Lim, Ming Y

Background: Splanchnic venous thrombosis (SVT) is a potentially severe and frequently underdiagnosed complication following splenectomy in patients with hematologic diseases. Despite its clinical importance, no standardized, evidence-based guidelines currently exist to inform perioperative prevention, diagnosis, or treatment in this population. Materials and Methods: A systematic review and meta-analysis were conducted following PRISMA guidelines to estimate the incidence and risk factors for SVT after splenectomy in patients with hematologic diseases. Twenty-eight observational studies comprising 5025 patients were included. Risk factor data were analyzed using random-effects models. In parallel, an international Delphi consensus process was performed involving 35 experts (hematologists and surgeons) from 14 countries. Experts were assigned to five domain-specific groups and developed clinical statements on prophylaxis, diagnosis, and management of SVT. Consensus was defined as ≥80% agreement, and recommendations were graded using the GRADE framework. Results: The pooled incidence of SVT after splenectomy was 11.4%, with higher rates in studies using routine imaging (20.7%) and those conducted at single centers (15.1%). Splenic size and weight were significant risk factors, while age, BMI, and platelet count were not. Disease-specific risk was highest in patients with myeloproliferative neoplasms, lymphoma, and thalassemia. The Delphi process generated 25 consensus statements, 14 of which were classified as strong recommendations. Key guidance included perioperative vaccination, individualized thromboprophylaxis with BMI-adjusted low molecular weight heparin, selective Doppler-based screening in high-risk patients, and stepwise anticoagulation regimens based on thrombus burden and clinical evolution. Conclusion: This study presents the first international consensus-based guidelines for managing SVT after splenectomy in patients with hematologic disease. Developed through systematic evidence synthesis and expert consensus, these recommendations provide a practical framework rather than definitive standards of care and support individualized prevention, detection, and treatment strategies in this high-risk population.

Abstract Systems-based hematology (SBH) is an emerging discipline focused on optimizing care delivery for patients with hematologic disorders within complex health care systems. Despite its growing importance, the field lacks a formal definition, standardized curriculum, and clear career pathway, hindering widespread adoption and training of future SBH experts. We sought to define core principles, competencies, challenges, and future directions of SBH to identify foundational components for a potential educational curriculum. Semistructured interviews were conducted with 8 SBH experts. Expert participants were identified through their committee involvement with the American Society of Hematology. Five overarching themes emerged: (1) The accidental expert: SBH careers have developed organically and reactively in response to pressing institutional needs, not through formal training; (2) Defining the unseen: experts define the field pragmatically by its function and roles; (3) The SBH toolkit: success requires a hybrid skillset combining clinical hematology expertise with health systems science (HSS) principles; (4) The architect's dilemma: the field's growth is hindered by interdependent challenges of building a curriculum, awareness, and securing resources; and (5) Charting the future: the discipline is poised for growth, driven by increasing health care complexity and specialization. SBH represents the nexus of HSS principles and hematology care. Formalizing SBH requires a multipronged approach, including developing a standardized curriculum that equips learners with a hybrid skillset, creating clear value for health systems and patients, and fostering a community of practice through professional societies. These findings provide a foundational framework for developing educational resources and institutional support necessary to continue advancing SBH.

Introduction: Systems-based hematology (SBH) is an emerging field focused on improving hematology care delivery through quality improvement (QI) and health systems science (HSS). However, a universal definition and standardized training curriculum are lacking. This study aimed to explore experts' perspectives on defining SBH, identify core knowledge and skills, and discuss challenges and opportunities in developing a curriculum. Methods: Semi-structured interviews were conducted with eight hematologists who have expertise in SBH through practical experience, scientific publications, and serve on related committees for the American Society of Hematology. These interviews were automatically transcribed through Microsoft Teams. Thematic analysis, using both inductive and deductive coding, was employed to identify themes and subthemes from the verbatim interview transcripts. This was accomplished with a large language model (LLM; Google Gemini Advanced, June 2024). Results: In combination, these semi-structured interviews lasted approximately 400 minutes and generated 231 pages of transcript text with 63117 words for analysis. Five main themes and associated subthemes were identified. (1) Defining SBH: experts highlighted the lack of a universal definition for SBH, emphasizing the reason it is often defined by its functions, such as improving healthcare delivery, ensuring appropriate use of resources, and addressing disparities in care. They often compared SBH to other fields like antimicrobial stewardship or implementation science to illustrate its expansive role and scope. (2) The Role and Scope of SBH: experts described SBH as encompassing a broad range of activities, including improving healthcare delivery, implementing QI initiatives, conducting pragmatic research, and advocating for policy changes at various levels. They emphasized the importance of data-driven approaches and collaboration with other healthcare professionals. (3) Training and Education in SBH: the lack of formal training programs and curricula for SBH was a recurring theme. Experts suggested that a comprehensive curriculum should include QI methodologies, implementation science, clinical informatics, health economics, leadership skills, and hematology-specific examples and case studies. They proposed various delivery methods, including asynchronous online modules, virtual workshops, and in-person sessions, targeting hematology fellows, junior faculty, and other healthcare professionals involved in hematology care. They unanimously agreed that a SBH curriculum could borrow heavily from an established HSS curriculum but should incorporate hematology-specific examples. (4) Challenges and Barriers to Implementing SBH: experts identified several challenges, including the lack of awareness and recognition of SBH among healthcare professionals and administrators, resource constraints, and the need for institutional buy-in. They also highlighted the technical difficulty of measuring and demonstrating the value of SBH interventions, particularly in terms of cost savings and improved patient outcomes. (5) The Future of SBH: despite the challenges, experts expressed optimism about the future of SBH, predicting its growing importance and expanding scope, including malignant hematology, community practice, and pediatrics. They envisioned SBH playing a crucial role in addressing rising healthcare costs, quality concerns, and disparities in care. They also anticipated the integration of new technologies like artificial intelligence, “virtual” care delivery, and molecular genetics into SBH practice. Conclusions: This study provides valuable insights into the current state of SBH and the need for a standardized curriculum. The findings can inform the development of educational resources and training programs to equip future practitioners with the necessary knowledge and skills to effectively practice SBH and improve hematology care delivery. This study also sheds light on the utility of qualitative research within SBH and the emerging analytical tools that will require further exploration and standardization (e.g., LLM prompt engineering).

