvement on Pediatric ERCP Procedures: Results From the Pediatric ERCP Initiative.

This study examines the role of trainee involvement with pediatric endoscopic retrograde cholangiopancreatography (ERCP) and whether it affects the procedure's success, post-procedural adverse outcomes, and duration. A secondary analysis of the Pediatric ERCP Database Initiative, an international database, was performed. Consecutive ERCPs on children <19 years of age from 18 centers were entered prospectively into the database. In total 1124 ERCPs were entered into the database, of which 320 (28%) were performed by trainees. The results showed that the presence of trainees did not impact technical success ( P = 0.65) or adverse events rates ( P = 0.43). Rates of post-ERCP pancreatitis, pain, and bleeding were similar between groups ( P > 0.05). Fewer cases involving trainees were in the top quartile (>58 minutes) of procedural time (19% vs 26%; P = 0.02). Overall, our findings indicate trainee involvement in pediatric ERCP is safe.

Pediatric ERCP in the Setting of Acute Pancreatitis: A Secondary Analysis of an International Multicenter Cohort Study.

Previous studies have demonstrated the safety of performing endoscopic retrograde cholangiopancreatography (ERCP) in the pediatric population; however, few have addressed the outcomes of children undergoing ERCP during acute pancreatitis (AP). We hypothesize that ERCP performed in the setting of AP can be executed with similar technical success and adverse event profiles to those in pediatric patients without pancreatitis. Using the Pediatric ERCP Database Initiative, a multi-national and multi-institutional prospectively collected dataset, we analyzed 1124 ERCPs. One hundred and ninety-four (17%) of these procedures were performed in the setting of AP. There were no difference in the procedure success rate, procedure time, cannulation time, fluoroscopy time, or American Society of Anesthesiology class despite patients with AP having higher American Society of Gastrointestinal Endoscopy grading difficulty scores. This study suggests that ERCP can be safely and efficiently performed in pediatric patients with AP when appropriately indicated.

Clinical Characteristics and Short-Term Outcomes of Children With Asparaginase-Associated Pancreatitis.

OBJECTIVES: Acute pancreatitis is a significant toxicity of l-asparaginase, a chemotherapeutic agent used to treat acute lymphoblastic leukemia. This case series describes the short-term clinical course and disposition of patients who developed asparaginase-associated pancreatitis (AAP) at one quaternary pediatric center. METHODS: Clinical data, including laboratory data, inpatient and intensive care unit (ICU) days, imaging findings, presence of complications such as need for ventilation, dialysis, and the development of pleural effusions, and mode of nutrition were abstracted from the medical record of patients with AAP. Pediatric criteria were used to classify episode severity based on the development of organ failure and local complications, such as pancreatic necrosis. RESULTS: Between 2005 and 2015, 34 patients had AAP with 43 distinct episodes of pancreatitis. The median inpatient length of stay was 10 days (range 2-65). Seven episodes (16.3%) required intensive care unit (ICU)-level care. Seventeen episodes (39.5%) were severe based on the development of organ failure or presence of pancreatic necrosis. Total parenteral nutrition (TPN) was used in 17 episodes (39.5%); for 34 episodes (79.1%), patients were discharged on entirely oral feeds. Antibiotics were administered in 20 episodes (46.5%). Pancreatic necrosis was identified within the first week in 12 episodes (27.9%). There were no deaths due to AAP. CONCLUSIONS: The clinical course varies widely among patients with AAP. Over one-third of the patients in this series developed severe pancreatitis. Although the prognosis of AAP is generally good, many patients develop systemic complications of AAP, requiring TPN or ICU-level care.

Predictors of Prolonged Fluoroscopy Exposure in Pediatric Endoscopic Retrograde Cholangiopancreatography: Results From the Large Pediatric Endoscopic Retrograde Cholangiopancreatography Database Initiative Multicenter Cohort.

BACKGROUND AND AIMS: Ionizing radiation exposure during endoscopic retrograde cholangiopancreatography (ERCP) is an important quality issue especially in children. We aim to identify factors associated with extended fluoroscopy time (FT) in children undergoing ERCP. METHODS: ERCP on children <18 years from 15 centers were entered prospectively into a REDCap database from May 2014 until May 2018. Data were retrospectively evaluated for outcome and quality measures. A univariate and step-wise linear regression analysis was performed to identify factors associated with increased FT. RESULTS: 1073 ERCPs performed in 816 unique patients met inclusion criteria. Median age was 12.2 years (interquartile range [IQR] 9.3-15.8). 767 (71%) patients had native papillae. The median FT was 120 seconds (IQR 60-240). Factors associated with increased FT included procedures performed on patients with chronic pancreatitis, ERCPs with American Society of Gastrointestinal Endoscopy (ASGE) difficulty grade >3, ERCPs performed by pediatric gastroenterologist (GI) with adult GI supervision, and ERCPs performed at non-free standing children's hospitals. Hispanic ethnicity was the only factor associated with lower FT. CONCLUSION: Several factors were associated with prolonged FTs in pediatric ERCP that differed from adult studies. This underscores that adult quality indicators cannot always be translated to pediatric patients. This data can better identify children with higher risk for radiation exposure and improve quality outcomes during pediatric ERCP.

