Peripheral blood stem cell collection in pediatric patients: feasibility of leukapheresis under anesthesia in uncompliant small children with solid tumors

Peripheral blood stem cell harvesting in young children weighing less than 15 kg

Autologous peripheral blood stem cell (PBSC) transplantation is crucial in pediatric cancer treatment, and tandem transplantation is beneficial in certain malignancies. Collecting PBSCs in small children with low body weight is challenging. We retrospectively analyzed data of pediatric cancer patients weighing <15 kg who underwent autologous PBSC harvesting in our hospital. Collections were performed in the pediatric intensive care unit over 2 or 3 consecutive days, to harvest sufficient stem cells (goal ≥2 × 106 CD34+ cells/kg per apheresate). From April 2006 to August 2021, we performed 129 collections after 50 mobilizations in 40 patients, with a median age of 1.9 (range, 0.6-5.6) years and a body weight of 11.0 (range, 6.6-14.7) kg. The median CD34+ cells in each apheresate were 4.2 (range, 0.01-40.13) × 106/kg. 78% and 56% of mobilizations achieved sufficient cell dose for single or tandem transplantation, respectively, without additional aliquoting. The preapheresis hematopoietic progenitor cell (HPC) count was highly correlated with the CD34+ cell yield in the apheresate (r = 0.555, P < 0.001). Granulocyte colony-stimulating factor alone was not effective for mobilization in children ≥2 years of age, even without radiation exposure. By combining the preapheresis HPC count ≥20/μL and the 3 significant host factors, including age <2 years, no radiation exposure and use of chemotherapy, the prediction rate of goal achievement was increased (area under the curve 0.787).

Safety of peripheral blood stem cell harvest in children under anaesthesia in the day care setting - A single centre experience

The use of cytokine mobilized peripheral blood stem cells (PBSC) for stem cell transplantation offers early engraftment, and less early transplant related mortality and morbidity. This can be done easily in the out-patient setting in an adult donor, but is difficult in children. The safety and efficacy of general anaesthesia outside the controlled operation room setting is quite challenging and demanding. We present our experience with paediatric PBSC harvest done under anaesthesia in the out-patient setting between January 2009 to June 2017. A total of 158 children underwent 164 PBSC harvests during the study period. Donors were predominantly females with a median age of 5 years (1-12) and a median weight of 17.5 kg (9.4-51). In 50% of the cases, induction of anaesthesia was by sevoflurane followed by total intravenous anaesthesia (TIVA) while in 32% it was sevoflurane induction followed by sedation. Hudson mask (48.5%) and laryngeal mask airway (50%) were the most common modes of airway and all patients were ventilated in the spontaneous mode. Propofol was the most commonly used maintenance agent (67%). There were no major complications except for acute pulmonary edema secondary to infusion of blood products requiring a short stay in ICU for one donor. All donors were discharged on the next day of harvest. No long term complications have been reported in any of these donors. Paediatric PBSC harvest can be safely done under anaesthesia with due precautions in the day care setting.

Comprehensive technical and patient-care optimization in the management of pediatric apheresis for peripheral blood stem cell harvesting

BACKGROUND

Pediatric apheresis for peripheral blood stem cell transplantation should be carried out with due concern for low corporeal blood volume and vulnerability to hypocalcemia-related complications, hypovolemic shock, and hypervolemic cardiac overload.

STUDY DESIGN AND METHODS

We retrospectively investigated a total of 267 apheresis procedures from 1990 to 2013 on 93 children between 0 and 10 years old, including 89 patients and 4 healthy donors, with body weights of 6.3 to 44.0 kg.

RESULTS

The median CD34+ cell yield per apheresis procedure was 2.3 × 10⁶ CD34+ cells/kg (0.2-77.9 × 10⁶ CD34+ cells/kg). Adverse events occurred in 11.6% of procedures (n = 31), including mild perivascular pain (n = 12), emesis (n = 9), hypotension (n = 3), urticaria (n = 2), numbness (n = 2), chest pain (n = 1), facial flush (n = 1), and abdominal pain (n = 1). Among hypotensive events, shock in a 9.6 kg one-year-old boy required emergency treatment in 1996. Thereafter, we adopted continuous injection of calcium gluconate, ionized calcium monitoring, central venous catheter access and circuit priming with albumin in addition to concentrated red cells. Since then we have had fewer complications: 16.4% per apheresis during 1990-1997 versus 5.8% during 1998-2013. No healthy pediatric donors suffered from any late-onset complications related to apheresis or G-CSF administration.

