CD34+/CD90+ cells infused best predict late haematopoietic reconstitution following autologous peripheral blood stem cell transplantation.

This study aimed to identify which graft product subset of cells might be the most predictive of late haematopoietic recovery (three to 12 months) following autologous peripheral blood stem cell transplantation (PBSCT). The relationships between the numbers of reinfused CD34+ cells and their immature subsets such as CD34+/CD90+, CD34+/AC133+, CD34+/CD38- and CD34+/HLA-DR- cells, and haemoglobin, white blood cell (WBC) and platelet counts at 3, 6, 9 and 12 months after PBSCT, were studied in 25 patients with haematological and solid malignancies. The total CD34+ cell number, as well as CD34+/CD90+ and CD34+/AC133+ cell numbers, correlated with platelet counts at 3, 6, 9 and 12 months after PBSCT, but the CD34+/CD90+ cells infused best predicted platelet recovery during the first 12 months after PBSCT (P < 0.0238 at any time-point). The CD34+/AC133+ cell dose also correlated with WBC counts at 3 months post PBSCT. In addition, all patients receiving more than 80 x 10(4) CD34+/CD90+ cells/kg showed platelet counts greater than 100 x 10(9)/l at all points after PBSCT, suggesting that this value of the CD34+/CD90+ cells infused was a threshold dose for durable haematopoietic engraftment after PBSCT.