Outcomes with allogeneic stem cell transplant using cryopreserved versus fresh hematopoietic progenitor cell products.

BACKGROUND: Allogeneic hematopoietic stem cell transplant (alloHSCT) is a mainstay of treatment for hematologic malignancies such as acute leukemias and aggressive lymphomas. Historically, fresh hematopoietic progenitor cell (HPC) products have been preferred to cryopreserved products (cryo-HPC) due to concerns of loss of stem cell viability and number with the cryopreservation procedure. OBJECTIVE: We aimed to analyze the outcomes of patients who received cryo-HPCs during the COVID-19 pandemic and compare this against historical cohorts that received fresh HPC. STUDY DESIGN: A retrospective chart review was conducted on all adult patients who received a peripheral blood alloHSCT in British Columbia, Canada between June 2017 and November 2021. Baseline characteristics, Kaplan-Meier (KM) overall survival (OS), engraftment, and incidences of acute and chronic graft versus host disease were compared between patients who received cryo-HPCs and fresh HPCs. Univariable analysis followed by multivariable analysis was performed using a backward stepwise selection procedure to generate predictors of OS, cumulative incidence of relapse (CIR), nonrelapse mortality (NRM), and primary and secondary graft failure. RESULTS: Three hundred eighty-three patients were included in the analysis, with cryo-HPC representing 40%. Median viability was higher in the fresh-HPC group at 99.2% (IQR 98.3-99.5) versus cryo-HPCs at 97.0% (96.0, 98.6) (P < 0.01). The 12-month actuarial survivals were 77% in the fresh HPC and 75% in the cryo-HPC groups (P = 0.21). There were no differences between cryo-HPCs and fresh HPCs on univariable analysis of OS, CIR, or NRM. There was a shorter median time to platelet engraftment in patients receiving fresh HPC at 17 days (IQR 16, 20) versus cryo-HPC at 21 days (IQR 18, 29), P < 0.001. There was a shorter median time to neutrophil engraftment in the fresh HPC group at 17 days (IQR 14, 20) versus 20 days (17, 23), P < 0.001. Cryo-HPC accounted for 5 out of 6 cases of primary graft failure (P = 0.04), and 3 out of five cases of secondary graft failure (P = 0.39). There were no significant differences in acute GVHD between the fresh HPC and cryo-HPC groups (P = 0.34). The incidence of moderate or severe chronic GVHD was 32% in the fresh-HPC group and 17% in the cryo-HPC group (P < 0.001). In multivariable analysis, cryopreservation did not emerge as an independent predictor of OS, CIR, NRM, primary GF or secondary GF. However, viability <90% on arrival at our center was a significant predictor of OS (HR 5.3, 2.3-12.3, P < 0.01), primary graft failure (OR 36.3, 5.4-210.2, P < 0.01), and secondary graft failure (OR 18.4, 1.7-121.1, P < 0.01). CONCLUSIONS: Patients who received cryo-HPCs had similar OS and relapse rates to those who received fresh-HPCs but typically took 2-3 days longer to achieve engraftment of platelets or neutrophils and were associated increased primary graft failure. However, after accounting for multiple variables, cryopreservation was no longer a significant predictor of survival or engraftment while viability <90% emerged as an important predictor of OS, primary graft failure, and secondary graft failure. If confirmed, this suggests that viability on arrival at the infusion center may be a good quality control indicator used to identify HPC products that may warrant recollection if the risk of graft failure is sufficiently increased.

VEXAS syndrome: A review of bone marrow aspirate and biopsies reporting myeloid and erythroid precursor vacuolation.

