Hematology

Steven Hardy presents sickle cell findings at ASPHO annual meeting

Steven Hardy

Steven Hardy, Ph.D.

Steven Hardy, Ph.D. recently joined medical leaders in Montréal for the American Society of Pediatric Hematology/Oncology’s 30th Annual Meeting, where he and his team presented key findings from their cognitive and psychosocial research program involving youth with Sickle Cell Disease (SCD).
The first presentation, “Processing Speed and Academic Fluency in Youth With Sickle Cell Disease,” showed that, on average, children with SCD are less able to quickly and efficiently process information than their healthy counterparts. This weakness negatively impacted their academic performance, particularly in math fluency, and increased the children’s odds of having to repeat a grade in school.

A second presentation, “Quality of Life and School Absences in Children With Sickle Cell Disease With and Without Asthma,” explored the differences in quality of life between children with SCD only and children with both SCD and asthma (a common comorbidity). Dr. Hardy and his team found that children with both diseases tend to experience a greater impact on quality of life. Other factors – such as the child’s IQ and the family’s financial, material and social resources – moderated this risk.

The presentations were met with enthusiasm from renowned medical professionals from around the world, all of whom came together for collaborative and constructive sessions to move the needle on pediatric care.

test tubes

2016: A banner year for innovation

test tubes

In 2016, clinicians and research scientists working at Children’s National Health System published more than 1,100 articles in high-impact journals about a wide array of topics. A Children’s Research Institute review group selected the top articles for the calendar year considering, among other factors, work published in top-tier journals with impact factors of 9.5 and higher.

“Conducting world-class research and publishing the results in prestigious journals represents the pinnacle of many research scientists’ careers. I am pleased to see Children’s National staff continue this essential tradition,” says Mark L. Batshaw, M.D., Physician-in-Chief and Chief Academic Officer at Children’s National. “While it was difficult for us to winnow the field of worthy contenders to this select group, these papers not only inform the field broadly, they epitomize the multidisciplinary nature of our research,” Dr. Batshaw adds.

The published papers explain research that includes discoveries made at the genetic and cellular levels, clinical insights and a robotic innovation that promises to revolutionize surgery:

  • Outcomes from supervised autonomous procedures are superior to surgery performed by expert surgeons
  • The Zika virus can cause substantial fetal brain abnormalities in utero, without microcephaly or intracranial calcifications
  • Mortality among injured adolescents was lower among patients treated at pediatric trauma centers, compared with adolescents treated at other trauma center types
  • Hydroxycarbamide can substitute for chronic transfusions to maintain transcranial Doppler flow velocities for high-risk children with sickle cell anemia
  • There is convincing evidence of the efficacy of in vivo genome editing in an authentic animal model of a lethal human metabolic disease
  • Sirt1 is an essential regulator of oligodendrocyte progenitor cell proliferation and oligodendrocyte regeneration after neonatal brain injury

Read the complete list.

Dr. Batshaw’s announcement comes on the eve of Research and Education Week 2017 at Children’s National, a weeklong event that begins April 24. This year’s theme, “Collaboration Leads to Innovation,” underscores the cross-cutting nature of Children’s research that aims to transform pediatric care.

Blood Transfusion

Hydroxycarbamide effective in sickle cell stroke prevention

Blood Transfusion

Hydroxycarbamide treatment is on par with blood transfusions for preventing stroke in patients with sickle cell anemia.

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What’s known

Strokes are common and devastating complications for patients with sickle cell anemia, often leading to severe and lifelong motor and neurocognitive problems for people with this congenital blood disorder. Results of a clinical trial published in 1998 showed that having regular blood transfusions could reduce the risk of having a first stroke by 90 percent in children with sickle cell anemia. Since then, doctors have employed this prophylactic treatment widely. However, blood transfusions can be painful, inconvenient and carry substantial risks themselves — including the potential of blood-borne infections, iron overload and immune-related reactions to blood products. Finding a way to reduce stroke risk without over-relying on blood transfusions could substantially benefit patients with sickle cell anemia.

