Orphanet Journal of Rare Diseases | Impact of Hematopoietic Stem Cell Transplantation on Quality of Life and Caregiver Burden in Infantile Krabbe Disease

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This study systematically evaluates the impact of HSCT on quality of life and caregiver burden in Krabbe disease using large-scale caregiver-reported data, providing key empirical support for newborn screening decisions.

 

Literature Overview

This article, 'Caregiver-reported disease burden in Krabbe disease: evaluating outcomes of hematopoietic stem cell transplantation,' published in the Orphanet Journal of Rare Diseases, reviews and summarizes the efficacy of hematopoietic stem cell transplantation (HSCT) in infantile (IKD) and late-infantile Krabbe disease (LIKD), with a focus on assessing the impact of HSCT on patient quality of life and caregiver burden. Using a mixed-methods design combining quantitative scales (LQLA, Likert scale) and qualitative interviews, the study systematically analyzed data from 40 caregivers. Results show that early HSCT significantly improves quality of life in IKD patients and reduces physical, emotional, and social burdens on caregivers, providing crucial evidence to support newborn screening (NBS) policies. The study also highlights limitations of HSCT in improving gross motor function, suggesting the need for future exploration of novel interventions such as gene therapy. This is currently the largest patient-centered outcomes study, filling a critical evidence gap regarding real-world caregiving experiences with HSCT.

Background Knowledge

Krabbe disease (KD) is a rare autosomal recessive lysosomal disorder caused by mutations in the GALC gene, leading to deficiency of β-galactocerebrosidase and accumulation of glycosphingolipids (e.g., psychosine), resulting in demyelination of the central and peripheral nervous systems. The disease has variable phenotypes, with infantile Krabbe disease (IKD) being the most severe form, accounting for 85% of cases. Symptoms typically appear before age one and include irritability, hypertonia, developmental regression, seizures, and loss of vision and hearing. Untreated patients have a median life expectancy of approximately two years. Late-infantile Krabbe disease (LIKD) manifests between ages 1–3, with milder symptoms but still leading to severe neurological impairment. Currently, hematopoietic stem cell transplantation (HSCT) is the only treatment that can alter disease progression, and multiple studies confirm that pre-symptomatic HSCT can significantly delay disease advancement. However, the long-term efficacy of HSCT in improving gross motor function is limited, and transplant-related risks remain. Although KD has been included in the U.S. Recommended Uniform Screening Panel (RUSP), only a few states have implemented screening. Policymakers and families lack systematic quality-of-life data from the caregiver perspective when making HSCT decisions, especially regarding the impact of HSCT on family functioning, psychological burden, and economic stress. Therefore, this study aims to fill this critical evidence gap by collecting multidimensional caregiver-reported data, providing real-world evidence for policy and clinical decision-making.

 

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Research Methods and Experiments

The study employed a non-interventional, mixed-methods design, enrolling 40 caregivers of patients with IKD or LIKD, divided into four groups: early HSCT for IKD, late/untransplanted IKD, early HSCT for LIKD, and late/untransplanted LIKD. Participants were recruited through patient organizations such as KrabbeConnect and were required to provide diagnostic or genetic test reports for disease confirmation. After completing electronic informed consent, all participants filled out a questionnaire containing demographic information, the LQLA scale, and the EQ-5D-5L. Subsequently, the research team conducted 90-minute semi-structured phone interviews covering the disease's impact on patients and the physical and emotional burdens on caregivers. Qualitative data were analyzed using MAXQDA 2020 for thematic analysis. Quantitative data primarily used the LQLA (Leukodystrophy Quality of Life Assessment) to assess patient quality of life, Likert scales to assess caregiver burden, supplemented by weighted analysis—where caregivers allocated relative weights to disease and caregiving burdens within a 100-point scale. Statistical analysis used unpaired t-tests, with P<0.05 considered significant.

Key Conclusions and Findings

• Early HSCT significantly improves quality of life in IKD patients, with higher total LQLA scores and significantly better scores in communication and activities of daily living subscales compared to late/untransplanted groups
• In LIKD patients, early HSCT also shows a trend toward improved quality of life, with higher total LQLA scores and better daily living and motor skills, though small sample size limits statistical power
• Among IKD caregivers, early HSCT significantly reduces physical burden, particularly in holding, supporting, and stretching the child
• IKD caregivers who received early HSCT reported less burden in sleep quality, mental health, spousal relationships, and relationships with other children, with statistically significant differences
• Although all caregivers face significant emotional and social burdens, the late/untransplanted group more frequently reported extreme stressors such as despair, constant vigilance, prolonged hospitalization, and end-of-life care
• Early HSCT group caregivers were more concerned about school or treatment issues, insufficient healthcare system support, and lack of external resource information
• Among IKD caregivers, the late/untransplanted group reported higher rates of missed educational and career opportunities and spent more weekly caregiving hours
• Irritability is a common early symptom in IKD; 94.7% of the late/untransplanted group reported it, compared to only 20% in the early transplant group, suggesting HSCT may delay or mitigate this symptom

Research Implications and Outlook

This study is the first to systematically assess the impact of HSCT on Krabbe disease from the caregiver perspective, providing high-quality patient-centered evidence. Results indicate that early HSCT not only improves patient quality of life but also significantly reduces multidimensional caregiver burden, offering strong support for advancing newborn screening policies. The study emphasizes that 90% of early-transplanted IKD children were diagnosed via NBS, highlighting the critical role of NBS in enabling early intervention. These data can help policymakers weigh screening costs against long-term family and societal benefits, accelerating the inclusion of KD in NBS programs across more states.

The study also reveals limitations of HSCT, particularly in improving gross motor function, with caregivers still facing long-term caregiving pressures, especially as children age. This suggests future therapeutic strategies should go beyond HSCT to explore novel interventions such as gene therapy and small-molecule drugs. Additionally, the study identifies unmet needs regarding healthcare system support and access to external resources, recommending the development of a more comprehensive care model. Future research should expand LIKD sample sizes and conduct longitudinal follow-ups to more precisely evaluate the long-term effects of HSCT.

 

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Conclusion

This study represents the largest caregiver-reported outcomes study in Krabbe disease to date, systematically evaluating the impact of hematopoietic stem cell transplantation (HSCT) on quality of life and caregiver burden in infantile (IKD) and late-infantile Krabbe disease (LIKD). The findings show that early HSCT significantly improves quality of life in IKD patients, enhancing communication abilities and independence in daily living, while substantially reducing physical, emotional, and social burdens on caregivers—including improved sleep, mental health, and family relationships. Although the LIKD group had a smaller sample size, a trend toward improved quality of life was also observed. The study emphasizes that 90% of early-transplanted IKD children were diagnosed through newborn screening (NBS), underscoring the central role of NBS in enabling early intervention. These real-world data from caregivers provide critical evidence for policymakers, supporting the inclusion of Krabbe disease in newborn screening programs across more states. At the same time, the study highlights the limitations of HSCT in improving gross motor function, suggesting the need for future exploration of novel therapies such as gene therapy, and for strengthening comprehensive care support systems to further improve long-term outcomes for patients and families.

 

Nicholas Alexander Bascou, Skyler Jackson, Patti Engel, Paul Orchard, and Stacy Pike-Langenfeld. Caregiver-reported disease burden in Krabbe disease: evaluating outcomes of hematopoietic stem cell transplantation. Orphanet Journal of Rare Diseases.