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Allogeneic hematopoietic cell transplantation (alloHCT) is indicated for patients with intermediate-risk or high-risk myelofibrosis (MF) and remains the sole potential cure. Reduced-intensity conditioning (RIC) is commonly used because of older patient age, comorbidities, and a high incidence of transplantation-related mortality. Patients with MF are at increased risk of graft failure (GF), which is more common with RIC regimens, and is associated with shortened overall survival (OS). Owing to the high rate of GF with conventional fludarabine (Flu) and busulfan (Bu) RIC, we added low-dose total body irradiation (TBI; 200 cGy) for patients with MF. We retrospectively compared alloHCT outcomes in adult patients with MF who received RIC with Flu/Bu/TBI and those who received RIC with Flu/Bu. The primary endpoint was the incidence of GF. Secondary endpoints included time to engraftment, acute and chronic graft-versus-host disease (GVHD), hepatic sinusoidal obstruction syndrome (SOS), nonrelapse mortality, overall response rate, progression-free survival, and OS. Of 33 patients who underwent alloHCT, 8 received Flu/Bu RIC and 25 received Flu/Bu/TBI RIC. GF occurred in 50% of the Flu/Bu recipients (all secondary GF) and in 4% of the Flu/Bu/TBI recipients (1 case of primary GF; relative risk, .08; 95% confidence interval [CI], .01 to .62; P = .0016). GF incidence was similar with related or unrelated donors and in patients who did and did not receive Janus-associated kinase inhibitors prior to alloHCT. Molecular remission and donor chimerism ≥99% were significantly more common with Flu/Bu/TBI. No significant differences in acute GVHD, chronic GVHD, or time to engraftment were observed. SOS occurred in none of the 8 patients who received Flu/Bu and in 6 of the 25 patients who received Flu/Bu/TBI, but this difference did not reach statistical significance. Progression or relapse at 1 year was less common with Flu/Bu/TBI (0% versus 63%; P.001). The median OS was 49 months for Flu/Bu/TBI recipients and 30.8 months for Flu/Bu recipients (hazard ratio, .98; 95% CI, .33 to 2.88; P = .97). Flu/Bu/TBI resulted in a significant reduction in GF and a significant improvement in the frequency of molecular remission and full donor chimerism compared with Flu/Bu. The addition of low-dose TBI to Flu/Bu successfully mitigates against GF in patients with MF without increased rates of complications.

CPX-351 and venetoclax and azacitidine (ven/aza) are both indicated as initial therapy for acute myeloid leukemia (AML) in older adults. In the absence of prospective randomized comparisons of these regimens, we used retrospective observational data to evaluate various outcomes for patients with newly diagnosed AML receiving either CPX-351 (n = 217) or ven/aza (n = 439). This study used both a nationwide electronic health record (EHR)-derived de-identified database and the University of Pennsylvania EHR. Our study includes 217 patients who received CPX-351 and 439 who received ven/aza. Paitents receiving ven/aza were older, more likely to be treated in the community, and more likely to have a diagnosis of de novo acute myeloid leukemia. Other baseline covariates were not statistically significantly different between the groups. Median overall survival (OS) for all patients was 12 months and did not differ based on therapy (13 months for CPX-351 vs 11 months for ven/aza; hazard ratio, 0.88; 95% confidence interval, 0.71-1.08; P = .22). OS was similar across multiple sensitivity analyses. Regarding safety outcomes, early mortality was similar (10% vs 13% at 60 days). However, documented infections were higher with CPX-351 as were rates of febrile neutropenia. Hospital length of stay, including any admission before the next cycle of therapy, was more than twice as long for CPX-351. In this large multicenter real-world dataset, there was no statistically significant difference in OS. Prospective randomized studies with careful attention to side effects, quality of life, and impact on transplant outcomes are needed in these populations.

Limited treatment options exist for patients with relapsed/refractory (R/R) acute myeloid leukemia (AML). Venetoclax (VEN) in combination with a hypomethylating agent (HMA) or low-dose cytarabine (LDAC) has been recently approved for treatment-naïve patients unfit for intensive induction. Limited data are available to characterize the efficacy of VEN combinations in R/R AML. We retrospectively analyzed 77 patients with a median of 1 prior therapy (range 0-5) treated with VEN combinations for R/R AML or AML secondary to myelodysplastic syndrome (MDS) progressing after HMA monotherapy. The median overall survival (OS) was 13.1 months (95% CI 9.2-15.1). The median progression-free survival (PFS) was 12 months (95% CI 8.2-15.4) with a median duration of response of 8.9 months (95% CI 5.7-13.9). Overall response rate (ORR) was 68% with a composite complete response (CR) and CR with incomplete hematologic recovery (CRi) rate of 53%. VEN combination therapy is efficacious in R/R AML and further prospective studies are warranted.

Introduction Granulocyte colony-stimulating factor (G-CSF) hastens neutrophil engraftment and reduces infections after allogeneic hematopoietic cell transplant (alloHCT), yet the optimal start date is unknown. Additionally, concurrent G-CSF and methotrexate for graft-vs-host disease (GVHD) prophylaxis may potentiate myelosuppression, and prolonged G-CSF is costly. Our institution changed from day + 4 to day + 12 G-CSF initiation following reduced intensity (RIC) alloHCT with methotrexate GVHD prophylaxis. Methods We retrospectively compared day + 4 and day + 12 G-CSF initiation after RIC alloHCT from 2017–2021. The primary endpoint was the time to neutrophil engraftment. Secondary endpoints included length of stay (LOS) and the time to platelet engraftment as well as the incidence of infectious events, acute GVHD (aGVHD), and mucositis. Results Thirty-two patients were included in each group with similar baseline characteristics. We observed faster neutrophil engraftment (median 12 vs. 15 days, p = 0.01) and platelet engraftment (median 13 vs. 15 days, p = 0.026) with day + 4 vs. day + 12 G-CSF initiation. Median LOS was 23 days (range, 19–32) with day + 4 initiation vs. 24 days (21–30) with day + 12 (p = 0.046). The incidence of culture-negative febrile neutropenia (p = 0.12), any grade aGVHD (p = 0.58), and grade 2-4 mucositis (p = 0.8) were similar between groups. Conclusion Compared to day + 4, day + 12 G-CSF initiation following RIC alloHCT had a longer time to neutrophil and platelet engraftment. Day + 12 initiation also resulted in longer LOS, which while statistically significant, was potentially of limited clinical significance. These findings are hypothesis generating.

