Cytokine-mediated CAR T therapy resistance in AML.

Acute myeloid leukemia (AML) is a rapidly progressive malignancy without effective therapies for refractory disease. So far, chimeric antigen receptor (CAR) T cell therapy in AML has not recapitulated the efficacy seen in B cell malignancies. Here we report a pilot study of autologous anti-CD123 CAR T cells in 12 adults with relapsed or refractory AML. CAR T cells targeting CD123+ cells were successfully manufactured in 90.4% of runs. Cytokine release syndrome was observed in 10 of 12 infused individuals (83.3%, 90% confidence interval 0.5-0.97). Three individuals achieved clinical response (25%, 90% confidence interval 0.07-0.53). We found that myeloid-supporting cytokines are secreted during cell therapy and support AML blast survival via kinase signaling, leading to CAR T cell exhaustion. The prosurvival effect of therapy-induced cytokines presents a unique resistance mechanism in AML that is distinct from any observed in B cell malignancies. Our findings suggest that autologous CART manufacturing is feasible in AML, but treatment is associated with high rates of cytokine release syndrome and relatively poor clinical efficacy. Combining CAR T cell therapies with cytokine signaling inhibitors could enhance immunotherapy efficacy in AML and achieve improved outcomes (ClinicalTrials.gov identifier: NCT03766126 ).

ASTCT Consensus Recommendations on Testing and Treatment of Patients with Donor-specific Anti-HLA Antibodies.

Donor-specific anti-HLA antibodies (DSA) are an important cause of engraftment failure and may negatively impact survival outcomes of patients receiving allogeneic hematopoietic stem cell transplantation (HSCT) using an HLA-mismatched allograft. The incidence of DSA varies across studies, depending on individual factors, detection or identification methods and thresholds considered clinically relevant. Although DSA testing by multiplex bead arrays remains semiquantitative, it has been widely adopted as a standard test in most transplant centers. Additional testing to determine risk of allograft rejection may include assays with HLA antigens in natural conformation, such as flow cytometric crossmatch, and/or antibody binding assays, such as C1q testing. Patients with low level of DSA (<2,000 mean fluorescence intensity; MFI) may not require treatment, while others with very high level of DSA (>20,000 MFI) may be at very high-risk for engraftment failure despite current therapies. By contrast, in patients with moderate or high level of DSA, desensitization therapy can successfully mitigate DSA levels and improve donor cell engraftment rate, with comparable outcomes to patients without DSA. Treatment is largely empirical and multimodal, involving the removal, neutralization, and blocking of antibodies, as well as inhibition of antibody production to prevent activation of the complement cascade. Desensitization protocols are based on accumulated multicenter experience, while prospective multicenter studies remain lacking. Most patients require a full intensity protocol that includes plasma exchange, while protocols relying only on rituximab and intravenous immunoglobulin may be sufficient for patients with lower DSA levels and negative C1q and/or flow cytometric crossmatch. Monitoring DSA levels before and after HSCT could guide preemptive treatment when high levels persist after stem cell infusion. This paper aims to standardize current evidence-based practice and formulate future directions to improve upon current knowledge and advance treatment for this relatively rare, but potentially serious complication in allogeneic HSCT recipients.

Genetic risk factors for COVID-19 and influenza are largely distinct.

Coronavirus disease 2019 (COVID-19) and influenza are respiratory illnesses caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and influenza viruses, respectively. Both diseases share symptoms and clinical risk factors1, but the extent to which these conditions have a common genetic etiology is unknown. This is partly because host genetic risk factors are well characterized for COVID-19 but not for influenza, with the largest published genome-wide association studies for these conditions including >2 million individuals2 and about 1,000 individuals3-6, respectively. Shared genetic risk factors could point to targets to prevent or treat both infections. Through a genetic study of 18,334 cases with a positive test for influenza and 276,295 controls, we show that published COVID-19 risk variants are not associated with influenza. Furthermore, we discovered and replicated an association between influenza infection and noncoding variants in B3GALT5 and ST6GAL1, neither of which was associated with COVID-19. In vitro small interfering RNA knockdown of ST6GAL1-an enzyme that adds sialic acid to the cell surface, which is used for viral entry-reduced influenza infectivity by 57%. These results mirror the observation that variants that downregulate ACE2, the SARS-CoV-2 receptor, protect against COVID-19 (ref. 7). Collectively, these findings highlight downregulation of key cell surface receptors used for viral entry as treatment opportunities to prevent COVID-19 and influenza.

