Re‐evaluation of progenitor thresholds and expectations for haematopoietic recovery based on an analysis of 810 autologous transplants: Implications for quality assurance

Haematological engraftment was assessed in 804 autologous transplants. Neutrophil recovery occurred in over 99% within 14 d but platelet recovery was delayed beyond this time in 14·8%. Time to recovery was dependent on the progenitor cell dose infused. The minimum CD 34 + cell threshold adopted in this study (2 × 10 6 /kg) was safe although recovery was faster with a dose >5 × 10 6 /kg. CD34 + cell doses of between 1 and 2 × 10 6 /kg were also acceptable if either the granulocyte‐macrophage colony‐forming cell dose exceeded 2 × 10 5 /kg or this dose was due to splitting a higher yield harvest. Prompt neutrophil recovery affords important quality assurance for laboratory processing.