Key Points Induction of Sbds deficiency in recipient BM niche cells impairs efficient engraftment of healthy donor HSC after transplantation.SBDS deficiency impairs multiple cellular signaling pathways in post-myeloablation marrow niches critical for restoration of hematopoiesis., Visual Abstract, Bone marrow (BM) niche-derived signals are critical for facilitating engraftment after hematopoietic stem cell (HSC) transplantation (HSCT). HSCT is required for restoration of hematopoiesis in patients with inherited BM failure syndromes (iBMFSs). Shwachman-Diamond syndrome (SDS) is a rare iBMFS associated with mutations in SBDS. Previous studies have demonstrated that SBDS deficiency in osteolineage niche cells causes BM dysfunction that promotes leukemia development. However, it is unknown whether BM niche defects caused by SBDS deficiency also impair efficient engraftment of healthy donor HSC after HSCT, a hypothesis that could explain morbidity noted after clinical HSCT for patients with SDS. Here, we report a mouse model with inducible Sbds deletion in hematopoietic and osteolineage cells. Primary and secondary BM transplantation (BMT) studies demonstrated that SBDS deficiency within BM niches caused poor donor hematopoietic recovery and specifically poor HSC engraftment after myeloablative BMT. We have also identified multiple molecular and cellular defects within niche populations that are driven by SBDS deficiency and are accentuated by or develop specifically after myeloablative conditioning. These abnormalities include altered frequencies of multiple niche cell subsets, including mesenchymal lineage cells, macrophages, and endothelial cells; disruption of growth factor signaling, chemokine pathway activation, and adhesion molecule expression; and p53 pathway activation and signals involved in cell cycle arrest. Taken together, this study demonstrates that SBDS deficiency profoundly impacts recipient hematopoietic niche function in the setting of HSCT, suggesting that novel therapeutic strategies targeting host niches could improve clinical HSCT outcomes for patients with SDS.

Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired blood disease caused by somatic mutations in the phosphatidylinositol glycan class A (PIGA) gene required to produce glycophosphatidyl inositol (GPI) anchors. Although PNH cells are readily identified by flow cytometry due to their deficiency of GPI-anchored proteins, the assessment of the clinical significance of a PNH clone is more nuanced. The interpretation of results requires an understanding of PNH pathogenesis and its relationship to immune-mediated bone marrow failure. Only about one-third of patients with PNH clones have classical PNH disease with overt hemolysis, its associated symptoms, and the highly prothrombotic state characteristic of PNH. Patients with classical PNH benefit the most from complement inhibitors. In contrast, two-thirds of PNH clones occur in patients whose clinical presentation is that of bone marrow failure with few, if any, PNH-related symptoms. The clinical presentations are closely associated with PNH clone size. Although exceptions occur, bone marrow failure patients usually have smaller, subclinical PNH clones. This review addresses the common scenarios that arise in evaluating the clinical significance of PNH clones and provides practical guidelines for approaching a patient with a positive PNH result.

Advances in genomic diagnostics hold promise for improved care of rare hematologic diseases. Here, we describe a novel targeted therapeutic approach for Ghosal hematodiaphyseal dysplasia, an autosomal recessive disease characterized by severe normocytic anemia and bone abnormalities due to loss-of-function mutations in thromboxane A synthase 1 (TBXAS1). TBXAS1 metabolizes prostaglandin H2 (PGH2), a cyclooxygenase (COX) product of arachidonic acid, into thromboxane A2. Loss-of-function mutations in TBXAS result in an increase in PGH2 availability for other PG synthases. The current treatment for Ghosal hematodiaphyseal dysplasia syndrome consists of corticosteroids. We hypothesize that nonsteroidal anti-inflammatory drugs (NSAIDs), which inhibit COX-1 and COX-2, could ameliorate the effects of TBXAS1 loss and improve hematologic function by reducing prostaglandin formation. We treated 2 patients with Ghosal hematodiaphyseal dysplasia syndrome, an adult and a child, with standard doses of NSAIDs (aspirin or ibuprofen). Both patients had rapid improvements concerning hematologic parameters and inflammatory markers without adverse events. Mass spectrometry analysis demonstrated that urinary PG metabolites were increased along with proinflammatory lipoxygenase (LOX) products 5-hydroxyeicosatetraenoic acid and leukotriene E4. Our data show that NSAIDs at standard doses surprisingly reduced both COX and LOX products, leading to the resolution of cytopenia, and should be considered for first-line treatment for Ghosal hematodiaphyseal dysplasia syndrome.

Acquired aplastic anemia (AA) is a life-threatening bone marrow aplasia caused by the autoimmune destruction of hematopoietic stem and progenitor cells. There are no existing diagnostic tests that definitively establish AA, and diagnosis is currently made via systematic exclusion of various alternative etiologies, including inherited bone marrow failure syndromes (IBMFSs). The exclusion of IBMFSs, which requires syndrome-specific functional and genetic testing, can substantially delay treatment. AA and IBMFSs can have mimicking clinical presentations, and their distinction has significant implications for treatment and family planning, making accurate and prompt diagnosis imperative to optimal patient outcomes. We hypothesized that AA could be distinguished from IBMFSs using 3 laboratory findings specific to the autoimmune pathogenesis of AA: paroxysmal nocturnal hemoglobinuria (PNH) clones, copy-number–neutral loss of heterozygosity in chromosome arm 6p (6p CN-LOH), and clonal T-cell receptor (TCR) γ gene (TRG) rearrangement. To test our hypothesis, we determined the prevalence of PNH, acquired 6p CN-LOH, and clonal TRG rearrangement in 454 consecutive pediatric and adult patients diagnosed with AA, IBMFSs, and other hematologic diseases. Our results indicated that PNH and acquired 6p CN-LOH clones encompassing HLA genes have ∽100% positive predictive value for AA, and they can facilitate diagnosis in approximately one-half of AA patients. In contrast, clonal TRG rearrangement is not specific for AA. Our analysis demonstrates that PNH and 6p CN-LOH clones effectively distinguish AA from IBMFSs, and both measures should be incorporated early in the diagnostic evaluation of suspected AA using the included Bayesian nomogram to inform clinical application.

Germline mutations in tubulin beta class I (TUBB), which encodes one of the β-tubulin isoforms, were previously associated with neurological and cutaneous abnormalities. Here, we describe the first case of inherited bone marrow (BM) failure, including marked thrombocytopenia, morphological abnormalities, and cortical dysplasia, associated with a de novo p.D249V variant in TUBB. Mutant TUBB had abnormal cellular localisation in transfected cells. Following interferon/ribavirin therapy administered for transfusion-acquired hepatitis C, severe pancytopenia and BM aplasia ensued, which was unresponsive to immunosuppression. Acquired chromosome arm 6p loss of heterozygosity was identified, leading to somatic loss of the mutant TUBB allele.