Symptomatic Heart Failure and Clonal Hematopoiesis-Related Mutations in Patients With Acute Myeloid Leukemia.

Clonal hematopoiesis of indeterminate potential (CHIP) is a common risk factor for hematologic malignancies and cardiovascular diseases. This study aimed to investigate the association between CHIP-related mutations and symptomatic heart failure (HF) in patients diagnosed with acute myeloid leukemia (AML). A total of 563 patients with newly diagnosed AML who underwent DNA sequencing of bone marrow before treatment were retrospectively investigated. Cox proportional hazard regression models and Fine and Gray's subdistribution hazard regression models were used to assess the association between CHIP-related mutations and symptomatic HF. A total of 79.0% patients had at least 1 CHIP-related mutation; the most frequent mutations were DNMT3A, ASXL1, and TET2. A total of 51 patients (9.1%) developed symptomatic HF. The incidence of symptomatic HF was more frequent in patients with DNMT3A mutations (p <0.01), with a 1-year cumulative incidence of symptomatic HF in patients with DNMT3A mutations of 11.4%, compared with 3.9% in patients with wild-type DNMT3A (p <0.01). After adjustment for age and anthracyclines dose, DNMT3A mutations remained independently correlated with HF (hazard ratio 2.32, 95% confidence interval 1.26 to 4.29, p = 0.01). In conclusion, in patients with AML, the presence of DNMT3A mutations was associated with a twofold increased risk for symptomatic HF, irrespective of age and anthracyclines use.

The role and novel use of natural killer cells in graft-versus-leukemia reactions after allogeneic transplantation.

Allogeneic hematopoietic cell transplantation (HCT) has transformed over the past several decades through enhanced supportive care, reduced intensity conditioning (RIC), improved human leukocyte antigen (HLA) typing, and novel graft-versus-host disease (GVHD)-prevention and treatment strategies. Most notably, the implementation of post-transplantation cyclophosphamide (PTCy) has dramatically increased the safety and availability of this life-saving therapy. Given reductions in nonrelapse mortality (NRM) with these advances, the HCT community has placed even greater emphasis on developing ways to reduce relapse - the leading cause of death after HCT. When using RIC HCT, protection from relapse relies predominantly on graft-versus-leukemia (GVL) reactions. Donor lymphocyte infusion (DLI), adoptive cellular therapy, checkpoint inhibition, and post-HCT maintenance strategies represent approaches under study that aim to augment or synergize with the GVL effects of HCT. Optimizing donor selection algorithms to leverage GVL represents another active area of research. Many of these strategies seek to harness the effects of T cells, which for decades were felt to be the primary mediators of GVL and the focus of investigation in relapse reduction. However, there is growing interest in capitalizing on the ability of natural killer (NK) cells to yield potent anti-tumor effects. A potential advantage of NK cell-based approaches over T cell-mediated is the potential to reduce NRM in addition to relapse. By decreasing infection, without increasing the risk of GVHD, NK cells may mitigate NRM, while still yielding relapse reduction through identification and clearance of cancer cells. Most T cell-focused relapse-prevention strategies must weigh the benefits of relapse reduction against the increased risk of NRM from GVHD. In contrast, NK cells have the potential to reduce both, potentially tipping the scales significantly in favor of survival. Here, we will review the role of NK cells in GVL, optimization of NK cell match or mismatch, and burgeoning areas of research in NK cell therapy such as adoptive transfer and chimeric antigen receptor (CAR) NK cells.

Tailoring Therapy in Older Adults With Hematologic Malignancies.