Myeloid and erythroid precursor vacuolation is a common dysplastic finding associated with myeloid malignancies, toxins, drug, and nutritional deficiencies. It has been described as a core morphologic feature in VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome. We sought to determine the number of cases attributable to VEXAS syndrome in bone marrow biopsies and aspirates (BAMB) reporting myeloid precursor vacuolation. We reviewed 1318 individual BAMB reports from January 2020 to July 2021 where "vacuole(s)," "vacuolation," or "vacuolated" was reported. Bone marrow biopsies with vacuolation confined to blasts or those completed as routine workup prior to stem cell transplant or post induction chemotherapy for AML (acute myeloid leukemia) were excluded. Myeloid and erythroid precursor vacuolation was noted in 219 reports representing 210 patients. The most common etiology was myelodysplastic syndrome (MDS) (38.6%), AML (16.7%), lymphoproliferative disorders and multiple myeloma (7.6%), drug or toxin exposure (5.2%) myeloproliferative neoplasm (MPN) or MPN/MDS overlap syndrome (4.3%). VEXAS syndrome was determined to be the etiology in 2.9% of patients. Two additional cases of VEXAS syndrome with bone marrow biopsies reported in the specified time frame did not explicitly report myeloid or erythroid precursor vacuolation but were identified based on clinical suspicion and repeat BAMB review. Myeloid and erythroid precursor vacuolation is a dysplastic feature attributable to VEXAS syndrome in at least 2.9% of cases. Standardized reporting of vacuolization, triaging of molecular sequencing and optimal treatment of this disorder are critical issues facing those seeing patients with suspected VEXAS syndrome.

A young woman with persistent sore throat, Epstein-Barr virus, lymphadenopathy, and aberrant CD4 + CD7- T-cells.

A young woman with persistent EBV viremia and lymphocytosis had an abnormal CD4- T cell population with aberrant loss of CD7. She had a diagnosis of chronic active EBV (CAEBV), a lymphoproliferative disorder for which she ultimately required allogeneic hematopoietic stem cell transplantation.

Management of Acute Myeloid Leukemia: A Review for General Practitioners in Oncology.

Acute myeloid leukemia (AML) is a hematologic malignancy that most frequently develops in older adults. Overall, AML is associated with a high mortality although advancements in genetic risk stratification and new treatments are leading to improvements in outcomes for some subgroups. In this review, we discuss an individualized approach to intensive therapy with a focus on the role of recently approved novel therapies as well as the selection of post-remission therapies for patients in first remission. We discuss the management of patients with relapsed and refractory AML, including the role of targeted treatment and allogeneic stem cell transplant. Next, we review non-intensive treatment for older and unfit AML patients including the use of azacitidine and venetoclax. Finally, we discuss the integration of palliative care in the management of patients with AML.

Germline CHEK2 and ATM Variants in Myeloid and Other Hematopoietic Malignancies.

PURPOSE OF REVIEW: An intact DNA damage response is crucial to preventing cancer development, including in myeloid and lymphoid malignancies. Deficiencies in the homologous recombination (HR) pathway can lead to defective DNA damage responses, and this can occur through inherited germline mutations in HR pathway genes, such as CHEK2 and ATM. We now understand that germline mutations can be identified frequently (~ 5-10%) in patients with myeloid and lymphoid malignancies, and among the most common of these are CHEK2 and ATM. We review the role that deleterious germline CHEK2 and ATM variants play in the development of hematopoietic malignancies, and how this influences clinical practice, including cancer screening, hematopoietic stem cell transplantation, and therapy choice. RECENT FINDINGS: In recent large cohorts of patients diagnosed with myeloid or lymphoid malignancies, deleterious germline loss of function variants in CHEK2 and ATM are among the most common identified. Germline CHEK2 variants predispose to a range of myeloid malignancies, most prominently myeloproliferative neoplasms and myelodysplastic syndromes (odds ratio range: 2.1-12.3), and chronic lymphocytic leukemia (odds ratio 14.83). Deleterious germline ATM variants have been shown to predispose to chronic lymphocytic leukemia (odds ratio range: 1.7-10.1), although additional studies are needed to demonstrate the risk they confer for myeloid malignancies. Early studies suggest there may also be associations between deleterious germline CHEK2 and ATM variants and development of clonal hematopoiesis. Identifying CHEK2 and ATM variants is crucial for the optimal management of patients and families affected by hematopoietic malignancies. OPENING CLINICAL CASE: "A 45 year-old woman presents to your clinic with a history of triple-negative breast cancer diagnosed five years ago, treated with surgery, radiation, and chemotherapy. About six months ago, she developed cervical lymphadenopathy, and a biopsy demonstrated small lymphocytic leukemia. Peripheral blood shows a small population of lymphocytes with a chronic lymphocytic leukemia immunophenotype, and FISH demonstrates a complex karyotype: gain of one to two copies of IGH and FGFR3; gain of two copies of CDKN2C at 1p32.3; gain of two copies of CKS1B at 1q21; tetrasomy for chromosome 3; trisomy and tetrasomy for chromosome 7; tetrasomy for chromosome 9; tetrasomy for chromosome 12; gain of one to two copies of ATM at 11q22.3; deletion of chromosome 13 deletion positive; gain of one to two copies of TP53 at 17p13.1). Given her history of two cancers, you arrange for germline genetic testing using DNA from cultured skin fibroblasts, which demonstrates pathogenic variants in ATM [c.1898 + 2 T > G] and CHEK2 [p.T367Metfs]. Her family history is significant for multiple cancers. (Fig. 1)." Fig. 1 Representative pedigree from a patient with germline pathogenic ATM and CHEK2 variants who was affected by early onset breast cancer and chronic lymphocytic leukemia. Arrow indicates proband. Colors indicate cancer type/disease: purple, breast cancer; blue, lymphoma; brown, melanoma; yellow, colon cancer; and green, autoimmune disease.

