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360: Pediatric patients with malignancies transplanted with plasma depleted cord blood (PD CB) – an audited analysis of 91 patients

Year: 2007

Type: article

Abstract: Cell dosage has a critical effect on cord blood transplantation (CBT) outcome; therefore pediatric patients are ideal for CBT. Younger recipient age is associated with better survival and neutrophil (ANC500) engraftment. However, even in young patients, outcome may be improved by increasing cell dose of the transplanted CB. CB banks practice red cell depletion (RCD) techniques to save storage space, which incur significant nucleated cell loss after processing; therefore, one method to minimize cell loss and still reduce volume after processing is to deplete plasma (PD), but not the red blood cells. Not washing UCB (NW) after thawing also minimizes cell loss. A large racially diverse PD UCB inventory of over 25,000 units is now available. There were 39 ALL, 23 AML, 5 JMML, 4 CML, and 20 other pediatric patients transplanted for malignant indications. Patients were classified as pediatric in two different ways: by age (less than 16 years) and by weight (less than 50kg). If the age definition is used, there were 88 pediatric patients transplanted with 89 PD UCB units (8 double cords); and if classified by weight, there were 78 patients transplanted with 78 PD UCB units (4 double cords). A retrospective audited analysis was performed on all 91 pediatric patients with engraftment and/or survival information. Of these, 24 patients had standard risks (26%), 58 patients (64%) with advanced risks and 9 risk status unknown (10%). The median age of combined patients was 5.8 years old (range 0.5-34); median weight 22 kg (range 5-91.6); male 66%. Transplant characteristics indicated a median # HLA ABDR matches of 5.0; median pre-freeze TNC dose 6.1 × 107/kg; median post-thaw TNC dose as reported by TC 5.5 × 107/kg; median pre-freeze CD34 dose 2.0 × 105/kg; transplants outside of U.S. 25%; double unit transplant 10%; non-myeloablative 9%. 56.5% of the transplanted UCB were washed post-thaw (W), 33.7% were infused without post-thaw wash (NW), with 9.8% of the units without available post-thaw data. Median follow-up time was 175.5 days (range 19-1402 days). Kaplan-Meier estimates were used for engraftment, relapse, TRM, OS and RFS rates with all patients who expired before engraftment counted as engraftment failures. Patients were also stratified by risk status. Results are summarized below. These results demonstrate that HSCT using unrelated PD UCB can be performed safely with outstanding results in pediatric patients with malignancies.Outcome SummaryANC500, median timePlt 20K, median timePlt 50K, median time1-Yr Relapse100 day & 1-Yr TRM1-Yr OS1-Yr RFSAge <16 yo89±4%, 25 days83±5%, 54 days75±6%, 64 days29±6%14±4%, 25±5%57±6%53±6%Wt <50 kg93±3%, 22 days81±5%, 52 days75±6%, 64 days32±6%14±4%, 25±6%55±6%49±6% Open table in a new tab

Source: Transplantation and Cellular Therapy

DOI: 10.1016/j.bbmt.2006.12.365