Inherited bone marrow failure (IBMF) syndromes are rare blood disorders characterized by hematopoietic cell dysfunction and predisposition to hematologic malignancies. Despite advances in the understanding of molecular pathogenesis of these heterogeneous diseases, genetic variant interpretation, genotype–phenotype correlation, and outcome prognostication remain difficult. As new IBMF and other myelodysplastic syndrome (MDS) predisposition genes continue to be discovered (frequently in small kindred studies), there is an increasing need for a systematic framework to evaluate penetrance and prevalence of mutations in genes associated with IBMF phenotypes. To address this need, we analyzed population-based genomic data from >125 000 individuals in the Genome Aggregation Database for loss-of-function (LoF) variants in 100 genes associated with IBMF. LoF variants in genes associated with IBMF/MDS were present in 0.426% of individuals. Heterozygous LoF variants in genes in which haploinsufficiency is associated with IBMF/MDS were identified in 0.422% of the population; homozygous LoF variants associated with autosomal recessive IBMF/MDS diseases were identified in only .004% of the cohort. Using age distribution of LoF variants and 2 measures of mutational constraint, LOEUF (“loss-of-function observed/expected upper bound fraction”) and pLI (“probability of being loss-of-function intolerance”), we evaluated the pathogenicity, tolerance, and age-related penetrance of LoF mutations in specific genes associated with IBMF syndromes. This analysis led to insights into rare IBMF diseases, including syndromes associated with DHX34, MDM4, RAD51, SRP54, and WIPF1. Our results provide an important population-based framework for the interpretation of LoF variant pathogenicity in rare and emerging IBMF syndromes.

Germline mutations in the shelterin component protection of telomeres 1 (POT1) were recently found to be associated with familial chronic lymphocytic leukemia (CLL), melanoma, glioma, and several other familial cancer syndromes. The role of POT1 mutations in myeloid neoplasms and other hematologic malignancies, however, remains unknown. To explore the role of POT1 variants in hematologic neoplasms, we analyzed POT1 variants in 3323 consecutive patients who underwent next-generation sequencing (NGS) of a panel of hematologic malignancy-associated genes at our institution and characterized the clinical and pathological characteristics of patients with germline and somatic POT1 mutations. Of 3323 consecutive patients who underwent NGS, 2770 patients had a hematologic malignancy (lymphoid n = 1299, myeloid n = 934, and both lymphoid and myeloid n = 537), while 553 patients were evaluated for non-malignant cytopenias. All 57 patients (2.06%) carrying either a POT1 disease-associated variant or variant of uncertain significance had a hematologic malignancy compared to no identified POT1 variants in 553 patients with benign cytopenias (OR = 23.5, p < 0.001), suggesting that the presence of POT1 variants was predictive of a hematologic malignancy. Of 57 patients, 33 had lymphoid malignancies, 23 had myeloid neoplasms, and 2 had a lymphoid and myeloid neoplasm (Fig 1). Patient variants were classified as germline or somatic using constitutional DNA sequencing, POT1 emergence/disappearance over time, or POT1 maintenance in remission. In the absence of these data, likely germline or likely somatic designations were made by assessing variant allele frequencies against clinical/pathologic characteristics. 18 patients (33%) were found to have germline or likely germline POT1 variants (29% and 42% in the lymphoid and myeloid malignancy groups, respectively). Another 6 patients (11%) had variants whose germline status could not be determined. Of the 17 unique germline POT1 variants, 10 were missense and located within mapped functional protein domains, while 7 were classified as predicted loss-of-function (pLOF) due to a disruption of start, premature stop, frameshift, or spice site alteration. Patients with hematological malignancies had a ~5-8x increased odds of having a germline pLOF POT1 variant compared to cancer-free individuals in the Genome Aggregation Database (gnomAD, n = 113,108 exomes, OR = 7.5, p < 0.001) or in the Penn Medicine BioBank (PMBB, n = 7877, OR = 5.0, p = 0.010), with a prevalence of 0.25% compared to 0.03% and 0.05%, respectively. Germline pLOF POT1 variants were significantly more enriched in patients with myeloid (gnomAD: OR = 6.1, p = 0.02) and lymphoid (gnomAD: OR = 9.8, p < 0.001; PMBB: OR = 6.5, p = 0.004) malignancies. In 33 patients with lymphoid malignancies and POT1 variants, the most common diagnoses were CLL/SLL (n = 21, germline n = 6, somatic n = 12), CD5- CD10- indolent B cell neoplasms (n = 4, germline n = 1, somatic n = 3), and multiple myeloma (n = 3, all somatic) (Table 1). Lymphoid malignancies with a germline POT1 variant had a relative paucity of additional mutations; in contrast, somatic POT1 variants frequently co-occurred with other mutations, most commonly with TP53 (Fig 2, n = 5, 23%). Among 23 patients with myeloid malignancies, patients with germline POT1 variants developed malignancies at a significantly younger age compared to those whose POT1 variants were somatic (median age 59.5 vs 70.5 years, p = 0.04). The most common diagnosis in patients with myeloid neoplasms carrying germline POT1 variants was MPN (germline n = 5, somatic n = 1). AML, MDS/MPN, and MDS occurred in 4, 3, and 1 patients respectively. All patients with myeloid neoplasms had additional disease-associated mutations, with the most common co-occurring variants in TET2 (n = 7), JAK2 (n = 6, co-occurring with 50% of germline POT1 myeloid variants), and NRAS (n = 6). In conclusion, this is the first comprehensive analysis of POT1 variants in an unselected hospital-based population undergoing molecular testing for variants associated with hematologic malignancies. Our results show that the presence of POT1 variants is predictive of having a hematologic neoplasm and that over 30% of POT1 variants in hematologic malignancy patients are germline. Our study expands the spectrum of POT1-associated familial neoplasms and highlights the needs for better recognition of familial hematologic cancer syndromes. Disclosures No relevant conflicts of interest to declare.