Tumor Infiltrating Lymphocytes Predict Survival in Solid Organ Transplant Recipients With Monomorphic Post-transplant Lymphoproliferative Disorders.

INTRODUCTION: The tumor microenvironment (TME) in post-transplant lymphoproliferative disorders (PTLDs) remains unexplored. Tumor infiltrating lymphocytes (TILs) are prognostic in other lymphomas. We assessed the prognostic impact of TILs in monomorphic B-cell PTLD. METHODS: TIL density (CD3+ cells/mm2) was determined by CD3 immunohistochemistry in archived diagnostic biopsies from patients diagnosed with monomorphic B-cell PTLD. RESULTS: Amongst monomorphic PTLDs (N = 107), low TIL-count was associated with inferior 2-year progression-free survival (PFS) (41% versus 86%, P = .003) and 2-year overall survival (OS) (52% versus 93%, P = .003) by Kaplan-Meier analysis. Low TIL-count was significant on Cox univariate regression for inferior PFS (HR 4.5, 95% CI 2.0-9.9, P < .001) and OS (HR 4.6, 95% CI 1.8-11.8, P < .001). Multivariate analysis with clinical variables (age ≥60 years, high LDH, stage III/IV, CNS involvement) and TIL-count showed significance for PFS (HR 3.3, 95% CI 1.3-8.3, P = .010) and a non-significant trend for OS (HR 2.6, 95% CI 0.9-7.3, P = .064). A composite score including TILs and clinical variables (age ≥60 years, high LDH, stage III/IV, CNS involvement) effectively stratified monomorphic PTLD patients by PFS and OS (2-year OS: low-risk 93%, intermediate-risk 61%, high-risk 23%, P < .001). CONCLUSIONS: The TME and TILs are prognostically relevant in monomorphic PTLD. Prognostic models including measures of the TME may improve risk stratification for patients with monomorphic PTLDs.

Inflammation and myeloid malignancy: quenching the flame.

Chronic inflammation with aging ("inflammaging") plays a prominent role in the pathogenesis of myeloid malignancies. Aberrant inflammatory activity affects many different cells in the marrow, including normal blood and stromal marrow elements and leukemic cells, in unique and distinct ways. Inflammation can promote selective clonal expansion through differential immune-mediated suppression of normal hematopoietic cells and malignant clones. We review these complex roles, how they can be understood by separating cell-intrinsic from extrinsic effects, and how this informs future clinical trials.

Incidence and socioeconomic factors in older adults with acute myeloid leukaemia: Real-world outcomes from a population-based cohort.

OBJECTIVES: Acute myeloid leukaemia (AML) is a disease of older adults, who are vulnerable to socio-economic factors. We determined AML incidence in older adults and the impact of socio-economic factors on outcomes. METHODS: We included 3024 AML patients (1996-2016) identified from a population-based registry. RESULTS: AML incidence in patients ≥60 years increased from 11.01 (2001-2005) to 12.76 (2011-2016) per 100 000 population. Among 879 patients ≥60 years in recent eras (2010-2016), rural residents (<100 000 population) were less likely to be assessed by a leukaemia specialist (39% rural, 47% urban, p = .032); no difference was seen for lower (43%, quintile 1-3) vs. higher (47%, quintile 4-5) incomes (p = .235). Similar numbers received induction chemotherapy between residence (16% rural, 18% urban, p = .578) and incomes (17% lower, 17% high, p = 1.0). Differences between incomes were seen for hypomethylating agent treatment (14% low, 20% high, p = .041); this was not seen for residence (13% rural, 18% urban, p = .092). Among non-adverse karyotype patients ≥70 years, 2-year overall survival was worse for rural (5% rural, 12% urban, p = .006) and lower income (6% low, 15% high, p = .017) patients. CONCLUSIONS: AML incidence in older adults is increasing, and outcomes are worse for older rural and low-income residents; these patients face treatment barriers.

