Prediction of target CD34 positive cells following leukopheresis in children with neuroblastoma

Autologous peripheral blood stem cell mobilization and apheresis in pediatric patients with cancer: A single-center report of 64 procedures

BACKGROUND

The published experience concerning autologous peripheral blood stem cell collection in children is very limited.

METHODS

The data of pediatric patients who underwent autologous stem cell mobilization and apheresis between January 2011 and April 2020 were analyzed retrospectively.

RESULTS

We studied retrospectively 64 mobilization and apheresis procedures in 48 pediatric patients (34 males, 14 females), mean age of 7.31 ± 5.38 (range, 1.5-19.7) years, the underlying disease was mostly neuroblastoma (NBL). The body weight of 21 patients (43.75%) was 15 kg or less. The targeted autologous peripheral stem cell apheresis (APSCA) was successfully achieved in 98% of patients. Neuroblastoma patients were younger than the rest of the patients and underwent apheresis after receiving fewer chemotherapy cycles than others and all of them mobilized within the first session successfully. Plerixafor was added to mobilization in nine heavily pretreated patients (18.7%), median two doses (range, 1-4 doses). 11 patients (22.9%) underwent radiotherapy (RT) before mobilization with doses of median 24 Gy (range, 10.8-54.0 Gy). Patients with RT were older at the time of apheresis and had received more chemotherapy courses than patients without RT. As a result, patients with a history of RT had significantly lower peripheral CD34+ cells and CD34+ yields than those without RT. In 17 patients (35.4%), 22 different complications were noted. The most common complications were catheter-related infections (n:10, 20.8%), followed by catheter-related thrombosis in eight patients (16.7%).

CONCLUSIONS

Patients who had far less therapy before apheresis were more likely to mobilize successfully. Our study provides a detailed practice approach including complications during APSCA aiming to increase the success rates of apheresis in transplantation centers.

The impact of recent vincristine on human hematopoietic progenitor cell collection in pediatric patients with central nervous system tumors

BACKGROUND

Central nervous system (CNS) malignancies represent 20% of all childhood cancers. To improve outcomes in infants and children with high-risk disease, treatment can include adjuvant chemotherapy and early autologous peripheral blood human progenitor cell collection (AHPCC), followed by high-dose chemotherapy and stem cell rescue. In many protocols, postoperative chemotherapy includes the administration of weekly vincristine (VCR) between induction chemotherapy cycles, regardless of scheduled AHPCC. We observed anecdotal AHPCC failures in children receiving midcycle VCR (MC-VCR).

STUDY DESIGN AND METHODS

The study was an 8-year retrospective chart review of all children with a CNS malignancy and who underwent AHPCC. Information included patient demographic and clinical data, mobilization regimen, VCR administration, product yields, infusion toxicity, and patient charges. Data were analyzed relative to MC-VCR administration. Graphics and statistical analysis (t-test, chi-square, linear regression) were performed with commercial software.

RESULTS

Twenty-four patients and 47 AHPCCs were available for analysis. Nine patients (37%) received MC-VCR within 7 days of scheduled AHPCC. MC-VCR was associated with delayed marrow recovery (17.9 days vs. 14.9 days, p=0.0012), decreased median peripheral CD34 counts (75 × 10(6) CD34/L vs. 352 × 10(6) CD34/L, p=0.03), decreased median CD34 yields (2.4 × 10(6) CD34/L vs. 17.8 × 10(6) CD34/kg, p=0.08), more AHPCCs per mobilization (2.9 vs. 1.1, p=0.01), and an increased rate of remobilization (33% vs. 6%). Mean patient charges were 2.5× higher in patients receiving MC-VCR than controls (p=0.01).

CONCLUSION

MC-VCR should be withheld before scheduled AHPCC to optimize CD34 collection.

Peripheral stem cell harvest using regular chemotherapy schedules in childhood cancer

Prediction of the best moment for the harvest of PBSCs after standard chemotherapy followed by filgrastim in children with cancer is difficult. We retrospectively analyzed the moment of harvesting of 152 procedures in 94 patients. The start of apheresis was guided by WBC count and CD34+ cell measurement in peripheral blood. We defined the first day of filgrastim administration, after completion of mobilizing chemotherapy, as day 1. Median time to harvest in different subgroups is as follows: neuroblastoma 11 days (range, 6-29 days), Ewing's sarcoma nine days (range, 7-15 days), brain tumor 10 days (range, 7-15 days), relapsed Wilms' tumor 16 days (range, 9-20 days), and extracranial GCT seven days (range, 6-14 days). Patients harvested after cyclophosphamide priming (time to harvest within a range of 8-9 days) were analyzed as a separate group. The optimal moment for harvesting in different types of tumors was highly variable, although most consistent in patients diagnosed with Ewing's sarcoma or brain tumors and after cyclophosphamide priming.

