Iron chelation improves ineffective erythropoiesis and iron overload in myelodysplastic syndrome mice.

Myelodysplastic syndrome (MDS) is a heterogeneous group of bone marrow stem cell disorders characterized by ineffective hematopoiesis and cytopenias, most commonly anemia. Red cell transfusion therapy for anemia in MDS results in iron overload, correlating with reduced overall survival. Whether the treatment of iron overload benefits MDS patients remains controversial. We evaluate underlying iron-related pathophysiology and the effect of iron chelation using deferiprone on erythropoiesis in NUP98-HOXD13 transgenic mice, a highly penetrant well-established MDS mouse model. Our results characterize an iron overload phenotype with aberrant erythropoiesis in these mice which was reversed by deferiprone-treatment. Serum erythropoietin levels decreased while erythroblast erythropoietin receptor expression increased in deferiprone-treated MDS mice. We demonstrate, for the first time, normalized expression of the iron chaperones Pcbp1 and Ncoa4 and increased ferritin stores in late-stage erythroblasts from deferiprone-treated MDS mice, evidence of aberrant iron trafficking in MDS erythroblasts. Importantly, erythroblast ferritin is increased in response to deferiprone, correlating with decreased erythroblast ROS. Finally, we confirmed increased expression of genes involved in iron uptake, sensing, and trafficking in stem and progenitor cells from MDS patients. Taken together, our findings provide evidence that erythroblast-specific iron metabolism is a novel potential therapeutic target to reverse ineffective erythropoiesis in MDS.

Venous thromboembolism and acute myeloid leukemia: risk factors and mortality in elderly white, black and Asian patients.

Risk factors for venous thromboembolism (VTE) in elderly patients with acute myeloid leukemia (AML) are not known by race. The aim of this study was to determine the association of VTE with known risk factors and the impact of VTE on mortality in elderly white, black and Asian patients with AML. The merged SEER-Medicare database (2000-2015) was used for patients aged at least 65 years diagnosed with AML. Multivariable logistic regression was used to examine the association of VTE with known risk factors and Cox proportional hazards regression was used to evaluate the association of VTE with mortality in white, black and Asian patients. Among 21 403 AML patients aged at least 65years, VTE was diagnosed in 10.6% of 18 731 white patients, 13.4% of 1362 black and 5.6% of 1310 Asian patients. Overall, the adjusted risk of VTE in black patients was similar to white patients, but Asian patients had a lower risk of VTE. Risk factors for VTE in white patients were age less than 75 years, female sex, chemotherapy and comorbid medical conditions, including hypertension, anemia, chronic kidney and lung disease, hyperlipidemia, heart failure and obesity. In black patients, hyperlipidemia, and heart failure and in Asian patients, age less than 75 years, female sex, chemotherapy and hypertension and myocardial infarction were associated with VTE. Central venous catheter placement was a predictor of VTE in all three races. Our study identified risk factors for VTE by race in elderly white, black and Asian AML patients.

Feasibility of Medical Student Mentors to Improve Transition in Sickle Cell Disease.

OBJECTIVE: Advances in medical care have resulted in nearly 95% of all children with sickle cell disease (SCD) living to adulthood. There is a lack of effective transition programming, contributing to high rates of mortality and morbidity among adolescents and young adults (AYAs) during the transition from pediatric to adult healthcare. This nonrandomized study evaluated the feasibility, acceptability, and preliminary outcomes of a novel medical student mentor intervention to improve transition outcomes for AYA with SCD. METHODS: Eligible participants were ages 18-25 years, either preparing for transition or had transferred to adult care within the past year. Twenty-four AYA with SCD (Mage = 20.3, SD = 2.6) enrolled in the program and were matched with a medical student mentor. Feasibility and acceptability of the intervention was assessed through enrollment rates, reasons for refusal, retention rates, engagement with the intervention, satisfaction, and reasons for drop-out. Dependent t-tests were used to evaluate the preliminary effects of the intervention on patient transition readiness, health-related quality of life, self-efficacy, SCD knowledge, medication adherence, and health literacy. RESULTS: Participants (N = 24) demonstrated adequate retention (75.0%), adherence to the intervention (M = 5.3 of 6 sessions), and satisfaction with the intervention components. Participants demonstrated significant improvements in transition readiness (p = .001), self-efficacy (p = .002), medication adherence (p = .02), and health literacy (p = .05). CONCLUSIONS: A medical student mentor intervention to facilitate transition from pediatric to adult care for AYA with SCD is both feasible and acceptable to patients and medical students. Preliminary results suggest benefits for patients, warranting a larger efficacy study.

