Correlation of hematopoietic progenitor cell count determined by the SE-automated hematology analyzer with CD34(+) cell count by flow cytometry in leukapheresis products

Determination of mononuclear cell count using peripheral smear and flow cytometry in peripheral blood stem cell products: A retrospective study from an Indian cancer center

BACKGROUND:

Mononuclear cells (MNCs) are considered equivalent to hematopoietic stem cells, and differential count using peripheral smear was routinely practiced to enumerate MNC. Flow cytometry plots used for CD34 enumeration assay can also be used in MNC enumeration as it counts more WBC events than manual methods. The aim was to determine the relationship and degree of agreement between peripheral smear and flow cytometry in MNC enumeration of peripheral blood stem cell (PBSC) products.

METHODS:

In 63 patients, 73 PBSC products were collected between January 2017 and September 2019. The differences in MNC count estimated by peripheral smear method and from flow cytometry plots used for CD34 enumeration were analyzed using Mann–Whitney test. Agreement between the two methods for MNC enumeration was determined by regression analysis. Receiver operating characteristic curve was performed to determine MNC threshold in peripheral blood and PBSC product for adequate mobilization and harvest.

RESULTS:

There was no difference in enumeration of median MNC count between peripheral smear and flow cytometry (52% vs. 59%, P = 0.185) in PBSC product. However, regression analysis indicated a constant and proportional difference between the methods with r = 0.52. Cumulative sum test for linearity showed deviation from linearity (P = 0.04). MNC counts in peripheral blood failed to achieve discrimination capacity in predicting adequate CD34+ yield/kg body weight in product.

CONCLUSION:

Peripheral smear estimated lower MNC counts than flow cytometry with weaker agreements between the two methods. Hence, MNC count derived from flow cytometry plot can substitute peripheral smear method for MNC dose calculations. MNC dose at 3.4 × 10⁸/kg consistently predicted >2 × 10⁶/kg CD34+ cells collected.

Simultaneous enumeration of CD34+ and CD45+ cells using EasyCounter image cytometer

Accurate counting of CD34-positive cells is important for successful hematopoietic stem cell transplantation that is applied to various diseases. The aim of this study was simultaneous counting of viable CD34⁺ (vCD34+) and CD45⁺ (vCD45+) cells in apheresis samples by automatic immunofluorescence counter - EasyCounter BC. CD34⁺ and CD45⁺ cells were counted using two conjugates anti-CD34 antibody - dR110 and anti-CD45 antibody - ATTO620, respectively. The conjugates were prepared by carbodiimide method. Dead nuclear cells were counted by using monomethine cyanine dye PO-TEDM 1. The linearity and reproducibility of EasyCounter BC for CD34⁺ cell counting were determined (R² = 0.99; CV values for vCD34+ cells were 6.8 ÷ 8.5% and for vCD45+ cells 4.1 ÷ 7.2%). The obtained results by EasyCounter BC were compared with those by other two standard methods - flow cytometry (Guava easyCyte 8HT) and fluorescence microscopic method (Olympus BX51) with the same conjugates. Passing-Bablok regression was performed to determine the relationship between the results of the three methods, analyzing 43 apheresis samples. Correlation coefficients for vCD45+ and vCD34+ between EasyCounter BC and Olympus microscope were 0.987 and 0.982, respectively (P < 0.0001). Better results were obtained between EasyCounter BC and flow cytometer Guava, 0.998 for vCD45+ and 0.998 for vCD34+ (P < 0.0001).

Peripheral Blood Stem Cell Harvest HPC Count Is an Effective Surrogate Marker for CD34+ Cell Count in Allogeneic Stem Cell Transplant Setting