Oropharyngeal mucositis (OPM) is common following conditioning for allogeneic hematopoietic cell transplantation (alloHCT) and results in pain, functional status decline, need for nutritional support, infections, and prolonged length of stay (LOS). Methotrexate (MTX) graft-versus-host disease (GVHD) prophylaxis exacerbates OPM and slows hematopoietic engraftment, which may prolong LOS. Previous studies have demonstrated reduced OPM and more rapid engraftment when leucovorin (LCV) is added following MTX GVHD prophylaxis, yet this practice is controversial. The primary objective of this study was to determine if the routine addition of LCV to MTX GVHD prophylaxis impacted the duration of grade 2 to 4 OPM. Secondary objectives included determination of the incidence of grade 2 to 4 and grade 3 to 4 OPM, time to engraftment, ability to receive all four planned MTX doses, use of total parenteral nutrition (TPN), use of patient-controlled analgesia (PCA), LOS, incidence of acute or chronic GVHD, relapse-free survival (RFS), and overall survival (OS). This single-center, retrospective cohort study compared alloHCT outcomes for 46 adult patients who received MTX 15 mg/m2 day +1; MTX 10 mg/m2 days +3, +6, and +11 (15-10-10-10); and LCV following days +3, +6, and +11 MTX compared to historical controls who did not. Patients who received myeloablative conditioning (MAC) and matched related donor (MRD) or matched unrelated donor (MUD) alloHCT were included. The addition of LCV resulted in significant reductions in the duration of grade 2 to 4 OPM (median, 6 days versus 10.5 days; P = .0004), duration of TPN (7 days versus 16 days; P = .001), PCA use (16% versus 39%; P = .0001), time to neutrophil engraftment (median, 18 versus 20 days; P = .008), and LOS (median, 27.5 versus 31 days; P = .017) compared to historical controls. Patients who received routine LCV had similar incidences of grade 2 to 4 acute GVHD (30% versus 28%; relative risk [RR], 1.08; 95% confidence interval [CI], .57 to 2.03; P = 1.0), grade 3 or 4 acute GVHD (2% versus 7%; RR, .33; 95% CI, .04 to 3.09; P = .62) and chronic GVHD (37% versus 30%; RR, 1.21; 95% CI, .67 to 2.16; P = .66) compared to historical controls. Graft failure occurred in 2% of patients in each group. In a multivariable logistic regression analysis, RFS was similar in the LCV group compared to historical controls (HR, .86; 95% CI, .24 to 1.2; P = .13); however, OS was improved in patients who received LCV (HR, .33; 95% CI, .13 to .83; P = .01). In patients undergoing MAC MRD/MUD alloHCT with four planned doses of MTX GVHD prophylaxis (15-10-10-10), LCV was associated with reduced duration of grade 2 to 4 OPM, faster neutrophil engraftment, reduced utilization of TPN and PCA, and shortened LOS compared to historical controls not receiving routine LCV. These benefits were apparent without an increased risk of acute or chronic GVHD or adverse effect on RFS. LCV improved OS; however, it is unclear if this was due to the intervention or an unmeasured confounder. A randomized, prospective trial of LCV prophylaxis in patients receiving MAC alloHCT and MTX 15-10-10-10 GVHD prophylaxis is warranted to confirm our findings.

Inherited bone marrow failure is caused by mutations in genes that are critical for normal cell development or intrinsic cell function. Because of the protean effects of the mutations, multi-organ involvement is common. Compromised growth and early senescence drive strong selective pressure to acquire oncogenic somatic abnormalities. Thus, testing should be performed on non-hematopoietic cells such as fibroblasts.

Acquired aplastic anemia (AA) is an immune-mediated bone marrow aplasia that is strongly associated with clonal hematopoiesis upon marrow recovery. More than 70% of AA patients develop somatic mutations in their hematopoietic cells. In contrast to other conditions linked to clonal hematopoiesis, such as myelodysplastic syndrome (MDS) or clonal hematopoiesis of indeterminate potential in the elderly, the top alterations in AA are closely related to its immune pathogenesis. Nearly 40% of AA patients carry somatic mutations in the PIGA gene manifested as clonal populations of cells with the paroxysmal nocturnal hemoglobinuria phenotype, and 17% of AA patients have loss of HLA class I alleles. It is estimated that between 20% and 35% of AA patients have somatic mutations associated with hematologic malignancies, most characteristically in the ASXL1, BCOR, and BCORL1 genes. Risk factors for evolution to MDS in AA include the duration of disease, acquisition of high-risk somatic mutations, and age at AA onset. Emerging data suggest that several HLA class I alleles not only predispose to the development of AA but may also predispose to clonal evolution in AA patients. Long-term prospective studies are needed to determine the true prognostic implications of clonal hematopoiesis in AA. This article provides a brief, but comprehensive, review of our current understanding of clonal evolution in AA and concludes with 3 cases that illustrate a practical approach for integrating results of next-generation molecular studies into the clinical care of AA patients in 2018.

BACKGROUND: Clostridium difficile infection (CDI) is a leading cause of infectious complications in allogeneic hematopoietic cell transplant recipients (alloHCT). We sought to evaluate whether prophylactic oral vancomycin reduces the incidence of CDI in alloHCT recipients. METHODS: We conducted a retrospective cohort study to examine the effectiveness of CDI prophylaxis with oral vancomycin, as compared to no prophylaxis, in 145 consecutive adult alloHCT recipients at the University of Pennsylvania between April 2015 and November 2016. Patients received oral vancomycin 125 mg twice daily, starting on admission and continuing until discharge. The primary outcome of interest was the association between oral vancomycin prophylaxis and CDI diagnosis. Secondary outcomes included graft-versus-host disease (GVHD) and relapse. RESULTS: There were no cases of CDI in patients that received prophylaxis (0/90, 0%), whereas 11/55 (20%) patients who did not receive prophylaxis developed CDI (P < .001). Oral vancomycin prophylaxis was not associated with a higher risk of acute, grades 2–4 GVHD (subhazard ratio [sHR] 1.59; 95% confidence interval [CI] 0.88–2.89; P = .12), acute, grades 3–4 GVHD (sHR 0.65; 95% CI 0.25–1.66; P = .36), or acute, grades 2–4 gastrointestinal GVHD (sHR 1.95; 95% CI 0.93–4.07; P = .08) at day 180 post-transplant. No associations between oral vancomycin and relapse or survival were observed. CONCLUSIONS: Prophylaxis with oral vancomycin is highly effective in preventing CDI in alloHCT recipients without increasing the risk of graft-versus-host disease or disease relapse. Further evaluation via a prospective study is warranted.

Steroid-refractory (SR) acute gastrointestinal (GI) graft-versus-host disease (GVHD) is associated with significant mortality in allogeneic hematopoietic cell transplantation recipients. We retrospectively evaluated the efficacy of tocilizumab for the treatment of SR biopsy-proven acute lower GI GVHD in 16 consecutive adult transplant recipients between October 2015 and July 2016. Tocilizumab 8 mg/kg was administered every 2 weeks until achievement of complete response, defined as resolution of all manifestations of GI GVHD, or until patients had progression or initiation of other therapy. Ten of 16 patients (62.5%; 95% CI, 0.39-82) achieved a complete response after a median time of 11 days (range, 2-28 days) from tocilizumab initiation. The median time to response onset (improvement in stage by at least 1) was 1 day (range, 1-4 days). Tocilizumab was administered at a median of 9 days (range, 3-75 days) from GVHD diagnosis and 10 days (range, 3-75 days) from initiation of high-dose steroids. At a median follow-up of 7.6 months (range, 0.8-27.7 months) from initiation of tocilizumab, 6/16 (37.5%) patients are alive and free of their underlying hematologic malignancy. Tocilizumab appears to be a highly active agent for the treatment of severe SR lower GI acute GVHD.

