Aldehyde Dehydrogenase Activity may Replace Colony Forming Units as A Quality Marker in Hematopoietic Peripheral Stem Cells Collections

Background and Objectives In daily routine stem cell harvests for stem cell transplantation are measured by CD34 antigen and the colony-forming ability (CFU) and checked for viability by 7-amino actinomycin D (7-AAD). We tested whether the stem cell marker ALDH could be useful for characterizing PBSC graft quality Materials and Methods In a prospective analysis we investigated the ALDH activity in freshly collected PBSC and in frozen products (n = 42) of 25 patients (15 males/10 females, median age 52 yrs., range 21-67). The results were correlated with CD34, viability and engraftment data in already transplanted patients (n = 7). Results In general we found a significant correlation between ALDH activity, CD34 yield and CFU-GM/unit in fresh and thawed products with a p value of < 0.05. A low ALDH activity was predictive for poor stem cell function, expressed as colony forming capacity of collected stem cells. Conclusion The ALDH assay is readily available and provides information about the quality of the majority of leukocyte-apheresis products instantly whic