Technical Outcomes in Pediatric Endoscopic Retrograde Cholangiopancreatography: Data from an International Collaborative.

OBJECTIVES: Endoscopic retrograde cholangiopancreatography (ERCP) in adults has been extensively studied through multicenter prospective studies. Similar pediatric studies are lacking. The Pediatric ERCP Database Initiative (PEDI) is a multicenter collaborative aiming to evaluate the indications and technical outcomes in pediatric ERCPs. METHODS: In this prospective cohort study, data were recorded for pediatric ERCPs performed across 15 centers. A pre-procedure, procedure, 2-week post-procedure follow-up, and adverse event form were completed for each ERCP performed. Univariate and stepwise linear regression was performed to identify factors associated with technically successful procedures and adverse events. RESULTS: A total of 1124 ERCPs were performed on 857 patients from May 1, 2014 to May 1, 2018. The median age was 13.5 years [interquartile range (IQR) 9.0-15.7]. Procedures were technically successful in the majority of cases (90.5%) with success more commonly encountered for procedures with biliary indications [odds ratio (OR) 4.2] and less commonly encountered for native papilla anatomy (OR 0.4) and in children <3 years (OR 0.3). Cannulation was more often successful with biliary cannulation (95.9%) compared to pancreatic cannulation via the major papilla (89.6%, P < 0.0001) or minor papilla (71.2%, P < 0.0005). The most commonly identified adverse events included post-ERCP pancreatitis (5%), pain not related to post-ERCP pancreatitis (1.8%), and bleeding (1.2%). Risk factors for the development of each were identified. CONCLUSIONS: This large prospective study demonstrates that ERCP is reliable and safe in the pediatric population. It highlights the utility of PEDI in evaluating the technical outcomes of pediatric ERCPs and demonstrates the potential of PEDI for future studies in pediatric ERCPs.

Triple gallbladder with heterotopic gastric mucosa: a case report.

BACKGROUND: Triple gallbladder is a rare congenital anomaly of the biliary tract that can be associated with heterotopic tissue. Gallbladder triplication results from the failure of rudimentary bile ducts to regress during embryological development, and can be difficult to distinguish from Todani type II choledochal cysts and biliary duplication cysts. CASE PRESENTATION: A 2-year-old patient presented to our institution with intermittent abdominal pain for 1 year. She had elevated transaminases with imaging concerning for a choledochal cyst. After assessment with magnetic resonance cholangiopancreatography and endoscopic retrograde cholangiopancreatography, she was diagnosed with a gallbladder multiplication and a common bile duct stricture. She underwent laparoscopic cholecystectomy, which confirmed the diagnosis of triple gallbladder. One of the three gallbladders demonstrated heterotopic gastric mucosa on final pathology, including at the cystic duct margin. Follow up testing with a technetium 99 m scan demonstrated a subtle focus of increased activity in the right upper abdomen at the expected location of the common bile duct, concerning for the presence of residual gastric mucosa. The patient remains well without abdominal pain. CONCLUSIONS: We describe the first case of heterotopic gastric mucosa in a triple gallbladder in a young patient presenting with chronic abdominal pain. We also demonstrate the safety and feasibility of laparoscopic cholecystectomy in young children with triple gallbladder. Finally, we propose an interdisciplinary approach to the management of common bile duct strictures in the setting of ectopic acid secretion, involving a combination of medical management, endoscopic intervention, and possible salvage laparoscopic Roux-en-Y hepaticojejunostomy.

Confluence of law enforcement, mental health, and race.

Disparities in victimization by law enforcement for both people of color and individuals with mental health disorders is gaining national attention following the deaths of George Floyd, Sandra Bland, TAmir Rice, and many others. Despite this, the discussion around the intersectionality of race, psychiatric illness, and law enforcement is still in its infancy, the purpose of this article is to discuss the confluence of race and psychiatric illness as vulnerabilities in various contacts with law enforcement in order to further highlight this issue and to ignite further needed research on this topic. Possible solutions such as police-hiring practices, bias training, and trauma-informed policing will be discussed.

Endoscopic Pancreatic Function Testing (ePFT) in Children: A Position Paper From the NASPGHAN Pancreas Committee.