What’s new

A team of researchers, including Naomi L.C. Luban, M.D., a Children’s National Health System hematologist and laboratory medicine specialist, tested transfusions against a drug treatment called hydroxycarbamide in a clinical trial to see if the pharmaceutical intervention could reduce strokes at least as well as transfusions. The clinical trial, known as “TCD With Transfusions Changing to Hydroxyurea (TWiTCH),” assigned 60 patients with sickle cell anemia who had abnormally high transcranial Doppler (TCD) flow velocities—a measure of blood flow in the brain that suggests elevated risk of stroke—to receive hydroxycarbamide instead of transfusions. The research team compared the outcomes for these patients with 61 other patients who received standard prophylactic transfusions. Over the 24-month study period, neither group experienced any strokes, although three transient ischemic attacks (a temporary blockage of blood flow in the brain) occurred in each group. These comparable findings suggest that hydroxycarbamide treatment, also known as hydroxyurea, is on par with transfusions for preventing strokes in patients with sickle cell anemia.

Questions for future research

Q: Does hydroxycarbamide offer a long-term way for patients with sickle cell anemia to avoid transfusions?
Q: Could hydroxycarbamide help patients with sickle cell anemia who already have suffered a stroke or who have had severe problems with blood vessels in their brains that impair blood flow?
Q: Which other treatments can help patients avoid the myriad complications that accompany sickle cell anemia?

Source: Hydroxycarbamide versus chronic transfusion for maintenance of transcranial doppler flow velocities in children with sickle cell anemia—TCD With Transfusions Changing to Hydroxyurea (TWiTCH): A multicentre, open-label, phase 3, non-inferiority trial.” Ware, R.E. B. R. Davis, W. H. Schultz, R.C. Brown, B. Aygun, S. Sarnaik, I. Odame, B. Fuh, A. George, W. Owen, L. Luchtman-Jones, Z.R. Rogers, L. Hilliard, C. Gauger, C. Piccone, M.T. Lee, J.L. Kwiatkowski, S. Jackson, S.T. Miller, C. Roberts, M.M. Heeney, T.A. Kalfa, S. Nelson, H. Imran, K. Nottage, O. Alvarez, M. Rhodes, A.A. Thompson, J.A. Rothman, K.J. Helton, D. Roberts, J. Coleman, M.J. Bonner, A. Kutlar, N. Patel, J. Wood, L. Piller, P. Wei, J. Luden, N.A. Mortier, S.E. Stuber, N. L. C. Luban, A.R. Cohen, S. Pressel and R.J. Adams. Published by The Lancet on Feb. 13, 2016.

cord blood

T-cell therapy success for relapsing blood cancer

cord blood

A unique immunotherapeutic approach that expands the pool of donor-derived lymphocytes (T-cells) that react and target three key tumor-associated antigens (TAA) is demonstrating success at reducing or eliminating acute leukemias and lymphomas when these cancers have relapsed following hematopoietic stem cell transplant (HSCT).

“There’s currently a less than 10 percent chance of survival for a child who relapses leukemia or lymphoma after a bone marrow transplant—in part because these patients are in a fragile medical condition and can’t tolerate additional intense therapy,” says Kirsten Williams, M.D., a blood and marrow transplant specialist in the Division of Hematology at Children’s National Health System, and principal investigator of the Research of Expanded multi-antigen Specifically Oriented Lymphocytes for the treatment of VEry High Risk Hematopoietic Malignancies (RESOLVE) clinical trial.

The unique manufactured donor-derived lymphocytes used in this multi-institutional Phase 1 dose-ranging study are receptive to multiple tumor-associated antigens within the cell, including WT1, PRAME, and Survivin, which have been found to be over-expressed in myelodysplastic syndromes (MDS), acute myeloid leukemia (AML), B-cell AML/MDS, B-cell acute lymphoblastic leukemia (ALL), and Hodgkins lymphoma. Modifying the lymphocytes for several antigens, rather than a single target, broadens the ability of the T-cells to accurately target and eradicate cancerous cells.

Preliminary results demonstrate a 78 percent response rate to treatment, and a 44 percent rate of total remission for participating patients. To date, nine evaluable patients with refractory and relapsed AML/MDS, B-cell ALL, or Hodgkins lymphoma have received 1-3 infusions of the expanded T-cells, and of those, seven have responded to the treatment, showing reduction in cancer cells after infusion with little or no toxicity. All of these patients had relapse of their cancer after hematopoietic cell transplantation. The study continues to recruit eligible patients, with the goal of publishing the full study results within the next 12 months.