Hematologic malignancies most often present in the sixth or seventh decade of life. Even so, many older adults may be unable to tolerate standard chemotherapy or require supplementary care or dose adjustments to do so. Both in community and academic centers, geriatric assessment (GA) can be used to improve the care of older adults with blood cancers. For example, hematologic oncologists can use GA to guide treatment selection, adjusting for patient frailty and goals, as well as prompt initiation of enhanced supportive care. After initial therapy, GA can improve the identification of older adults with aggressive myeloid malignancies who would benefit from hematopoietic cell transplantation (HCT), inform shared decision making, as well as allow transplanters to tailor conditioning regimen, donor selection, graft-versus-host disease prophylaxis, and pre- and post-HCT treatments. As in HCT, GA can improve the care of older patients with relapsed lymphoma or multiple myeloma eligible for chimeric antigen receptor-T therapy, identifying patients at higher risk for toxicity and providing a baseline for subsequent neurocognitive testing. Here, we review the data supporting GA for the care of older adults with blood cancers, from the community to the academic center. In addition, we explore future directions to optimize outcomes for older adults with hematologic malignancies.

Age barriers in allogeneic hematopoietic cell transplantation: Raising the silver curtain.

Allogeneic hematopoietic cell transplantation (HCT) is no longer exclusively for the young. With an aging population, development of non-intensive remission-inducing strategies for hematologic malignancies, and novel graft-versus-host disease-prevention platforms, an older population of patients is pursuing HCT. The evolving population of HCT recipients requires an overhaul in the way we risk-stratify and optimize patients prior to HCT. Here, we review the history and current state of HCT for older adults and propose an assessment and intervention flow to bridge the gaps in today's clinical guidelines.

A US payer perspective health economic model assessing value of monitoring disease activity to inform discontinuation and re-initiation of DMT in multiple sclerosis.

OBJECTIVES: We evaluate the potential clinical and cost impacts of discontinuing disease-modifying therapy (DMT) in people with multiple sclerosis (PwMS) when age-related immunosenescence can reduce DMT efficacy while increasing associated risks. METHODS: A Markov model simulated clinical and cost impacts to the patient and payers when a proportion of eligible patients with relapsing remitting multiple sclerosis (RRMS) discontinue DMT. Eligibility was defined as age >55 years, an RRMS diagnosis of >5 years, and no history of relapses for 5 years. Increasing the proportion of eligible patients willing to discontinue therapy was also modeled. Clinical and cost inputs were from published literature. RESULTS: Difference in EDSS progression between eligible patients who did and did not attempt discontinuation was not significant. After 1 year of eligibility, per-patient costs were $96k lower in the cohort that attempted discontinuation; however a higher proportion of relapses were seen in this group. When the proportion of patients willing to discontinue DMT increased, clinical findings remained consistent while the average cost per patient decreased. CONCLUSION: While there are increased clinical and cost benefits as more eligible patients attempt discontinuation, the risk of relapses can increase. Timely disease monitoring is required to manage safe DMT discontinuation.

Preconditioning Frailty Phenotype Influences Survival and Relapse for Older Allogeneic Transplantation Recipients.

