Outcomes of pediatric patients with therapy-related myeloid neoplasms.

Long-term outcomes after allogeneic hematopoietic cell transplantation (HCT) for therapy-related myeloid neoplasms (tMNs) are dismal. There are few multicenter studies defining prognostic factors in pediatric patients with tMNs. We have accumulated the largest cohort of pediatric patients who have undergone HCT for a tMN to perform a multivariate analysis defining factors predictive of long-term survival. Sixty-eight percent of the 401 patients underwent HCT using a myeloablative conditioning (MAC) regimen, but there were no statistically significant differences in the overall survival (OS), event-free survival (EFS), or cumulative incidence of relapse and non-relapse mortality based on the conditioning intensity. Among the recipients of MAC regimens, 38.4% of deaths were from treatment-related causes, especially acute graft versus host disease (GVHD) and end-organ failure, as compared to only 20.9% of deaths in the reduced-intensity conditioning (RIC) cohort. Exposure to total body irradiation (TBI) during conditioning and experiencing grade III/IV acute GVHD was associated with worse OS. In addition, a diagnosis of therapy-related myelodysplastic syndrome and having a structurally complex karyotype at tMN diagnosis were associated with worse EFS. Reduced-toxicity (but not reduced-intensity) regimens might help to decrease relapse while limiting mortality associated with TBI-based HCT conditioning in pediatric patients with tMNs.

Double apheresis of peripheral blood stem cells in a single day in children mobilized by granulocyte colony-stimulating factor for transplantation.

Due to the movement of hematopoietic stem cells through the bone marrow environment, it may be possible to effectively harvest peripheral blood stem cells in a second apheresis within a few hours after a first apheresis. In a retrospective analysis, 107 aphereses were performed in consecutive 33 pediatric and six healthy pediatric donors who received granulocyte-colony stimulating factor at 10 microg/kg/day or 400 microg/m(2)/day for five days. The median age and weight of cases were seven yr (range 1-19) and 20 kg (range 8-87). The toxicities related to apheresis procedure were minimal in both aphereses. In 22 double aphereses, the average number of CD34-positive cells per body weight (kg) collected was 5.3 +/- 4.2 (range 0.6-16.6) and 4.7 +/- 3.1 (range 0.2-10.9) x 10(6) in the first and second aphereses, respectively (p = 0.569). Multivariate analysis showed that number of CD34-positive cells collected in the first apheresis (p = 0.008) was an independent factor of increased CD34-positive cells in the second apheresis. Double apheresis in a single day was feasible and this procedure may be able to lessen the burden of apheresis compared to two consecutive-day apheresis.

Successful allogeneic unrelated bone marrow transplantation using reduced-intensity conditioning for the treatment of X-linked adrenoleukodystrophy in a one-yr-old boy.

The childhood cerebral form of X-linked ALD is a demyelinating disorder of the central nervous system, which rapidly leads to total disability and death. Allogeneic stem cell transplantation benefits patients who show early evidence of the demyelination. We report here a one-yr-old boy with ALD who received HLA-matched unrelated BMT in an early stage of the disease after careful planning and observation since his birth. BMT was performed when MRI began to show slight signal intensity changes in the white matter of the brain. Pretransplant conditioning consisted of fludarabine, l-PAM and TBI (2 Gy). GVHD prophylaxis consisted of cyclosporine A and short-course methotrexate. The patient showed an uneventful BMT course with fast and stable engraftment. Following BMT, the plasma levels of VLCFA decreased gradually and MRI changes improved. The patient did not have any evidence of further neurological deterioration 22 months following the transplant. Although this is still a short follow-up, it has been shown that BMT should be considered when a child has a biochemical diagnosis and MRI findings of ALD without any neurological signs. RIST should be considered as a pretransplant conditioning for ALD.

Treatment of unresectable malignant rhabdoid tumor of the orbit with tandem high-dose chemotherapy and gamma-knife radiosurgery.

Malignant rhabdoid tumor (MRT) is a rare and highly aggressive tumor that primarily occurs in very young children. We report here a patient with a primary MRT of the orbit who received tandem high-dose chemotherapy and gamma-knife radiosurgery. Although the tumor was not completely removed, and the initial chemotherapy failed, the patient achieved long-term survival after this modality of treatment. This approach may be one to be further considered in patients with MRT.

Effect of granulocyte colony-stimulating factor on bone metabolism during peripheral blood stem cell mobilization.

Granulocyte colony-stimulating factor (G-CSF) has been shown to affect the biochemical markers of bone metabolism, including serum bone alkaline phosphatase (BALP), serum osteocalcin, and urine deoxypyridinoline. To determine the association between bone resorption and formation and the G-CSF-induced mobilization of peripheral blood stem cells (PBSC), we examined these markers during mobilization in 19 healthy donors. The average (+/- SEM) serum BALP level before treatment was 81.6 +/- 17.0 IU/dL, and the level increased significantly to 117.7 +/- 15.8 IU/dL on day 5 of G-CSF administration (P < .0001). The urine deoxypyridinoline level before treatment was 12.3 +/- 2.4 nmol/mmol creatinine, and this level also increased significantly to 19.4 +/- 3.0 nmol/mmol creatinine on day 5 of G-CSF administration (P < .0001). In contrast, the average level of serum osteocalcin significantly decreased from 8.07 +/- 2.88 ng/mL to 1.53 +/- 0.18 ng/mL on day 5 (P = .0353). During G-CSF administration, we also studied the serum levels of various cytokines (IL-1beta, osteoclastogenesis inhibitory factor [OCIF], IL-6, tumor necrosis factor alpha, transforming growth factor beta, interferon-gamma, macrophage colony-stimulating factor) related to bone metabolism. Only the kinetics of OCIF were significantly affected. The serum level of OCIF increased immediately after the start of G-CSF administration and remained high during G-CSF administration. These results demonstrate that high-dose G-CSF affects bone metabolism and that OCIF may play a role in bone metabolism. Consistent with the notion that G-CSF affects bone metabolism, a significant correlation was observed between CD34+ cell yield and the increase in urine deoxypyridinoline but not for the changes in serum BALP and osteocalcin levels. This result suggests that bone resorption is either directly or indirectly related to the mobilization of PBSC by G-CSF.