New frontiers in pediatric Allo-SCT

Viral infections and immune reconstitution interaction after pediatric allogenic hematopoietic stem cell transplantation

Background: Viral infections are a major cause of morbidity and mortality after hematopoietic stem cell transplantation (HSCT). Although immune suppression plays a central role, the literature shows conflicting results on interplay between post-transplant immune reconstitution (IR) and viral infections. Methods: We prospectively studied viral infections and IR in 30 pediatric patients undergoing allogenic HSCT, with a follow-up time of 24 months. In total, 1337 blood (CMV, EBV, HHV-6, ADV and BKV) and urine (BKV and JCV) virus samples were analyzed. IR including B-cells (CD19+), T cells (CD3+, CD4+, CD8+) and NK-cells were measured. Clinical outcomes included overall survival (OS), non-relapse mortality (NRM), graft-versus-host disease (GVHD) and occurrence of blood culture positive bacterial infections. Results: We found BKV reactivation to be most frequent, 47% of the children had viremia and 77% viruria. The frequencies of CMV, HHV-6 and adeno viremia were 37%, 37% and 6%, respectively. Viremias beyond 3 months post-HSCT were uncommon. Factors such as GVHD, use of steroids, EBV and CMV infections and pre-transplant irradiation affected IR. No specific viral infection or IR related factor was associated to OS or NRM. Conclusions: Viral infections and IR interact in a bi-directional manner. Accordingly, close follow-up of both IR and viral loads is warranted.

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.

Five-year direct costs of acute lymphoblastic leukemia pediatric patients undergoing allogeneic stem cell transplant

Aim

To assess the 5-year healthcare resource utilization (HRU) and direct payer costs following allogeneic hematopoietic stem cell transplants (HSCTs) in acute lymphoblastic leukemia pediatric patients using data from two large US administrative databases.

Patients & methods

Among the 209 patients with acute lymphoblastic leukemia, HRU and costs were described over the up to 5 years after the HSCT.

Results

HRU and costs following the HSCTs were substantial. The highest average costs and most intensive HRU were observed within the first year following the HSCTs (49 outpatient visits; 29 laboratory service visits; 68 inpatient days), with a first year cost of US$683,099 and substantial costs over the following years.

Conclusion

HRU and direct costs associated with allogeneic HSCTs are substantial.

Cellular engineering and therapy in combination with cord blood allografting in pediatric recipients

Cord blood (CB) transplantation is an alternate source of human hematopoietic progenitor cells for allogeneic stem cell transplantation in children and adolescents with both malignant and nonmalignant diseases. Current limitations included delay in hematopoietic reconstitution, increased incidence of primary graft failure and slow cellular immunoreconstitution. These limitations lead to a significant increase in primary graft failure, infectious complications and increased transplant-related mortality. There is a number of experimental approaches currently under investigation including cellular engineering to circumvent these limitations. In this review, we summarize the recent findings of utilizing ex vivo CB expansion with Notch1 ligand Delta 1, mesenchymal progenitor cells, the use of human placenta-derived stem cells and CB-derived natural killer cells. Early and preliminary results suggest some of these experimental cellular strategies may in part ameliorate the incidence of primary graft failure, delays in hematopoietic reconstitution and/or slowness in cellular immune reconstitution following unrelated CB transplantation.