Timing of autologous stem cell transplantation from last chemotherapy affects lymphocyte collection and survival in non-Hodgkin lymphoma

Autograft absolute lymphocyte count (A-ALC) is a prognostic factor for survival in non-Hodgkin lymphoma (NHL) after autologous stem cell transplantation (ASCT). An A-ALC is dependent upon the preaphaeresis absolute lymphocyte count (PA-ALC) at the time of aphaeresis. It was hypothesised that the time interval from last chemotherapy (TILC) to aphaeresis affects PA-ALC. One hundred and sixty consecutive NHL patients who underwent ASCT at the Mayo Clinic between 1996 and 2001 were evaluated. A strong correlation between TILC and PA-ALC (r = 0.67, P < 0.0001) was identified. Higher PA-ALC was observed in TILC ≥55 d compared with TILC <55 d [median: 7.0 vs. 3.8 × 10(9)/l], P < 0.0001). TILC as a continuous variable was identified as a prognostic factor for overall survival (OS) [hazard ratio (HR) = 0.989, P < 0.01] and progression-free survival (PFS) (HR = 0.992, P < 0.0492). Median OS and PFS were longer in the TILC ≥55 d vs. TILC <55 d group (not reached vs. 21 months, P < 0.0008; 76 vs. 9 months, P < 0.0025, respectively). Multivariate analysis demonstrated TILC to be an independent prognostic indicator for OS and PFS. These findings suggest that the immune status of the host at the time of aphaeresis may predict survival after ASCT.