Peripheral venous catheter collection of immune effector cells and hematopoietic stem cells is feasible and safe in older pediatric patients.

BACKGROUND: The Collection of hematopoietic stem cells (HSC) and immune effector cells (IEC) has unique challenges in children. To maintain adequate blood flow, central venous catheters (CVCs) remain the standard of care in many centers, but are associated with procedural risks and increased resource utilization. The goal of this study was to determine feasibility and safety of peripheral venous catheter (PVC) cell collection in older children. METHODS: Patients and donors requiring venous access with weight >25 kg, age >8 years were screened for PVC collection via 18G PVCs. Those with poor venous access (on history/exam/pre-screening ultrasound) or unable to maintain suitable procedural position were excluded. Comparison was made to CVC collections in a matched patient cohort. RESULTS: Thirty-eight individuals were screened and met age/weight criteria for PVC collection. Five did not have PVC collection attempted due to poor access (n = 4) or behavioral concerns (n = 1). Thirty-three had PVC collection attempt (HSC = 22; IEC = 11) with median age 15.3 year (range 9.7-18.0) and weight 58.5 kg (range 27.9-115.4). Thirty-two of 33 (97%) patients were collected successfully by PVC without adverse events. Comparing PVC to matched CVC collection cohort (n = 18), there was no significant difference in flow rate (48.2 mL/h vs 53.9 mL/h, p = 0.12), collection time (266 min vs 262 min, p = 0.85) or collection efficiency (IEC/CD3 60.9% vs 60.8% p = 0.99; HSC/CD34 53.6% vs 41.3% p = 0.05). CONCLUSION: PVC collection of HSC and IEC is feasible and safe in older children with comparable collection efficiency to CVC collections. Ultrasound screening may reduce failure rates. PVC collections can reduce the risk of CVC insertions and associated healthcare costs.

Comparison between intermittent and continuous leukapheresis protocols for autologous hematopoietic stem cell collections in children.

BACKGROUND: Peripheral hematopoietic stem cell (HSC) collections are needed for autologous hematopoietic stem cell transplantation (HSCT). Since 2015, our institution has utilized a secondary chamber mononuclear cell (MNC) protocol on the Spectra Optia apheresis system. Recently, a new continuous mononuclear collection protocol (CMNC) was developed for the same device. As there is limited data available regarding the use of the CMNC protocol in children, we compared collection efficiency (CE2), side effects, and clinical feasibility between the two protocols in patients <18 years old. STUDY DESIGN AND METHODS: We prospectively collected clinical, laboratory, and technical collection data from HSC collection procedures performed with the Spectra Optia apheresis system utilizing the CMNC protocol. Data were compared to retrospectively collected data utilizing the MNC protocol. Data collection included donor demographics, precollection peripheral CD34+ cell counts, total CD34+ cells collected, collection efficiency, side effects, and collection product characteristics. RESULTS: A total of 96 HSC collection procedures were performed on 79 pediatric patients utilizing either the MNC (61 patients) or CMNC (18 patients) protocol. The collection efficiencies were comparable between MNC and CMNC cohorts (52.9% vs 54.9%, P = 0.711). Platelet loss was significantly lower in the CMNC cohort (P = 0.002), especially in children weighing <15 kg. Product volumes were higher with CMNC. No significant collection-related side effects were noted with either protocol. CONCLUSIONS: MNC and CMNC protocols have comparable collection efficiencies and are both feasible and safe for the use in children. Centers may choose between the methods depending on clinical needs.

Optimizing autologous nonmobilized mononuclear cell collections for cellular therapy in pediatric patients with high-risk leukemia.

BACKGROUND: The manufacturing of cellular products for immunotherapy, such as chimeric antigen receptor T cells, requires successful collection of mononuclear cells. Collections from children with high-risk leukemia present a challenge, especially because the established COBE Spectra apheresis device is being replaced by the novel Spectra Optia device (Optia) in many institutions. Published experience for mononuclear cell collections in children with Optia is lacking. Our aim was to compare the two collection devices and describe modified settings on the Optia to optimize mononuclear cell collections. STUDY DESIGN AND METHODS: As a quality initiative, we retrospectively collected and compared data from mononuclear cell collections on both devices. Collected data included patient's clinical characteristics; collection parameters, including precollection lymphocyte/CD3 counts, total blood volumes processed, runtimes, and side effects (including complete blood count and electrolyte changes); and product characteristics, including volumes and cell counts. Collection efficiencies and collection ratios were calculated. RESULTS: Twenty-six mononuclear cell collections were performed on 20 pediatric patients: 11 with COBE and 15 with Optia. Adequate mononuclear cell products were successfully collected with a single procedure from all patients except one, with mean calculated mononuclear cell collection efficiency that was significantly higher from Optia collections compared with COBE collections (57.9 ± 4.6% vs 40.3 ± 6.2%, respectively; p = 0.04). CD3-positive yields were comparable on both machines (p = 0.34) with significantly smaller blood volumes processed on Optia. Collected products had larger volumes on Optia. No significant side effects attributed to the procedure were noted. CONCLUSION: Mononuclear cell apheresis using the Optia device in children is more efficient and is as safe as that with the COBE device.

Comparison of two apheresis systems for autologous stem cell collections in pediatric oncology patients.

BACKGROUND: Peripheral stem cell collections can be challenging in the pediatric population and respective experience is limited. Since February 2015 our institution is utilizing the new Spectra Optia (Optia) apheresis device, which has replaced the former COBE Spectra (COBE) device. As a quality initiative we collected and compared collection efficiency (CE2) and other collection variables between the two devices. STUDY DESIGN AND METHODS: In this retrospective study we collected and compared clinical, laboratory, and technical collection data from stem cell collection procedures done with the Optia and COBE devices. The collected data included patient demographics, precollection peripheral CD34+ cell counts, total CD34+ cells collected, complete blood count, electrolytes before and after collection, side effects attributed to the collection, total blood volumes processed (TBVs), collection times, and calculated CE2 and collection ratios. RESULTS: Forty-one collection procedures performed on 29 pediatric patients with the Optia device were compared to 41 collections performed on 27 patients with the COBE device. The TBVs through the Optia device were significantly smaller than the COBE (3.9 ± 0.2 × TBV vs. 5.5 ± 0.1 × TBV, respectively; p < 0.001), requiring significantly less anticoagulant and providing similar amounts of stem cells while collection times were significantly shorter (mean, 238 ± 9 min vs. 264 ± 9 min, respectively; p < 0.05). Collections on the Optia caused significantly smaller reductions of plasma calcium and magnesium. No significant side effects attributed to the procedure were noted. CONCLUSION: Stem cell apheresis with the Optia device in children is safe and feasible with smaller blood volumes with shorter collection times.