The JAK2 V617F mutation is characteristic of most Philadelphia chromosome-negative myeloproliferative neoplasms (MPNs) and occurs rarely in de novo acute myeloid leukaemia (AML). We sought to characterize AMLs that harbour this mutation and distinguish those that arise de novo (AML-DN) from those that reflect transformation of an underlying MPN (AML-MPN). Forty-five patients with JAK2 V617F-mutated AML were identified; 15 were AML-DN and 30 were AML-MPN. AML-MPN cases were more likely to have splenomegaly (P = 0·02), MPN-like megakaryocytes and higher mean JAK2 V617F VAF at diagnosis (P = 0·04). Mutations involving TET2 were exclusively identified in AML-DN patients. Mutations of genes affecting DNA methylation were more common in AML-DN (P < 0·01). A complex karyotype was more frequent in AML-MPN cases than in AML-DN (P < 0·01), with AML-DN more likely to display a normal karyotype (P = 0·02). Bone marrow histology after recovery from induction chemotherapy in AML-DN cases revealed no morphological evidence of any previously occult MPNs, while this was evident in most of the AML-MPN specimens (P < 0·01). These findings in this largest study of JAK2 V617F-mutated AMLs indicate that AML-DN is distinct from AML-MPN.

Myeloproliferative neoplasms arise from hematopoietic stem cells with somatically altered tyrosine kinase signaling. Classification of myeloproliferative neoplasms is based on hematologic, histopathologic and molecular characteristics including the presence of the BCR-ABL1 and JAK2 V617F. Although thought to be mutually exclusive, a number of cases with co-occurring BCR-ABL1 and JAK2 V617F have been identified. To characterize the clinicopathologic features of myeloproliferative neoplasms with concomitant BCR-ABL1 and JAK2 V617F, and define the frequency of co-occurrence, we conducted a retrospective multi-institutional study. Cases were identified using a search of electronic databases over a decade at six major institutions. Of 1570 patients who were tested for both BCR-ABL1 and JAK2 V617F, six were positive for both. An additional five patients were identified via clinical records providing a total of 11 cases for detailed evaluation. For each case, clinical variables, hematologic and genetic data, and bone marrow histomorphologic features were analyzed. The sequence of identification of the genetic abnormalities varied: five patients were initially diagnosed with a JAK2 V617F+ myeloproliferative neoplasm, one patient initially had BCR-ABL1+ chronic myeloid leukemia, while both alterations were identified simultaneously in five patients. Classification of the BCR-ABL1-negative myeloproliferative neoplasms varied, and in some cases, features only became apparent following tyrosine kinase inhibitor therapy. Seven of the 11 patients showed myelofibrosis, in some cases before identification of the second genetic alteration. Our data, reflecting the largest reported study comprehensively detailing clinicopathologic features and response to therapy, show that the co-occurrence of BCR-ABL1 and JAK2 V617F is rare, with an estimated frequency of 0.4%, and most often reflects two distinct ('composite') myeloproliferative neoplasms. Although uncommon, it is important to be aware of this potentially confounding genetic combination, lest these features be misinterpreted to reflect resistance to therapy or disease progression, considerations that could lead to inappropriate management.

Key Points Success of hematopoietic stem cell transplantation for MIRAGE syndrome may be limited by syndrome-specific comorbidities. SAMD9 mutations associated with MIRAGE syndrome are a newly described cause of congenital amegakaryocytic thrombocytopenia.

