Pediatric large volume peripheral blood progenitor cell collections from patients under 25kg: A primer

Abstract

Collection of peripheral blood progenitor cells from small pediatric patients provides many social and technical challenges not faced when collecting from adult patients. This paper provides a single institutions experience with 85 collections from 14 patients less than 25 kg of weight over a 2 year period. Specific challenges include obtaining venous access, anticoagulation, volume shifts, and obtaining patient cooperation. A systematic analysts of options for access, alternative modes of anticoagulation, and the effect of large ratios of extra‐corporeal volume to patient's blood volume are discussed. Access uniformly required central venous catheters (CVC) ranging from 7–10 Fr Anticoagulation included systemic heparmization titrating dose by activated clotting time in all cases and combined with nitrate at a ratio of 1:25 · 1:30 in most cases. Collections were performed on a COBE. Spectra, after priming with leukoreduced irradiated red cells and omitting both the initial 120cc diversion and rinse back of red cells at the end Social challenges include issues of assent and ability to distract patients for the duration of a prolonged collection. Progenitor yields from collections from 14 patients were quantitiated by CD34+ assay in all cases and C???GM in ten of 14 patients. A median of 4.5 + 106/kg CD34+ cells were obtained for each collection. Complications, including those related to catheter access are enumerated. In summary, large volume peripheral blood progenitor collection can be safely and efficaciously performed in small pediatric patients. © 1996 Wiley‐Liss, Inc.

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

“…[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.…”

“…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.…”

“…In these cases, peripheral venous cannula with a lumen greater than 1.0 mm may be used as the draw line, and the silicone CVC as return line. 6,7,15 When these alternatives fail, it is still possible to install a non-tunneled polyurethane CVC in the subclavian or jugular vein under local or general anesthesia. The large bore double lumen polyurethane CVCs, usually used for dialysis, have stiffer walls and do not easily collapse.…”

Safety and efficacy of allogeneic PBSC collection in normal pediatric donors: The Pediatric Blood and Marrow Transplant Consortium Experience (PBMTC) 1996–2003

“…Hypocalcemia is a toxicity of citrate administration 18,19 and is thought to be more common in pediatric patients receiving citrate than adults. 12,20 Hypocalcemia was screened for in 77% of the donors and measured in 4% (three with ionized Ca 2 þ o0.8 mmol/l (CTC grade 4), one between 0.8 and 0.9 mmol/l (CTC grade 3), and three between 0.9 and 1.0 mmol/l (CTC grade 2)). Symptoms thought to be caused by hypocalcemia (lip smacking, abdominal pain, tingling of lips, tongue, and fingers) occurred in 6% of patients (Table 3).…”

“…10 An impediment to further evaluation of PBSC in pediatrics is a lack of safety data regarding pediatric sibling donors. 11 There is published experience in the collection of PBSC in younger cancer patients for autologous use, [12][13][14][15] but only a limited number of studies with small patient numbers address normal pediatric donor safety and collection efficacy. [6][7][8]16 Most pediatric donors are close in age to their recipient siblings and therefore young and small.…”