Distribution of Silent Cerebral Infarcts in Adults With Sickle Cell Disease

BACKGROUND AND OBJECTIVES

Previously we demonstrated that 90% of infarcts in children with sickle cell anemia occur in the border zone regions of cerebral blood flow (CBF). We tested the hypothesis that adults with sickle cell disease (SCD) have silent cerebral infarcts (SCIs) in the border zone regions, with a secondary hypothesis that older age and traditional stroke risk factors would be associated with infarct occurrence in regions outside the border zones.

METHODS

Adults with SCD 18-50 years of age were enrolled in a cross-sectional study at 2 centers and completed a 3T brain MRI. Participants with a history of overt stroke were excluded. Infarct masks were manually delineated on T2-fluid-attenuated inversion-recovery MRI and registered to the Montreal Neurological Institute 152 brain atlas to generate an infarct heatmap. Border zone regions between anterior, middle, and posterior cerebral arteries (ACA, MCA, and PCA) were quantified using the Digital 3D Brain MRI Arterial Territories Atlas, and logistic regression was applied to identify relationships between infarct distribution, demographics, and stroke risk factors.

RESULTS

Of 113 participants with SCD (median age 26.1 years, interquartile range [IQR] 21.6-31.4 years, 51% male), 56 (49.6%) had SCIs. Participants had a median of 5.5 infarcts (IQR 3.2-13.8). Analysis of infarct distribution showed that 350 of 644 infarcts (54.3%) were in 4 border zones of CBF and 294 (45.6%) were in non-border zone territories. More than 90% of infarcts were in 3 regions: the non-border zone ACA and MCA territories and the ACA-MCA border zone. Logistic regression showed that older participants have an increased chance of infarcts in the MCA territory (odds ratio [OR] 1.08; 95% CI 1.03-1.13; p = 0.001) and a decreased chance of infarcts in the ACA-MCA border zone (OR 0.94; 95% CI 0.90-0.97; p < 0.001). The presence of at least 1 stroke risk factor did not predict SCI location in any model.

DISCUSSION

When compared with children with SCD, in adults with SCD, older age is associated with expanded zones of tissue infarction that stretch beyond the traditional border zones of CBF, with more than 45% of infarcts in non-border zone regions.

Bone Marrow Harvest: A White Paper of Best Practices by the NMDP Marrow Alliance

Data on recent bone marrow harvest (BMH) collections from the NMDP has shown that bone marrow (BM) quality has decreased based on total nucleated cell count in the product. To ensure that quality BM products are available to all recipients, the NMDP Marrow Alliance was formed in April 2021 to increase the capability of BM collection centers to safely deliver high-quality products consistently and to identify and disseminate guidelines for performing BMH. This white paper describes the best practices for BMH as defined by the NMDP Marrow Alliance.

Transcranial doppler velocity in iron-deficient Nigerian children with sickle cell anemia

Oral iron supplementation in iron deficient children with sickle cell anemia and normal transcranial Doppler ultrasound (TCD) velocities does not reduce arterial flow in the middle cerebral artery.

An International Learning Collaborative Phase 2 Trial for Haploidentical Bone Marrow Transplant in Sickle Cell Disease

In the setting of a learning collaborative, we conducted an international multicenter phase 2 clinical trial testing the hypothesis that non-myeloablative related haploidentical BMT with thiotepa and post-transplant cyclophosphamide (PTCy) will result in 2-year event-free survival (no graft failure or death) of at least 80%. A total of 70 participants (median age 19.1 (IQR 14.1 - 25.0) were evaluable based on the conditioning protocol. Graft failure occurred in 11.4% (8/70) and only in participants <18 years (p=0.001); all had autologous reconstitution. After a median follow-up of 2.4 years (IQR 1.5-3.9), the 2-year Kaplan-Meier-based probability of event-free survival was 82.6% (95% CI 71.4%-89.7%). The 2-year overall survival was 94.1% (95% CI 84.9%-97.7%) with no difference between the child and adult participants (p=0.889). After excluding participants with graft failure (n=8), participants with engraftment had median whole blood donor chimerism values at D+180 and D+365 post-transplant of 100.0% (IQR 99.8 - 100.0%; n=59) and 100.0% (IQR 100.0 - 100.0%; n=58), respectively, and 96.6% (57/59) were off immunosuppression at 1-year post-transplant. The 1-year grades III-IV acute graft versus host disease (GvHD) rate was 10.0% (95% CI 4.6 - 18.6%), and the 2-year moderate-severe chronic GvHD rate was 10.0% (95% CI 4.6 - 18.6%). Five participants (7.1%) died from infectious complications. We demonstrate that non-myeloablative haploidentical BMT with thiotepa and PTCy is a readily available curative therapy for most adults, even those with organ damage, instead of the more expensive myeloablative gene therapy and gene editing. Additional strategies are required for children to decrease graft failure rates (ClinicalTrials.gov identifier NCT01850108).

Burden of employment loss and absenteeism in adults and caregivers of children with sickle cell disease

ABSTRACT

Sickle cell disease (SCD) is a genetic disorder affecting 100 000 people with an estimated annual medical cost of $3 billion in the United States; however, the economic impact on patients is not well described. We aimed to examine the indirect economic burden and test the hypothesis that socioeconomic status and greater social vulnerability risks are associated with increased absenteeism and employment loss. We surveyed adults and caregivers of children with SCD at 5 US centers from 2014 to 2021. Logistic regression models were used to examine the associations of employment loss and missed days of work with demographics and social determinants. Indirect costs were estimated by multiplying the self-reported missed days of work and job loss by 2022 average wages by the state of the participating institution. Of the 244 participants, 10.3% reported employment loss in the last 5 years, and 17.5% reported missing 10 or more days of work. Adults had 3 times more employment loss compared with caregivers of children with SCD (OR, 3.18; 95% CI, 1.12-9.01) but fewer missed days of work (OR, 0.24; 95% CI, 0.11-0.0.51). Participants who did not live with a partner reported increased employment loss (OR, 4.70; 95% CI, 1.04-21.17) and more missed days of work (OR, 4.58; 95% CI, 1.04-20.15). The estimated annual indirect economic burden was $2 266 873 ($9290 per participant). Adults with SCD and caregivers of children with SCD commonly report employment loss and missed days of work as important risk factors. The high indirect economic burden suggests that future economic evaluations of SCD should include SCD-related indirect economic burden.