Hematologic malignancies disproportionately affect older adults. Hematopoietic cell transplantation (HCT) is potentially curative, but poor overall survival (OS) has limited its use in older adults. Fried's frailty phenotype (FFP) is a geriatric assessment tool that combines objective and subjective performance measures: gait speed, grip strength, activity level, exhaustion, and weight loss. People meeting ≥3 criteria are classified as frail; 1 or 2 criteria, as pre-frail; and 0 criteria, as fit. To evaluate the association of pre-HCT FFP with post-HCT outcomes, we assessed FFP prior to conditioning for 280 HCT recipients age ≥60 years with acute leukemia or a myeloid neoplasm at 3 institutions. When analyzing survival by age group, patients age ≥70 years had inferior OS compared to patients age 60 to 69 years (P = .002), with corresponding OS estimates of 38.9% (95% confidence interval [CI], 27.8% to 49.9%) and 59.3% (95% CI, 51.9% to 65.9%). Nonrelapse mortality (NRM) also was significantly higher in the older patients (P = .0005); the 2-year cumulative incidences of NRM were 38.5% (95% CI, 27.5% to 49.2%) and 17.2% (95% CI, 12.3% to 22.8%), for older and younger recipients, respectively. The cumulative incidences of relapse did not differ by age group (P = .3435). Roughly one-third (35.5%) of the patients were fit, 57.5% were pre-frail, and 7.5% were frail, with corresponding 2-year OS estimates of 68.4% (95% CI, 57.9% to 76.8%), 45.5% (95% CI, 37.4% to 53.2%), and 45.8% (95% CI, 23.4% to 65.8%) (P = .013). FFP was not significantly associated with NRM, but being frail or pre-frail was associated with a higher rate of disease-related deaths (33.3% and 27.3%, respectively, compared with 17.4% for fit patients; P = .043). In univariate modeling of restricted mean survival time with a 3-year horizon (RMST_3y), the factors that were significantly associated were FFP, age, Karnofsky Performance Status (KPS), Disease Risk Index (DRI), and HCT-specific Comorbidity Index (HCT-CI). Of those factors, only FFP (P = .006), age (P = .006), KPS (P = .004), and DRI (P = .005) were significantly associated in multivariate modeling of RMST_3y. Estimates of RMST_3y were computed and 5 risk-groups were created with survival ranging from 31.4 months for those who were age 60 to 69 years, fit, had KPS 90 to 100, and low/intermediate-risk DRI compared to 10.5 months for those who had high-risk features for all the evaluated factors. In univariate and multivariate analyses for restricted mean time to relapse with a 3-year horizon (RMRT_3y), FFP (pre-frail versus fit, P = .007; frail versus fit, P = .061) and DRI (P = .001) were the only significant factors. Predicted RMRT_3y was longest (30.6 months) for those who were fit and had low/intermediate-risk DRI scores and shortest (19.1 months) for those who were frail and had high-risk or very high-risk DRI scores. Both age and FFP impact survival after HCT. Incorporation of FFP into pre-HCT evaluations may improve decision-making and counseling regarding HCT risk for older adults. Our findings support future trials designed to reverse frailty, such as pre-HCT supervised exercise programs, and correlative analyses to unravel the connection of frailty and relapse to generate future targets for intervention. Finally, exploration of novel HCT platforms to reduce relapse in pre-frail and frail patients, as well as reduce NRM in adults age >70 years, are warranted.

Proteomic signatures of physical, cognitive, and imaging outcomes in multiple sclerosis.

BACKGROUND: A quantitative measurement of serum proteome biomarkers that would associate with disease progression endpoints can provide risk stratification for persons with multiple sclerosis (PwMS) and supplement the clinical decision-making process. MATERIALS AND METHODS: In total, 202 PwMS were enrolled in a longitudinal study with measurements at two time points with an average follow-up time of 5.4 years. Clinical measures included the Expanded Disability Status Scale, Timed 25-foot Walk, 9-Hole Peg, and Symbol Digit Modalities Tests. Subjects underwent magnetic resonance imaging to determine the volumetric measures of the whole brain, gray matter, deep gray matter, and lateral ventricles. Serum samples were analyzed using a custom immunoassay panel on the Olink™ platform, and concentrations of 18 protein biomarkers were measured. Linear mixed-effects models and adjustment for multiple comparisons were performed. RESULTS: Subjects had a significant 55.6% increase in chemokine ligand 20 (9.7 pg/mL vs. 15.1 pg/mL, p < 0.001) and neurofilament light polypeptide (10.5 pg/mL vs. 11.5 pg/mL, p = 0.003) at the follow-up time point. Additional changes in CUB domain-containing protein 1, Contactin 2, Glial fibrillary acidic protein, Myelin oligodendrocyte glycoprotein, and Osteopontin were noted but did not survive multiple comparison correction. Worse clinical performance in the 9-HPT was associated with neurofilament light polypeptide (p = 0.001). Increases in several biomarker candidates were correlated with greater neurodegenerative changes as measured by different brain volumes. CONCLUSION: Multiple proteins, selected from a disease activity test that represent diverse biological pathways, are associated with physical, cognitive, and radiographic outcomes. Future studies should determine the utility of multiple protein assays in routine clinical care.