OBJECTIVE: We assessed the predictive potential of XN-HPC for CD34+ cell count as obtained through Sysmex automated hematology analyzers (XN-1000). METHODS: This study was conducted at the National Institute of Blood Diseases and Bone Marrow Transplantation in 84 donors between December 2012 and December 2017 in the first phase and later validated in 112 donors between December 2017 and December 2018. Sysmex XN-1000 and BD FACS Calibur estimated XN-HPC and CD34+ cells of peripheral blood apheresis product, respectively. Spearman's correlation was assessed between XN-HPC and CD34+ cell count followed by receiver operating characteristic curve calculation to determine the XN-HPC cutoff for a CD34+ count of ≥2 million cells/kg of recipient's body weight RESULTS: There is a moderately positive correlation (P value = .003) between XN-HPC and CD34+ count. Receiver operating characteristic curve analyses demonstrated that a cutoff value for XN-HPC of ≥1·845×10⁶cells/kg of recipient's body weight has a specificity and sensitivity of 100% and 78·2%, respectively, for predicting the CD34+ count of ≥2 million cells/kg of recipient's body weight. This cutoff value of XN-HPC was prospectively validated in 112 donors. The positive predictive value was found to be 100%, while negative predictive value was 17%. CONCLUSION: XN-HPC has a highly promising potential to serve as a cost-effective and time-saving surrogate for CD34+ cell count.

Impact of Hematopoietic Progenitor Cell Count as an Indicator for Optimal Timing of Peripheral Stem Cell Harvest in Clinical Practice

For optimizing CD34+ cell collection, appropriately timing peripheral blood stem cell harvest (PBSCH) initiation is crucial. Automatic cell analyzers with the immature myeloid information channel provide hematopoietic progenitor cell (HPC) count, a surrogate marker of CD34+ cells, which can be obtained within a few minutes without requiring monoclonal antibodies. The final decision on PBSCH initiation can be made using the HPC count obtained on the morning of the harvest day. Herein, we evaluated the impact of the HPC count as an indicator for the optimal timing of PBSCH in clinical practice over 9 years. One hundred and eighteen aphereses from 72 cases had a definite number of CD34+ cells/kg in the PBSC yield. A correlation was found between the HPC count in the PB and the CD34+ cell count (R = 0.563, p ＜ 0.001), whereas no correlation existed between the white blood cell and CD34+ cell counts (R = 0.0418, p = 0.65). We defined ＞ 2.0 × 10⁶/kg of CD34+ cells in a single apheresis as good mobilization. Multivariate analysis demonstrated that an HPC count of ＞ 21/μL, myeloblast count of ＞ 12/μL, and age at PBSCH of ＜ 50 years were independently associated with good mobilization (p = 0.001, p ＜ 0.001, and p = 0.005, respectively). Our findings suggest that the HPC count is a good indicator for the optimal timing of PBSCH.

Hematopoietic stem cell mobilization: a clinical protocol

Autologous hematopoietic stem cell transplantation is the standard treatment for a wide variety of malignancies. At present, most hematopoietic progenitor/stem cell (HPC) collections are collected from the peripheral blood via leukapheresis following chemotherapy and/or growth factor-mediated mobilization. Most mobilization regimens consist of chemotherapy followed by one or more growth factors such as G-CSF, GM-CSF, or plerixafor. Occasionally a subset of patients will prove unable to mobilize effectively and will not collect at least 2.0 × 310(6) CD34+ cells/kg, the number of HPC currently considered to be appropriate for transplant in order to achieve timely engraftment and recovery of hematopoiesis. When this occurs it may be necessary to either remobilize, possibly with a different method, or to do a marrow harvest. Recent research has explored the benefits of using HPC outside of the oncology arena, notably in the area of cardiac regeneration following infarction, making the subject of mobilization potentially important to many areas of medicine.

SCT without growth factor in multiple myeloma: engraftment kinetics, bacteremia and hospitalization

SCT is important in the management of multiple myeloma. In the United States, the standard of care is administration of growth factors to accelerate neutrophil recovery after SCT. The need for growth factors after transplant has not been investigated recently. We analyzed a cohort of 166 patients at our institution who underwent autologous transplant for multiple myeloma without receiving growth factors after transplant and compared them with 498 patients who received standard filgrastim beginning on posttransplant day 5. A neutrophil count of 500/μL was achieved in a median of 12.5 days in patients receiving growth factor, compared with 13.5 days in those not receiving growth factor (P<0.001). Platelet engraftment was identical (median, 14.5 days; P=0.12) in both groups, despite a lower median number of CD34+ cells infused in patients who did not receive growth factors. Incidence of nonstaphylococcal bacteremia was identical in both groups. The median hospital stay was 3.5 days shorter in the group not receiving growth factor. It is feasible and reasonable to perform autologous SCT for multiple myeloma without administering growth factors.