Cerebral hemodynamic changes after haploidentical hematopoietic stem cell transplant in adults with sickle cell disease

ABSTRACT

Preliminary evidence from a series of 4 adults with sickle cell disease (SCD) suggests that hematopoietic stem cell transplant (HSCT) improves cerebral hemodynamics. HSCT largely normalizes cerebral hemodynamics in children with SCD. We tested the hypothesis in adults with SCD that cerebral blood flow (CBF), oxygen extraction fraction (OEF), and cerebral metabolic rate of oxygen (CMRO2) measured using magnetic resonance imaging, normalized to healthy values, comparing measurements from ∼1 month before to 12 to 24 months after HSCT (n = 11; age, 33.3 ± 8.9 years; 389 ± 150 days after HSCT) with age-, race- and sex-matched values from healthy adults without sickle trait (n = 28; age, 30.2 ± 5.6 years). Before transplant, 7 patients had neurological indications for transplant (eg, overt stroke) and 4 had nonneurological reasons for haploidentical bone marrow transplant (haplo-BMT). All received haplo-BMT from first-degree relatives (parent, sibling, or child donor) with reduced-intensity preparation and maintained engraftment. Before transplant, CBF was elevated (CBF, 69.11 ± 24.7 mL/100 g/min) compared with that of controls (P = .004). Mean CBF declined significantly after haplo-BMT (posttransplant CBF, 48.2 ± 13.9 mL/100 g/min; P = .003). OEF was not different from that of controls at baseline and did not change significantly after haplo-BMT (pretransplant, 43.1 ± 6.7%; posttransplant, 39.6 ± 7.0%; P = .34). After transplant, CBF and OEF were not significantly different from controls (CBF, 48.2 ± 13.4 mL/100 g/min; P = .78; and OEF, 39.6 ± 7.0%; P > .99). CMRO2 did not change significantly after haplo-BMT (pretransplant, 3.18 ± 0.87 mL O2/100 g/min; posttransplant, 2.95 ± 0.83; P = .56). Major complications of haplo-BMT included 1 infection-related death and 1 severe chronic graft-versus-host disease. Haplo-BMT in adults with SCD reduces CBF to that of control values and maintains OEF and CMRO2 on average at levels observed in healthy adult controls. The trial was registered at www.clinicaltrials.gov as #NCT01850108.

The range of haploidentical transplant protocols in sickle cell disease: all haplos are not created equally

The ideal curative therapy for sickle cell disease (SCD) must be applicable across all ages and include individuals with strokes and preexisting heart, lung, and kidney disease. Myeloablative, matched sibling donor hematopoietic stem cell transplant (HCT) for children with SCD has shown excellent outcomes over the past 3 decades but has been restricted due to the limited availability of a human leukocyte antigen-matched sibling donor (10%-15%) and increased treatment-related death in adults with myeloablative conditioning. To overcome these 2 significant barriers to curative therapy in SCD, related haploidentical HCT has become an active area of research. The use of related haploidentical donors (first- and second-degree relatives) increases the donor pool to at least 90% of those eligible across the life span. Importantly, most adults, even with strokes or significant comorbidities, can tolerate the nonmyeloablative conditioning regimen without treatment-related death. Since 2013, at least 3 related haploidentical HCT strategies have emerged as potential curative therapies for SCD: (1) a nonmyeloablative, T-cell replete, bone marrow transplant with thiotepa and posttransplant cyclophosphamide with a goal of complete donor chimerism; (2) a nonmyeloablative, in vivo T-cell depletion, using peripheral blood stem cells (PBSCs) with a goal of stable mixed donor-recipient chimerism; and (3) a myeloablative, ex vivo T-cell depletion using PBSCs and advanced-technology graft manipulation, with a goal of complete donor chimerism. We review the similarities, differences, outcomes, and gaps in knowledge with these 3 haploidentical HCT approaches for SCD.

A feasibility randomized controlled trial of an mHealth app vs booklets for patient-facing guidelines in adults with SCD

Despite the increased number of evidence-based guidelines for sickle cell disease (SCD), dissemination of evidence-based guidelines in lay language for individuals or families with SCD has not been evaluated. We conducted a feasibility randomized controlled trial to determine the acceptability of a mobile health (mHealth) app with patient-facing guidelines to improve the knowledge of individuals with SCD about SCD-specific knowledge and reduce hospitalizations. Primary outcome measures include recruitment, retention, and adherence rates. Adults with SCD were enrolled at 2 sickle cell centers between 2018 and 2022. Participants were randomized to receive either an mHealth app + booklet with patient-facing guidelines or a booklet with the guidelines alone. Participants completed surveys at baseline and a final 6-month visit. Approximately 67 of 74 (91%) agreed to participate and were randomized, with 50 of 67 (75%) completing all the study components. All participants who completed the study in the treatment arm used the app. Our results demonstrated high recruitment, retention, and adherence rate for the first randomized trial for an mHealth app with patient-facing guidelines in adults with SCD. This clinical trial was registered at https://www.clinicaltrials.gov/ as #NCT03629678.

