Factors predicting haematopoietic recovery in patients undergoing autologous transplantation: 11-year experience from a single centre

Engraftment outcomes following autologous transplantation correlate poorly to infused stem cell number. We evaluated 446 consecutive patients who underwent autologous transplantation at our centre between 2001 and 2012. The impact of pre-transplant and collection factors together with CD34⁺ dosing ranges on engraftment, hospital length of stay (LOS) and survival endpoints were assessed in order to identify factors which might be optimized to improve outcomes for patients undergoing autologous transplantation using haemopoietic progenitor cells–apheresis (HPC-A). Infused CD34⁺ cell dose correlated to platelet but not neutrophil recovery. Time to platelet engraftment was significantly delayed in those receiving low versus medium or high CD34⁺ doses. Non-remission status was associated with slower neutrophil and platelet recovery. Increasing neutrophil contamination of HPC-A was strongly associated with slower neutrophil recovery with infused neutrophil dose/kg recipient body weight ≥3 × 10⁸/kg having a significant impact on time to neutrophil engraftment (p = 0.001). Higher neutrophil doses/kg in HPC-A were associated with days of granulocyte colony stimulation factor (G-CSF) use, HPC-A volumes >500 ml and higher NCC in HPC-A. High infused neutrophil dose/kg and age >65 years were associated with longer hospital LOS (p = 0.002 and 0.011 respectively). Only age, disease and disease status predicted disease-free survival (DFS) and overall survival (OS) in our cohort (p < 0.005). Non-relapse mortality was not affected by low dose of CD34⁺ (<2 × 10⁶/kg). In conclusion, our study shows that CD34⁺ remains a useful and convenient marker for assessing haemotopoietic stem cell content and overall engraftment capacity post-transplant. Neutrophil contamination of HPC-A appears to be a key factor delaying neutrophil recovery. Steps to minimize the degree of neutrophil contamination in HPC-A product may be associated with more rapid neutrophil engraftment and reduced hospital LOS.