Hematopoietic Stem Cell Transplantation (HSCT) Using Plasma Depleted Umbilical Cord Blood (UCB) That Were Not Red Cell Depleted.

Abstract

UCB is an attractive source for HSCT; however, limiting cell dose has hampered its widespread use. The red cell depletion (RCD) techniques that are widely used incur significant nucleated cell loss after processing; therefore, to minimize cell loss and still reduce volume during processing, a technique was devised to deplete plasma (PD) but not red blood cells. A large racially diverse inventory of over 25,000 PD UCB is available on stem cell registries. Of the 265 PD UCB transplanted into 240 patients up to May 2006, an updated retrospective audited analysis of all 205 patients with engraftment and/or survival data was performed. The characteristics for the patients were: median age 8.8 yo, range 0.3–59, 76 ≥16 yo (32%); median weight 29 kg, range 5–137, 84 ≥50kg (35%); male 59%; median # HLA ABDR matches 4.0; median pre-freeze TNC dose 5.31 × 107/kg (n=229); transplant center reported median post-thaw TNC dose 4.92 × 107/kg (n=112); median pre-freeze CD34 dose 1.7 × 105/kg; malignant indications 71%; transplants outside U.S. 39%; double transplant 23%; and non-myeloablative 15%. For all engrafted patients, the median time to engraftment for ANC 500 (n=192), platelet 20K (n=174) and 50K (n=169) were 22.0 days (range 7–64), 49.5 days (range 12–181), and 63.5 days (range 21–374) respectively. Kaplan-Meier estimates of engraftment of ANC500, platelet 20K and 50K engraftment were 88±3%, 82±4% and 76±4% respectively. The incidence of grade III–IV acute GVHD and extensive chronic GVHD were 13% and 14% respectively. One-year relapse rate was 23±4% for all patients (n=190), and TRM was 29±3% (n=203) at 1 year. With a median follow-up of 178 days (range 4–1402 days) for the surviving patients, the Kaplan-Meier estimates of 1-year OS (n=203) and DFS (n=190) are 59±4% and 54±4% respectively for all patients. These results demonstrate that HSCT using PD UCB can be performed safely and effectively.