Silent infarction in sickle cell disease is associated with brain volume loss in excess of infarct volume

Introduction

Sickle cell disease (SCD) increases cerebral infarct risk, but reported effects on brain volume have varied. More detailed information using larger cohorts and contemporary methods could motivate the use of longitudinal brain volume assessment in SCD as an automated marker of disease stability or future progression. The purpose of this study was to rigorously evaluate whether children and young adults with SCD have reduced gray matter volume (GMV) and white matter volume (WMV) compared to healthy controls using high-resolution MRI. We tested the hypotheses that (i) elevated CBF, a marker of cerebral hemodynamic compensation in SCD, is associated with global and regional brain atrophy, and (ii) silent cerebral infarct burden is associated with brain atrophy in excess of infarct volume.

Methods

Healthy controls (n = 49) and SCD participants without overt stroke (n = 88) aged 7-32 years completed 3 T brain MRI; pseudocontinuous arterial spin labeling measured CBF. Multivariable linear regressions assessed associations of independent variables with GMV, WMV, and volumes of cortical/subcortical regions.

Results

Reduced hemoglobin was associated with reductions in both GMV (p = 0.032) and WMV (p = 0.005); reduced arterial oxygen content (CaO2) was also associated with reductions in GMV (p = 0.035) and WMV (p = 0.006). Elevated gray matter CBF was associated with reduced WMV (p = 0.018). Infarct burden was associated with reductions in WMV 30-fold greater than the infarct volume itself (p = 0.005). Increased GM CBF correlated with volumetric reductions of the insula and left and right caudate nuclei (p = 0.017, 0.017, 0.036, respectively). Infarct burden was associated with reduced left and right nucleus accumbens, right thalamus, and anterior corpus callosum volumes (p = 0.002, 0.002, 0.009, 0.002, respectively).

Discussion

We demonstrate that anemia and decreased CaO2 are associated with reductions in GMV and WMV in SCD. Increased CBF and infarct burden were also associated with reduced volume in subcortical structures. Global WMV deficits associated with infarct burden far exceed infarct volume itself. Hemodynamic compensation via increased cerebral blood flow in SCD seems inadequate to prevent brain volume loss. Our work highlights that silent cerebral infarcts are just a portion of the brain injury that occurs in SCD; brain volume is another potential biomarker of brain injury in SCD.

Hydroxyurea for secondary stroke prevention in children with sickle cell anemia in Nigeria: a randomized controlled trial

We tested the hypothesis that fixed oral moderate-dose hydroxyurea (20 mg/kg per day) for initial treatment of secondary stroke prevention results in an 80% relative risk reduction of stroke or death when compared with fixed oral low-dose hydroxyurea (10 mg/kg per day) in a phase 3 double-blind, parallel-group, randomized controlled trial in children with sickle cell anemia (SCA) living in Nigeria. A total of 101 participants were randomly allocated to low-dose (n = 49) and moderate-dose (n = 52) hydroxyurea treatment groups. The median participant follow-up was 1.6 years (interquartile range, 1.0-2.3), with a planned minimum follow-up of 3.0 years. A total of 6 recurrent strokes and 2 deaths vs 5 recurrent strokes and 3 deaths occurred in the low- and moderate-dose groups, respectively. The incidence rate ratio (IRR) of the primary outcome measure of stroke or death in the low- and moderate-dose hydroxyurea treatment groups was 0.98 (95% confidence interval [CI], 0.32-3.00; P = .97). The trial was stopped early owing to no clinical difference in the incidence rates of the primary outcome measure. The incidence rates of recurrent strokes were 7.1 and 6.0 per 100 person-years in the low- and moderate-dose groups, respectively, (IRR, 1.18; 95% CI, 0.30-4.88; P = .74). As a measure of adherence to the oral hydroxyurea therapy, the median percent of returned pills was 3.0% and 2.6% in the low- and moderate-dose groups, respectively. No participant had hydroxyurea therapy stopped for myelosuppression. For children with SCA in low-income settings without access to regular blood transfusion therapy, initial low-dose hydroxyurea is a minimum known efficacious dose for secondary stroke prevention.

Relapsed or refractory large B-cell lymphoma after chimeric antigen receptor T-cell therapy: Current challenges and therapeutic options

Chimeric antigen receptor (CAR) T-cell (CAR-T) therapy can provide durable remission in patients with relapsed or refractory diffuse large B-cell lymphoma (DLBCL) after failure of chemoimmunotherapy. However, patients who are refractory or relapsing after CAR-T therapy have poor outcomes. Multiple mechanisms of CAR-T therapy failure have been proposed but management of these patients remains a challenge. As CAR-T therapy moves earlier in the treatment of DLBCL, we urgently need trials focused on patients with relapse after CAR-T therapy. Recent advances in novel immunotherapies such as bispecific antibodies, antibody-drug conjugates and next-generation CAR-T therapies may provide avenues for treatment. Here we review the available data on using these drugs after failure of CAR-T therapy and provide a framework for the ideal sequencing of these novel agents.

Debating the Future of Sickle Cell Disease Curative Therapy: Haploidentical Hematopoietic Stem Cell Transplantation vs. Gene Therapy

Hematopoietic stem cell transplantation (HSCT) is a well-established curative therapy for patients with sickle cell disease (SCD) when using a human leukocyte antigen (HLA)-matched sibling donor. Most patients with SCD do not have a matched sibling donor, thereby significantly limiting the accessibility of this curative option to most patients. HLA-haploidentical HSCT with post-transplant cyclophosphamide expands the donor pool, with current approaches now demonstrating high overall survival, reduced toxicity, and an effective reduction in acute and chronic graft-vs.-host disease (GvHD). Alternatively, autologous genetic therapies appear promising and have the potential to overcome significant barriers associated with allogeneic HSCT, such as donor availability and GvHD. Here the authors each take a viewpoint and discuss what will be the future of curative options for patients with SCD outside of a matched sibling transplantation, specifically haploidentical HSCT vs. gene therapy.

