An educational symposium for patients with sickle cell disease and their families: results from surveys of knowledge and factors influencing decisions about hematopoietic stem cell transplant

Across the Myeloablative Spectrum: Hematopoietic Cell Transplant Conditioning Regimens for Pediatric Patients with Sickle Cell Disease

One out of every five hundred African American children in the United States has sickle cell disease (SCD). While multiple disease-modifying therapies are available, hematopoietic cell transplantation (HCT) remains the only curative option for children with SCD. HLA-matched sibling HCT has demonstrated excellent efficacy, but its availability remains limited; alternative donor strategies are increasingly explored. While Busulfan-Cyclophosphamide has become the most widespread conditioning regimen employed in HCT for pediatric SCD, many other regimens have been examined. This review explores different conditioning regimens across the intensity spectrum: from myeloablative to non-myeloablative. We describe survival and organ function outcomes in pediatric SCD patients who have received HCT and discuss the strengths and weaknesses of the various conditioning intensities. Finally, we posit novel directions in allogeneic HCT for SCD.

Navigating decisional conflict as a family when facing the decision of stem cell transplant for a child or adolescent with sickle cell disease

OBJECTIVE

Patients with sickle cell disease (SCD) face unpredictable disease, with stem cell transplant being a curative treatment option with risks. The aim of this study was to describe the level and source of decisional conflict in families of children/adolescents with SCD facing a transplant decision.

METHODS

A multiple-case study approach described decisional conflict in various SCD severity/donor risk decisional contexts. Cases included parents, child/adolescent with SCD, and sibling donor. The level and source of conflict was measured via O'Connor's Decisional Conflict Scale and analyzed using pattern-matching and cross-case synthesis. In-depth descriptions of conflict sources were obtained through thematic analysis of observation and interview data.

RESULTS

Among 11 participants in four cases (i.e. family units) decisional conflict was not unique not to the decisional context. Conflict levels represented a level that can be linked with feeling unsure and decisional delay. The theme, 'navigating decisional conflict together', described how family units discussed uncertainties.

CONCLUSION

Varying levels and sources of decisional conflict exist in pediatric patients with SCD and their families considering transplant.

PRACTICE IMPLICATIONS

In our cases, decisional conflict and the transplant decision occurred at the family-level. Clinicians should encourage all family members to participate in discussions concerning transplant.

Hydroxycarbamide exposure and ovarian reserve in women with sickle cell disease in the Multicenter Study of Hydroxycarbamide

The application of modern ovarian reserve measures to women with sickle cell disease (SCD) may help answer longstanding questions about whether SCD or hydroxycarbamide (HC; also known as hydroxyurea) affect women's reproductive lifespan. Anti-Müllerian hormone (AMH), an established marker of ovarian reserve, is used to assess the ovarian follicle pool. We used a standard clinical assay to measure AMH in 285 banked samples from 93 female subjects with haemoglobin SS from the historic Multicenter Study of Hydroxyurea (MSH), which led to the United States Food and Drug Administration approval of HC for adults with SCD. No samples from the randomised portion of the MSH remain, so samples from the decade-long MSH follow-up studies were analysed. Most subjects were exposed to HC (86/93). The median AMH levels were lower in study subjects than in age- and sex-matched reference values. The median AMH levels consistent with diminished ovarian reserve, a risk factor for infertility, occurred in subjects starting at the age of 25-30 years; in healthy women, this occurs after the age of 40 years. In multivariate analysis, taking HC was independently associated with a low AMH (β = 0·001, 95% confidence interval -0·002 to 0·000; P = 0·006). These results suggest that ovarian reserve is prematurely reduced in women with haemoglobin SS and raise the possibility that HC contributes to this finding.

Assessment of Patient and Caregiver Attitudes and Approaches to Decision-Making Regarding Bone Marrow Transplant for Sickle Cell Disease: A Qualitative Study

IMPORTANCE

Bone marrow transplant (BMT) is a potentially curative treatment for sickle cell disease (SCD). Patient and caregiver attitudes toward BMT for SCD and the willingness to accept risks of BMT vary, but these attitudes are not well understood.

OBJECTIVE

To understand patient and caregiver perceptions of and attitudes toward BMT for SCD and decision-making about BMT.

