Young Hematopoietic Stem Cell Transplantation Research Articles

Immunogenicity of Vero Cell Culture-derived Japanese Encephalitis Vaccine in Pediatric and Young Hematopoietic Stem Cell Transplantation Recipients.

Children and young adults undergoing hematopoietic stem cell transplantation (HSCT) typically lose their immunity to vaccine-preventable diseases, including Japanese encephalitis (JE). Revaccination against JE in this population has not been well characterized. This prospective study evaluated the immunogenicity of inactivated Vero cell culture-derived JE vaccine in children and young adults (<25 years of age) who had completed HSCT >1 year prior. Each patient received inactivated Vero cell culture-derived JE vaccine at enrollment and 1 month after enrollment, as well as a booster dose 13 months after enrollment. Serum JE plaque reduction neutralization test and JE-specific T lymphocyte count assay were performed at baseline, 1 month after the second dose, on the day of the booster dose, and 1 month after the booster dose. Thirty-seven patients were enrolled. At baseline, 15 patients (40.5%) had plaque reduction neutralization titer >10, which is considered protective. Among 22 seronegative patients, 15 (68.2%) and 19 (86.4%) exhibited seroconversion after revaccination and booster dose, respectively. Median JE-specific T lymphocyte counts also increased. Twenty of 111 (18.0%) vaccination doses resulted in self-limiting side effects. The inactivated Vero cell culture-derived JE vaccine may be safe and effective for immunization against JE virus in children and young adults who have undergone HSCT.

Active Music Engagement and Cortisol as an Acute Stress Biomarker in Young Hematopoietic Stem Cell Transplant Patients and Caregivers: Results of a Single Case Design Pilot Study.

This paper reports the results of a single case design pilot study of a music therapy intervention [the Active Music Engagement (AME)] for young children (age 3.51 to 4.53 years) undergoing hematopoietic stem cell transplantation (HCST) and their caregivers. The primary aims of the study were to determine feasibility/acceptability of the AME intervention protocol and data collection in the context of HCST. Secondary aims were to examine caregivers’ perceptions of the benefit of AME and whether there were changes in child and caregiver cortisol levels relative to the AME intervention. Results indicated that the AME could be implemented in this context and that data could be collected, though the collection of salivary cortisol may constitute an additional burden for families. Nevertheless, data that were collected suggest that families derive benefit from the AME, which underscores the need for devising innovative methods to understand the neurophysiological impacts of the AME.

Human cytomegalovirus-specific CD4+ and CD8+ T-cell response determination: Comparison of short-term (24h) assays vs long-term (7-day) infected dendritic cell assay in the immunocompetent and the immunocompromised host

Human cytomegalovirus (HCMV)-specific CD4(+) and CD8(+) T-cells were measured in the immunocompetent host as well as in 13 solid-organ transplant recipients (SOTR), and 12 young hematopoietic stem cell transplant recipients (HSCTR) by using a long-term (7-day) assay based on PBMC stimulation by HCMV-infected dendritic cells (iDC), and two short-term (24h) assays, one for CD4(+) stimulation by infected cell lysate (iCL), and the other for CD8(+) stimulation by a pool of 34 epitopic peptides (pep-pool). In the immunocompetent, the number of T-cells activated by either iCL or the pep-pool was significantly reduced with respect to iDC. In both SOTR and HSCTR, the number of T-cells activated by iDC was comparable to that activated by iCL or the pep-pool. A significant correlation between iDC-activated T-cells and T-cells activated by either iCL or the pep-pool was observed. In conclusion, whenever a rapid result is needed, short-term assays may efficiently replace the iDC assay.