Stem cell mutations can be detected in myeloma patients years before onset of secondary leukemias.

Therapy-related acute myeloid leukemia and myelodysplastic syndromes (t-AML/t-MDS) are secondary hematologic malignancies associated with poor prognosis, warranting insights into their predisposing conditions and cells of origin. We identified patients with myeloma who developed t-AML/t-MDS and analyzed their stem and progenitor cells collected years before the onset of secondary disease. We demonstrate that aberrant stem cells with high CD123 expression can be detected long before the onset of overt leukemia. Rigorous sorting, followed by targeted sequencing, resulted in ultradeep functional depth of sequencing and revealed preexisting mutant hematopoietic stem cell (HSC) clones, mainly harboring TP53 mutations, that became the dominant population at the time of leukemic presentation. Taken together, these data show that HSCs can act as reservoirs for leukemia-initiating cells many years before the onset of myeloid leukemia.

Phase II Study of the ALK5 Inhibitor Galunisertib in Very Low-, Low-, and Intermediate-Risk Myelodysplastic Syndromes.

PURPOSE: Overactivation of TGF-ß signaling is observed in myelodysplastic syndromes (MDS) and is associated with dysplastic hematopoietic differentiation. Galunisertib, a first-in-class oral inhibitor of the TGF-ß receptor type 1 kinase (ALK5) has shown effectiveness in preclinical models of MDS and acceptable toxicity in phase I studies of solid malignancies. PATIENTS AND METHODS: A phase II multicenter study of galunisertib was conducted in patients with very low-, low-, or intermediate-risk MDS by the Revised International Prognostic Scoring System criteria with hemoglobin ≤ 10.0 g/dL. Patients received oral galunisertib 150 mg twice daily for 14 days on/14 days off. RESULTS: Ten of 41 evaluable patients (24.4%; 95% confidence interval, 12.4-40.3) achieved hematologic improvement erythroid response by International Working Group (IWG) 2006 criteria. A total of 18 of 41 patients (43.9%) achieved erythroid response as per IWG 2000 criteria. Nine of 28 (32.1%) of transfusion-dependent patients had hematologic improvement. A total of 18 of 41 (44%) patients had a significant reduction in fatigue. Overall median duration of response was 90 days in all patients. Rigorous stem and progenitor flow cytometry showed that patients with an early stem cell differentiation block were more likely to respond to galunisertib. The most common treatment-emergent adverse events were grade 1 or 2 in 20 (49%) of 41 patients, including any-grade fatigue (8/41, 20%), diarrhea (7/41, 17%), pyrexia (5/41, 12%), and vomiting (5/41, 12%). CONCLUSIONS: In summary, galunisertib treatment has an acceptable safety profile and was associated with hematologic improvements in lower- and intermediate-risk MDS, with responses in heavily transfusion-dependent patients and in those with signs of an early stem cell differentiation block.

HIV portends a poor prognosis in myelodysplastic syndromes.

Even though HIV is associated with worse prognosis in many malignancies, the clinical course of myelodysplastic syndrome (MDS) in HIV + patients has not been well studied. Determining the clinical presentation and outcomes of MDS in these patients would be important for future diagnostic strategies, as anemia and other cytopenias are commonly seen in HIV + patients. Unique data mining software was used to identify cases of MDS or AML in adult patients who were also HIV + at Albert Einstein/Montefiore Medical Center between 1 January 2003 and 1 January 2017. Using Chi-Square and Fisher's exact test, characteristics of the HIV + MDS patients were compared to 135 HIV - MDS patients from the same institution diagnosed between 1997 and 2011. Fourteen biopsy proven MDS patients were identified with concomitant HIV. HIV + MDS patients presented at a younger age (59 vs. 71 yrs, p = .001) had higher risk disease, faster progression to acute leukemia, and worse overall survival (median survival 11.2 vs. 69.1 mo, p < .001) compared to HIV - MDS controls. Additionally, there was a higher prevalence of clonal-hematopoiesis related mutations (ASXL1, DNMT3A) and a higher proportion of patients with high risk cytogenetics. Analysis of the largest single center cohort of HIV + MDS patients demonstrated that these individuals present at a significantly younger age and with higher risk disease than their HIV - counterparts.

Misidentification of MLL3 and other mutations in cancer due to highly homologous genomic regions.