Reduction in seroprevalence of viral transfusion-transmitted infections in southwest Nigeria in children with sickle cell disease using an enhanced screening strategy

Blood transfusion is an integral component in the management of children and adults with sickle cell disease (SCD). Concerns about blood safety due to the high risk of bloodborne infections in sub-Saharan Africa limits the application of this cost-effective strategy in the management of individuals with SCD. In a single-centre, retrospective, longitudinal study in southwest Nigeria, we hypothesised that the use of stringent blood donor selection, along with very sensitive enzyme-linked immunosorbent assay (ELISA) screening methods would reduce transfusion-transmitted infections (TTIs). Among 45 002 eligible blood donors at the Lagos University Teaching Hospital in Nigeria, over a 5-year review period (2015-2019), the seroprevalence rate of viral TTIs was 9.83%. The seroprevalence rates for human immunodeficiency, hepatitis B, and hepatitis C viruses were 1.37%, 6.2%, and 2.25% respectively. Among 172 children with SCD, 71% (122/172) on regular blood transfusion and 29% (50/172) who had never been transfused or had less than two transfusions per lifetime, none acquired any TTIs using our enhanced screening approach during the study period. Thus, safe blood transfusion practices can be provided for children with SCD in sub-Saharan Africa with the use of stringent donor selection protocols and fourth-generation ELISA kits for TTI screening.

Characterizing Intracranial Hemodynamics in Sickle Cell Anemia: Impact of Patient-Specific Viscosity

PURPOSE

Pediatric and adult patients with sickle cell anemia (SCA) are at increased risk of stroke and cerebrovascular accident. In the general adult population, there is a relationship between arterial hemodynamics and pathology; however, this relationship in SCA patients remains to be elucidated. The aim of this work was to characterize circle of Willis hemodynamics in patients with SCA and quantify the impact of viscosity choice on pathophysiologically-relevant hemodynamics measures.

METHODS

Based on measured vascular geometries, time-varying flow rates, and blood parameters, detailed patient-specific simulations of the circle of Willis were conducted for SCA patients (n = 6). Simulations quantified the impact of patient-specific and standard blood viscosities on wall shear stress (WSS).

RESULTS

These results demonstrated that use of a standard blood viscosity introduces large errors into the estimation of pathophysiologically-relevant hemodynamic parameters. Standard viscosity models overpredicted peak WSS by 55% and 49% for steady and pulsatile flow, respectively. Moreover, these results demonstrated non-uniform, spatial patterns of positive and negative WSS errors related to viscosity, and standard viscosity simulations overpredicted the time-averaged WSS by 32% (standard deviation = 7.1%). Finally, differences in shear rate demonstrated that the viscosity choice alters the simulated near-wall flow field, impacting hemodynamics measures.

CONCLUSIONS

This work presents simulations of circle of Willis arterial flow in SCA patients and demonstrates the importance and feasibility of using a patient-specific viscosity in these simulations. Accurately characterizing cerebrovascular hemodynamics in SCA populations has potential for elucidating the pathophysiology of large-vessel occlusion, aneurysms, and tissue damage in these patients.

Evaluation of healthcare-associated infection rates in patients with hematologic malignancies and stem cell transplantation during the coronavirus disease 2019 (COVID-19) pandemic

Objective

To evaluate whether rates of healthcare-associated infections (HAIs) changed during the coronavirus disease 2019 (COVID-19) pandemic in malignant hematology and stem cell transplant patients.

Design

A retrospective, cohort study.

Patients

The study included malignant hematology and stem cell transplant patients admitted between March 1, 2019, through July 31, 2019, and March 1, 2020, through July 31, 2020.

Methods

Rates of catheter-associated urinary tract infections (CAUTIs), central-line-associated bloodstream infections (CLABSIs), central-line-associated mucosal barrier injury infections (CLAMBIs), and Clostridioides difficile infections (CDIs) during the pandemic were compared to those in a control cohort. Secondary outcomes included the rate of non-COVID-19 respiratory viruses.

Results

The rate of CAUTIs per 1,000 hospital days was 0.435 before the pandemic and 0.532 during the pandemic (incidence rate ratio [IRR], 1.224; 95% confidence interval [CI], 0.0314-47.72; P = .899). The rate of CLABSIs was 0.435 before the pandemic and 1.064 during the pandemic (IRR, 2.447; 95% CI, 0.186-72.18; P = .516). The rate of CLAMBIs was 2.61 before the pandemic and 1.064 during the pandemic (IRR 0.408, 95% CI 0.057-1.927; P = .284). The rate of CDIs was 2.61 before the pandemic and 1.579 during the pandemic (IRR, 0.612; 95% CI, 0.125-2.457; P = .512). Non-COVID-19 respiratory virus cases decreased significantly from 12 (30.8%) to 2 cases (8.3%) (P = 0.014).

Conclusions

There was no significant difference in HAIs among inpatient malignant hematology and stem cell transplant patients during the COVID-19 pandemic compared to those of a control cohort. Rates of infection were low among both cohorts. Rates of community-acquired respiratory viruses decreased significantly during the pandemic among this population.

Capacity Building for Primary Stroke Prevention Teams in Children Living With Sickle Cell Anemia in Africa

BACKGROUND

Nigeria has the highest proportion of children with sickle cell anemia (SCA) globally; an estimated 150,000 infants with SCA are born annually. Primary stroke prevention in children with SCA must include Nigeria. We describe capacity-building strategies in conjunction with two National Institutes of Health-funded primary stroke prevention trials (a feasibility trial and phase III randomized controlled trial) with initial hydroxyurea treatment for children with SCA and abnormal transcranial Doppler (TCD) velocities in Nigeria. We anticipated challenges to conducting clinical trials in a low-resource setting with a local team that had not previously been involved in clinical research and sought a sustainable strategy for primary stroke prevention.

METHODS

This is a descriptive, prospective study of challenges, solutions, and research teams in two trials that enrolled a total of 679 children with SCA.

