Multi-laboratory evaluation of procedures for reducing the volume of cord blood: influence on cell recoveries

Single laboratory evaluation of umbilical cord blood units processing methodologies for banking

OBJECTIVE

To compare the efficiency of 3 different processing methods (Sepax, AutoXpress [AXP], and manual processing with hydroxyethyl starch [HES] sedimentation) used at Stemlab during a 10-year period.

METHODS

Historical data were compiled and the analytical results obtained for the 3 different methods were compared.

RESULTS

The manual processing (HES) method yielded the highest level of total nucleated cell recovery after processing, and the AXP system yielded the highest CD34+ cell number. The red blood cell reduction was also significantly higher with the HES method. Also, HES showed comparable results to Toticyte technology for umbilical cord blood (UCB) processing.

CONCLUSION

These results show that the HES method is as effective as automated technologies for UCB volume reduction; hence, it is a suitable methodology for private and public UCB banks. The HES method also proved to be superior to Toticyte technology for medical applications, with higher recovery yields of total nucleated cells after thawing and equivalent CD34+ cell recovery and functionality.

Umbilical cord stem cells: Background, processing and applications

Stem cells have currently gained attention in the field of medicine not only due to their ability to repair dysfunctional or damaged cells, but also they could be used as drug delivery system after being engineered to do so. Human umbilical cord is attractive source for autologous and allogenic stem cells that are currently amenable to treatment of various diseases. Human umbilical cord stem cells are -in contrast to embryonic and fetal stem cells- ethically noncontroversial, inexpensive and readily available source of cells. Umbilical cord, umbilical cord vein, amnion/placenta and Wharton's jelly are all rich of many types of multipotent stem cell populations capable of forming many different cell types. This review will focus on umbilical cord stem cells processing and current application in medicine.

Cord blood collection and processing with hydroxyethyl starch or non-hydroxyethyl starch

BACKGROUND

Collection and processing characteristics influencing quality of cord blood (CB) units play an essential role to cord blood banks (CBBs). At many CBBs, volume reduction is performed using hydroxyethyl starch (HES) and the Sepax (Biosafe) automated cell processing system. Due to the withdrawal of HES from the European market, a validation of the nonHES protocol was performed.

METHODS

This partially retrospective study identified CB characteristics such as gestational age and CB volume/cell count correlated with higher quality. For the nonHES validation, CB was analyzed for total nucleated cell (TNC), mononuclear cell (MNC) recovery, hematocrit (HCT) and colony-forming units (CFUs). Viabilities of CD34(+) and CD45(+) cells were determined by 7-aminoactinomycin D (7-AAD) and AnnexinV (AnnV) staining and compared for 21 mL and 42 mL buffy coat (BC) samples applying the HES/nonHES protocol.

RESULTS

Factors affecting the potency of CB transplants were the gestational age and the volume reduction to a defined BC volume. High initial cell counts and CB volumes correlated negatively with post-processing TNC recovery for lower BC volumes. Post-processing HES and nonHES results were comparable, but nonHES revealed a significantly lower post-thaw recovery of viable CD34(+) cells measured by 7-AAD/AnnV (21 mL: 45.4 ± 16.4%; 42 mL: 67.3 ± 14.5%) as compared with HES (21 mL: 72.7 ± 14.4%, P = 0.0164; 42 mL: 83.4 ± 14.7%, P = 0.0203).

DISCUSSION

Due to the lower post-thaw CD34(+) cell viability (AnnV(-)/7-AAD(-)) for nonHES samples, the use of HES is recommended, ideally combined with a high BC volume. The post-processing HCT has no statistically significant impact on the post-thaw CD34(+) cell viability (AnnV(-)/7-AAD(-)).

