Apheresis instrument settings influence infused absolute lymphocyte count affecting survival following autologous peripheral hematopoietic stem cell transplantation in non-Hodgkin's lymphoma: the need to optimize instrument setting and define a lymphocyte collection target.

Autograft absolute lymphocyte count (A-ALC) is an independent prognostic factor for survival after autologous peripheral blood hematopoietic stem cell transplantation (APHSCT) for non-Hodgkin's lymphoma (NHL). Factors enhancing A-ALC collections are unknown. We hypothesize that apheresis instrument settings could affect A-ALC. Data from 127 NHL patients collected from 15 January 1999 to 30 July 2004 using a single apheresis instrument (COBE Spectra (SP), Baxter Amicus (AM), and CS3000 Plus (CS)) were analyzed. The primary end point of the study was to assess the correlation between apheresis instrument settings and A-ALC. The secondary end point was to determine the effect of apheresis instrument on survival post-APHSCT. Patients collected using SP achieved higher A-ALC compared to AM (with modified settings) or CS (P<0.05) and demonstrated superior overall (OS) and progression-free survival (PFS) (P<0.03). Multivariate analysis demonstrated A-ALC and not the apheresis instrument as an independent prognostic factor for OS and PFS, cancelling the prognostic effect of the apheresis instruments observed in the univariate analysis. The survival advantage observed by SP was from the higher A-ALC collected compared to AM and CS. These data suggest that apheresis instrument settings should be optimized to collect CD34(+) cells as well as an A-ALC target, with direct impact on survival post-APHSCT.