Optimal timing of G-CSF administration for effective autologous stem cell collection

The best time of G-CSF administration for PBPC collection remains to be defined. We aimed to identify optimal G-CSF administration timing for efficient autologous stem cell collection. A total of 262 lymphoma or multiple myeloma patients, who underwent PBPC collection from January 2000 to March 2008, were included. PBPCs were mobilized with chemotherapy followed by lenograstim at 10 μg/kg/day. Patients received lenograstim at 2000 hours, about half a day before leukapheresis (PM group) before November 2004, and at 0600 hours, 3 h before apheresis (AM group) subsequently. In the AM group, the median number of total collected CD34+ cells/kg was greater over a shorter duration of apheresis, and the median number of collected CD34+ cells/kg at first leukapheresis was larger. Stem cell collection efficacy (ratio of total collected CD34+ cells/kg per number of leukapheresis procedures) was higher, and proportion of patients who yielded an optimum harvest was larger. The statistically significant between-group difference was observed only in patients with high-dose CY chemotherapy for stem cell mobilization in subgroup analysis. The present study showed that G-CSF injection 3 h before apheresis improved the efficacy of autologous stem cell collection.

Use of the haematopoietic progenitor cell parameter in optimizing timing of peripheral blood stem cell harvest

BACKGROUND AND OBJECTIVES

Timing of peripheral blood stem cell (PBSC) harvest is typically based on quantification of peripheral blood (PB) CD34+ cells. CD34 enumeration is expensive, requires expertise and takes a minimum of 1-2 h to perform. The Sysmex XE2100 is an automated haematology analyser that can rapidly and inexpensively identify haematopoietic progenitor cell (HPC) populations in PB. The aim of this study was to examine if HPC can be used to optimize timing of PBSC harvest.

MATERIALS AND METHODS

White blood cell (WBC), HPC and CD34 counts were determined in a total of 60 mobilized donors. Data were analysed to examine the utility of WBC and HPC counts in predicting preharvest CD34+ counts.

RESULTS

In adults presenting for autologous collection, a PB HPC threshold of > 30/microl predicts a preharvest CD34+ count of > 20/microl with sensitivity of 86% and positive predictive value (PPV) of 100%. Among paediatric patients with a diagnosis of neuroblastoma, an HPC threshold of > 16/microl yielded sensitivity and PPV of 100%, while in children with other diagnoses, an HPC cut-off of > 44/microl yielded sensitivity and PPV of 67% and 100%, respectively. Eighty per cent of adequately mobilized allogeneic donors were identified using an HPC threshold > 15/microl, with a PPV of 100%. PB WBC can also aid in predicting CD34 counts in most patient groups, albeit with lower sensitivity than HPC.

CONCLUSION

By virtue of being a sensitive and accurate predictor of preharvest CD34+ counts, our data support the use of the HPC parameter in optimizing the timing of PBSC harvest.

Platelet count is a sensitive predictor of autologous peripheral blood progenitor cell collection yield in previously treated plasma cell disease patients

BACKGROUND

It is often a clinical dilemma to determine when to collect autologous peripheral blood progenitor cells (PBPCs) in patients who received prior chemotherapy. It is also challenging to predict if the collected cells will be enough for one or two transplants.

STUDY DESIGN AND METHODS

A total of 103 PBPC donors were followed to evaluate factors that predict poor autologous PBPC collection. The donors were categorized into three groups: plasma cell disorders (PCDs), lymphomas, and normal allogeneic donors.

RESULTS

Our evaluation showed that platelet (PLT) count before growth factor administration significantly correlated with total CD34+ cell yield (Spearman r = 0.38, p < 0.001). Further analysis showed this correlation was only significant in plasma cell disease patients who received prior chemotherapy (Spearman r = 0.5, p = 0.008). Baseline PLT counts did not correlate with PBPC collection yield in untreated PCD, lymphoma, and normal allogeneic donors. In addition, daily PLT count during PBPC harvest correlated with CD34+ cell yield for that day (Spearman r = 0.41, p < 0.001). With a multiple linear regression model (adjusted R(2) = 0.31, AIC = 63.1), it has been determined that the baseline PLT count significantly correlates with total CD34+ cell yield in treated PCD patients.