Introduction Increasingly clinicians face the choice between CPX-351 (NCT01696084) and venetoclax and azacitadine (ven/aza, NCT02993523) in front-line acute myeloid leukemia (AML), especially for frailer older adults with comorbidities. Given no prospective data, we examined retrospective observational survival outcomes for patients with newly diagnosed AML receiving either CPX-351 or ven/aza as initial therapy. Methods After local Institutional Review Board approval, we included patients from both the University of Pennsylvania ("HUP", n=111) and the Flatiron Health electronic health record (EHR) derived, de-identified database with a first incident AML diagnosed between January 2017 and 2021, and with documented receipt of CPX-351 or venetoclax and azacitadine as initial therapy (n=548). Given a total of 219 patients received CPX-351 and 440 received ven/aza, there was 90% power to detect a hazard ratio (HR) of 0.77 or smaller with alpha 0.05. Overall Survival (OS) was analyzed by the Kaplan-Meier method and compared between arms using the log-rank test. Pre-planned sensitivity analyses included restriction and multiple imputation (MI) to address missingness with inverse-probability of treatment weighting (IPTW) to balance baseline covariates with treatment effect estimates from each imputed dataset combined via Rubin's rules. Results For all patients, baseline covariates showed patients receiving ven/aza were older (75 vs 65 years old median age), more likely to have Medicare (29% vs 20%), have de-novo AML vs secondary or therapy-related disease (52% vs 29%) and be treated in the community rather than an academic center (66% vs 52%). All other baseline covariates-including ELN cytogenetic risk groups, high risk mutations (TP53, ASXL1, RUNX1), FLT3, IDH, HCT-comorbidity index-were not statistically significant different between groups (table 1). Missing values in the HUP dataset was Median OS (mOS) was 12 months for all patients and 13 months for CPX-351 versus 11 months for ven/aza (HR 0.87, 95% CI 0.70-1.07, p-value 0.184, Fig 1a). There was no clear subset with improved OS with CPX-351 vs ven/aza (Fig 1b); in multi-variate analysis controlling for all covariates with univariate p-value < 0.20 induction choice did not affect overall survival (limited to complete cases n=133, HR 0.63, p-value 0.73). Restricting to only the population eligible for CPX-351 pivotal trial, there was no significant difference in OS (CPX-351 n=160 mOS=10, ven/aza n=181 mOS=12 HR 0.86 p-value 0.33). After MI and IPTW, survival remained similar with HR 0.95 p-value 0.77 (Fig 1c). Adjusting further for variables with absolute standardized difference >10% after MI and IPTW (baseline HCT-comorbidity index, race and insurance status), multivariable Cox model gave similar results (HR 0.93, p-value 0.70). Regarding safety outcomes, early mortality was similar. However, documented diagnosed infections were higher in CPX-351 patients and within the HUP cohort, rates of febrile neutropenia and culture positive infection were also higher (Fig 1d). Length of stay, including any admission prior to next cycle of therapy, was more than twice as long for CPX-351 in the HUP cohort. Additional analyses, including detailed assessment of baseline covariates, multivariate analysis with transplant as a time-varying dependent covariate, event free survival, disease free survival also available for presentation. Conclusion In this multi-center real word dataset with over 600 patients, there was no statistically significant difference in overall survival between induction with CPX-351 and ven/aza. This large retrospective dataset is limited by missingness in covariates, risk of misclassification bias and lack of power for formal equivalence testing. However, a consistent lack of superiority for CPX-351 or ven/aza within a robust, manual chart-review of an academic institution, a large national real world database and combined analyses of these cohorts supports clinical equipoise. Given the apparent lack of a large survival benefit further work is needed. Prospective studies to confirm similar effectiveness with careful attention to side effects, quality of life and impact on transplant outcomes may help clinicians decide between these therapies. Figure 1 Figure 1. Disclosures Perl: Syndax: Consultancy; Loxo: Consultancy; Forma: Consultancy; AbbVie: Consultancy, Research Funding; Roche: Consultancy; Actinium: Consultancy; Genentech: Consultancy; Astellas: Consultancy, Research Funding; Daiichi Sankyo: Consultancy, Research Funding; Fujifilm: Research Funding; BMS/Celgene: Consultancy; Arog: Research Funding; Onconova: Consultancy; Sumitomo Dainippon: Consultancy. Luger: Syros: Honoraria; Agios: Honoraria; Daiichi Sankyo: Honoraria; Jazz Pharmaceuticals: Honoraria; Brystol Myers Squibb: Honoraria; Acceleron: Honoraria; Astellas: Honoraria; Pfizer: Honoraria; Onconova: Research Funding; Celgene: Research Funding; Biosight: Research Funding; Hoffman LaRoche: Research Funding; Kura: Research Funding. Frey: Kite Pharma: Consultancy; Novartis: Research Funding; Sana Biotechnology: Consultancy; Syndax Pharmaceuticals: Consultancy. Gill: Interius Biotherapeutics: Current holder of stock options in a privately-held company, Research Funding; Carisma Therapeutics: Current holder of stock options in a privately-held company, Research Funding; Novartis: Other: licensed intellectual property, Research Funding. Hexner: Blueprint medicines: Membership on an entity's Board of Directors or advisory committees, Research Funding; PharmaEssentia: Membership on an entity's Board of Directors or advisory committees; Tmunity Therapeutics: Research Funding. Porter: American Society for Transplantation and Cellular Therapy: Honoraria; ASH: Membership on an entity's Board of Directors or advisory committees; DeCart: Membership on an entity's Board of Directors or advisory committees; Genentech: Current Employment, Current equity holder in publicly-traded company; Incyte: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; Kite/Gilead: Membership on an entity's Board of Directors or advisory committees; National Marrow Donor Program: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding; Unity: Patents & Royalties; Wiley and Sons Publishing: Honoraria. Stadtmauer: Oncopeptides: Consultancy; Amgen: Consultancy; BMS Celgene: Consultancy; GSK: Consultancy; Janssen: Consultancy; AbbVie: Consultancy, Research Funding. Maillard: Regeneron: Research Funding. Margolis: Pfizer: Consultancy; Leo: Consultancy; Sanofi: Consultancy; National Eczema Association: Membership on an entity's Board of Directors or advisory committees. Pratz: Abbvie: Consultancy, Honoraria, Research Funding; Agios: Consultancy; BMS: Consultancy, Honoraria; Novartis: Consultancy; Astellas: Consultancy, Honoraria, Research Funding; Cellgene: Consultancy, Honoraria; Millenium: Research Funding; University of Pennsylvania: Current Employment.

Fanconi anemia (FA), a genetic disorder affecting DNA repair, is characterized by bone marrow failure and cancer susceptibility. In FA mouse models, metformin (N,N-dimethylguanide) a biguanide metabolic agent, improves blood counts and delays tumor development. Given these findings, we conducted a single institution pilot study of metformin in non-diabetic patients with FA to assess feasibility, tolerability, and impact of metformin on hematologic response as defined by modified MDS International Working Group (IWG) criteria (Table 1). Fourteen of 15 patients with at least 1 cytopenia (hemoglobin Figure 1 Figure 1. Disclosures Pollard: Kura Oncology: Membership on an entity's Board of Directors or advisory committees; Syndax: Membership on an entity's Board of Directors or advisory committees. Furutani: Keros Therapeutics: Current Employment, Current equity holder in publicly-traded company. Esrick: bluebird bio: Consultancy. Nakano: Novartis: Consultancy. Thompson: Celgene: Consultancy, Research Funding; bluebird bio: Consultancy, Research Funding; Biomarin: Research Funding; Vertex: Research Funding; Graphite Bio: Research Funding; Baxalta: Research Funding; CRISPR Therapeutics: Research Funding; Novartis: Research Funding; Agios Pharmaceuticals: Consultancy; Beam Therapeutics: Consultancy; Global Blood Therapeutics: Current equity holder in publicly-traded company. OffLabel Disclosure: metformin- use in Fanconi anemia in an effort to improve hematopoiesis

BCR-ABL1-negative myeloproliferative neoplasms (MPNs) are clonal stem cell disorders defined by proliferation of one or more myeloid lineages, and carry an increased risk of vascular events and progression to myelofibrosis and leukemia. Portal hypertension (pHTN) occurs in 7-18% of MPN patients via both thrombotic and nonthrombotic mechanisms and portends a poor prognosis. Transjugular intrahepatic portosystemic shunt (TIPS) has been used in the management of MPN-associated pHTN; however, data on long-term outcomes of TIPS in this setting is limited and the optimal management of medically refractory MPN-associated pHTN is not known. In order to assess the efficacy and long-term outcomes of TIPS in MPN-associated pHTN, we performed a retrospective analysis of 29 MPN patients who underwent TIPS at three academic medical centers between 1997 and 2016. The majority of patients experienced complete clinical resolution of pHTN and its clinical sequelae following TIPS. One, two, three, and four-year overall survival post-TIPS was 96.4%, 92.3%, 84.6%, and 71.4%, respectively. However, despite therapeutic anticoagulation, in-stent thrombosis occurred in 31.0% of patients after TIPS, necessitating additional interventions. In conclusion, TIPS can be an effective intervention for MPN-associated pHTN regardless of etiology. However, TIPS thrombosis is a frequent complication in the MPN population and indefinite anticoagulation post-TIPS should be considered.