RESULTS

As part of the capacity-building component of the trials, over eight years, 23 research personnel (physicians, nurses, research coordinators, a statistician, and a pharmacist) completed a one-month research governance and ethics training program at Vanderbilt University Medical Center, USA. A lead research coordinator for each site completed the Society of Clinical Research Professionals certification. TCD machines were donated; radiologists and nonradiologists were trained and certified to perform TCD. A scalable E-prescription was implemented to track hydroxyurea treatment. We worked with regional government officials to support ongoing TCD-based screening and funding for hydroxyurea for children with SCA at a high risk of stroke.

CONCLUSIONS

Our trials and capacity building demonstrate a sustainable strategy to initiate and maintain pediatric SCA primary stroke prevention programs in Africa.

Haploidentical Allogeneic Stem Cell Transplantation in Sickle Cell Disease: A Systematic Review and Meta-Analysis

Allogeneic hematopoietic stem cell transplantation (SCT) is the sole established curative treatment option for patients with sickle cell disease (SCD). However, a lack of HLA-identical sibling donors is a limiting factor. Haploidentical related donors are a promising donor pool, potentially extending SCT as a curative treatment option to a larger group of patients with no other meaningful treatment options for their severe SCD. In the present study, we aimed to systematically review the results of haploidentical SCT in patients with SCD. A comprehensive search was performed in MEDLINE/PubMed and Embase up to May 2021. Data were extracted by 2 reviewers independently, and the Newcastle-Ottawa Quality Assessment Scale was used to assess the quality of the studies. Fourteen studies met our inclusion criteria. To provide an overview of the results of haploidentical SCT, we grouped the studies into myeloablative conditioning versus nonmyeloablative conditioning as well as into in vitro versus in vivo (ie, with post-transplantation cyclophosphamide) T cell depletion with a subgroup meta-analysis of proportions. All the included studies were observational cohort studies. Only 3 of these studies reported data for both matched sibling donor (MSD) SCT and haploidentical SCT. Based on a comparative meta-analysis of the 3 studies that included both haploidentical and MSD transplantation, graft failure was significantly higher in the haploidentical group than in the MSD group (odds ratio, 5.3; 95% confidence interval [CI], 1.0 to 27.6). Overall survival was not significantly different between the groups. A subgroup meta-analysis of the results of haploidentical SCT showed relatively low overall pooled proportions of graft failure (7%; 95% CI, 2% to 20%), acute graft-versus-host disease (GVHD) (4%; 95% CI, 2% to 12%), and chronic GVHD (11%; 95% CI, 7% to 16%). Overall survival (OS) was high in all the included studies (91%; 95% CI, 85% to 94%). Adjustments to the conditioning regimens, robust pretransplantation and post-transplantation T cell depletion, and improved supportive care have resulted in reduced graft failure and improved OS following haploidentical SCT in patients with SCD. We conclude that the safety of haploidentical SCT in SCD patients has improved significantly, and that this should be considered as a curative option in patients with severe SCD.

Cerebral Hemodynamics and Executive Function in Sickle Cell Anemia

BACKGROUND AND PURPOSE

Individuals with sickle cell anemia experience cognitive deficits, even in the absence of cerebral infarcts or strokes. This study tested the hypothesis that elevated cerebral blood flow and oxygen extraction fraction are associated with lower executive function in individuals with sickle cell anemia.

METHODS

Three-Tesla brain magnetic resonance imaging was performed, including anatomic, gray matter cerebral blood flow, and global oxygen extraction fraction imaging. Executive function was measured using the working memory index from an age-appropriate Wechsler battery and tasks from the National Institutes of Health Toolbox Cognition Battery. Bivariate and multivariate models were examined (significance: P<0.05).

RESULTS

Fifty-four participants (age range=6-31 years) with sickle cell anemia were enrolled. Hematocrit was positively related to fluid cognition, cerebral blood flow was inversely related to working memory and inhibitory control, and oxygen extraction fraction was inversely related to processing speed. Associations remained significant in multivariate analyses controlling for age, income, and infarcts.

CONCLUSIONS

Elevated cerebral blood flow and oxygen extraction fraction, markers of hemodynamic impairment, are associated with deficits in executive function in individuals with sickle cell anemia.

New-onset post-transplant diabetes mellitus after haploidentical hematopoietic cell transplant with post-transplant cyclophosphamide

Haploidentical hematopoietic cell transplantation (haplo‐HCT) with posttransplant cyclophosphamide (PTCY) is utilized for patients with hematological disorders but without conventional donors. The effects of new‐onset posttransplant diabetes mellitus (PTDM) following haplo‐HCT are unknown. We examined PTDM incidence and outcomes after haplo‐HCT with PTCY. Patients without diabetes receiving haplo‐HCT (n = 64) were analyzed for PTDM diagnosis (defined as blood glucose ≥ 200 mg/dL). By day 100, 14 (22%) patients developed PTDM (median, 18 days). Hyperglycemia (blood glucose ≥ 200 mg/dL) preceded corticosteroids in 11 (79%) individuals. PTDM patients had increased death/relapse (P = .029). PTDM occurs frequently, precedes corticosteroids, and leads to inferior outcomes following haplo‐HCT. PTDM prophylaxis/treatment may improve HCT survival.

Reduced oxygen extraction efficiency in sickle cell anemia patients with evidence of cerebral capillary shunting

Arterial spin labeling (ASL) magnetic resonance imaging (MRI) utilizes arterial blood water as an endogenous contrast agent to provide a quantitative measure of cerebral blood flow (CBF). Recently, hyperintense signal within dural venous sinuses in ASL images of sickle cell anemia (SCA) patients has been shown to be consistent with elevated flow velocities and may indicate capillary shunting and reduced oxygen extraction. Here, we performed oxygen extraction fraction (OEF) and CBF measurements in adults (cumulative n = 114) with (n = 69) and without (n = 45) SCA to test the hypothesis that hyperintense venous ASL signal is associated with reduced OEF. Higher categorical scores of shunting on ASL MRI were associated with lower OEF in participants with silent cerebral infarcts or white matter hyperintensities (p = 0.003), but not in those without lesions (p = 0.551). These findings indicate that venous hyperintense signal in ASL images in SCA patients may represent a marker of capillary-level disturbances in oxygen exchange efficiency and small vessel pathology.