CONCLUSION

Baseline PLT count is a sensitive indicator of autologous PBPC mobilization in PCD patients who received prior chemotherapy. This finding may be considered before growth factor administration to determine the optimal period to mobilize treated PCD patients and to predict if enough cells can be collected for one or two transplants.

A randomized comparison of peripheral blood hematopoietic progenitor cell level of 5/mm3 versus 50/mm3 as a surrogate marker to initiate efficient autologous blood stem cell collection

We previously showed that at least 5/mm(3) hematopoietic progenitor cells (HPCs) could be used as a marker for initiating autologous blood stem cell collection (ABSCC). However, the timing of efficient ABSCC following mobilization is still to be determined. We conducted a prospective, randomized comparison of 5/mm(3) versus 50/mm(3) peripheral blood (PB) HPCs as a surrogate marker to initiate efficient ABSCC. Forty-five consecutive patients, 26 with multiple myeloma (MM) and 19 with non-Hodgkin's lymphoma (NHL), were enrolled between October 2004 and October 2006. Chemotherapy was cyclophosphamide 4 g/m(2) for MM and ESHAP (etoposide, methylprednisolone, high-dose cytarabine, and cisplatin), with or without Rituximab, for NHL. Circulating HPCs were monitored daily with the Sysmex SE9000 automated hematology analyzer, and harvested CD34+ cells were counted by flow cytometry. ABSCC was initiated when HPC levels reached at least 5/mm(3) (HPC5 group) or 50/mm(3) (HPC50 group). The median number of harvested CD34+ cells was 15.0 x 10(6)/kg and 21.0 x 10(6)/kg in the HPC5 and HPC50 groups, respectively (P = 0.23). Optimal collection (>5 x 10(6) CD34+ cells/kg) in a single session (day 1) was attained in 15 HPC5 patients (63%) and in 14 HPC50 patients (67%), and targeted collection of 5 x 10(6) CD34+ cells/kg was achieved in 100 and 95% of HPC5 and HPC50 patients, respectively (P = 0.47), with a median number of 1 apheresis in both groups (P = 0.58). There were no between group differences in optimal collection rate on day 1, median number of aphereses to achieve optimal collection, and overall optimal collection rate. HPC > or = 5/mm(3) and > or =50/mm(3) are both reliable indices for the timing of ABSCC.

Rituximab-ESHAP as a mobilization regimen for relapsed or refractory B-cell lymphomas: a comparison with ESHAP

BACKGROUND

It has previously been shown that ESHAP was an effective mobilization regimen for patients with pretreated lymphoma. To extend these observations, the efficacy and feasibility of rituximab plus ESHAP regimen in CD20+ B-cell NHL were assessed.

STUDY DESIGN AND METHODS

The mobilization efficacy and engraftment characteristics were compared in the 22 patients who received the rituximab plus ESHAP (R-ESHAP) with 33 historical controls who received ESHAP.

RESULTS

The two treatment groups were well matched in patient characteristics. In the R-ESHAP group, 62 pheresis procedures were performed. Apheresis procedures were started on median Day 16 (range, Days 13-18). The median number of collected CD34+ cells was 10.6 x 10(6) per kg (range, 4.9 x 10(6)-52.6 x 10(6)/kg). Nineteen (95%) patients achieved optimal peripheral blood hematopoietic progenitor cell (PBPC) collection, defined as at least 5 x 10(6) CD34+ cells per kg. There were no significant differences between the two groups with respect to mobilization efficacy. Sixteen patients in the R-ESHAP group (73%) underwent autologous peripheral blood progenitor cell transplantation (APBPCT). The median time to absolute neutrophil count at least 0.5 x 10(9) per L was 10 days (range, 8-17 days), and the median time to a platelet count of at least 20 x 10(9) per L was 12 days (range, 7-27 days). Lymphocyte recovery was slower in the R-ESHAP group, but the rate of infectious complications was similar in the two groups. In the R-ESHAP group, the 2-year overall survival and progression-free survival after APBPCT were 63.2 and 57.4 percent, respectively.