In this issue of Blood, Simon et al evaluated 430 samples from patients with acute myeloid leukemia (AML) for germline and somatic mutations in RUNX family transcription factor 1 (RUNX1). They found that nearly 30% of the identified variants were germline.(1)

Acquired aplastic anemia (AA) and paroxysmal nocturnal hemoglobinuria (PNH) are pathogenically related nonmalignant bone marrow failure disorders linked to T-cell–mediated autoimmunity; they are associated with an increased risk of secondary myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). Approximately 15% to 20% of AA patients and 2% to 6% of PNH patients go on to develop secondary MDS/AML by 10 years of follow-up. Factors determining an individual patient’s risk of malignant transformation remain poorly defined. Recent studies identified nearly ubiquitous clonal hematopoiesis (CH) in AA patients. Similarly, CH with additional, non-PIGA, somatic alterations occurs in the majority of patients with PNH. Factors associated with progression to secondary MDS/AML include longer duration of disease, increased telomere attrition, presence of adverse prognostic mutations, and multiple mutations, particularly when occurring early in the disease course and at a high allelic burden. Here, we will review the prevalence and characteristics of somatic alterations in AA and PNH and will explore their prognostic significance and mechanisms of clonal selection. We will then discuss the available data on post-AA and post-PNH progression to secondary MDS/AML and provide practical guidance for approaching patients with PNH and AA who have CH.

Key Points Acquired aplastic anemia is a T-cell–mediated autoimmune bone marrow aplasia, without a known etiologic trigger. Clonal expansion of CD8+ effector T lymphocytes can occur following vaccination and accompany graft dysfunction or aplastic anemia relapse.

Eltrombopag (EPAG) received approval from the US Food and Drug Administration for the treatment of refractory severe aplastic anemia (rSAA) based on treatment of 43 patients with doses escalating from 50 to 150 mg daily for 12 weeks. Response kinetics suggested that more prolonged administration of EPAG at a dose of 150 mg could speed and improve response rates. We enrolled 40 patients with rSAA in a study of EPAG 150 mg daily, with a primary end point of response at 24 weeks. Twenty (50%) of 40 patients responded at 24 weeks; 5 (25%) of 20 would have been deemed nonresponders at 12 weeks, the end point of the previous study. Fifteen of the 19 responding patients continuing on EPAG had drug discontinued for robust response; 5 of the 15 required EPAG re-initiation for relapse, with all recovering response. To analyze risk of clonal progression, we combined long-term data from the 83 patients with rSAA enrolled in both studies. Evolution to an abnormal karyotype occurred in 16 (19%), most within 6 months of EPAG initiation. Targeted deep sequencing/whole-exome sequencing was performed pre-EPAG and at primary response end point and/or time of clonal evolution or longest follow-up. Cytogenetic evolution did not correlate with mutational status, and overall mutated allele fractions of myeloid cancer genes did not increase on EPAG. In summary, extended administration of EPAG at a dose of 150 mg for 24 weeks rescued responses in some patients with rSAA not responding at 12 weeks. The temporal relationship between clonal evolution and drug exposure suggests that EPAG may promote expansion of dormant preexisting clones with an aberrant karyotype. The studies were registered at www.clinicaltrials.gov as #NCT00922883 and #NCT01891994.

Idiopathic acquired aplastic anemia (AA) is a rare lymphocyte-mediated bone marrow aplasia. No specific mechanisms or triggers of AA have been identified. We recently observed several patients who developed AA after Hodgkin lymphoma (HL). We hypothesized that the co-occurrence of HL and AA is not random and may be etiologically significant. To test this hypothesis, we determined the incidence of AA in HL patients at our institution. We identified four patients with co-occurring HL and AA, with the incidence of AA in HL patients >20-fold higher compared to the general population. We identified 12 additional patients with AA and HL through a systematic literature review. Of the 16 total patients,15 (93.8%) developed AA after or concurrent with a HL diagnosis. None of the patients had marrow involvement by HL. Five of 15 patients were in complete remission from HL at the time of AA diagnosis, and six had a concurrent presentation with no prior cytotoxic therapy, with diagnostic timeframe information unavailable for four patients. The median interval between HL diagnosis and AA onset was 16 months, ranging from concurrent to 14 years after a HL diagnosis. The median survival after AA diagnosis was 14 months (range: 1 month to 20 years). Our results show that patients with HL have a higher incidence of AA compared to the general population and suggest that HL-related immune dysregulation may be a risk factor for AA. Better recognition and management of AA in HL patients is needed to improve outcomes in this population.

Importance Health care workers (HCWs) caring for patients with coronavirus disease 2019 (COVID-19) are at risk of exposure to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Currently, to our knowledge, there is no effective pharmacologic prophylaxis for individuals at risk. Objective To evaluate the efficacy of hydroxychloroquine to prevent transmission of SARS-CoV-2 in hospital-based HCWs with exposure to patients with COVID-19 using a pre-exposure prophylaxis strategy. Design, Setting, and Participants This randomized, double-blind, placebo-controlled clinical trial (the Prevention and Treatment of COVID-19 With Hydroxychloroquine Study) was conducted at 2 tertiary urban hospitals, with enrollment from April 9, 2020, to July 14, 2020; follow-up ended August 4, 2020. The trial randomized 132 full-time, hospital-based HCWs (physicians, nurses, certified nursing assistants, emergency technicians, and respiratory therapists), of whom 125 were initially asymptomatic and had negative results for SARS-CoV-2 by nasopharyngeal swab. The trial was terminated early for futility before reaching a planned enrollment of 200 participants. Interventions Hydroxychloroquine, 600 mg, daily, or size-matched placebo taken orally for 8 weeks. Main Outcomes and Measures The primary outcome was the incidence of SARS-CoV-2 infection as determined by a nasopharyngeal swab during the 8 weeks of treatment. Secondary outcomes included adverse effects, treatment discontinuation, presence of SARS-CoV-2 antibodies, frequency of QTc prolongation, and clinical outcomes for SARS-CoV-2–positive participants. Results Of the 132 randomized participants (median age, 33 years [range, 20-66 years]; 91 women [69%]), 125 (94.7%) were evaluable for the primary outcome. There was no significant difference in infection rates in participants randomized to receive hydroxychloroquine compared with placebo (4 of 64 [6.3%] vs 4 of 61 [6.6%];P > .99). Mild adverse events were more common in participants taking hydroxychloroquine compared with placebo (45% vs 26%;P = .04); rates of treatment discontinuation were similar in both arms (19% vs 16%;P = .81). The median change in QTc (baseline to 4-week evaluation) did not differ between arms (hydroxychloroquine: 4 milliseconds; 95% CI, −9 to 17; vs placebo: 3 milliseconds; 95% CI, −5 to 11;P = .98). Of the 8 participants with positive results for SARS-CoV-2 (6.4%), 6 developed viral symptoms; none required hospitalization, and all clinically recovered. Conclusions and Relevance In this randomized clinical trial, although limited by early termination, there was no clinical benefit of hydroxychloroquine administered daily for 8 weeks as pre-exposure prophylaxis in hospital-based HCWs exposed to patients with COVID-19. Trial Registration ClinicalTrials.gov Identifier:NCT04329923

