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.

Successful Reduced Intensity Allogeneic Transplant With Full Donor Chimerism and Good Quality of Life in Adolescent Patient With Wiskott-Aldrich Syndrome.

Wiskott-Aldrich syndrome (WAS) is an X-linked disease characterized by microthrombocytopenia, eczema, immune deficiency, and autoimmune phenomena. Allogeneic hematopoietic stem cell transplantation (HSCT) is the only curative treatment. Myeloablative conditioning is the most common regimen used for HSCT in patients with WAS to avoid the risk of mixed donor chimerism and autoimmunity post-HSCT. There is limited data on the use of reduced intensity conditioning for HSCT in patients with WAS. Here, we report a case with severe phenotype of WAS transplanted successfully with reduced intensity conditioning, which is an acceptable conditioning regimen and can be considered in patients with WAS with significantly impaired organ functions.

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.