CONCLUSION

Addition of rituximab to ESHAP chemotherapy did not have any adverse effects on PBPC mobilization. Further studies are needed, however, to determine whether addition of rituximab improves outcomes.

Hematopoietic progenitor cells (HPC) and immature reticulocytes evaluations in mobilization process: new parameters measured by conventional blood cell counter

Monitoring the timing of leukapheresis in peripheral blood stem cells (PBSC) mobilization is an important clinical decision that requires an accurate analytical tool. The present study assessed hematopoietic progenitor cells (HPC) and immature reticulocyte fraction (IRF) counts provided by a routine automated blood counter as potential parameters for predicting the appropriate time for harvesting. The HPC and IRF values were compared with white blood cell (WBC) and CD34+ cell counts obtained by flow cytometry in 30 adult patients with hematological malignancies undergoing PBSC mobilization. It was observed that there was a significant correlation between HPC counts and CD34(+) cells in peripheral blood counts (r=0.61, P=0.0003) and between the number of HPC and CD34+cells collected by leukapheresis (r=0.5733, P=0.0009). Comparing HPC, IRF, WBC, and CD34+ cells parameters as a sign of hematological recovery showed that the raise in immature reticulocytes counts preceded the increase of WBC (P=0.0002), HPC (P=0.0001), and CD34(+) (P=0.0001) cells in peripheral blood counts. According to our results, HPC and IRF parameters may be integrated into clinical protocols to evaluate the timing of leukapheresis. IRF, as previously demonstrated in bone marrow transplantation, is the earliest sign of hematopoietic recovery in mobilization process.

Prospective randomized comparative observation of single- vs split-dose lenograstim to mobilize peripheral blood progenitor cells following chemotherapy in patients with multiple myeloma or non-Hodgkin’s lymphoma

In patients with hematologic malignancies, granulocyte colony-stimulating factor (G-CSF) following chemotherapy is widely used to mobilize peripheral blood progenitor cells (PBPCs), but there have been no trials comparing schedules of G-CSF following chemotherapy. We conducted a prospective randomized comparative observation of the mobilization with a single dose (10 microg kg once a day) or split dose (5 microg kg twice a day) of lenograstim following chemotherapy in 25 multiple myeloma (MM) and 15 non-Hodgkin's lymphoma (NHL) patients. Chemotherapy was cyclophosphamide 4 g/m2 for MM and ESHAP with or without Rituximab for NHL. The median number of harvested CD34+ cells was 19.4 x 10(6)/kg and 15.8 x 10(6)/kg in the single- and split-dose groups, respectively (p=0.47). Targeted collection of 5 x 10(6) CD34+ cells/kg was achieved in 18/20 patients in the single-dose group and in all 20 patients of the split-dose group (p=0.24), with the median number of sessions 1 and 2 in the single- and split-dose groups, respectively (p=0.13). We could not observe statistically significant differences between a single-dose and split-dose lenograstim following chemotherapy in enhancing the mobilization of PBPCs in MM or NHL patients.

ESHAP plus G-CSF as an effective peripheral blood progenitor cell mobilization regimen in pretreated non-Hodgkin's lymphoma: comparison with high-dose cyclophosphamide plus G-CSF

The ESHAP (etoposide, methylprednisolone, high-dose cytarabine, and cisplatin) regimen has been shown to be effective as an active salvage therapy for lymphoma. Mobilizing stem cells following ESHAP should decrease time to transplantation by making separate mobilizing chemotherapy (MC) unnecessary, while controlling a patient's lymphoma. We therefore assessed the mobilization potential of ESHAP plus G-CSF in 26 patients (ESHAP group) with non-Hodgkin's lymphoma (NHL) and compared these results with those of 24 patients with NHL who received high-dose (4 g/m2l) cyclophosphamide (HDCY) as MC (HDCY group). The age, sex, and radiotherapy to the axial skeleton were well matched between groups, but the number of patients with poor mobilization predictors was higher in the ESHAP group. Significantly higher numbers of CD34+ cells (x 10(6)/kg) (17.1+/-18.8 vs 5.8+/-5.0, P=0.03) and apheresis day 1 CD34+ cells (x 10(6)/kg) (5.5+/-6.6 vs 1.7+/-2.0, P=0.014) were collected from the ESHAP group than from the HDCY group, and the number of patients who achieved an optimal CD34+ cell target of 5 x 10(6)/kg was higher in the ESHAP group (81 vs 50%, P=0.022). Log-rank test revealed that time to target peripheral blood progenitor cell collection (> or =5 x 10(6)/kg) was shorter in the ESHAP group (P=0.007). These results indicate that ESHAP plus G-CSF is an excellent mobilization regimen in patients with relapsed and poor-risk aggressive NHL.