Acquired aplastic anemia (aAA) results from the T cell-mediated autoimmune destruction of hematopoietic stem cells. Factors predicting response to immune suppression therapy (IST) or development of myelodysplastic syndrome (MDS) are beginning to be elucidated. Our recent data suggest most patients with aAA treated with IST develop clonal somatic genetic alterations in hematopoietic cells. One frequent acquired abnormality is copy-number neutral loss of heterozygosity on chromosome 6p (6p CN-LOH) involving the human leukocyte antigen (HLA) locus. We hypothesized that because 6p CN-LOH clones may arise from selective pressure to escape immune surveillance through deletion of HLA alleles, the development of 6p CN-LOH may affect response to IST. We used single nucleotide polymorphism array genotyping and targeted next-generation sequencing of HLA alleles to assess frequency of 6p CN-LOH, identity of HLA alleles lost through 6p CN-LOH, and impact of 6p CN-LOH on response to IST. 6p CN-LOH clones were present in 11.3% of patients, remained stable over time, and were not associated with development of MDS-defining cytogenetic abnormalities. Notably, no patient with 6p CN-LOH treated with IST achieved a complete response. In summary, clonal 6p CN-LOH in aAA defines a unique subgroup of patients that may provide insights into hematopoietic clonal evolution.

Hepatitis‐associated aplastic anemia (HAA) is a variant of acquired aplastic anemia (AA) in which immune‐mediated bone marrow failure (BMF) develops following an acute episode of seronegative hepatitis. Dyskeratosis congenita (DC) is an inherited BMF syndrome characterized by the presence of short telomeres, mucocutaneous abnormalities, and cancer predisposition. While both conditions may cause BMF and hepatic impairment, therapeutic approaches are distinct, making it imperative to establish the correct diagnosis. In clinical practice, lymphocyte telomere lengths (TL) are used as a first‐line screen to rule out inherited telomeropathies before initiating treatment for AA. To evaluate the reliability of TL in the HAA population, we performed a retrospective analysis of TL in 10 consecutively enrolled HAA patients compared to 19 patients with idiopathic AA (IAA). HAA patients had significantly shorter telomeres than IAA patients (P = 0.009), including four patients with TL at or below the 1st percentile for age‐matched controls. HAA patients had no clinical features of DC and did not carry disease‐causing mutations in known genes associated with inherited telomere disorders. Instead, short TLs were significantly correlated with severe lymphopenia and skewed lymphocyte subsets, features characteristic of HAA. Our results indicate the importance of caution in the interpretation of TL measurements in HAA, because, in this patient population, short telomeres have limited specificity. Am. J. Hematol. 91:243–247, 2016. © 2015 The Authors. American Journal of Hematology Published by Wiley Periodicals, Inc.

Acquired aplastic anemia (AA) is a life-threatening bone marrow failure caused by an autoimmune cytotoxic T lymphocyte attack on hematopoietic stem and progenitor cells. Factors contributing to aberrant autoimmune activation in AA include a deficit of T regulatory cells and high levels of inflammatory cytokines. Several acquired conditions of immune dysregulation and genetic polymorphisms in inflammatory cytokines and human leukocyte antigen genes have been linked to an increased risk of AA. However, AA has not been reported in patients with Mendelian disorders of immune regulation. Here we report a patient with familial common variable immunodeficiency (CVID) caused by a pathogenic variant in NFKB1, who developed AA as an adult. The patient had a difficult clinical course and was unable to tolerate standard AA therapy with cyclosporine A and eltrombopag, with complications attributed in part to the effect of cyclosporine A on NF-κB signaling. Our case suggests a novel link between genetic disorders of immune regulation and AA and highlights the importance of recognizing inherited autoimmunity syndromes in AA patients for the selection of optimal therapy and prognostic counseling.

The introduction of Janus kinase (JAK) 1/2 inhibitor ruxolitinib into the armamentarium of myelofibrosis therapies has allowed to effectively control systemic symptoms, reduce splenomegaly, and imp...

Comprehensive genomic profiling of myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML) cases have enabled the detection and differentiation of driver and subclonal mutations, informed risk prognostication, and defined targeted therapies. These insights into disease biology, and management have made multigene-acquired mutation testing a critical part of the diagnostic assessment of patients with sporadic MDS and AML. More recently, our understanding of the role of an increasing number of inherited genetic factors on MDS/AML risk and management has rapidly progressed. In recognition of the growing impact of this field, clinical guidelines and disease classification systems for both MDS and AML have recently incorporated familial MDS/AML predisposition syndromes into their diagnostic algorithms. In this perspective piece, we contemplate the advantages, disadvantages, and barriers that would need to be overcome to incorporate inherited MDS/AML genetic testing into the upfront molecular diagnostic work-up of every MDS/AML patient. For centers already performing panel-based tumor-only testing, including genes associated with familial forms of MDS/AML (e.g., RUNX1, CEBPA, GATA2, TP53), we advocate optimizing these tests to detect all types of germline variants in these genes and moving toward upfront paired tumor/germline testing to maximize detection and streamline patient care.

Myelodysplastic syndrome (MDS) is a clonal blood disorder characterized by ineffective hematopoiesis, cytopenias, dysplasia and an increased risk of acute myeloid leukemia (AML). With the growing availability of clinical genetic testing, there is an increasing appreciation that a number of genetic predisposition syndromes may underlie apparent de novo presentations of MDS/AML, particularly in children and young adults. Recent findings of clonal hematopoiesis in acquired aplastic anemia add another facet to our understanding of the mechanisms of MDS/AML predisposition. As more predisposition syndromes are recognized, it is becoming increasingly important for hematologists and oncologists to have familiarity with the common as well as emerging syndromes, and to have a systematic approach to diagnosis and screening of at risk patient populations. Here, we provide a practical algorithm for approaching a patient with a suspected MDS/AML predisposition, and provide an in-depth review of the established and emerging familial MDS/AML syndromes caused by mutations in the ANKRD26, CEBPA, DDX41, ETV6, GATA2, RUNX1, SRP72 genes. Finally, we discuss recent data on the role of somatic mutations in malignant transformation in acquired aplastic anemia, and review the practical aspects of MDS/AML management in patients and families with predisposition syndromes.