Differentiation therapy for myeloid malignancies: beyond cytotoxicity.

Blocked cellular differentiation is a central pathologic feature of the myeloid malignancies, myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). Treatment regimens promoting differentiation have resulted in incredible cure rates in certain AML subtypes, such as acute promyelocytic leukemia. Over the past several years, we have seen many new therapies for MDS/AML enter clinical practice, including epigenetic therapies (e.g., 5-azacitidine), isocitrate dehydrogenase (IDH) inhibitors, fms-like kinase 3 (FLT3) inhibitors, and lenalidomide for deletion 5q (del5q) MDS. Despite not being developed with the intent of manipulating differentiation, induction of differentiation is a major mechanism by which several of these novel agents function. In this review, we examine the new therapeutic landscape for these diseases, focusing on the role of hematopoietic differentiation and the impact of inflammation and aging. We review how current therapies in MDS/AML promote differentiation as a part of their therapeutic effect, and the cellular mechanisms by which this occurs. We then outline potential novel avenues to achieve differentiation in the myeloid malignancies for therapeutic purposes. This emerging body of knowledge about the importance of relieving differentiation blockade with anti-neoplastic therapies is important to understand how current novel agents function and may open avenues to developing new treatments that explicitly target cellular differentiation. Moving beyond cytotoxic agents has the potential to open new and unexpected avenues in the treatment of myeloid malignancies, hopefully providing more efficacy with reduced toxicity.

Mitochondrial metabolism: powering new directions in acute myeloid leukemia.

There has been an explosion of knowledge about the role of metabolism and the mitochondria in acute myeloid leukemia (AML). We have also recently seen several waves of novel therapies change the treatment landscape for AML, such as the selective B-cell lymphoma 2 (BCL-2) inhibitor venetoclax. In this new context, we review the rapidly advancing literature on the role of metabolism and the mitochondria in AML pathogenesis, and how these are interwoven with the mechanisms of action for novel therapeutics in AML. We also review the role of oxidative phosphorylation (OxPhos) in maintaining leukemia stem cells (LSCs), how recurrent genomic alterations in AML alter downstream metabolism, and focus on how the BCL-2 pathway and the mitochondria are inextricably linked in AML. Thus, we provide an overview of the mitochondria and metabolism in the context of our new therapeutic world for AML and outline how targeting these vulnerabilities may produce novel therapeutic strategies.

A clinical transcriptome approach to patient stratification and therapy selection in acute myeloid leukemia.

As more clinically-relevant genomic features of myeloid malignancies are revealed, it has become clear that targeted clinical genetic testing is inadequate for risk stratification. Here, we develop and validate a clinical transcriptome-based assay for stratification of acute myeloid leukemia (AML). Comparison of ribonucleic acid sequencing (RNA-Seq) to whole genome and exome sequencing reveals that a standalone RNA-Seq assay offers the greatest diagnostic return, enabling identification of expressed gene fusions, single nucleotide and short insertion/deletion variants, and whole-transcriptome expression information. Expression data from 154 AML patients are used to develop a novel AML prognostic score, which is strongly associated with patient outcomes across 620 patients from three independent cohorts, and 42 patients from a prospective cohort. When combined with molecular risk guidelines, the risk score allows for the re-stratification of 22.1 to 25.3% of AML patients from three independent cohorts into correct risk groups. Within the adverse-risk subgroup, we identify a subset of patients characterized by dysregulated integrin signaling and RUNX1 or TP53 mutation. We show that these patients may benefit from therapy with inhibitors of focal adhesion kinase, encoded by PTK2, demonstrating additional utility of transcriptome-based testing for therapy selection in myeloid malignancy.

Classic Hodgkin lymphoma post-transplant lymphoproliferative disorders (PTLD) are often preceded by discordant PTLD subtypes.

