PBSC collection in extremely low weight infants: a single-center experience

Small but mighty: Case report and practical guidance for peripheral blood stem cell collection in small infants

Modern apheresis devices, with increased procedural precision, automation, and monitoring, have been shown to allow for safe delivery of apheresis therapies in young children. Medical advances are increasing demand for apheresis procedures like mononuclear cell collection in infants <10 kg, including stem-cell supported chemotherapy, cell collection for chimeric antigen receptor T cell development, and now ex vivo gene therapies for rare genetic diseases. Nevertheless, safe delivery in small infants involves a range of unique considerations and challenges, beyond just size, and experience will vary between centers. In this case report we describe our experience performing mononuclear cell collection in our smallest patient to date and outline a practice guideline developed following a literature review and discussion with both international experts and device representatives. This case may help to inform other clinicians aiming to provide apheresis care to very small infants in their own centers.

Safety and efficacy of peripheral blood stem cells collection in healthy children and pediatric patients with thalassemia major weighing 20 kg or less

BACKGROUND

Peripheral blood stem cell (PBSC) collection in children poses challenges due to their small size, low body weight (BW), and unique pediatric physiology, especially among children weighing 20 kg (kg) or less.

METHODS

PBSC collection data of both healthy children and patients with thalassemia major (TM) weighing 20 kg or less between January 2013 and December 2020 were reviewed. Moreover, PBSCs characteristics along with various aspects of efficiency and safety between healthy donors and patients with TM were compared.

RESULTS

A total of 262 PBSC procedures were performed on 255 children. Of these, 91 procedures were carried out on 85 allogeneic healthy donors, and 171 auto-backup collections were performed on 170 patients with TM to ensure PBSC availability and prevent transplantation failure. A minimum pre-apheresis hemoglobin (HGB) level of 60 g/L was discovered to be safe and feasible in patients with TM. The median CD34+ cell dose in the PBSC product during the initial apheresis procedure was higher in healthy donors compared to patients with TM (7.29 ± 5.28 × 106 cells/kg vs5.88 ± 4.23 × 106 cells/kg, P = .043). The total CD34+ cells/kg recipient weight exhibited a positive correlation with pre-apheresis monocyte counts, but a negative correlation with donor weight. Apheresis significantly reduced hematocrit and platelet counts in the allogeneic group compared to the autologous group. Patients with TM experienced a higher occurrence of bone pain related to granulocyte colony-stimulating factor treatment. Notably, no serious complications related to PBSCs mobilization, central venous catheter placement, or the apheresis procedure were observed in either group.

CONCLUSIONS

PBSCs collection was both safe and effective in healthy children and pediatric patients with TM weighing 20 kg or less.

Peripheral blood stem cells collection by apheresis in very low-weight children with malignant diseases-A single center experience

BACKGROUND

Hematopoietic stem cell transplantation is used in the treatment of children with malignant and non-malignant diseases. However, apheresis of peripheral blood stem cells (PBSC) represents a challenge in children below 10 kg.

METHODS

A retrospective trial was conducted in the Cellular Therapy Department of Portuguese Oncology Institute of Porto.

INCLUSION CRITERIA

children with body weight inferior to 10 kg who underwent autologous PBSC apheresis until 2021. Demographic and clinical data were collected and our institutional protocol was described. COBE Spectra apheresis system (TerumoBCT, Lakewood, Colorado) until 2012 and then Spectra Optia (TerumoBCT) were used.

RESULTS

Sixteen leukocytaphereses were performed in 13 patients-nine females (69%). Mean age and weight were 13.31 months (±5.26) and 8.31 kg (±1.17), respectively. The initial CD34+ cells/μL in peripheral blood was 70.8 (±61.9). A central venous catheter (CVC) was exclusively used in all but one patient, in whom a peripheral vein was also required. In 10 procedures, both heparin and anticoagulant citrate dextrose solution-formula A (ACD-A) were used; in the remaining ones, only ACD-A was employed. The median duration of each procedure was 168 minutes (±45) and 2.96 blood volumes (±0.31) were processed. Median CD34+ cells yield per leukocytapheresis was 6.52 × 10⁶ /kg (±9.87 × 10⁶ ). CD34+ cell extraction rates were not significantly different between the two apheresis systems. Platelet and magnesium levels were significantly lower after collection (P < .001 and P = .009, respectively).

CONCLUSIONS

Although recommendations are lacking, we have successfully and safely performed leukocytaphereses in children with body weight below 10 kg. The authors believe that a permanent and dynamic comprehensive evaluation of each child is paramount for attaining good results.

Peripheral blood stem cell collection in children with extremely low body weight (≤8 kg). What have we learned over the past 25 years and where are the limits?

Hematopoietic progenitor cells-apheresis (HPC-A) collection is now a routine procedure for autologous hematopoietic stem cell transplantation. Here we present our 25 years' experience of HPC-A collection in children weighing 8 kg or less, with a focus on the evolution of our standard operating procedures, and the safety limits for these young patients, in the Pediatric Apheresis Unit of Clermont-Ferrand University Hospital (France). Fifteen children weighing 8 kg or less underwent 26 HPC-A collections over 25 years. Median CD34+ cell yield by leukapheresis was 4.4 10⁶ /kg. No procedure-related complications were encountered during or after the collection. No patient had profound thrombocytopenia or anemia that needed post-collection transfusions. Our experience in pediatric oncology patients who underwent HPC-A collections shows that this procedure can be performed even in the smallest of children with no increase in toxicity provided all precautions are taken to ensure that the procedure is carried out under the ideal conditions.

Performance and safety of femoral central venous catheters in pediatric autologous peripheral blood stem cell collection

INTRODUCTION

Autologous peripheral blood hematopoietic progenitor cell collection (A-HPCC) in children typically requires placement of a central venous catheter (CVC) for venous access. There is scant published data regarding the performance and safety of femoral CVCs in pediatric A-HPCC.

METHODS

Seven-year, retrospective study of A-HPCC in pediatric patients collected between 2009 and January 2017. Inclusion criteria were an age ≤ 21 years and A-HPCC using a femoral CVC for venous access. Femoral CVC performance was examined by CD34 collection rate, inlet rate, collection efficiency (MNC-FE, CD34-FE), bleeding, flow-related adverse events (AE), CVC removal, and product sterility testing. Statistical analysis and graphing were performed with commercial software.

RESULTS

A total of 75/119 (63%) pediatric patients (median age 3 years) met study criteria. Only 16% of children required a CVC for ≥ 3 days. The CD34 collect rate and CD34-FE was stable over time whereas MNC-FE decreased after day 4 in 80% of patients. CD34-FE and MNC-FE showed inter- and intra-patient variability over time and appeared sensitive to plerixafor administration. Femoral CVC showed fewer flow-related AE compared to thoracic CVC, especially in pediatric patients (6.7% vs. 37%, P = 0.0005; OR = 0.12 (95%CI: 0.03-0.45). CVC removal was uneventful in 73/75 (97%) patients with hemostasis achieved after 20-30 min of pressure. In a 10-year period, there were no instances of product contamination associated with femoral CVC colonization.

CONCLUSION

Femoral CVC are safe and effective for A-HPCC in young pediatric patients. Femoral CVC performance was maintained over several days with few flow-related alarms when compared to thoracic CVCs.