CONCLUSION

By employing appropriate measures, peripheral blood stem cell apheresis for small children can have an improved safety profile, even for children weighing <10 kg.

Large volume leukapheresis is efficient and safe even in small children up to 15 kg body weight

BACKGROUND

The collection of peripheral blood stem cells, although now a routine procedure, is still a challenge in low body weight children because of specific technical and clinical issues. For paediatric patients it is crucial to obtain an adequate number of CD34+ cells with the minimum number of procedures: this can be done using large volume leukapheresis (LVL).

MATERIALS AND METHODS

We analysed the efficacy and safety of 54 autologous LVL performed in 50 children (33 [66%] males and 17 [34%] females), median age 2 years (range, 1-5) and median body weight 12 kg (range, 6-15). The procedures were performed with a COBE Spectra previously primed with red blood cells; ACD-A solution and heparin were used as anticoagulants.

RESULTS

The target CD34+ cell dose (≥5×10/kg body weight) were collected with one LVL in 46 (92%) patients, while four (8%) patients needed another procedure. All our LVL were well tolerated. Side effects were observed in five (9.2%) patients and one procedure had to be discontinued because of catheter-related haemorrhage. The platelet count decreased significantly (p<0.001) after each procedure but without bleeding or need for transfusion support.

DISCUSSION

Our experience confirms that LVL is efficient and safe even in small children, if the procedure is adjusted considering the weight and age of child. The most important factors are good venous access, adequate preparation of the child's electrolyte status, and surroundings in which the small child as well as parents feel comfortable, and can tolerate the procedure better. Although a median platelet loss of 50% can be expected, LVL is safe and reduces the overall number of procedures required. It can be recommended for peripheral blood stem cell collection even in small body weight children with malignant diseases, particularly those who mobilise low numbers of CD34+ cells.

Mobilization and collection of CD34(+) cells for autologous transplantation of peripheral blood hematopoietic progenitor cells in children: analysis of two different granulocyte-colony stimulating factor doses

INTRODUCTION

The use of peripheral hematopoietic progenitor cells (HPCs) is the cell choice in autologous transplantation. The classic dose of granulocyte-colony stimulating factor (G-CSF) for mobilization is a single daily dose of 10μg/kg of patient body weight. There is a theory that higher doses of granulocyte-colony stimulating factor applied twice daily could increase the number of CD34(+) cells collected in fewer leukapheresis procedures.

OBJECTIVE

The aim of this study was to compare a fractionated dose of 15μg G-CSF/kg of body weight and the conventional dose of granulocyte-colony stimulating factor in respect to the number of leukapheresis procedures required to achieve a minimum collection of 3×10(6) CD34(+) cells/kg body weight.

METHODS

Patients were divided into two groups: Group 10 - patients who received a single daily dose of 10μg G-CSF/kg body weight and Group 15 - patients who received a fractioned dose of 15μg G-CSF/kg body weight daily. The leukapheresis procedure was carried out in an automated cell separator. The autologous transplantation was carried out when a minimum number of 3×10(6) CD34(+) cells/kg body weight was achieved.

RESULTS

Group 10 comprised 39 patients and Group 15 comprised 26 patients. A total of 146 apheresis procedures were performed: 110 (75.3%) for Group 10 and 36 (24.7%) for Group 15. For Group 10, a median of three (range: 1-7) leukapheresis procedures and a mean of 8.89×10(6) CD34(+) cells/kg body weight (±9.59) were collected whereas for Group 15 the corresponding values were one (range: 1-3) and 5.29×10(6) cells/kg body weight (±4.95). A statistically significant difference was found in relation to the number of apheresis procedures (p-value <0.0001).

CONCLUSIONS

To collect a minimum target of 3×10(6) CD34(+) cells/kg body weight, the administration of a fractionated dose of 15μg G-CSF/kg body weight significantly decreased the number of leukapheresis procedures performed.

Leukapheresis in children weighing less than 20 kg

Augmentation of standard chemotherapy with peripheral blood stem cells (PBSC) rescue is a standard treatment strategy. However, in pediatric patients weighing less than 20 kg, the collection of PBSC presents a challenge. We report our experience with nine pediatric patients weighing between 4.33 and 19.9 kg and a total of 23 PBSC collection aphereses. None of our patients experienced any major complications. We conclude that PBSC apheresis in children is a safe method. It should be based on a standardized procedure that includes the determination of clinical and laboratory parameters and appropriate monitoring.