Classic Hodgkin lymphoma (CHL) is the rarest post-transplant lymphoproliferative disorder (PTLD) subtype. Few cases of patients with metachronous discordant PTLD episodes including CHL-PTLD have been reported, but the incidence of and risk factors for this phenomenon are unknown. Patients with CHL-PTLD were identified from an institutional PTLD database. Of 13 patients identified with CHL-PTLD six (46%) had antecedent non-CHL-PTLD: three had polymorphic PTLD, two monomorphic PTLD, and one nondestructive PTLD. Patients with prior metachronous non-CHL-PTLD were younger at transplant and had a longer latency time to CHL-PTLD post-transplant. The prevalence of EBV seronegativity at transplant was high in both groups, but prolonged high-level EBV DNAemia only occurred in some with metachronous non-CHL-PTLD. In conclusion, patients with CHL-PTLD have metachronous non-CHL-PTLD diagnoses with discordant histology more commonly than previously recognized. Primary EBV infection with chronically elevated EBV viral loads may represent unique risk factors for CHL-PTLD following an initial non-CHL-PTLD event.

Failure of rituximab is associated with a poor outcome in diffuse large B cell lymphoma-type post-transplant lymphoproliferative disorder.

Post-transplant lymphoproliferative disorder (PTLD) may arise after solid organ transplantation, and the most common subtype resembles diffuse large B cell lymphoma (DLBCL). In DLBCL-type PTLD, the anti-CD20 antibody rituximab (R) may be combined with chemotherapy (R-CHOP) or use a strategy (R-primary; similar to the PTLD-1 clinical trial) consisting of induction with four weekly doses of R-alone, without any chemotherapy or sequential R-CHOP follow-up. Here we report on a multicentre retrospective cohort of solid organ transplant patients with DLBCL-type PTLD that were treated with R. In 168 adults, two-year overall survival (OS) was 63·7% [95% CI (confidence interval) 56·6-71·7%]. No difference in OS was observed, whether patients were treated with R-CHOP versus the R-primary strategy. In the 109 patients treated with R-primary, multivariate analysis found that baseline IPI score and the response to R-induction predicted OS. Patients who responded to R-induction had durable remissions without the addition of chemotherapy. Conversely, of the 46 patients who had stable or progressive disease after R-induction (R-failure), those who received R-CHOP had an only marginally improved outcome, with a two-year OS of 45% (23·1-65·3%) vs. no R-CHOP at 32% (14·7-49·8%). In real-world patients, R-failure and high IPI scores predict a poor outcome in DLBCL-type PTLD.

Epstein-Barr virus associated smooth muscle tumors in solid organ transplant recipients: Incidence over 31 years at a single institution and review of the literature.

INTRODUCTION: Epstein-Barr virus (EBV) associated smooth muscle tumors (EBV-SMT) are a rare complication of solid organ transplantation (SOT). Incidence data related to this EBV-SMT are limited. EBV DNA is universally present in these tumors. How these cells get infected with EBV, whether this is a result of primary EBV infection vs reactivation, and how persistent active EBV infection post-transplant influences EBV-SMT pathogenesis remains unknown. METHODS: Among 5006 SOT recipients (474 pediatric, 4532 adult) receiving SOT at our center between Jan 1984 and Dec 2015, three cases of post-transplant EBV-SMT were identified. RESULTS: All cases were pediatric heart transplants who were EBV seronegative prior to transplant, and experienced primary EBV infection with persistently elevated EBV viral loads, despite antiviral therapy. Two are deceased at 3.2 and 0.9 years post-diagnosis, while one remains alive 6.2 years post diagnosis. The overall local incidence of post-transplant EBV-SMT at our institution was 0.7 (95% CI, 0.2-1.7) per 1000 patient years, and 2.6 (95% CI, 0.6-6.7) per 1000 patient years in pediatric heart transplants. A literature review identified 36 pediatric and 51 adult cases of post-transplant EBV-SMT. CONCLUSIONS: We hypothesize that pre-transplant EBV seronegativity, followed by primary EBV infection and persistently high EBV viral loads, represents a unique risk factor for post-transplant EBV-SMT. Pediatric heart transplant recipients were found to be disproportionately affected by post-transplant EBV-SMT at our institution.