Primary prevention of stroke in children with sickle cell anemia in sub-Saharan Africa: rationale and design of phase III randomized clinical trial

Strokes in children with sickle cell anemia (SCA) are associated with significant morbidity and premature death. Primary stroke prevention in children with SCA involves screening for abnormal transcranial Doppler (TCD) velocity coupled with regular blood transfusion therapy for children with abnormal velocities, for at least one year. However, in Africa, where the majority of children with SCA live, regular blood transfusions are not feasible due to inadequate supply of safe blood, cost, and the reluctance of caregivers to accept transfusion therapy for their children. We describe the Primary Prevention of Stroke in Children with Sickle Cell Disease in Nigeria Trial [StrokePreventioninNigeria (SPRING) trial, NCT02560935], a three-center double-blinded randomized controlled Phase III clinical trial to 1) determine the efficacy of moderate fixed-dose (20 mg/kg/day) versus low fixed-dose (10 mg/kg/day) hydroxyurea therapy for primary stroke prevention; 2) determine the efficacy of moderate fixed-dose hydroxyurea for decreasing the incidence of all cause-hospitalization (pain, acute chest syndrome, infection, other) compared to low fixed-dose hydroxyurea. We will test the primary hypothesis that there will be a 66% relative risk reduction of strokes in children with SCA and abnormal TCD measurements, randomly allocated, for a minimum of three years to receive moderate fixed-dose versus low fixed-dose hydroxyurea (total n = 220). The results of this trial will advance the care of children with SCA in sub-Saharan Africa, while improving research capacity for future studies to prevent strokes in children with SCA.

Intracranial and Extracranial Vascular Stenosis as Risk Factors for Stroke in Sickle Cell Disease

BACKGROUND

Prevalence and contribution of intracranial and extracranial arterial stenosis to stroke risk were assessed prospectively in children and young adults with sickle cell disease.

METHODS

In this cross-sectional study, children and young adults (mean = 19.4 years) with sickle cell disease underwent neurological examination, brain MRI, and magnetic resonance angiography of the head and neck. Two neuroradiologists independently recorded infarcts and arterial stenosis. Clinical features and stroke outcomes were compared between participants with and without stenosis and between children and young adults. Logistic regression analysis assessed the association of variables of interest with overt stroke and silent cerebral infarct.

RESULTS

Of 167 participants (79 children and 88 young adults), 20 (12.0%) had intracranial stenosis, all in the anterior circulation, and nine had concurrent extracranial stenosis. No participants had isolated extracranial stenosis. Participants with intracranial stenosis were more likely than those without stenosis to have an overt stroke (70% vs 5%, P < 0.001) or silent cerebral infarct (95% vs 35%, P < 0.001). Logistic regression analysis indicated that intracranial stenosis was strongly associated with overt stroke when compared with participants with silent cerebral infarct alone and strongly associated with silent cerebral infarct when compared with participants with normal brain MRI; male sex and age were also significant predictors of silent cerebral infarct.

CONCLUSIONS

Intracranial stenosis was strongly associated with both overt stroke and silent cerebral infarct; prevalence of intracranial stenosis was similar to prior estimates in sickle cell disease. Extracranial stenosis without concurrent intracranial stenosis did not occur and thus could not be evaluated as an independent risk factor for stroke.

Low rates of anti-recipient isohemagglutinins in ABO incompatible hematopoietic stem cell transplants

INTRODUCTION

Isohemagglutinins occur naturally and form in an 'opposite' (antigen-negative) pattern to a patient's ABO blood type. Patients undergoing minor and bidirectional ABO incompatible hematopoietic stem cell transplantation (HSCT) may demonstrate detectable antibodies against their native blood type. In this study, we sought to characterize the rates of such antibody formation and evaluate the clinical significance of our findings.

MATERIALS AND METHODS

An internal database of HSCT patients at an academic medical center was queried for ABO incompatible transplant patients from 2009-2019. Serum typing results, clinical histories, and laboratory data were compiled and reviewed.

RESULTS

A total of 182 minor and bidirectional ABO incompatible HSCT patients were identified. Anti-recipient isohemagglutinins were found in 9% (16/182) of the HSCT patients. The rate was higher in patients with minor incompatibility (12%: 15/127) versus bidirectional ABO incompatibility (2%: 1/55) (p = 0.04). No anti-recipient isohemagglutinins were identified in umbilical cord HSCT patients (0%: 0/7). Serologic agglutination reactions of recipient isohemagglutinins were overall mostly weak (13/16 weak + to 1+). There was a trend towards a higher rate of acute graft-versus-host-disease in patients with anti-recipient isohemagglutinins compared to those without (75% vs. 53%; p = 0.12), though not statistically significant. Rates of alloimmunization to minor red cell antigens were similar between the two groups. Few patients showed laboratory evidence of hemolysis at 12 months follow up.

DISCUSSION AND CONCLUSIONS

Anti-recipient isohemagglutinins occur at low rates in ABO incompatible HSCT and are significantly more common in minor ABO incompatible transplant compared to bidirectional transplants. Larger cohort studies are needed to better understand the relationship between anti-recipient isohemagglutinins and HSCT outcomes.

Increased Patient Activation Is Associated with Fewer Emergency Room Visits and Hospitalizations for Pain in Adults with Sickle Cell Disease

OBJECTIVE

Recurrent vaso-occlusive pain episodes, the most common complication of sickle cell disease (SCD), cause frequent health care utilization. Studies exploring associations between patient activation and acute health care utilization for pain are lacking. We tested the hypothesis that increased activation and self-efficacy are associated with decreased health care utilization for pain in SCD.

