Using at least 5x10(6)/kg CD34(+) cells for autologous stern cell transplantation significantly reduces febrile complications and use of antibiotics after transplantation

For autologous stem cell transplantation, it is common practice to infuse a t least 2 x 10(6)/kg CD34(+) cells to ensure rapid engraftment, However it was recently claimed that increasing the threshold to 5 x 10(6)/kg leads to a faster platelet engraftment, To evaluate these threshold values in our p atient population we undertook a retrospective analysis of 127 autologous t ransplants performed at our institution between 1992 and 1998, Diagnoses in cluded Hodgkin's and non-Hodgkin's lymphoma, myeloma, acute leukaemias and solid tumours, The transplant was peripheral blood stem cells in 107 cases and CD34-selected peripheral blood stem cells in 20 cases, The median numbe r of transplanted CD34(+) cells was 3.2 x 10(6)/kg (range 0.64-25.9 x 10(6) /kg) Haematopoietic recovery to a neutrophil count >0.5 x 10(9)/l took a me dian of 10 (range 5-16) days from transplant, When comparing patients recei ving at least 5 x 10(6)/kg and 2-5 x 10(6)/kg CD34(+) cells we found a sign ificant reduction in the median number of days with fever (1 vs 3.5 days, P = 0.0025), incidence of fever (78.8 vs 92.1%, P = 0.032) as well as durati on of antibiotic treatment (7 vs 10 days, P = 0.038), This was paralleled b y a faster neutrophil recovery to 0.5 x 10(9)/l (9 vs 10 days, P = 0.047), There was no significant difference in the number of platelet or red cell t ransfusions between the two groups. We conclude that transplantation with a stem cell dose of at least 5 x 10(6)/kg CD34(+) cells reduces infectious c omplications and should thereby increase the safety of this type of therapy while reducing duration (and cost) of antibiotic therapy. The transplantat ion threshold should thus not remain at 2 x 10(6)/kg particularly in patien ts with a good stem cell mobilisation capacity.