Summary:The number of CD34 þ cells infused into patients at the time of autologous or allogeneic transplantation is a clinically important variable, but the viability of these cells has not been extensively documented. In this study, we analyzed the recovery of viable CD34 þ cells before and after cryopreservation on 79 autologous stem cell products, using a novel flow cytometry assay without red cell lysis. For 70 PBSC harvest samples, the mean viable CD34 þ cell count was 5.98 Â 10 6 /kg (range 0.3-23 Â 10 6 / kg) before freezing and 5.4 Â 10 6 /kg (range 0.2-23 Â 10 6 / kg) after thawing. The median recovery was 93% (range 48-107%), with 90% recovery for NHL (range 48-100%, n ¼ 34), 83% for multiple myeloma (range 56-106%, n ¼ 11), 92.3% for acute leukemia (range 71-100% n ¼ 7) and 94.5% for nonhematological malignancies (range 50-107% n ¼ 18). Similarly, for autologous bone marrows (n ¼ 9) the median recovery of viable CD34 þ cells was 90% (range 68-100%). The recovery of viable CD34 þ cells for adult (n ¼ 51) and pediatric (n ¼ 28) stem cell collections was 91 and 94%, respectively. Further examination of the correlation between the kinetics of hematological recovery and the number of viable progenitor cells infused, particularly at the lower end of the accepted dose range, may be warranted.
In this study, we retrospectively analysed the utility of CD110 expression on CD34 þ cells as a predictor of delayed platelet transfusion independence in 39 patients who underwent autologous peripheral blood stem cell transplantation. Absolute CD34 þ cells and CD34 þ subsets expressing CD110 were enumerated using flow cytometry. Of the 39 patients, 7 required 21 days or more to achieve platelet transfusion independence. Six of the seven patients received a dose of CD34 þ CD110 þ cells below 6.0 Â 10 4 /kg while 30 of 32 patients who achieved platelet transfusion independence in o21 days received a dose of CD34 þ CD110 þ cells 46.0 Â 10 4 /kg (Po0.001). Patients with delayed platelet engraftment received a median dose of 5.2 Â 10 4 CD34 þ CD110 þ cells/kg compared with a median dose of 16.4 Â 10 4 cells/kg for those engrafting within 21 days (P ¼ 0.003). Further analysis showed that 46.0 Â 10 4 CD34 þ CD110 þ cells/ kg was highly sensitive (93.8%) and highly specific (85.7%) for achieving platelet transfusion independence within 21 days. Delay in platelet transfusion independence translated into an increased requirement for platelet transfusion (median 6 vs 2 transfusions, Po0.0001). The dose of CD34 þ /CD110 þ cells/kg infused at time of transplantation appears to be an important factor identifying patients at risk of delayed platelet engraftment.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.