Feasibility of a PB CD34+ cell transplantation procedure using standard leukapheresis products in very small children

Abstract

Summary:ings is unknown at present, some centers currently prefer to transplant these patients with PBSCs that have been depleted of potentially contaminating tumor cells. One To evaluate the feasibility and efficacy of CD34 ؉ cell immunoselection from routine peripheral blood stem possible method of reducing tumor cell contamination of the PBSC preparations is the positive selection of CD34 ϩ cell (PBSC) harvests in very small children a prospective study was performed in 15 children with advanced hematopoietic progenitor cells. 3 Initial trials of autografts with CD34 ϩ PBSCs have mainly been performed in adult neuroblastoma weighing 20 kg or less. Products of two consecutive leukaphereses carried out on a COBE Specpatients 4-6 and, outside of our team, 7 and so thus far there have been no reports of studies performed in small children. tra separator after G-CSF alone mobilization were pooled for immunoselection on Ceprate column. TheThe principal reasons for the restriction in the use of this technique in children with low body mass are PBSC collecmedian number of CD34 ؉ cells and total CFU-GM collected were respectively 5.9 ؋ 10 6 /kg (range 2.3-23.4) tion-associated difficulties (venous access, flow rate, metabolic and hemodynamic problems). In particular, when and 126.9 ؋ 10 4 /kg (range 52.9-559.9). After separation the median number of CD34 ؉ cells in the adsorbed fraclarge-scale collection is planned, which may require the processing of a considerable number of blood volumes, the tion was 2.6 ؋ 10 6 /kg (range 1-9.8) with a median purity of 54% (range 21-82) and a median of 95.7-fold safety of the procedure is of special importance. [8][9][10][11][12][13] We report the results of a prospective study designed to (range 35-250) enrichment. Thirteen patients underwent autografts with CD34 ؉ PBSCs after a busuldetermine whether sufficient numbers of CD34 ϩ cells can be obtained to provide reliable post-graft hematopoietic fan 600 mg/m 2 ؉ melphalan 180 mg/m 2 preparative regimen. The median number of days to achieve an reconstitution in very small children, after positive immunoselection of routinely collected leukaphereses products. absolute granulocyte count of 0.5 ؋ 10 9 /l and a platelet count of 20 ؋ 10 9 /l were respectively, 12 (range 10-24)We have investigated the feasibility and efficacy of this technique using the avidin-immunoaffinity column device and 35 (range 25-43). The median number of platelet transfusions was nine (range 2-15). We conclude that (Ceprate Stem Cell Concentrator; CellPro, Bothell, WA, USA) in 15 children with advanced neuroblastoma. These safe and effective immunoselection and transplantation of CD34 ؉ PBSC can be accomplished in children with patients may theoretically benefit from the isolation of CD34 ϩ hematopoietic progenitors, since the target CD34 low body mass.

Permanent tunneled silicone central venous catheters for autologous PBPC harvest in children and young adults

“…Harvest results, efficiency and changes in peripheral blood and serum values after apheresis are comparable or superior to results reported by other groups using different central venous catheters. [5][6][7][8][9] The influence of body size or age on harvest efficiency was neg- Table 5 Side-effects ligible, and the need for additional CVC apheresis placements could be reduced to a minimum. When using tunneled silicone rubber catheters for PBPC harvesting, pitfalls can be prevented by appropriate placement of the catheter tip.…”

“…[1][2][3][4] Most problems, such as reduced harvest efficiency and tolerability have been improved by adaptations of the cell separator and by reduction of extracorporal volume. [5][6][7][8] However, the management of safe vascular access, allowing a sustained adequate flow ratio over an extended time frame on repeated occasions, remains a serious practical problem.…”

Peripheral blood stem cell collection in 24 low-weight infants: experience of a single centre

“…PBSC can be nevertheless be successfully performed with caution 6,9 even in small children. [10][11][12] Red blood cell priming of the extracorporeal circuit (alone or with albumin) is frequently required in small children to improve haemodynamic tolerance and efficacy. 6,11 We try to avoid systematic transfusion when possible because of the risks of infection (viral and other) and immunological problems related to multiple transfusions.…”

Successful large volume leukapheresis on a small infant allogeneic donor

“…Others have previously reported their experience with young children who served as autologous stem cell donors, [1][2][3][4][5][6] with only one citation focusing on pediatric allogeneic donors. 7 We believe our normal donor is the smallest child reported to date to have undergone an apheresis procedure.…”