Contributions
Abstract: PB1775
Type: Publication Only
Session title: Stem cell transplantation - Clinical
Background
Hematopoietic stem cell transplantation is widely perfomed for the treatment of hematological malignancies. Hematopoietic stem cells are mostly collected from peripheral blood. A minimum of 2x106 CD34+ cells/kg is needed for a successful transplant. The amount of CD34+ cells in peripheral blood must be 20/μl in order to collect this amount. The optimal time for stem cell collection varies between patients and the time of initiating stem cell collection should be determined according to peripheral blood stem cell count. The gold standard method for determining the amount of peripheral blood stem cells is flow cytometry. However, this method is expensive and time laboring. In Sysmex XN 1000 (Sysmex Corporation, Kobe, Japan) automatic complete blood count (CBC) analyzers; immature granulocytes(IG) are counted in white blood cell differential (WDF) channel and nucleated red blood cells (NRBC) are counted in white cell nucleated (WNR) channel with fluorescent flow cytometry method. IG is expressed as the sum of metamyelocytes, myelocytes and promyelocytes and NRBC reflects the increase in erythropoietic activity.
Aims
In this sudy; we compared IG and NRBC counts, the routine components of our CBC parameters,with peripheral blood CD34+ cell counts and aimed to find the role of these parameters in determining the time of stem cell collection.
Methods
86 patients who underwent stem cell mobilization between October 2018 and August 2020 were included in the study. Mobilization and stem cell collection records were evaluated retrospectively. Peripheral blood CD34+ cells were analyzed with flow cytometer (Becton Dickinson Biosciences FACS Calibur, California,US) according to ISHAGE guidelines. The time of analyzes were determined according to white blood cell count.(WBC) IG and NRBC analyzes were performed by Sysmex XN 1000 (Sysmex Corporation, Kobe, Japan) on the same day with flow cytometry which was also the first day of stem cell collection. Patients were divided into 2 groups according to periheral blood CD 34+ cell count/μl (≤20= group 1 vs >20= group 2). IG ratio was calculated with the formula of IG count x 100 / WBC count and NRBC ratio was calculated with the formula of NRBC count x 100 / RBC count.
Results
The median age was 56 years and 48.8% were female. The diagnosis were multiple myeloma in 56, non Hodgkin lymphoma in 18, Hodgkin lymphoma in 8, plasma cell leukemia in 2, amyloidosis in 1 and multiple plasmositoma in 1 of the patients. Mobilization regimens were cyclophosphamide + G-CSF in 55, DHAP + G-CSF in 7, ICE + G-CSF in 12, hyperCVAD + G-CSF in 5, plerixafor + G-CSF in 2, G-CSF alone in 4 and etoposide + G-CSF in 1 of the patients. When we compared CBC parameters we found that only IG ratio, NRBC ratio and NRBC counts were different between 2 groups (p< 0.001, p= 0.011 and p= 0.012, respectively). IG ratio, NRBC ratio and NRBC counts were positively correlated with peripheral blood CD34+ cell counts. The index formulated with multivariate logistic regression analysis was -1.7 + (IG% x 0.12) + (NRBC% x 2) and the cut off was zero. According to these results, the parameter with the highest diagnostic accuracy was the new index with an AUC of 0.766 (0.665 – 0.867). The sensitivity of the index was 76% and specifity was 72% with a cut off of zero.
Conclusion
In conclusion, the new index formulated from the CBC parameters can predict the time for beginning stem cell collection with a more fast and less expensive way compared with the gold standard flow cytometry. However, this data must be validated with larger multicenter prospective studies.
Keyword(s): CD34+ cells, Flow cytometry, Stem cell mobilization
Abstract: PB1775
Type: Publication Only
Session title: Stem cell transplantation - Clinical
Background
Hematopoietic stem cell transplantation is widely perfomed for the treatment of hematological malignancies. Hematopoietic stem cells are mostly collected from peripheral blood. A minimum of 2x106 CD34+ cells/kg is needed for a successful transplant. The amount of CD34+ cells in peripheral blood must be 20/μl in order to collect this amount. The optimal time for stem cell collection varies between patients and the time of initiating stem cell collection should be determined according to peripheral blood stem cell count. The gold standard method for determining the amount of peripheral blood stem cells is flow cytometry. However, this method is expensive and time laboring. In Sysmex XN 1000 (Sysmex Corporation, Kobe, Japan) automatic complete blood count (CBC) analyzers; immature granulocytes(IG) are counted in white blood cell differential (WDF) channel and nucleated red blood cells (NRBC) are counted in white cell nucleated (WNR) channel with fluorescent flow cytometry method. IG is expressed as the sum of metamyelocytes, myelocytes and promyelocytes and NRBC reflects the increase in erythropoietic activity.
Aims
In this sudy; we compared IG and NRBC counts, the routine components of our CBC parameters,with peripheral blood CD34+ cell counts and aimed to find the role of these parameters in determining the time of stem cell collection.
Methods
86 patients who underwent stem cell mobilization between October 2018 and August 2020 were included in the study. Mobilization and stem cell collection records were evaluated retrospectively. Peripheral blood CD34+ cells were analyzed with flow cytometer (Becton Dickinson Biosciences FACS Calibur, California,US) according to ISHAGE guidelines. The time of analyzes were determined according to white blood cell count.(WBC) IG and NRBC analyzes were performed by Sysmex XN 1000 (Sysmex Corporation, Kobe, Japan) on the same day with flow cytometry which was also the first day of stem cell collection. Patients were divided into 2 groups according to periheral blood CD 34+ cell count/μl (≤20= group 1 vs >20= group 2). IG ratio was calculated with the formula of IG count x 100 / WBC count and NRBC ratio was calculated with the formula of NRBC count x 100 / RBC count.
Results
The median age was 56 years and 48.8% were female. The diagnosis were multiple myeloma in 56, non Hodgkin lymphoma in 18, Hodgkin lymphoma in 8, plasma cell leukemia in 2, amyloidosis in 1 and multiple plasmositoma in 1 of the patients. Mobilization regimens were cyclophosphamide + G-CSF in 55, DHAP + G-CSF in 7, ICE + G-CSF in 12, hyperCVAD + G-CSF in 5, plerixafor + G-CSF in 2, G-CSF alone in 4 and etoposide + G-CSF in 1 of the patients. When we compared CBC parameters we found that only IG ratio, NRBC ratio and NRBC counts were different between 2 groups (p< 0.001, p= 0.011 and p= 0.012, respectively). IG ratio, NRBC ratio and NRBC counts were positively correlated with peripheral blood CD34+ cell counts. The index formulated with multivariate logistic regression analysis was -1.7 + (IG% x 0.12) + (NRBC% x 2) and the cut off was zero. According to these results, the parameter with the highest diagnostic accuracy was the new index with an AUC of 0.766 (0.665 – 0.867). The sensitivity of the index was 76% and specifity was 72% with a cut off of zero.
Conclusion
In conclusion, the new index formulated from the CBC parameters can predict the time for beginning stem cell collection with a more fast and less expensive way compared with the gold standard flow cytometry. However, this data must be validated with larger multicenter prospective studies.
Keyword(s): CD34+ cells, Flow cytometry, Stem cell mobilization