Contributions
Abstract: PB2164
Type: Publication Only
Background
Autologous stem cells transplantation (ASCT) has become necessary part in therapy of hematological diseases. Transfusion of at least 2×106 CD34+ HSCs per kg of patient’s weight allows achieving an adequate hematopoiesis after high-dose chemotherapy. The most optimal is to collect ≥2×106 CD34+ cells/kg with single harvest apheresis. Different mobilization regimens lead to variations in white blood cell count (WBC) and the number of circulating HSCs. Deciding on the time of the first leukapheresis is very important.
Aims
The aim was to identify significant parameter predicting efficiency of CD34+ cells collection.
Methods
The study included 142 patients (pts) who undergo ASCT (80 m, 62 f, median age 53 y.o., 81 were diagnosed with multiple myeloma, 10 - Hodgkin's lymphoma, 51 – non-Hodgkin's lymphomas). WBC and absolute CD34+ number in the blood before the first apheresis and the number of CD34+/kg in the apheresis product were determined for each patient. There were three different mobilization regimens: 12 pts received 10 μg/kg/day G-CSF in the stable hematopoiesis for 5-6 days; 86 pts - 4 g/m2 cyclophosphamide and 5-10 μg/kg/day G-CSF (Cph+G-CSF); 44 pts - DHAP: 40 mg dexamethasone, 100 mg/m2 cisplatin, 2g/m2 cytarabine and 10 μg/kg/day G-CSF (DHAP+G-CSF). CD34+ HSCs were evaluated with ISHAGE-protocol by BD FACSCanto II flow cytometer. Results are presented as mean±SEM. ROC-analysis was performed for WBC and the absolute number of CD34+ HSCs in the blood as the predictor markers for HSCs successful harvesting (≥2×106 CD34+/kg for fist apheresis).
Results
WBC mean was higher in pts with G-CSF mobilization scheme compared to Cph+G-CSF and DHAP+G-CSF (28.5±3.5 vs 10.4±0.9 and 9.0±1.8×109/l, respectively, p<0.0001), but the absolute number of CD34+ HSCs in the blood (26.3±9.3 vs 55.5±5.6 and 93.1±22.3/μl, p=0.03) and the number of CD34+/kg in the leukapheresis product (1.9±0.7 vs 5.2±0.6 and 6.9±1.3×106/kg, p=0.01) were lower. Differences between Cph+G-CSF and DHAP+G-CSF in all parameters were not found. There was not any relationship between WBC and the number of CD34+/kg: the area under ROC-curve (AUC) didn’t differ from 0.5 for all mobilization regimens. Then absolute number of CD34+ in blood was investigated as predictor for harvest success, AUCs were 0.964, 0.938 and 0.979 (p<0.0001) for G-CSF, Cph+G-CSF and DHAP+G-CSF, respectively. In the ROC-analysis showed the optimal CD34+ number in blood than most likely to collect ≥ 2×106 CD34+/kg for first leukapheresis. It was 29 CD34+cells/μl in G-CSF mobilization, 24 CD34+cells/μl – in Cph+G-CSF and 27 CD34+cells/μl - in DHAP+G-CSF. To calculate universal level of absolute CD34+ number all data from 142 pts was used. In this case AUC was 0.952 and a threshold of successful harvesting was 20 CD34+cells/μl in blood before apheresis with sensitivity of 96% and specificity of 81%.
Conclusion
Various mobilization regimens differ in count of leucocytes and CD34+ HSCs in peripheral blood: WBC was significant higher in G-CSF than in Cph+G-CSF and DHAP+G-CSF, but the absolute number of CD34+ cells was higher in chemotherapy-based mobilization and G-CSF than in G-CSF alone. The absolute number of leucocytes in blood before apheresis was not a predictor factor of harvest success in all variants of mobilization regimens. If there is at least 20 CD34+cells/μl in blood before apheresis it is possible to collect ≥ 2×106 CD34+/kg for single leukapheresis with high sensitivity and specificity independent of mobilization regimen.