ABSTRACT: Endoscopic pancreatic function testing (ePFT) is one of the few ways to directly diagnose exocrine pancreatic insufficiency, and considerable confusion regarding indications, utility, and interpretation of the test remains. This position paper of the Pancreas Committee of the North American Society of Pediatric Gastroenterology, Hepatology and Nutrition reviews the history and indications for ePFT in children. We compare various methods in current practice and determine their strengths and limitations, and based on data from children and adults we provide guidance on a protocol on how to perform ePFT in children. Lastly, we pose areas in need of further research relating to ePFT in children.

Medical Management of Chronic Pancreatitis in Children: A Position Paper by the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition Pancreas Committee.

ABSTRACT: This position paper summarizes the current understanding of the medical management of chronic pancreatitis (CP) in children in light of the existing medical literature, incorporating recent advances in understanding of nutrition, pain, lifestyle considerations, and sequelae of CP. This article complements and is intended to integrate with parallel position papers on endoscopic and surgical aspects of CP in children. Concepts and controversies related to pancreatic enzyme replacement therapy (PERT), the use of antioxidants and other CP medical therapies are also reviewed. Highlights include inclusion of tools for medical decision-making for PERT, CP-related diabetes, and multimodal pain management (including an analgesia ladder). Gaps in our understanding of CP in children and avenues for further investigations are also reviewed.

Acute pancreatitis in children: a review with clinical perspectives to enhance imaging interpretation.

Pediatric acute pancreatitis has distinct etiologic, clinical and prognostic characteristics in contrast to the adult form of the disease. This review offers a comprehensive imaging update that emphasizes the importance of recognizing specific findings that are relevant from the clinical standpoint. Knowledge of these features facilitates communication among multidisciplinary team members and ultimately could lead to the improved care of pediatric acute pancreatitis patients.

Lipase Elevation in Patients With COVID-19.

INTRODUCTION: Although coronavirus disease (COVID-19) has been associated with gastrointestinal manifestations, its effect on the pancreas remains unclear. We aimed to assess the frequency and characteristics of hyperlipasemia in patients with COVID-19. METHODS: A retrospective cohort study of hospitalized patients across 6 US centers with COVID-19. RESULTS: Of 71 patients, 9 (12.1%) developed hyperlipasemia, with 2 (2.8%) greater than 3 times upper limit of normal. No patient developed acute pancreatitis. Hyperlipasemia was not associated with poor outcomes or symptoms. DISCUSSION: Although a mild elevation in serum lipase was observed in some patients with COVID-19, clinical acute pancreatitis was not seen.

Updates in Pediatric Pancreatology: Proceedings of the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition Frontiers in Pediatric Pancreatology Symposium.

The Pancreas Committee of the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition aims to promote awareness of pediatric pancreatic diseases, support clinical and basic science research in the field, educate pediatric gastroenterologists, and advocate on behalf of pediatric patients with pancreatic disorders. At the 2017 Annual North American Society for Pediatric Gastroenterology, Hepatology and Nutrition meeting, the Pancreas Committee held a full day symposium on pediatric pancreatic diseases, entitled, "Frontiers in Pediatric Pancreatology." The symposium served as a timely and novel academic meeting that brought together individuals with a vested interest in the care of children with pancreatic disorders. The objective of this day-long course was to update practicing gastroenterologists on the latest advances in research, management algorithms, endoscopic therapies, radiographic resources, surgical approaches, and novel drug therapies targeted to pediatric pancreatitis. Presentations were divided into 4 modules: diagnosis, risk factors, and natural history of pancreatitis; pancreatic imaging and exocrine function; management of pancreatitis; and new frontiers in pediatric pancreatitis research. The course fostered a unique ecosystem for interdisciplinary collaboration, in addition to promoting discussion and stimulating new research hypotheses regarding pediatric pancreatic disorders. Oral presentations by experts in various fields of pancreatology led to thought-provoking discussion; in addition, a meet-the-professor luncheon stimulated critical evaluation of current research in pediatric pancreatic diseases, highlighting knowledge gaps and future research endeavors. The current report summarizes the major learning points from this novel symposium focusing on the growing demographic of pediatric pancreatic diseases.

Platelet-biased stem cells reside at the apex of the haematopoietic stem-cell hierarchy.