Haploidentical donor hematopoietic cell transplantation for myelodysplastic/myeloproliferative overlap neoplasms: results from a North American collaboration.

Haploidentical donors offer a potentially readily available donor, especially for non-White patients, for hematopoietic cell transplantation (HCT). In this North American collaboration, we retrospectively analyzed outcomes of first HCT using haploidentical donor and post-transplantation cyclophosphamide (PTCy) in myelodysplastic syndrome/myeloproliferative neoplasm (MDS/MPN) overlap neoplasms (MDS/MPN). We included 120 consecutive patients who underwent HCT using a haploidentical donor for MDS/MPN across 15 centers. Median age was 62.5 years and 38% were of non-White/Caucasian ethnicity. The median follow-up was 2.4 years. Graft failure was reported in seven of 120 (6%) patients. At 3 years, nonrelapse mortality (NRM) was 25% (95% confidence interval [CI]: 17-34), relapse 27% (95% CI: 18-36), grade 3-4 acute graftversus- host disease 12% (95% CI: 6-18), chronic graft-versus-host disease requiring systemic immunosuppression 14% (95% CI: 7-20), progression-free survival (PFS) 48% (95% CI: 39-59), and overall survival (OS) 56% (95% CI: 47-67). On multivariable analysis, NRM was statistically significantly associated with advancing age at HCT (per decade increment, subdistribution hazard ratio [sdHR] =3.28; 95% CI: 1.30-8.25); relapse with the presence of mutation in EZH2/RUNX1/SETBP1 (sdHR=2.61; 95% CI: 1.06-6.44); PFS with advancing age at HCT (per decade increment, HR=1.98, 95% CI: 1.13-3.45); and OS with advancing age at HCT (per decade increment, HR=2.01; 95% CI: 1.11-3.63) and splenomegaly at HCT/prior splenectomy (HR=2.20; 95% CI: 1.04-4.65). Haploidentical donors are a viable option for HCT in MDS/MPN, especially for those disproportionately represented in the unrelated donor registry. Hence, donor mismatch should not preclude HCT for patients with MDS/MPN, an otherwise incurable malignancy. In addition to patient age, disease-related factors including splenomegaly and high-risk mutations dominate outcomes following HCT.

Real-world effectiveness of intensive chemotherapy with 7&3 versus venetoclax and hypomethylating agent in acute myeloid leukemia.

Intensive chemotherapy with cytarabine and anthracycline (7&3) remains the standard therapy for patients medically fit for induction, but the assessment of fitness remains controversial. Venetoclax and hypomethylating agent (ven/HMA) combination therapy has improved outcomes in unfit patients but no prospective study has assessed ven/HMA versus 7&3 as initial therapy in older, fit patients. Given no studies and expectation of ven/HMA use in patients outside of trial criteria, we evaluated retrospective outcomes among newly diagnosed patients. A nationwide electronic health record (EHR)-derived database and the University of Pennsylvania EHR identified 312 patients receiving 7&3 and 488 receiving ven/HMA who were 60-75 years old without history of organ failure. Ven/HMA patients were older and more likely to have secondary AML, adverse cytogenetics, and adverse mutations. Median overall survival (OS) for patients receiving intensive chemotherapy was 22 versus 10 months for ven/HMA (HR 0.53, 95% CI 0.40-0.60). Controlling for measured baseline characteristic imbalances reduced survival advantage by half (HR 0.71, 95% CI 0.53-0.94). A sub-group of patients with equipoise, likelihood at least 30%-70% of receiving either treatment, had similar OS outcomes (HR 1.10, 95% CI 0.75-1.6). Regarding safety outcomes, 60-day mortality was higher for ven/HMA (15% vs. 6% at 60 days) despite higher documented infections and febrile neutropenia for 7&3. In this multicenter real-word dataset, patients selected for intensive chemotherapy had superior OS but a large group had similar outcomes with ven/HMA. Prospective randomized studies, controlling for both measured and unmeasured confounders, must confirm this outcome.