Abstract Immune thrombotic thrombocytopenic purpura (iTTP) is a chronically relapsing disorder caused by autoantibody-mediated deficiency of ADAMTS13. Rituximab is frequently administered to prevent relapses, but whether the durability of rituximab effect is maintained with subsequent treatment courses has not been studied. Using the United States Thrombotic Microangiopathy Consortium (USTMA) retrospective iTTP registry, we evaluated clinical relapse-free survival (RFS) with subsequent courses of rituximab treatment in multiply relapsing patients. Separately, we evaluated overall RFS (composite of time to clinical relapse, ADAMTS13 relapse, or preemptive rituximab) in a prospective iTTP cohort from the Johns Hopkins University and the University of Minnesota. In the USTMA registry, median clinical RFS was shorter after the second or subsequent rituximab-treated episode than the first (2.1 vs 6.0 years; P = .04). White patients’ clinical relapse risk after the second and subsequent rituximab courses was not significantly different compared with the first (hazard ratio [HR], 1.86; 95% confidence interval [CI], 0.22-15.80; P = .57), whereas for Black patients, clinical relapse risk was significantly higher after the second or subsequent courses (HR, 2.82; 95% CI, 1.52-5.24; P = .001). In the prospective cohort, overall RFS progressively shortened after each episode of rituximab treatment with the first episode having the longest RFS (2.8 years; interquartile range, 2.0-6.0) and this loss of response durability was most pronounced in Black patients. The durability of rituximab’s effect declines with subsequent treatments, which is more pronounced in Black patients, who may benefit from closer monitoring and alternative immunomodulatory approaches such as maintenance rituximab and consideration of other agents.

The NCCN Guidelines for Cancer-Associated Venous Thromboembolic Disease provide strategies for the prevention, diagnosis, and treatment of venous thromboembolism (VTE) in adult patients with cancer. VTE is a common and life-threatening condition in patients with cancer, and its management often requires multidisciplinary efforts. The NCCN panel is comprised of specialists spanning various fields, including cardiology, hematology, medical oncology, internal medicine, interventional radiology, and pharmacology. The content featured in this issue specifically addresses the evaluation and recommended treatment options outlined in the NCCN Guidelines for the diverse subtypes of cancer-associated VTE.

Abstract Immune-mediated thrombotic thrombocytopenic purpura (iTTP) is characterized by recurring episodes of thrombotic microangiopathy, causing ischemic organ impairment. Black patients are overrepresented in iTTP cohorts in the United States, but racial disparities in iTTP outcome and response to therapy have not been studied. Using the United States Thrombotic Microangiopathies Consortium iTTP Registry, we evaluated the impact of race on mortality and relapse-free survival (RFS) in confirmed iTTP in the United States from 1995 to 2020. We separately examined the impact of rituximab therapy and presentation with newly diagnosed (de novo) or relapsed iTTP on RFS by race. A total of 645 participants with 1308 iTTP episodes were available for analysis. Acute iTTP mortality did not differ by race. When all episodes of iTTP were included, Black race was associated with shorter RFS (hazard ratio [HR], 1.60; 95% CI, 1.16-2.21); the addition of rituximab to corticosteroids improved RFS in White (HR, 0.37; 95% CI, 0.18-0.73) but not Black patients (HR, 0.96; 95% CI, 0.71-1.31). In de novo iTTP, rituximab delayed relapse, but Black patients had shorter RFS than White patients, regardless of treatment. In relapsed iTTP, rituximab significantly improved RFS in White but not Black patients. Race affects overall relapse risk and response to rituximab in iTTP. Black patients may require closer monitoring, earlier retreatment, and alternative immunosuppression after rituximab treatment. How race, racism, and social determinants of health contribute to the disparity in relapse risk in iTTP deserves further study.

Venous thromboembolism (VTE) is a major complication in all patients with cancer. Compared with the general population, patients with multiple myeloma (MM) have a 9-fold increase in VTE risk, likely because of their malignancy, its treatments, and other additional patient-related factors. In MM, thromboembolism events tend to occur within 6 months of treatment initiation, regardless of treatment regimen; however, the use of immunomodulatory agents such as thalidomide or lenalidomide, especially in combination with dexamethasone or multiagent chemotherapy, is known to create a significant risk for VTE. Currently, official recommendations for VTE prophylaxis in MM outlined in various national guidelines or multidisciplinary society panels are based on expert opinion, because data from randomized controlled trials are scarce. Large studies which have mainly focused on the efficacy of thromboprophylaxis in patients with cancer at higher risk for VTE either had a very low representation of patients with MM, or excluded them all together, limiting our ability to draw evidence-based conclusions on how to effectively protect MM population from VTE. In this brief perspective, we highlight some of the greatest challenges that have hampered the field concerning the availability of high-quality clinical trial data for the formulation of best VTE prophylaxis strategies in patients with newly diagnosed MM, as well as the rationale for the latest updates in the NCCN Guidelines on this topic.