Bone marrow-derived cells are implicated as a source of lymphatic endothelial progenitors in human breast cancer

Bone marrow-derived endothelial progenitor cells (EPCs) infiltrate into sites of neovascularization in adult tissues and mature into functional blood endothelial cells (BECs) during a process called vasculogenesis. Human marrow-derived EPCs have recently been reported to display a mixed myeloid and lymphatic endothelial cell (LEC) phenotype during inflammation-induced angiogenesis; however, their role in cancer remains poorly understood. We report the in vitro differentiation of human cord blood CD133⁺CD34⁺ progenitors into podoplanin⁺ cells expressing both myeloid markers (CD11b, CD14) and the canonical LEC markers vascular endothelium growth factor receptor 3 (VEGFR-3), lymphatic vessel endothelial hyaluronan receptor 1 (LYVE-1), and prospero homeobox 1 (PROX-1). These podoplanin⁺ cells displayed sprouting behavior comparable to that of LECs in vitro and a dual hemangiogenic and lymphangiogenic activity in vivo in an endothelial cell sprouting assay and corneal vascularization assay, respectively. Furthermore, these cells expressed vascular endothelium growth factor (VEGF) family members A, -C, and -D. Thus, bone-marrow derived EPCs stimulate hemangiogenesis and lymphangiogenesis through their ability to differentiate into LECs and to produce angiogenic factors. Importantly, plasma from patients with breast cancer induced differentiation of CD34⁺ cord blood progenitors into hemangiogenic and lymphangiogenic CD11b⁺ myeloid cells, whereas plasma from healthy women did not have this effect. Consistent with these findings, circulating CD11b⁺ cells from breast cancer patients, but not from healthy women, displayed a similar dual angiogenic activity. Taken together, our results show that marrow-derived EPCs become hemangiogenic and lymphangiogenic upon exposure to cancer plasma. These newly identified functions of bone-marrow derived EPCs are expected to influence the diagnosis and treatment of breast cancer.

Current thawing and infusion practice of cryopreserved cord blood: the impact on graft quality, recipient safety, and transplantation outcomes

Methods of handling, thawing, and infusion of cord blood (CB) products vary substantially among thaw/transplant centers (TCs). This review 1) compares currently available CB product types and thaw methods recommended by CB banks (CBBs), 2) discusses causes of inconsistency in thaw method application at TCs, 3) advises elements to consider in thaw method approval or selection at the TC, 4) provides a procedural template for the traditional thaw methods, and 5) suggests acceptable time from product thaw to infusion and other considerations for safe infusion. It also compares postinfusion adverse reaction and engraftment data as functions of thaw methods. Remarks and suggestions made throughout this review are: 1) not intended to supersede manufacturer's instructions but meant to support the standardization of preparative procedures recommended by CBBs and 2) intended to help TCs to investigate relevant quality issues and handle challenges, especially when the TC is unable to follow recommendations due to foreseeable technical, quality, and/or clinical factors.

Exploring the use of expanded erythroid cells for autologous transfusion for anemia of prematurity

BACKGROUND

Autologous cord blood (CB) red blood cells (RBCs) can partly substitute transfusion needs in premature infants suffering from anemia. To explore whether expanded CB cells could provide additional autologous cells suitable for transfusion, we set up a simple one-step protocol to expand premature CB cells.

STUDY DESIGN AND METHODS

CB buffy coat cells and isolated CD34-positive (CD34(pos) ) cells from premature and full-term CB and adult blood were tested with several combinations of growth factors while omitting xenogeneic proteins from the culture medium. Cell differentiation was analyzed serially during 21 days using flow cytometry, progenitor assays, and high-performance liquid chromatography.

RESULTS

Expanded CB buffy coat cells resulted in a threefold higher number of erythroblasts than the isolated CD34(pos) cells. However, the RBCs contaminating the buffy coat remained present during the culture with uncertain quality. Premature and full-term CB CD34(pos) cells had similar fold expansion capacity and erythroid differentiation. With the use of interleukin-3, stem cell factor, and erythropoietin, the fold increases of all CD34(pos) cell sources were similar: CB 3942 ± 1554, adult peripheral mobilized blood 4702 ± 1826, and bone marrow (BM) 4143 ± 1908. The proportion of CD235a expression indicating erythroblast presence on Day 21 was slightly higher in the adult CD34(pos) cell sources: peripheral blood stem cells (96.7 ± 0.8%) and BM (98.9 ± 0.5%) compared to CB (87.7 ± 2.7%; p = 0.002). We were not able to induce further erythroid maturation in vitro.