METHODS

In this cross-sectional study of adults with SCD at a tertiary medical center, we collected demographics, SCD phenotype, Patient Activation Measure levels, and self-efficacy scores using structured questionnaires. We reviewed charts to obtain disease-modifying therapy and acute health care utilization, defined as emergency room visits and hospitalizations, for vaso-occlusive pain episodes. Negative binomial regression analyses were used to test the hypothesis.

RESULTS

We surveyed 67 adults with SCD. The median age was 27.0 years, 53.7% were female, and 95.5% were African American. Median health care utilization for pain over one year (range) was 2.0 (0-24). Only one-third of participants (38.8%) were at the highest activation level (median [range] = 3 [1-4]). Two-thirds (65.7%) of participants had high self-efficacy (median [range] = 32.0 [13-45]). Regressions showed significant association between health care utilization and activation (incidence rate ratio [IRR] = 0.663, P = 0.045), self-efficacy (IRR = 0.947, P = 0.038), and male sex (IRR = 0.390, P = 0.003). Two outliers with high activation, self-efficacy, and health care utilization also had addictive behavior.

CONCLUSIONS

Many individuals with SCD have suboptimal activation and reduced self-efficacy. Higher activation and self-efficacy were associated with lower health care utilization for pain. Additional studies are needed to evaluate interventions to improve activation and self-efficacy and reduce acute health care utilization for pain.

Minimal residual disease negativity and lenalidomide maintenance therapy are associated with superior survival outcomes in multiple myeloma

Modern combinations of therapies for multiple myeloma have led to improvement in survival outcomes with near 100% overall response rate and 25% complete response rates, particularly with autologous hematopoietic cell transplant (AHCT). Minimal residual disease (MRD) assessment with multiparameter flow cytometry is a valid prognostic biomarker for progression-free survival (PFS) and overall survival (OS). However, few data exist regarding whether MRD positivity or negativity will meaningfully influence treatment decisions. We evaluated 433 patients who received induction therapy, followed by AHCT. Participants had MRD assessment by multiparameter flow cytometry before and at days +100 and +365 following AHCT. They also received either lenalidomide, bortezomib, or no maintenance therapy following AHCT. Maintenance treatment with lenalidomide improved MRD negativity at day +365 compared to bortezomib (92.9% vs 41.6%, p = 0.01), or no maintenance therapy (92.9% vs 24.4%, p = 0.012). The median PFS for patients who were MRD negative at day + 365 was 42 vs 17.5 months (p < 0.001) and median OS was 80.6 vs 59 months (p = 0.02). Maintenance therapy following AHCT for multiple myeloma improves the depth of response as assessed by MRD.

Low educational level of head of household, as a proxy for poverty, is associated with severe anaemia among children with sickle cell disease living in a low-resource setting: evidence from the SPRING trial

Severe anaemia, defined as haemoglobin level < 6·0 g/dl, is an independent risk factor for death in individuals with sickle cell disease living in resource-limited settings. We conducted a cross-sectional study of 941 children with sickle cell anaemia, who had been defined as phenotype HbSS or HbSβ⁰ thalassaemia, aged five to 12 years, and were screened for enrollment into a large primary stroke prevention trial in Nigeria (SPRING; NCT02560935). The main aim of the study was to determine the prevalence and risk factors for severe anaemia. We found severe anaemia to be present in 3·9% (37 of 941) of the SPRING study participants. Severe anaemia was significantly associated with the lower educational level of the head of the household (P = 0·003), as a proxy for poverty, and a greater number of children per room in the household (P = 0·004). Body mass index was not associated with severe anaemia. The etiology of severe anaemia in children living with sickle cell anaemia in Nigeria is likely to be multifactorial with an interplay between an individual's disease severity and other socio-economic factors related to poverty.

Using novel magnetic resonance imaging methods to predict stroke risk in individuals with sickle cell anemia

Sickle cell anemia (SCA) is a well-characterized monogenetic disorder with a high prevalence of cerebral vasculopathy, silent cerebral infarcts, and strokes. A significant mechanism for cerebral infarction in SCA is hemodynamic imbalance. To compensate for reduced oxygen-carrying capacity due to anemia, individuals with SCA have chronically elevated cerebral blood flow to maintain viable oxygen delivery to the brain tissue. Often the oxygen extraction fraction (ratio of oxygen consumed to oxygen delivered) is increased in more severely affected individuals. Subsequently, cerebrovascular reserve capacity, the ability of arterioles to dilate and further increase the cerebral blood volume and flow, will be reduced. These hemodynamic profiles have been associated with prior cerebral infarcts and increased evidence of disease severity. These cerebral hemodynamic parameters can be assessed noninvasively with noncontrast magnetic resonance imaging (MRI) of the brain utilizing specific MRI methods. This review focuses on using advanced neuroimaging methods to assess stroke risk in individuals with SCA, and such methods may be utilized before and after bone marrow or hematopoietic stem cell transplant to assess cerebral hemodynamic response. This manuscript is part of the Proceeding of The European Group for Blood and Marrow Transplantation (EBMT) Congress on Sickle Cell Disease, 16th-17 May 2019, Regensburg, Germany.