The Transplantation Ecosystem: A New Concept to Improve Access and Outcomes for Older Allogeneic Hematopoietic Cell Transplantation Patients.

Allogeneic hematopoietic cell transplantation (HCT) is increasingly offered to older adults with hematologic malignancies, even though nonrelapse mortality remains a major concern in older patients owing to more comorbidities and greater frailty compared with their younger counterparts. The importance of patient fitness, a well-matched donor, and disease control to the success of allogeneic HCT have been well documented; however, these factors fail to account for the impact of the complex transplantation ecosystem (TE) that older adult HCT candidates must navigate. We propose a definition of the TE modeled after the social determinants of health. Furthermore, we outline a research agenda aimed at increasing understanding of the roles of individual social determinants of transplantation health in the larger ecosystem and how they may benefit or harm older adult HCT candidates. Herein we define the TE and its individual tenets, the social determinants of transplantation health. We review the available literature while incorporating the expertise of the membership of the American Society for Transplantation and Cellular Therapy (ASTCT) Special Interest Group for Aging. The membership of the ASTCT Special Interest Group for Aging identify knowledge gaps and strategies to address them for each of the described social determinants of transplantation health. The ecosystem is an essential but underappreciated pillar for transplant access and success. We put forth this novel research agenda seeking to gain a better understanding of the complexity of HCT in older adults and develop strategies to improve access to HCT, survival, and quality of life.

Relapse after allogeneic transplantation with post-transplant cyclophosphamide: Shattering myths and evolving insight.

Early studies in allogeneic blood or marrow transplantation (alloBMT) demonstrated that HLA-mismatching was protective again relapse. However, benefits in relapse reduction were outweighed by a high risk of graft-versus-host disease (GVHD) when using conventional pharmacological immunosuppression. Post-transplant cyclophosphamide(PTCy)-based platforms abated the risk of GVHD thereby overcoming the negative effects of HLA-mismatching on survival. However, since its inception, PTCy has been shadowed by a reputation for a greater risk of relapse when compared with traditional GVHD prophylaxis. Specifically, whether PTCy reduces the anti-tumor efficacy of HLA-mismatched alloBMT by killing alloreactive T cells has been the subject of debate since the early 2000's. Here we review the many studies demonstrating the potent graft-versus-malignancy (GVM) properties of alloBMT with PTCy. We discuss the laboratory data from PTCy platforms supporting that T regulatory cells may be a major mechanism of prevention of GVHD and that natural killer (NK) cells may be early effectors of GVM. Finally, we propose potential paths to optimize GVM through selecting for class II mismatching and augmenting NK cell activity.

Haploidentical Donor Blood or Marrow Transplantation for Myelodysplastic/Myeloproliferative Overlap Neoplasms: Results from a North American Collaboration.

Haploidentical donors offer a potentially readily available donor, especially for non-White patients, for blood or marrow transplantation (BMT). In this collaboration across North America, we retrospectively analyzed outcomes of first BMT using haploidentical donor and posttransplantation cyclophosphamide (PTCy) in MDS/MPN-overlap neoplasms (MDS/MPN), an otherwise incurable hematological neoplasm. We included 120 patients, 38% of non-White/Caucasian ethnicity, across 15 centers with median age at BMT 62.5 years. The median follow-up is 2.4 years. Graft failure was reported in 6% patients. At 3-years, nonrelapse mortality (NRM) was 25%, relapse 27%, grade 3-4 acute graft versus host disease (GVHD) 12%, chronic GVHD requiring systemic immunosuppression 14%, progression-free survival (PFS) 48% and overall survival (OS) 56%. On multivariable analysis, statistically significant associations included older age at BMT (per decade increment) with NRM (sdHR 3.28, 95%CI 1.30-8.25), PFS (HR 1.98, 95% 1.13-3.45) and OS (HR 2.01, 95% CI 1.11-3.63), presence of mutation in EZH2/RUNX1/SETBP1 with relapse (sdHR 2.61, 95%CI 1.06-6.44), and splenomegaly at BMT/prior splenectomy with OS (HR 2.20, 95%CI 1.04-4.65). Haploidentical donors are a viable option for BMT in MDS/MPN, especially for those disproportionately represented in the unrelated donor registry. Disease-related factors including splenomegaly and high-risk mutations dominate outcomes following BMT.