CONCLUSION

This explorative study showed that fairly pure autologous erythroid-expanded cell populations could be obtained by a simple culture method, which should be optimized. Future challenges comprise obtaining ex vivo enucleation of RBCs with the use of a minimal manipulating approach, which can add up to autologous RBCs derived from CB in the treatment of anemia of prematurity.

Quality-assessments of characteristics of placental/umbilical cord blood associated with maternal age- and parity-related factor

Umbilical cord blood (CB) has been widely used for unrelated allogeneic stem cell transplantation. It is important to determine the quality of CB units to avoid frequent problem of limited cell yields. However, no practical and/or optimum obstetric factors to predict them are yet available. This study analyzed the relationship between maternal/neonatal obstetric factors and the laboratory parameters of CB units to identify the optimum factors associated with a high yield of total nucleated cells (TNC). Primiparae in their early 30s may be one of the first selection criteria for CB donors to obtain higher yield of TNC.

Analysis of 120 pediatric patients with nonmalignant disorders transplanted using unrelated plasma-depleted or -reduced cord blood

BACKGROUND

Unrelated cord blood (CB) is an important stem cell source for unrelated hematopoietic cell transplantation (HCT) of patients with nonmalignant disorders. Processing methods to prepare red blood cell-reduced CB units incur significant nucleated cell loss. In contrast, plasma depletion or reduction (PDR) processing of CB units entails the removal of only a portion of the plasma with minimal nucleated cell loss. However, there are relatively limited data regarding outcomes of CB transplants using units processed by PDR.

STUDY DESIGN AND METHODS

A Center for International Blood and Marrow Transplant Research (CIBMTR)-audited analysis was performed on 120 pediatric patients with nonmalignant disorders transplanted between November 2001 and January 2008 at 29 US and 17 international centers using PDR CB units from two CB banks.

RESULTS

Transplant characteristics were as follows: median age, 3.5 years (range, 0.1-14 years); median patient weight, 15 kg (range, 4-61 kg); 58% male; HLA matches (intermediate-resolution HLA-A and HLA-B and high-resolution HLA-DRB1) of the units used in these patients six of six in 26, five of six in 48, four of six in 47, and three of six or two of six in 6; median prefreeze total nucleated cell dose, 10.5×10(7)/kg; median prefreeze CD34+ dose, 3.7×10(5)/kg; and nonmyeloablative regimen in 24%. The median times to myeloid and platelet engraftment were 21 and 49 days, respectively. The cumulative incidence of reported Grade II to IV acute graft-versus-host disease (aGVHD) was 38±5%, and 19±4% had Grade III to IV aGVHD. The Kaplan-Meier estimates of 3-year transplant-related mortality, overall survival, and disease-free survival were 20±4, 79±4, and 70±6%, respectively.

CONCLUSION

These data demonstrate the effectiveness of PDR CB units for HCT.

Cell recovery comparison between plasma depletion/reduction- and red cell reduction-processing of umbilical cord blood

BACKGROUND AIMS

Limited cell dose has hampered the use of cord blood transplantation (CBT) in adults. One method of minimizing nucleated cell loss in cord blood (CB) processing is to deplete or reduce plasma but not red blood cells - plasma depletion/reduction (PDR).

METHODS

The nucleated cell loss of PDR was studied, and determined to be less than 0.1% in the discarded supernatant plasma fraction in validation experiments. After testing and archival sampling, the median nucleated cell recovery for PDR processing was 90%, and median CD34(+) cell recovery 88%. In a CB bank inventory of 12 339 products with both pre- and post-processing total nucleated cells (TNC), PDR processing resulted in median post-processing TNC recoveries of 90.0% after testing and archival samples removal. Using the same 10 CB units divided into two halves, we compared directly the recovery of PDR against hydroxyethyl starch red cell reduction (RCR) for TNC, CD34(+) cells and colony-forming units (CFU-GM, CFU-E, CFU-GEMM and total CFU) after parallel processing. We also compared the loss of very small embryonic-like stem cells (VSEL).