Overcoming Proteasome Inhibitor-Refractory Multiple Myeloma With Elotuzumab, Bortezomib, Nelfinavir, and Dexamethasone

Multiple myeloma is a common plasma cell malignancy with a median overall survival of fewer than 10 years. Proteasome inhibitors comprise an important part of the treatment regimen for this disease. The present study reports the case of a 57-year-old man who experienced a second relapse of multiple myeloma 6 years after initial treatment with bortezomib, lenalidomide, dexamethasone (VRD) followed by autologous hematopoietic cell transplant. The first relapse had been successfully treated with VRD, but this approach failed to control his second relapse. Given the lack of response to VRD therapy and relapse while on bortezomib maintenance, the patient was deemed proteasome inhibitor-refractory and received a new treatment of elotuzumab, lenalidomide, and dexamethasone. Four and a half cycles were completed before the treatment was stopped due to grade 4 cytopenias. The patient received a novel combination of elotuzumab, bortezomib, nelfinavir, and dexamethasone. After six cycles, the serum M-protein level was improved to 0.6 g/dL and the kappa light chains dropped from 3.49 to 1.04 mg/dL. A bone marrow biopsy conducted after five treatment cycles demonstrated < 1% plasma cells by immunohistochemistry and achievement of minimal residual disease status. Overall, this case study suggests that proteasome inhibitor-refractory multiple myeloma may be successfully re-treated with proteasome inhibitors when co-administered with nelfinavir.

Technology use and preferences to support clinical practice guideline awareness and adherence in individuals with sickle cell disease

Objective

Sickle cell disease (SCD) is a chronic condition affecting over 100 000 individuals in the United States, predominantly from vulnerable populations. Clinical practice guidelines, written for providers, have low adherence. This study explored knowledge about guidelines; desire for guidelines; and how technology could support guideline awareness and adherence, examining current technology uses, and user preferences to inform design of a patient-centered guidelines application in a chronic disease.

Methods

This cross-sectional mixed-methods study involved semi-structured interviews, surveys, and focus groups of adolescents and adults with SCD. We evaluated interest, preferences, and anticipated benefits or barriers of a patient-centered adaptation of SCD practice guidelines; prospective technology uses for health; and barriers to technology utilization.

Results

Forty-seven individuals completed surveys and interviews, and 39 participated in three separate focus groups. Most participants (91%) were unaware of SCD guidelines, but almost all (96%) expressed interest in a guidelines application, identifying benefits (knowledge, activation, individualization, and rewards), and barriers (poor information, low motivation, and resource limitations). Current technology health uses included information access, care coordination, and reminders about health-related actions. Prospective technology uses included informational messaging and timely alerts. Barriers to technology use included lack of interest, lack of utility, and preference for direct communication.

Conclusions

This study's findings can inform the design of clinical practice guideline applications, suggesting a promising role for technology to engage patients, facilitate care decisions and actions, and improve outcomes.

Prospective Study of Cardiac Events During Proteasome Inhibitor Therapy for Relapsed Multiple Myeloma

PURPOSE

Cardiovascular adverse events (CVAEs) can occur during proteasome inhibitor (PI) therapy. We conducted a prospective, observational, multi-institutional study to define risk factors and outcomes in patients with multiple myeloma (MM) receiving PIs.

PATIENTS AND METHODS

Patients with relapsed MM initiating carfilzomib- or bortezomib-based therapy underwent baseline assessments and repeated assessments at regular intervals over 6 months, including cardiac biomarkers (troponin I or T, brain natriuretic peptide [BNP], and N-terminal proBNP), ECG, and echocardiography. Monitoring occurred over 18 months for development of CVAEs.

RESULTS

Of 95 patients enrolled, 65 received carfilzomib and 30 received bortezomib, with median 25 months of follow-up. Sixty-four CVAEs occurred, with 55% grade 3 or greater in severity. CVAEs occurred in 51% of patients treated with carfilzomib and 17% of those treated with bortezomib (P = .002). Median time to first CVAE from treatment start was 31 days, and 86% occurred within the first 3 months. Patients receiving carfilzomib-based therapy with a baseline elevated BNP level higher than 100 pg/mL or N-terminal proBNP level higher than 125 pg/mL had increased risk for CVAE (odds ratio, 10.8; P < .001). Elevated natriuretic peptides occurring mid-first cycle of treatment with carfilzomib were associated with a substantially higher risk of CVAEs (odds ratio, 36.0; P < .001). Patients who experienced a CVAE had inferior progression-free survival (log-rank P = .01) and overall survival (log-rank P < .001). PI therapy was safely resumed in 89% of patients, although 41% required chemotherapy modifications.

CONCLUSION

CVAEs are common during PI therapy for relapsed MM, especially with carfilzomib, particularly within the first 3 months of therapy. CVAEs were associated with worse overall outcomes, but usually, discontinuation of therapy was not required. Natriuretic peptides were highly predictive of CVAEs; however, validation of this finding is necessary before uniform incorporation into the routine management of patients receiving carfilzomib.

Preliminary evidence for cerebral capillary shunting in adults with sickle cell anemia

Elevated flow velocities in adults with sickle cell anemia (SCA) may cause rapid erythrocyte transit through capillaries. This phenomenon could present as dural venous sinus hyperintensity on arterial spin labeling (ASL)-MRI and could be indicative of capillary shunting. Here, the prevalence of ASL venous hyperintensities and association with relevant physiology in adults with SCA was investigated. SCA ( n = 46) and age-matched control ( n = 16) volunteers were recruited for 3.0 T MRI. Pseudo-continuous ASL-MRI was acquired for cerebral blood flow (CBF) calculation and venous hyperintensity determination; venous signal intensity and a categorical venous score (three raters; 0 = no hyperintensity, 1 = focal hyperintensity, and 2 = diffuse hyperintensity) were recorded. Flow velocity in cervical internal carotid artery segments was determined from phase contrast data (v_enc = 40 cm/s) and whole-brain oxygen extraction fraction (OEF) was determined from T₂-relaxation-under-spin-tagging MRI. Cerebral metabolic rate of oxygen was calculated as the product of OEF, CBF, and blood oxygen content. ASL venous hyperintensities were significantly ( p < 0.001) more prevalent in SCA (65%) relative to control (6%) participants and were associated with elevated flow velocities ( p = 0.03). CBF ( p < 0.001), but not OEF, increased with increasing hyperintensity score. Prospective trials that evaluate this construct as a possible marker of impaired oxygen delivery and stroke risk may be warranted.