Central line-associated Rhizobium radiobacter bloodstream infection in two allogeneic hematopoietic cell transplant recipients.

INTRODUCTION: Rhizobium radiobacter is a gram-negative, opportunistic phytopathogen that rarely causes human infections. We report two cases of Rhizobium radiobacter central line-associated bloodstream infection (CLABSI) in allogeneic hematopoietic cell transplantation (alloHCT) recipients. We review previous reports and common microbiological characteristics associated with this organism. CASE REPORTS: Two adult males developed R. radiobacter CLABSIs at day +81 and day +77 post-alloHCT. Patient one was asymptomatic on presentation while patient two was febrile. One patient had a polymicrobial infection, which has not been previously described. The presence of high-level ceftazidime resistance in both patients suggests third-generation cephalosporin resistance may be more common than previously recognized. MANAGEMENT AND OUTCOME: For both patients, microbiologic clearance was achieved through peripherally inserted central catheter removal and initiation of intravenous cefepime. Antibiotic therapy was narrowed to oral levofloxacin for a total 14-day course from the time of first negative blood culture. There has been no subsequent recurrence of R. radiobacter infection at 12 and 5 months of follow-up for patients one and two, respectively. DISCUSSION: These two cases add to the scant literature characterizing R. radiobacter infection following alloHCT. Immunosuppressive agents for graft-versus-host disease prophylaxis may have predisposed these patients to R. radiobacter infection. Our reports, and previously reported cases, suggest R. radiobacter exhibits low virulence, mild symptom burden, and does not confer a high mortality risk. In the alloHCT setting, further accumulation of cases is needed to aid in understanding clinical features and characteristics of R. radiobacter infection.

How I prevent GVHD in high-risk patients: posttransplant cyclophosphamide and beyond.

Advances in conditioning, graft-versus-host disease (GVHD) prophylaxis and antimicrobial prophylaxis have improved the safety of allogeneic hematopoietic cell transplantation (HCT), leading to a substantial increase in the number of patients transplanted each year. This influx of patients along with progress in remission-inducing and posttransplant maintenance strategies for hematologic malignancies has led to new GVHD risk factors and high-risk groups: HLA-mismatched related (haplo) and unrelated (MMUD) donors; older recipient age; posttransplant maintenance; prior checkpoint inhibitor and autologous HCT exposure; and patients with benign hematologic disorders. Along with the changing transplant population, the field of HCT has dramatically shifted in the past decade because of the widespread adoption of posttransplantation cyclophosphamide (PTCy), which has increased the use of HLA-mismatched related donors to levels comparable to HLA-matched related donors. Its success has led investigators to explore PTCy's utility for HLA-matched HCT, where we predict it will be embraced as well. Additionally, combinations of promising new agents for GVHD prophylaxis such as abatacept and JAK inhibitors with PTCy inspire hope for an even safer transplant platform. Using 3 illustrative cases, we review our current approach to transplantation of patients at high risk of GVHD using our modern armamentarium.

Clofarabine and Busulfan Myeloablative Conditioning in Allogeneic Hematopoietic Cell Transplantation for Patients With Active Myeloid Malignancies.

