FACS analysis of CD4 and CD8 T-cell subsets in patients after autologous PBSC transplantation. Mean ratio of CD3⁺CD4⁺ helper T lymphocytes to CD3⁺CD8⁺ suppressor T lymphocytes during the posttransplant period in nine patients transplanted with FACS-sorted CD34⁺ HPC (○). Mean CD4/CD8 ratio of T cells in the blood of 11 patients receiving unmanipulated PBSC autografts (▵).