The MLL3 gene has been shown to be recurrently mutated in many malignancies including in families with acute myeloid leukemia. We demonstrate that many MLL3 variant calls made by exome sequencing are false positives due to misalignment to homologous regions, including a region on chr21, and can only be validated by long-range PCR. Numerous other recurrently mutated genes reported in COSMIC and TCGA databases have pseudogenes and cannot also be validated by conventional short read-based sequencing approaches. Genome-wide identification of pseudogene regions demonstrates that frequency of these homologous regions is increased with sequencing read lengths below 200 bps. To enable identification of poor quality sequencing variants in prospective studies, we generated novel genome-wide maps of regions with poor mappability that can be used in variant calling algorithms. Taken together, our findings reveal that pseudogene regions are a source of false-positive mutations in cancers.

Direct Activation of BAX by BTSA1 Overcomes Apoptosis Resistance in Acute Myeloid Leukemia.

The BCL-2 family protein BAX is a central mediator of apoptosis. Overexpression of anti-apoptotic BCL-2 proteins contributes to tumor development and resistance to therapy by suppressing BAX and its activators. We report the discovery of BTSA1, a pharmacologically optimized BAX activator that binds with high affinity and specificity to the N-terminal activation site and induces conformational changes to BAX leading to BAX-mediated apoptosis. BTSA1-induced BAX activation effectively promotes apoptosis in leukemia cell lines and patient samples while sparing healthy cells. BAX expression levels and cytosolic conformation regulate sensitivity to BTSA1. BTSA1 potently suppressed human acute myeloid leukemia (AML) xenografts and increased host survival without toxicity. This study provides proof-of-concept for direct BAX activation as a treatment strategy in AML.

Acquired Von Willebrand's Syndrome in Systemic Lupus Erythematosus.

Acquired von Willebrand syndrome (AVWS) is an uncommon, underdiagnosed, and heterogeneous disease which is increasingly recognized as a cause of bleeding diatheses. Systemic lupus erythematosus (SLE) is an infrequent cause of AVWS. Herein, we report a case of AVWS diagnosed during the initial presentation of SLE in a previously healthy young man with no family history of bleeding diathesis who presented with worsening epistaxis, gastrointestinal bleeding, and anasarca. He was found to have severe anemia and prolonged activated partial thromboplastin time (aPTT) with severely decreased levels of von Willebrand factor (VWF) measurements in addition to markedly decreased factor VIII levels. Further evaluation revealed nephrotic syndrome and interstitial lung disease due to SLE. He initially received combination therapy with intravenous immunoglobulin (IVIG) and von Willebrand factor/factor VIII concentrates without significant improvement. Treatment with steroids, cyclophosphamide, and rituximab was followed by clinical improvement evidenced by cessation of bleeding. The short follow-up did not allow us to definitely prove the therapeutic effect of immunosuppressive treatment on AVWS in SLE patients. This case adds to the literature supporting the relationship between AVWS and SLE and highlights the importance of combination therapy in the treatment of severe AVWS as well as the role of IVIG, cyclophosphamide, and rituximab in AVWS associated with SLE.

Epidemiologic study of myelodysplastic syndromes in a multiethnic, inner city cohort.

Little is known about the epidemiology of MDS in minority populations. The IPSS and newly released IPSS-R are important clinical tools in prognostication of patients with MDS. Therefore, we conducted a retrospective epidemiological analysis of MDS in an ethnically diverse cohort of patients. Demographics, disease characteristics, and survival were determined in 161 patients seen at Montefiore Medical Center from 1997 to 2011. We observed that Hispanics presented at a younger age than blacks and whites (68 vs. 73.7 vs. 75.6 years); this difference was significant (p = 0.01). A trend towards greater prevalence of thrombocytopenia in Hispanics was observed, but this was not significant (p = 0.08). No other differences between the groups were observed. Overall median survival after diagnosis was the highest among Hispanics (8.6 years) followed by blacks (6.2 years) and Caucasians (3.7). Adjusted hazard ratios however did not show significant differences in risk of death between the groups. The IPSS-R showed slightly better discrimination when compared to the IPSS in this cohort (Somers Dxy 0.39 vs. 0.35, respectively) but observed survival more was more closely approximated by IPSS than by IPSS-R. Our study highlights the possibility of ethnic differences in the presentation of MDS and raises questions regarding which prognostic system is more predictive in this population.

Multiplicative interaction between mean corpuscular volume and red cell distribution width in predicting mortality of elderly patients with and without anemia.