“Our preliminary data also shows that this new approach has few if any side effects for the patient, in part because the infused T-cells target antigens that are found only in cancer cells and not found in healthy tissues,” Dr. Williams notes.

The approach used to expand existing donor-derived TAA-lymphocytes, rather than using unselected T cells or genetically modified T-cells as in other trials, also seems to reduce the incidence of post infusion graft versus host disease and other severe inflammatory side effects. Those side effects typically occur when the infused lymphocytes recognize healthy tissues as foreign and reject them or when the immune system reacts to the modified elements of the lymphocytes, she adds.

“These results are exciting because they may present a truly viable option for the 30 to 40 percent of children who will relapse post-transplant,” Dr. Williams concludes. “Many of the patients who participated were given two options: palliative care or this trial. To see significant success and fewer side effects gives us, and families with children facing relapsing leukemia, some hope for this new treatment.”

Dr. Williams discussed the early outcomes of the RESOLVE trial during an oral presentation at the American Society for Blood and Marrow Transplantation meeting on February 22, 2017.

“The early indicators are very promising for this patient population,” says Catherine Bollard, M.D., M.B.Ch.B., Chief of the Division of Allergy and Immunology, Director of the Program for Cell Enhancement and Technologies for Immunotherapy (CETI) at Children’s National, and senior author of the study. “If we can achieve this, and continue to see good responses with few side effects, it’s possible these methods could become a viable alternative to HSCT for patients with no donor match or who aren’t likely to tolerate transplant.”

This is one of the first immunotherapeutic approaches to successfully capitalize on the natural ability of human T-cells to kill cancer, though previous research has shown significant success for this approach in reducing the deadly impact of several viruses, including Epstein-Barr virus, adenovirus, and cytomegalovirus, post HSCT. These new findings have led to the development of additional clinical trials to investigate applications of this method of TAA-lymphocyte manufacture and infusion for pre-HSCT MDS/AML, B-cell ALL, Hodgkins Lymphoma, and even some solid tumors.

In Brief- Fetal Medicine

Cognitive training exercises at home help kids with sickle cell boost visuospatial working memory

A team led by Children’s National Health System clinicians and research scientists attempted to identify novel approaches to boost working memory in children who suffer from sickle cell disease.

A team led by Children’s National Health System clinicians and research scientists attempted to identify novel approaches to boost working memory in children who suffer from sickle cell disease.

Youths with sickle cell disease who used hand-held computers to play game-like exercises that get harder as a user’s skill level rises improved their visuospatial working memory (WM). Children with sickle cell disease, however, completed fewer training sessions during an initial study compared with children with other disease-related WM deficits.

A team led by Children’s National Health System clinicians and research scientists attempted to identify novel approaches to boost WM in children who suffer from sickle cell disease. Kids who have this red blood cell disorder inherit abnormal hemoglobin genes from each parent. Rather than slipping through large and small vessels to ferry oxygen throughout the body, their stiff, sickle-shaped red blood cells stick to vessel walls, impeding blood supply and triggering sudden pain. Children with sickle cell disease have more difficulty completing tasks that place demands on one’s WM, the brain function responsible for temporarily remembering information and manipulating that information to facilitate learning and reasoning. As a result, they’re more likely to repeat a grade, require special academic services, and to have difficulty maintaining employment as adults.

Because computerized cognitive training programs have been used with success to boost WM for children with other health conditions, such as childhood cancer, the research team sought to examine the feasibility of using the technique for kids with sickle cell disease. “This small study highlights the challenges and opportunities of implementing a home-based cognitive training intervention with youths who have sickle cell disease,” says Steven J. Hardy, PhD, a pediatric psychologist in the Divisions of Hematology, Oncology, and Blood and Marrow Transplantation at Children’s National. “While a larger, randomized controlled clinical trial is needed to better characterize efficacy, our initial work indicates that Cogmed is acceptable and moderately feasible in this population.”

