Unraveling stem cell and progenitor subsets in autologous grafts according to methods of mobilization: implications for prediction of hematopoietic recovery

Abstract Background aims In the autologous setting, granulocyte colony-stimulating factor (G-CSF) (G), or, when failing, G plus plerixafor (G+P), are common regimens for mobilization of stem cells into peripheral blood. To delineate mobilization effects on graft composition and hematopoietic recovery, we compared contents of stem cells and progenitor cells in products of G+P- and G patients. Paired samples of G+P patients and prior insufficient G mobilization were available for analyses. Methods Subset analyses of grafts were performed by flow cytometry and myeloid colony-forming assay. In search of new markers to ascertain graft quality, we determined the fractions of aldehyde dehydrogenase bright (ALDH br ) cells. Results G grafts contained higher percentages of CD34+ cells, CD34+CD38- cells, and committed progenitors (CD34+CD38+) compared with G+P grafts. A detailed characterization of the mobilized CD34+ cell subset showed higher percentages of CD38– among the CD34+ cells of the G+P group ( P  = 0.032). In contrast, the CD34+ cell subset in G grafts was characterized by a higher percentage of ALDH br cells ( P br cells correlated best to both platelet ( r  = 0.565, P  = 0.002) and neutrophil reconstitution ( r  = 0.366, P  = 0.06). Conclusions Besides showing dissimilar distributions of CD34+CD38– cells and progenitors in G and G+P grafts, this study further designated ALDH br as a promising marker in determination and prediction of graft quality and hematopoietic recovery.