RESULTS

We demonstrated significantly higher recoveries using PDR for TNC (124%), CD34(+) cells (121%), CFU-GM (225%), CFU-GEMM (201%), total CFU (186%) and VSEL (187%). The proportion of high TNC products was compared between 10 912 PDR and 38 819 RCR CB products and found to be 200% higher for products that had TNC ≥150 × 10(7) (P = 0.0001) for the PDR inventory.

CONCLUSIONS

Our data indicate that PDR processing of CB provides a significantly more efficient usage of this valuable and scarce resource.

Processing of hematopoietic stem cells from peripheral blood before cryopreservation: use of a closed automated system

BACKGROUND

Hematopoietic stem cell transplantation is commonly used to treat several oncohematologic diseases. The autologous hematopoietic progenitor cells collected through apheresis (HPC-A) must be cryopreserved and stored before use in vivo. Cell processing that precedes cryopreservation of HPC-A includes volume reduction aimed at reducing the amount of dimethyl sulfoxide used, as well as storage space.

STUDY DESIGN AND METHODS

The aim of our study was to assess the effectiveness of volume reduction performed with an automated closed system, namely, the Sepax S100 cell separation device (Biosafe SA). A total of 165 procedures were carried out on concentrates collected from 104 adult and pediatric patients. As a control group, 30 HPC-A units processed according to the standard method (i.e., centrifugation at a speed of 850 × g for 10 minutes, followed by manual plasma reduction) were evaluated.

RESULTS

The volume reduction obtained was 59% (range, 20.54%-84.21%; standard deviation [SD], ± 12.19%), going from 236 mL (range, 100-443 mL; SD, ± 80.41 mL) to 97 mL (range, 33.00-263.00 mL; SD, ± 47.41 mL); recovery of nucleated cells was 90% (range, 64.84%-105.93%; SD, ± 8.76%), while that of CD34+ cells was 91% (range, 59.30%-119.37%; SD, ± 13.30%). These values did not differ from those obtained using the standard method. Automated processing required 20 minutes versus 40 minutes of manual processing.

DISCUSSION

Our data demonstrate that volume reduction carried out with the Sepax S100 automated system was particularly effective; cell recovery was excellent and the time spent was short. Moreover, the closed system allows cell processing to be carried out in a contamination-controlled environment, in accordance with good manufacturing practice guidelines.

A simple filtration system for red blood cell depletion and volume reduction in routine processing of human umbilical cord blood

BACKGROUND AND OBJECTIVES

Currently, stem cells and other progenitor cells are obtained from human umbilical cord blood (HUCB) using a variety of methods that are designed primarily for red blood cell depletion and volume reduction prior to freezing and storage. Some of these methods are very cumbersome and involve several steps that may result in significant cell loss. Therefore, processes that minimize the loss of haematopoietic stem and progenitor cells (HSPC) remains very critical. In the present study, we describe a simple filtration process for achieving both volume reduction and red blood cell depletion in a 'closed sterile system' with significant recovery of viable HSPC.

MATERIALS AND METHODS

About 80-100 ml of HUCB were collected into citrate-phosphate-dextrose-adenine 1 anticoagulant. Each HUCB was divided into 25-70-ml aliquots and then either diluted with isotonic saline or filtered without any prior dilution with an experimental Red Cell Volume Reduction System (RCVRS). The HSPCs were recovered by retrograde rinsing of the filter with an isotonic stem cell recovery solution. The viability, colony forming properties, leucocytes and CD34+ cells recoveries were determined.

