Rabbit anti-human T-lymphocyte globulin and hematopoietic transplantation

Impact of Anti-T-lymphocyte globulin dosing on GVHD and Immune reconstitution in matched unrelated myeloablative peripheral blood stem cell transplantation

Data on the influence of different Anti-lymphocyte globulin (ATLG) doses on graft versus host disease (GVHD) incidence and immune reconstitution in matched unrelated (MUD) allogeneic Stem cell transplantation (allo-SCT) is limited. This retrospective study conducted at the University Medical-Center Hamburg compares GVHD and Immune reconstitution after myeloablative MUD (HLA 10/10) PBSC allogeneic stem cell transplant between 30 mg/Kg (n = 73) and 60 mg/Kg (n = 216) ATLG. Detailed phenotypes of T, B natural killer (NK), natural killer T (NKT) cells were analyzed by multicolor flow at day 30, 100, and 180 posttransplant. Neutrophil and platelet engraftments were significantly delayed in the 60 mg/kg group with a higher Cumulative incidence of Infections (67% vs 75% p = 0.049) and EBV (21% vs 41% p = 0.049) reactivation at day 100 in this group. In the 30 mg/kg group, we observed a faster reconstitution of naïve-B cells (p < 0.0001) and γδ T cells (p = 0.045) at day+30 and a faster naïve helper T-cell (p = 0.046), NK-cells (p = 0.035), and naïve B-cell reconstitution (p = 0.009) at day+180. There were no significant differences in aGVHD, cGVHD, NRM, RI, PFS, and OS between the groups. The choice of ATLG dose has significant impact on IR but not on GVHD after MUD-allo-SCT. Higher doses are associated with delayed engraftment and increased infections.

The Role of Allogeneic Hematopoietic Stem Cell Transplantation in Pediatric Leukemia

Allogeneic hematopoietic stem cell transplantation (HSCT) offers potentially curative treatment for many children with high-risk or relapsed acute leukemia (AL), thanks to the combination of intense preparative radio/chemotherapy and the graft-versus-leukemia (GvL) effect. Over the years, progress in high-resolution donor typing, choice of conditioning regimen, graft-versus-host disease (GvHD) prophylaxis and supportive care measures have continuously improved overall transplant outcome, and recent successes using alternative donors have extended the potential application of allotransplantation to most patients. In addition, the importance of minimal residual disease (MRD) before and after transplantation is being increasingly clarified and MRD-directed interventions may be employed to further ameliorate leukemia-free survival after allogeneic HSCT. These advances have occurred in parallel with continuous refinements in chemotherapy protocols and the development of targeted therapies, which may redefine the indications for HSCT in the coming years. This review discusses the role of HSCT in childhood AL by analysing transplant indications in both acute lymphoblastic and acute myeloid leukemia, together with current and most promising strategies to further improve transplant outcome, including optimization of conditioning regimen and MRD-directed interventions.

Hematopoietic Stem Cell Transplantation in Pediatric Acute Lymphoblastic Leukemia

PURPOSE OF REVIEW

The remarkable improvement in the prognosis of children with acute lymphoblastic leukemia (ALL) has been mainly achieved through the administration of risk-adapted therapy, including allogeneic hematopoietic stem cell transplantation (HSCT). This paper reviews the current indications to HSCT in ALL children, as well as the type of donor and conditioning regimens commonly used. Finally, it will focus on future challenges in immunotherapy.

RECENT FINDINGS

As our comprehension of disease-specific risk factors improves, indications to HSCT continue to evolve. Future studies will answer the year-old question on the best conditioning regimen to be used in this setting, while a recent randomized controlled study fixed the optimal anti-thymocyte globulin dose in unrelated donor HSCT. HSCT, the oldest immunotherapy used in clinical practice, still represents the gold standard consolidation treatment for a number of pediatric patients with high-risk/relapsed ALL. New immunotherapies hold the promise of further improving outcomes in this setting.