Recent studies have shown that an elevated red cell distribution width (RDW) is an important predictor of adverse outcomes. However, the strength of this biomarker has not been tested in a large outpatient elderly population. Also since increased RDW can be due to a variety of etiologies, additional biomarkers are needed to refine the prognostic value of this variable. We assembled a cohort of 36,226 elderly (≥65yo) patients seen at an outpatient facility within the Einstein/Montefiore system from January 1st 1997 to May 1st 2008 who also had a complete blood count performed within 3 months of the initial visit. With a maximum follow-up of 10 years, we found that an elevated RDW (>16.6) was associated with increased risk of mortality in both non-anemic (HR = 3.66, p < 0.05) and anemic patients (HR = 1.87, p < 0.05). The effect of RDW on mortality is significantly increased in non-anemic patients with macrocytosis (HR = 5.22, p < 0.05) compared to those with normocytosis (HR = 3.86, p < 0.05) and microcytosis (HR = 2.46, p < 0.05). When comparing non-anemic patients with both an elevated RDW and macrocytosis to those with neither, we observed an elevated HR of 7.76 (higher than expected in an additive model). This multiplicative interaction was not observed in anemic patients (HR = 2.23). Lastly, we constructed Kaplan-Meier curves for each RDW/MCV subgroup and found worsened survival for those with macrocytosis and an elevated RDW in both anemia and non-anemic patients. Based on our results, the addition of MCV appears to improve the prognostic value of RDW as a predictor of overall survival in elderly patients.

Transverse dorsal arachnoid web and syringomyelia: case report.

OBJECTIVE: We present a case of syringomyelia attributed to a transverse thoracic arachnoid web at T4. The cerebrospinal fluid pressure caudal to the web was higher than the cerebrospinal fluid pressure rostral to the web, causing a syrinx in the thoracic and cervical spinal cord above the web. CLINICAL PRESENTATION: A 43-year-old man presented with numbness and a burning pain in his left upper back and extremities. Magnetic resonance imaging showed a cervical-thoracic syrinx that terminated relatively abruptly at T4. Because of the abrupt termination of the syrinx at T4 and the slight ventral displacement of the spinal cord at this level, a dorsal arachnoid web was suspected. INTERVENTION: A T4 laminectomy was performed. Intraoperative ultrasound before opening of the thecal sac showed a pulsating transverse dorsal arachnoid web. The dura was opened and the web resected, thus widely communicating the dorsal subarachnoid space. The syrinx dramatically decreased in size and the patient's pain improved but did not resolve completely. CONCLUSION: In patients with presumed idiopathic syringomyelia, imaging studies should be closely inspected for the presence of a transverse arachnoid web. Surgical resection of a transverse thoracic arachnoid web with syringomyelia can result in resolution of the syringomyelia and improvement in neurological function. Syrinx formation in patients with these webs may occur in the area of the spinal cord where there is lower cerebrospinal fluid pressure, which may be either rostral or caudal to the arachnoid web. We evaluate this hypothesis by comparing our case with other published cases.

Tumoricidal effect of calicheamicin immuno-conjugates using a passive targeting strategy.

Calicheamicin is a potent chemotherapeutic with a low therapeutic index that requires targeting to tumor cells for its use in the clinic. To treat acute myeloid leukemia, calicheamicin has been conjugated to an antibody that recognizes CD33 (gemtuzumab ozogamicin). The application range of this 'active' targeting strategy is limited since it depends on specific antigen expression by tumor cells. This limitation could be reduced by using an antigen-independent 'passive targeting' strategy for calicheamicin. 'Passive targeting' relies on the dysfunctional vasculature of a neoplastic tumor that allows enhanced retention of macromolecules. We studied the efficacy of calicheamicin conjugated to various carrier molecules: i.e. immunoglobulin, albumin or PEGylated Fc fragments. In nude mice, a conjugate of anti-CD33 and calicheamicin accumulates in human tumor xenografts in the absence of detectable amounts of targeting antigen. Passive targeting provided sufficient accumulation of this conjugate to inhibit tumor growth of 10 different CD33-negative xenograft models. This efficacy depended on the use of an acid-labile linker between antibody and calicheamicin. Substitution of immunoglobulin as a carrier with either albumin or PEGylated Fc reduced or eliminated the efficacy of the conjugate. The results showed that using 'non-specific' immunoglobulin for passive targeting of calicheamicin might be an effective mode of cancer therapy.