The blood system is maintained by a small pool of haematopoietic stem cells (HSCs), which are required and sufficient for replenishing all human blood cell lineages at millions of cells per second throughout life. Megakaryocytes in the bone marrow are responsible for the continuous production of platelets in the blood, crucial for preventing bleeding--a common and life-threatening side effect of many cancer therapies--and major efforts are focused at identifying the most suitable cellular and molecular targets to enhance platelet production after bone marrow transplantation or chemotherapy. Although it has become clear that distinct HSC subsets exist that are stably biased towards the generation of lymphoid or myeloid blood cells, we are yet to learn whether other types of lineage-biased HSC exist or understand their inter-relationships and how differently lineage-biased HSCs are generated and maintained. The functional relevance of notable phenotypic and molecular similarities between megakaryocytes and bone marrow cells with an HSC cell-surface phenotype remains unclear. Here we identify and prospectively isolate a molecularly and functionally distinct mouse HSC subset primed for platelet-specific gene expression, with enhanced propensity for short- and long-term reconstitution of platelets. Maintenance of platelet-biased HSCs crucially depends on thrombopoietin, the primary extrinsic regulator of platelet development. Platelet-primed HSCs also frequently have a long-term myeloid lineage bias, can self-renew and give rise to lymphoid-biased HSCs. These findings show that HSC subtypes can be organized into a cellular hierarchy, with platelet-primed HSCs at the apex. They also demonstrate that molecular and functional priming for platelet development initiates already in a distinct HSC population. The identification of a platelet-primed HSC population should enable the rational design of therapies enhancing platelet output.

Initial Pain Management in Pediatric Acute Pancreatitis: Opioid Versus Non-opioid.

Nearly all patients with acute pancreatitis (AP) experience some degree of abdominal pain that is severe enough to prompt medical evaluation and necessitate analgesia. Effective analgesia is a priority in caring for such patients. Despite its importance, strategies for pain management in AP have been poorly studied, particularly in the field of pediatrics. Presently, no published data examine the management of pain because of AP in children at the time of initial presentation. Management approaches are often extrapolated from adult practice and based on anecdotal experience in the absence of objective data. The aim of our study was to examine the initial provision of analgesia to children who presented to a pediatric emergency department with AP.

Management of Acute Pancreatitis in the Pediatric Population: A Clinical Report From the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition Pancreas Committee.

BACKGROUND: Although the incidence of acute pancreatitis (AP) in children is increasing, management recommendations rely on adult published guidelines. Pediatric-specific recommendations are needed. METHODS: The North American Society for Pediatric Gastroenterology, Hepatology and Nutrition Pancreas committee performed a MEDLINE review using several preselected key terms relating to management considerations in adult and pediatric AP. The literature was summarized, quality of evidence reviewed, and statements of recommendations developed. The authorship met to discuss the evidence, statements, and voted on recommendations. A consensus of at least 75% was required to approve a recommendation. RESULTS: The diagnosis of pediatric AP should follow the published INternational Study Group of Pediatric Pancreatitis: In Search for a CuRE definitions (by meeting at least 2 out of 3 criteria: (1) abdominal pain compatible with AP, (2) serum amylase and/or lipase values ≥3 times upper limits of normal, (3) imaging findings consistent with AP). Adequate fluid resuscitation with crystalloid appears key especially within the first 24 hours. Analgesia may include opioid medications when opioid-sparing measures are inadequate. Pulmonary, cardiovascular, and renal status should be closely monitored particularly within the first 48 hours. Enteral nutrition should be started as early as tolerated, whether through oral, gastric, or jejunal route. Little evidence supports the use of prophylactic antibiotics, antioxidants, probiotics, and protease inhibitors. Esophago-gastro-duodenoscopy, endoscopic retrograde cholangiopancreatography, and endoscopic ultrasonography have limited roles in diagnosis and management. Children should be carefully followed for development of early or late complications and recurrent attacks of AP. CONCLUSIONS: This clinical report represents the first English-language recommendations for the management of pediatric AP. Future aims should include prospective multicenter pediatric studies to further validate these recommendations and optimize care for children with AP.

Pharmacological targeting of the Wdr5-MLL interaction in C/EBPα N-terminal leukemia.

The CEBPA gene is mutated in 9% of patients with acute myeloid leukemia (AML). Selective expression of a short (30-kDa) CCAAT-enhancer binding protein-α (C/EBPα) translational isoform, termed p30, represents the most common type of CEBPA mutation in AML. The molecular mechanisms underlying p30-mediated transformation remain incompletely understood. We show that C/EBPα p30, but not the normal p42 isoform, preferentially interacts with Wdr5, a key component of SET/MLL (SET-domain/mixed-lineage leukemia) histone-methyltransferase complexes. Accordingly, p30-bound genomic regions were enriched for MLL-dependent H3K4me3 marks. The p30-dependent increase in self-renewal and inhibition of myeloid differentiation required Wdr5, as downregulation of the latter inhibited proliferation and restored differentiation in p30-dependent AML models. OICR-9429 is a new small-molecule antagonist of the Wdr5-MLL interaction. This compound selectively inhibited proliferation and induced differentiation in p30-expressing human AML cells. Our data reveal the mechanism of p30-dependent transformation and establish the essential p30 cofactor Wdr5 as a therapeutic target in CEBPA-mutant AML.