DESIGN, SETTING, AND PARTICIPANTS

Qualitative study of interview transcripts from a convenience sample. Transcripts were from adults with SCD and caregivers of patients with SCD recruited from national and regional SCD conferences, symposia, and sickle cell clinics in 2 cities. Interview transcripts were used from the needs assessment phase to develop a patient-decision aid in 2013 to 2014 (group 1) and from the baseline point in 2015 to 2016 (group 2) of the parent trial, a randomized clinical trial of adults and caregivers of patients with SCD to evaluate the effectiveness of a patient decision aid.

MAIN OUTCOMES AND MEASURES

Participant perspectives on decision-making regarding BMT for SCD.

RESULTS

Fifty-seven transcripts from adults with SCD and 50 transcripts from caregivers of patients with SCD were included. Median (interquartile range [IQR]) age of adults with SCD was 34 (21-50) years in group 1 and 30 (23-38) years in group 2. The median (IQR) age of caregivers was 42.5 (31-52) years in group 1 and 41 (35-46.5) years in group 2. Most transcripts from adults with SCD (75.0% in group 1 and 72.4% in group 2) and caregivers of patients with SCD (76.7% in group 1 and 85.0% in group 2) were from female participants. Bone marrow transplant was perceived as a treatment option associated with serious risks. Reported attitudes toward BMT occurred on a continuum ranging from unfavorable to favorable. Participants reported serious decisional dilemma regarding BMT for SCD. Most participants expressed interest in learning about BMT or curative treatments.

CONCLUSIONS AND RELEVANCE

This qualitative study found a continuum in attitudes toward BMT for SCD and highlights the complexity of decision-making in BMT for SCD. Patients and families with SCD expressed an interest in learning about BMT. Future prospective studies of patient decision-making regarding BMT, especially in the context of emerging curative and novel disease-modifying therapies for SCD, are warranted.

How I treat sickle cell disease with hematopoietic cell transplantation

Sickle cell disease (SCD) leads to significant morbidity and early mortality, and hematopoietic cell transplantation (HCT) is the only widely available cure, with impacts seen on SCD-related organ dysfunction. Outcomes are excellent following matched-related donor (MRD) HCT, leading to significantly expanded application of this treatment over the past decade. The majority of SCD patients lack an MRD, but outcomes following alternative donor HCT continue to improve on clinical trials. Within this framework, we aim to provide our perspective on how to apply research findings to clinical practice, for an individual patient. We also emphasize that the preparation of SCD recipients for HCT and supporting them through HCT have special nuances that require awareness and close attention. Through the use of clinical vignettes, we provide our perpsective on the complex decision-making process in HCT for SCD as well as recommendations for the evaluation and support of these patients through HCT.

Hematopoietic stem cell transplantation for sickle cell disease: Progress and challenges

Sickle cell disease (SCD) presents challenges to hematopoietic stem cell transplantation (HSCT), including donor availability and morbidity with age/disease severity. However, severe SCD causes irreversible organ damage that HSCT can mitigate. This benefit must be balanced against preparative regimen toxicity, graft-versus-host disease, and mortality risk. We review efforts to balance HSCT complications with the promise of cure, and knowledge gaps that warrant further investigation. We highlight the burden of SCD, HSCT risks and benefits, and SCD families' approach to this balance. We emphasize the necessity for information exchange to ensure a joint decision-making process between providers and patients.

Views of parents of children with sickle cell disease on pre-implantation genetic diagnosis

Pre-implantation genetic diagnosis (PGD) is an option for parents who have a child with sickle cell disease (SCD) to have another child without SCD. We conducted a survey of 19 parents with at least one child with SCD to investigate views on PGD. Before education, 44% of parents were aware of PGD. All parents rated PGD education as important. All parents considering another child also reported interest in using PGD if insurance covered its costs. Parents who have a child with SCD appear to be interested in PGD and educational tools informing this group about PGD should be developed.

Decision making in pediatric hematopoietic cell transplantation: Influential factors vary among diseases

Hematopoietic cell transplantation (HCT) is not a trivial treatment decision in pediatrics. We sought to understand what influences this decision-making process from the perspectives of the pediatric patients, their family, and physicians. Using integrative review methods, we identified 19 relevant studies: six qualitative, ten quantitative, and three mixed methods. Synthesis of the results revealed six themes describing patient, family, and provider decision-making processes with distinct subthemes contrasting influential factors among malignant and nonmalignant diseases. Identification of what influences HCT decision making will aid in development of decision support, education, and communication strategies. The child/adolescent voice and provider perspective warrant more attention.

