Aldehyde Dehydrogenase Enzyme in Relation to Cord Blood stem cells Potency

Introduction/Objective

In umbilical cord blood transplantation (UCBT), the number of cluster of differentiation (CD)34+ cells and colony-forming units (CFUs) in the cord blood (CB) graft positively correlate with patient survival. Since aldehyde dehydrogenase (ALDH) activity is high in hematopoietic stem cells, the number of ALDH-bright (ALDHbr) cells was examined in comparison with the number of CD34+ cells and CFUs for the quality assessment of CB units, Aim and objectives; to correlate the aldehyde dehydrogenase (ALDH) enzyme assay with colony-forming unit–granulocyte/macrophage (CFU-GM) assay before cryopreservation of cord blood buffy coats (CBBC), in order to investigate the hypothesis that the ALDH assay might exclude apoptotic cells since it is based on enzyme activity.

Methods/Case Report

This study was carried out at Benha University Hospital on Fifty (50) samples of Human Umbilical Cord Blood which were processed for mononuclear cells (MNC) separation by density gradient centrifugation method using Ficoll-Paque media that layered on the diluted blood.

In parallel, 1 million nucleated cells were sampled and prepared for flow cytometry for analysis of ALDH activity according to the manufacturer’s

instructions.

Results (if a Case Study enter NA)

CD34+ ALDH+ (%) (Of MNC) showed significant positive correlation with ALDH++ (%) (Of CD34+) and numbers of total CFU/40000 cells. Also ALDH++ (%) (Of CD34+) showed significant positive correlation with numbers of total CFU/40000 cells.

Conclusion

The ALDH assay excludes nonviable and apoptotic cells, and therefore correlates well with CFU enumeration compared to the number of viable CD34+ cells. We propose that the ALDH assay might replace the CFU-GM method in CBU potency measurements.