RESULTS

The mean volume of the HUCB before processing was reduced from 43.9 +/- 7.9 ml to 11.8 +/- 0.7 ml (n = 55) with red blood cell depletion of 85.2 +/- 3.7%. Diluting the HUCB with isotonic saline prior to processing with RCVRS increased the red blood cell depletion to 91.9 +/- 3.0% (n = 7) without any significant loss in viability or cell recovery. The mean viability of the RCVRS-processed HUCB was not significantly different from the control unprocessed blood (96.60 +/- 1.90 vs. 96.63 +/- 2.12%; P > 0.05). The mean recoveries of the CD34+ and the haematopoietic clonogenic progenitor cells with the filter were 83.9 +/- 26.8 (n = 40) and 99.9 +/- 27.9% (n = 35), respectively.

CONCLUSION

The present results show that the RCVRS provides a simple and easy-to-use process for obtaining red blood cell depletion and volume reduction of HUCB with good cell viability and recoveries.

A strategy of splitting individual high volume cord blood units into two half subunits prior to processing increases the recovery of cells and facilitates ex vivo expansion of the infused haematopoietic progenitor cells in adults

This study was designed to maximize the recovery of the desirable cell populations contained in the cord blood (CB) freezing bag, in order to optimize donor selection for adolescents and adults. To evaluate this hypothesis, high volume CB units (CBUs) were categorized into three volume collection groups (120-139, 140-159 and >or=160 ml) and were randomly split before volume reduction into two half low volume CBUs; (a) and (b). Using the SEPAX Cell Processing System, all CBUs were standardized to 26 ml. In 128 high volume split CBUs, the WBC, mononuclear cell and CD34+ cell recoveries were significantly higher (P Collapse

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MESH Headings

• Blood Banking/methods
• Blood Cell Count
• Blood Preservation/methods
• Cell Separation/methods
• Cell Survival
• Cord Blood Stem Cell Transplantation/methods
• Female
• Fetal Blood
• Hematopoietic Stem Cells
• Humans

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Affiliation(s)

A C Papassavas Hellenic Cord Blood Bank, Foundation for Biomedical Research, Academy of Athens, Athens, Greece.
V Gioka
T Chatzistamatiou
T Kokkinos
I Anagnostakis
G Gecka
I Redoukas
G Paterakis
C Stavropoulos-Giokas

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Development of a biological resource center for cellular therapy and biobanking in a public polyclinic university hospital

A model of a university hospital facility for biobanking and clinical grade cell manipulation is described. The facility is based on the model of the Biological Resource Center described by the Organisation for the Economic Cooperation and Development in 1999. This model integrates several critical aspects of collection, characterization, storage and use of biological materials for research purposes and therapeutic applications, thus providing potential advantages of optimizing the use of resources, improving standardization, protecting the rights of both donors and recipients of biological materials, and facilitating international cooperation.

Analysis of hematopoietic cell transplants using plasma-depleted cord blood products that are not red blood cell reduced

Limited cell dose hampers wider use of cord blood transplantation (CBT). By depleting plasma but not RBC during processing, nucleated cell (NC) loss is reduced to <0.1% which increases significantly the proportion of high cell dose products-3-fold for products with NC >or=200 x 10(7). Clinical outcome for plasma depleted (PD) CBT was previously unavailable. A retrospective audited analysis was performed on 118 PD CBT, with mean and median NC doses of 7.6 x 10(7)/kg and 5.6 x 10(7)/kg, respectively, for this mostly pediatric population. The median times to engraftment and engraftment rates for ANC 500 and platelet 20K were 22 and 50 days, respectively, and 90% +/- 3% and 77% +/- 5%, respectively. The incidences of grade III-IV acute graft-versus-host disease (aGVHD) and extensive chronic GVHD (cGVHD) were 13% +/- 4% and 17% +/- 6%, respectively. Relapse rate for malignancies was 25% +/- 6% and 100-day treatment-related mortality (TRM) was 16% +/- 3%. With a median follow-up of 557 days, the 1-year overall survival and relapse-free survival are 65% +/- 5% and 51% +/- 6%, respectively. These results demonstrate that PD CBT is safe and effective, and that eliminating RBC reduction or depletion improves cell recovery during CB processing, resulting in a larger proportion of the inventory with high NC number.