Children’s National is home to the Sickle Cell Disease (SCD) Program, one of the nation’s largest, most comprehensive pediatric programs that cares for 1,350 patients younger than 21 annually. Over 15 months, the team recruited youths aged 7 to 16 participating in the program who had an intelligence quotient of at least 70 and an absolute or relative memory deficit. Those who lacked access to a tablet computer were loaned an iPad Mini 2 loaded with Cogmed RM, an interactive audiovisual cognitive training program that consists of exercises that get progressively more challenging. A clinical psychologist provided coaching and moral support through weekly telephone calls to review progress and challenges, and to offer tips on how to optimize the youths’ progress.

Six of 12 eligible participants – all girls – completed by finishing at least 20 sessions of the program. The mean number of sessions completed was 15.83, and the kids spent a median of 725 minutes working actively on Cogmed exercises. “Participants who completed Cogmed indicated that they perceived greater levels of social support from teachers,” Hardy and colleagues write in the study, published by Pediatric Blood & Cancer. “[T]here was not a statistical difference in perceived parent support.”

Among those children who completed Cogmed, standard scores increased an average of 5.05 on a measure of visuospatial short-term memory, 19.72 on a measure of verbal WM, 27.53 on a measure of visuospatial short-term memory, and 23.82 on a measure of visuospatial WM. The researchers also observed a normalizing of memory functioning for those who finished Cogmed, as a significant portion of participants scored below the average range before using Cogmed and most scored in the average range or higher on memory tests after finishing the program.

“In this initial feasibility trial, adherence to Cogmed was lower than expected (50 percent completion) compared to adherence rates of other samples of children with medical histories, including patients with symptomatic epilepsy and youth treated for cancer,” Hardy and co-authors write. “Thus, additional modifications may be needed to achieve consistent delivery of the intervention to youth with SCD.”

Related Resources: Research at a Glance

Feasibility of home-based computerized WM training for sickle cell disease

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What’s Known
Cognitive deficits are a common complication affecting about one-third of kids who have the higher risk sickle cell disease genotypes, HbSS and HbSβ0 thalassemia. While such deficits have been well-documented, no treatment has been proven to recover cognitive function for kids with sickle cell disease. Sickle cell disease is a group of red blood cell disorders in which abnormal genes that children inherit from parents cause their bodies to make sickle-shaped hemoglobin S. Kids with sickle cell disease are at heightened risk for neurocognitive deficits, which can have practical implications for their ability to learn and to succeed academically.

What’s New
Because home-based computerized cognitive training programs have helped to improve working memory (WM) for children with epilepsy and for childhood cancer survivors, a team led by Children’s National Health System researchers and clinicians sought to gauge the feasibility of using such an approach for a small number of children with sickle cell disease. The pilot study found that girls were more likely to complete the cognitive training exercises than boys. Additionally, children whose teachers showed a high level of support spent more time working on the exercises, completed more sessions, and were more likely to finish the program. The mean number of completed sessions was 15.83. Participants who reported experiencing fewer functional limitations as a result of sickle cell disease-related pain completed more sessions. Overall, children who completed Cogmed exercises showed improvements in verbal WM, and visuospatial short-term memory and WM.

Questions for Future Research
Q: Because sickle cell disease is often accompanied by sudden attacks of severe pain, would concurrent delivery of pain-management interventions impact children’s ability to complete cognitive training exercises?
Q: Would adding functional magnetic resonance imaging help to clarify the association between adaptive cognitive skills training and changes to physiological processes, such as alterations in prefrontal and parietal cortical activity, and functional connectivity?

Source: S.J. Hardy, K.K. Hardy, J.C. Schatz, A.L. Thompson, and E.R. Meier. Feasibility of Home-Based Computerized Working Memory Training With Children and Adolescents With Sickle Cell Disease.” Published online by Pediatric Blood & Cancer May 26, 2016.

Feasibility of home-based computerized working memory training with sickle cell disease patients

Children with sickle cell disease are at heightened risk for neurocognitive deficits. The research team sought to fill a gap in the research by evaluating the feasibility of using a home-based computerized working memory (WM) training intervention for children aged 7 to 16 years with sickle cell disease. Study participants used loaner iPads and were asked to work on Cogmed five days a week for five weeks – or a maximum of 25 sessions. According to research published by Pediatric Blood and Cancer, girls were more likely to complete the assignments, compared with boys. The mean number of sessions completed was 15.83.