Autograft composition and outcome-towards an optimal graft?

The amount of CD34⁺ cells has been for decades the most important marker of autologous graft quality, but other graft cells, including various lymphocyte subsets, have gained some interest. This review attempts to summarize what is known about autograft cellular composition regarding post-transplant outcomes. The amount of CD34⁺ cells in the graft is associated with tempo of platelet recovery. It also has been associated with improved progression-free (PFS) and overall survival (OS) in many studies in patients with non-Hodgkin lymphoma and in some studies in patients with multiple myeloma. A greater number of lymphocytes in the graft has been linked with earlier lymphocyte recovery, which on the other hand has been associated with better post-transplant outcomes. In prospective studies, a greater number of T lymphocytes has been found to correlate with better PFS and OS in patients with non-Hodgkin lymphoma and multiple myeloma. Some studies also indicate that the number of natural killer cells in grafts is prognostically important. At present, it is challenging to define a so-called optimal graft in the autologous setting. In addition to adequate CD34⁺ cell counts, more lymphocytes also should be collected to achieve immune autografts, which may translate to improved patient outcomes. More data are needed regarding the functional status of various lymphocyte subset for post-transplant outcomes.