Session topic: 22. Stem cell transplantation - Clinical
Keyword(s): Stem cell mobilization, Autologous hematopoietic stem cell transplantation
Abstract: PB2164
Type: Publication Only
Background
Autologous stem cells transplantation (ASCT) has become necessary part in therapy of hematological diseases. Transfusion of at least 2×106 CD34+ HSCs per kg of patient’s weight allows achieving an adequate hematopoiesis after high-dose chemotherapy. The most optimal is to collect ≥2×106 CD34+ cells/kg with single harvest apheresis. Different mobilization regimens lead to variations in white blood cell count (WBC) and the number of circulating HSCs. Deciding on the time of the first leukapheresis is very important.
Aims
The aim was to identify significant parameter predicting efficiency of CD34+ cells collection.
Methods
The study included 142 patients (pts) who undergo ASCT (80 m, 62 f, median age 53 y.o., 81 were diagnosed with multiple myeloma, 10 - Hodgkin's lymphoma, 51 – non-Hodgkin's lymphomas). WBC and absolute CD34+ number in the blood before the first apheresis and the number of CD34+/kg in the apheresis product were determined for each patient. There were three different mobilization regimens: 12 pts received 10 μg/kg/day G-CSF in the stable hematopoiesis for 5-6 days; 86 pts - 4 g/m2 cyclophosphamide and 5-10 μg/kg/day G-CSF (Cph+G-CSF); 44 pts - DHAP: 40 mg dexamethasone, 100 mg/m2 cisplatin, 2g/m2 cytarabine and 10 μg/kg/day G-CSF (DHAP+G-CSF). CD34+ HSCs were evaluated with ISHAGE-protocol by BD FACSCanto II flow cytometer. Results are presented as mean±SEM. ROC-analysis was performed for WBC and the absolute number of CD34+ HSCs in the blood as the predictor markers for HSCs successful harvesting (≥2×106 CD34+/kg for fist apheresis).
Results
WBC mean was higher in pts with G-CSF mobilization scheme compared to Cph+G-CSF and DHAP+G-CSF (28.5±3.5 vs 10.4±0.9 and 9.0±1.8×109/l, respectively, p<0.0001), but the absolute number of CD34+ HSCs in the blood (26.3±9.3 vs 55.5±5.6 and 93.1±22.3/μl, p=0.03) and the number of CD34+/kg in the leukapheresis product (1.9±0.7 vs 5.2±0.6 and 6.9±1.3×106/kg, p=0.01) were lower. Differences between Cph+G-CSF and DHAP+G-CSF in all parameters were not found. There was not any relationship between WBC and the number of CD34+/kg: the area under ROC-curve (AUC) didn’t differ from 0.5 for all mobilization regimens. Then absolute number of CD34+ in blood was investigated as predictor for harvest success, AUCs were 0.964, 0.938 and 0.979 (p<0.0001) for G-CSF, Cph+G-CSF and DHAP+G-CSF, respectively. In the ROC-analysis showed the optimal CD34+ number in blood than most likely to collect ≥ 2×106 CD34+/kg for first leukapheresis. It was 29 CD34+cells/μl in G-CSF mobilization, 24 CD34+cells/μl – in Cph+G-CSF and 27 CD34+cells/μl - in DHAP+G-CSF. To calculate universal level of absolute CD34+ number all data from 142 pts was used. In this case AUC was 0.952 and a threshold of successful harvesting was 20 CD34+cells/μl in blood before apheresis with sensitivity of 96% and specificity of 81%.
Conclusion
Various mobilization regimens differ in count of leucocytes and CD34+ HSCs in peripheral blood: WBC was significant higher in G-CSF than in Cph+G-CSF and DHAP+G-CSF, but the absolute number of CD34+ cells was higher in chemotherapy-based mobilization and G-CSF than in G-CSF alone. The absolute number of leucocytes in blood before apheresis was not a predictor factor of harvest success in all variants of mobilization regimens. If there is at least 20 CD34+cells/μl in blood before apheresis it is possible to collect ≥ 2×106 CD34+/kg for single leukapheresis with high sensitivity and specificity independent of mobilization regimen.
Session topic: 22. Stem cell transplantation - Clinical
Keyword(s): Stem cell mobilization, Autologous hematopoietic stem cell transplantation