Genetic treatment of a molecular disorder: gene therapy approaches to sickle cell disease

Effective medical management for sickle cell disease (SCD) remains elusive. As a prevalent and severe monogenic disorder, SCD has been long considered a logical candidate for gene therapy. Significant progress has been made in moving toward this goal. These efforts have provided substantial insight into the natural regulation of the globin genes and illuminated challenges for genetic manipulation of the hematopoietic system. The initial γ-retroviral vectors, next-generation lentiviral vectors, and novel genome engineering and gene regulation approaches each share the goal of preventing erythrocyte sickling. After years of preclinical studies, several clinical trials for SCD gene therapies are now open. This review focuses on progress made toward achieving gene therapy, the current state of the field, consideration of factors that may determine clinical success, and prospects for future development.

Current attitudes of parents and patients toward hematopoietic stem cell transplantation for sickle cell anemia

BACKGROUND

Allogeneic hematopoietic stem cell transplantation (HSCT) is the only available cure for sickle cell anemia (SCA). HSCT-associated risks are one of many barriers to its widespread use for SCA. The study objective was to assess parent and patient perceptions of HSCT in the era of more widespread knowledge about HSCT for SCA.

PROCEDURE

We surveyed parents of children with SCA and adolescents with SCA using the standard reference gamble paradigm. Survey responses between Africans (A) and African Americans (AA) and between parents and adolescents were compared.

RESULTS

Seventy-two percent (64/89) of the respondents were willing to accept ≥ 5% risk of mortality, while 57% said they would accept a risk of ≥ 10% of graft versus host disease (GVHD). Twenty-two percent were unwilling to accept any risk of mortality or GVHD. Risk averseness did not differ between A or AA respondents. Fifty-six percent of respondents were willing to accept infertility post-HSCT.

CONCLUSIONS

These data suggest that the majority of parents and adolescents are willing to accept the current risks associated with matched sibling HSCT for SCA. However, there continue to be significant numbers of parents and adolescents who are unwilling to accept any risk of HSCT-associated mortality or GVHD.

Gene therapy for hemoglobinopathies: the state of the field and the future

After nearly two decades of struggle, gene therapy for hemoglobinopathies using vectors carrying β or γ-globin gene has finally reached the clinical doorsteps. This was made possible by advances made in our understanding of critical regulatory elements required for high level of globin gene expression and improved gene transfer vectors and methodologies. Development of gene editing technologies and reprogramming somatic cells for regenerative medicine holds the promise of genetic correction of hemoglobinopathies in the future. This article will review the state of the field and the upcoming technologies that will allow genetic therapeutic correction of hemoglobinopathies.

The Future of Prenatal Diagnosis and Screening

The future of prenatal diagnosis and screening lies in developing clinical approaches and laboratory technologies applicable to genetic analyses and therapeutic interventions during embryonic development.

Themes reported by families as important when proceeding with pediatric hematopoietic stem cell transplantation

BACKGROUND

Hematopoietic stem cell transplantation (HSCT) is an accepted treatment for pediatric malignant and non-malignant conditions. Agreeing to HSCT can be challenging for families. This study explored themes reported by family members as influencing their acceptance of HSCT as a necessary treatment intervention.

PROCEDURE

In a four-site study, 107 individuals within 30 families pursuing HSCT for a pediatric malignancy, and 25 individuals within 6 families pursuing HSCT for a pediatric non-malignancy were interviewed pre-HSCT. Semantic content analysis was used in this secondary analysis to identify relevant themes.

RESULTS

Fifty-eight parents (and surrogates) 19 patients, 16 donor siblings, and 39 non-donor siblings, half-siblings and cousins, participated. Thirteen themes were identified as influencing the acceptance of HSCT. The most frequently reported were: "recommendation by the child's physician," viewing HSCT as the "best chance for cure," and "desiring a more normal and better quality of life for the patient and family." Seven themes were reported by all categories of family members, though at different frequencies. Two themes ("HSCT being part of the upfront treatment plan": "hearing of HSCT success in others") were only reported by the malignancy group, and one theme ("worrying about disease progression and losing a window of HSCT opportunity") was only reported by the non-malignancy group.

CONCLUSION

Parents, patients, and other family members can articulate multiple themes that influence their considerations of HSCT. Understanding these themes may guide discussions between families and healthcare teams.