Analysis of pediatric autologous PBSC apheresis and transplant: age is a major factor affecting post-transplant toxicity

BACKGROUND

High-dose chemotherapy followed by autologous hematopoietic cell transplantation (HCT) is used in many therapeutic protocols for pediatric intra- and extra-cranial solid tumors. HCT can be curative, but is associated with significant toxicity.

PROCEDURE

Between January 2001 and June 2009, 92 solid tumor patients (age 6 months to 27 years) underwent 94 autologous apheresis procedures at Children's National Medical Center. Out of that group, 71 patients, who underwent 162 autologous HCT, were analyzed for transplant outcomes. Multiple variable modeling was used to identify independent variables related to transplant toxicity outcome measures, such as bacteremia, intensive care admission, and death. Other outcome measures (time to pre-apheresis peripheral blood CD34+ count, product yield, and time to engraftment) were also analyzed. Independent variables included patient-specific variables (age, weight, tumor type, chemotherapy administered, and primary vs. relapsed disease) and harvest or transplant-related variables (total white blood cell and CD34+ cell counts prior to transplant, and quantity of total nucleated cells and CD34+ cells infused during transplant).

RESULTS

Transplant toxicity was significantly greater in younger patients (P = 0.001) and in neuroblastoma patients (P = 0.003). The time to neutrophil engraftment, controlling for weight, age, and chemotherapy, was positively related to absolute CD34+ cells/kg infused (P = 0.01). The time to CD34+ recovery pre-apheresis was affected by patient diagnosis (P = 0.05).

CONCLUSIONS

Younger patients had increased transplant toxicity, with infants <1 year of age at highest risk for fever, bacteremia, admission to intensive care, and death. Infants would likely benefit from hospitalization after autologous HCT until neutrophil recovery.

Mobilization and collection of peripheral blood stem cells: guidelines for blood volume to process, based on CD34-positive blood cell count in adults and children

We report 189 mobilizations and 489 collections of peripheral blood stem cells (PBSC) performed in 139 autologous transplantation patients and in 28 donors for allogeneic transplantations whose ages ranged from 2-68 years. We observed a correlation (P < .001; Pearson's coefficient 0.64) between CD34-positive cells and granulocyte-macrophage colony-forming units examined to estimate PBSC. In a subset of 287 collections (97 adults and 49 children) we obtained peripheral blood (PB) CD34-positive cell counts at 2 to 4 hours before leukapheresis. We noted a correlation between PB CD34-positive cell counts before leukapheresis and the number of CD34-positive cells per kilogram of body weight collected in the whole apheresis of the day (P < .001; Pearson's coefficient 0.82). An even better correlation was obtained between PB CD34-positive cells preapheresis and the yield of each individual blood volume (BV) processed (P < .001; Pearson's coefficient 0.87). Healthy donors and patients in each age group behaved similarly. In addition, the collection yield was greater among children than adults. These findings allowed us to develop a simple predictive model to estimate the BV to process for a target dose of CD34-positive cells per kilogram, based on the level of PBSC before apheresis in children and adults.

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.

Granulocyte colony stimulating factor alters the phenotype of neuroblastoma cells: implications for disease-free survival of high-risk patients

INTRODUCTION

Granulocyte colony stimulating factor (GCSF) is commonly used for the treatment of chemotherapy-induced neutropenia. Despite high-dose intensive chemotherapy for advanced-stage neuroblastoma, the survival rate remains poor. Granulocyte colony stimulating factor therapy is quite common in these children; thus, we questioned its effect on neuroblastoma cells. We hypothesized that exogenous GCSF stimulates the proliferation and invasive character of neuroblastoma cells.

METHODS

Expression of a GCSF receptor in 5 different neuroblastoma cell lines was determined by polymerase chain reaction. In addition, we determined the effect of increasing doses of GCSF (0, 1 ng/mL, 10 ng/mL, 1 microg/mL, and 10 microg/mL) on DNA synthesis (BrdU assay), invasiveness (Matrigel invasion chambers), and cell proliferation.

RESULTS

We tested 5 neuroblastoma cell lines; all expressed the GCSF receptor. Granulocyte colony stimulating factor treatment resulted in significantly increased proliferation of SK-N-SH, SK-N-AS, and SHSY-5Y cells. Likewise, increased invasiveness of SK-N-SH cells was observed with GCSF treatment.

CONCLUSIONS

Our results indicate that neuroblastoma cell lines express the GCSF receptor and respond to exogenous GCSF by increased proliferation and invasiveness. These findings suggest that GCSF may stimulate the growth of neuroblastoma cells in patients undergoing high-dose chemotherapy with GCSF rescue and could have a significant impact on the ability to eradicate these tumors.