Patients with refractory or relapsed and refractory myeloid malignancies have a poor prognosis. Allogeneic hematopoietic cell transplantation (HCT) with myeloablative conditioning (MAC) in patients with active, chemotherapy-refractory myeloid disease is historically associated with high rates of relapse and nonrelapse mortality (NRM). A MAC regimen combining clofarabine with busulfan (Clo/Bu4) has been reported to exhibit antileukemic activity with acceptable toxicity in patients age ≤70 years. Here we describe the clinical outcomes of a real-world population of patients with active myeloid malignancies undergoing allogeneic HCT with Clo/Bu4 MAC. In a single-center retrospective descriptive analysis, we identified patients who underwent HCT for myeloid malignancies not in remission using Clo/Bu4 MAC between 2012 and 2020. We report event-free survival (EFS) and overall survival (OS), cumulative incidences of relapse and NRM, and the incidence and severity of acute and chronic graft-versus-host disease (GVHD). We identified 69 patients with a median age of 60 years (range, 22 to 70 years). Most patients had relapsed/refractory or primary refractory acute myelogenous leukemia (AML; n = 55) or refractory myelodysplastic syndrome (MDS; n = 12); 1 patient had chronic myelogenous leukemia, and 1 patient had a blastic plasmacytoid dendritic cell neoplasm. Fifty patients (72.5%) had complete remission at day 100 post-transplantation. Two-year EFS and OS were 30% (95% confidence interval [CI], 20% to 44%) and 40% (95% CI, 29% to 54%), respectively. Patients with AML had a 2-year EFS and OS of 28% (95% CI, 18% to 44%) and 38% (95% CI, 27% to 54%), respectively; those with MDS had a 2-year EFS and OS of 47% (95% CI, 25% to 88%) and 56% (95% CI, 33% to 94%), respectively. The cumulative incidence of relapse at 2 years was 39% (95% CI, 27% to 51%) for all patients, including 45% (95% CI, 31% to 58%) in the patients with AML and 18% (95% CI, 2% to 45%) in those with MDS. NRM at 2 years was 31% (95% CI, 20% to 42%), including 27% (95% CI, 15% to 39%) in patients with AML and 35% (95% CI, 10% to 63%) in those with MDS. The total incidence of acute GVHD (aGVHD) of any severity was 80%, and the incidence of grade III-IV aGVHD was 22%. In patients who achieved remission, those who required systemic immunosuppression for aGVHD (58%) had poorer 2-year EFS (29% versus 54%; P = .05) and 2-year OS (39% versus 70%; P = .04) compared to those who did not. The 2-year cumulative incidence of chronic GVHD was 44% (95% CI, 28% to 58%). Clo/Bu4 MAC followed by allogeneic HCT for patients with active myeloid malignancies is an effective transplantation strategy for patients up to age 70, particularly those with advanced MDS. The high incidence of and poor outcomes associated with aGVHD highlight the importance of optimizing preventative strategies.

COVID-19 susceptibility and severity risks in a cross-sectional survey of over 500 000 US adults.

OBJECTIVES: The enormous toll of the COVID-19 pandemic has heightened the urgency of collecting and analysing population-scale datasets in real time to monitor and better understand the evolving pandemic. The objectives of this study were to examine the relationship of risk factors to COVID-19 susceptibility and severity and to develop risk models to accurately predict COVID-19 outcomes using rapidly obtained self-reported data. DESIGN: A cross-sectional study. SETTING: AncestryDNA customers in the USA who consented to research. PARTICIPANTS: The AncestryDNA COVID-19 Study collected self-reported survey data on symptoms, outcomes, risk factors and exposures for over 563 000 adult individuals in the USA in just under 4 months, including over 4700 COVID-19 cases as measured by a self-reported positive test. RESULTS: We replicated previously reported associations between several risk factors and COVID-19 susceptibility and severity outcomes, and additionally found that differences in known exposures accounted for many of the susceptibility associations. A notable exception was elevated susceptibility for men even after adjusting for known exposures and age (adjusted OR=1.36, 95% CI=1.19 to 1.55). We also demonstrated that self-reported data can be used to build accurate risk models to predict individualised COVID-19 susceptibility (area under the curve (AUC)=0.84) and severity outcomes including hospitalisation and critical illness (AUC=0.87 and 0.90, respectively). The risk models achieved robust discriminative performance across different age, sex and genetic ancestry groups within the study. CONCLUSIONS: The results highlight the value of self-reported epidemiological data to rapidly provide public health insights into the evolving COVID-19 pandemic.