Initiation of peripheral blood progenitor cell harvest based on peripheral blood hematopoietic progenitor cell counts enumerated by the Sysmex SE9000

BACKGROUND

The most reliable index for timing peripheral blood progenitor cell (PBPC) collection following mobilization is still to be determined. The techniques to enumerate peripheral blood (PB) CD34+ cells are expensive and time-consuming. The SE9000 (Sysmex) provides an estimate of immature cells, called hematopoietic progenitor cells (HPCs). The aim of this study was to prospectively evaluate the efficacy of PB HPC levels for timing PBPC harvest.

STUDY DESIGN AND METHODS

Thirty-five patients (15 non-Hodgkin's lymphoma and 20 multiple myeloma) were enrolled. PB HPCs and harvested CD34+ cells were counted with the SE9000 and flow cytometry, respectively. Circulating HPCs were monitored daily. PBPC harvest was initiated when HPC levels reached at least 5 per mm(3).

RESULTS

HPC levels reached 5 per mm(3) or more on Median Day 12 (range, days 9 to 16) of mobilizing chemotherapy. The median number of CD34+ cells collected per patient was 19.40 x 10(6) per kg (range, 1.94 x 10(6)-52.55 x 10(6) per kg). Both successful and optimal harvest was achieved in 97 percent of patients. PBPCs were successfully harvested in 25 patients (71%) in one session. An optimal harvest in a single session was attained in 16 patients (46%).

CONCLUSION

This might be the first prospective study showing the PB HPC level for timing PBPC harvest.

Analysis of the optimal blood sampling conditions for estimation of hematopoietic progenitor cell count by the SE-9000 automated hematolyzer

We evaluated the optimal conditions for blood sampling for hematopoietic progenitor cells (HPCs) as estimated by the immature information program of the SE-9000 automated hematology analyzer. The HPC count was most stable when the blood samples were incubated at room temperature with ethylene-diaminetetraacetic acid dipotassium (EDTA-2K) as an anticoagulant. The HPC count should, however, be measured within 4 h after blood collection, even under optimal conditions. In contrast, the CD34+ cell count estimated by flow cytometric analysis was stable for at least 21 h after the blood samples were incubated with EDTA-2K at room temperature or 4 degrees C. When appropriate blood samples were used, the HPC count in the peripheral blood significantly correlated with the CD34+ cell count in the peripheral blood and in the apheresis yields (r = 0.798 and 0.635, respectively); therefore, the HPC count is a reliable predictor for initiation of apheresis procedures to obtain sufficient HPCs for peripheral blood stem cell transplantation.

Low-dose lenograstim to enhance engraftment after autologous stem cell transplantation: a prospective randomized evaluation of two different fixed doses

BACKGROUND

G-CSF is used to enhance hematopoietic recovery after autologous stem cell transplantation (ASCT), but the optimal dose of G-CSF during engraftment has not been established. The medical cost of ASCT is a serious financial burden in developing countries, and G-CSF is the most costly drug used in this procedure. We evaluated whether a lower, vial-size fitted dose of lenograstim is clinically equivalent to a higher fixed dose.

STUDY DESIGN AND METHODS

A prospective randomized study was performed on 33 patients (11 non-Hodgkin's lymphoma, 8 multiple myeloma, 14 breast cancer) undergoing ASCT. Patients were randomly administered 100 micro g or 250 micro g lenograstim daily starting on the next day of ASCT, with a minimum infusion of 3 x 10(6) CD34+ cells per kg.

RESULTS

For both lenograstim doses, median time to neutrophil engraftment was 9 days and median time to PLT engraftment was 11 days. Episodes of clinically documented infections were 10 per 379 patient-days in the 100 microg per day group and 10 per 320 patient-days in the 250 microg per day group. There were no between-group differences in requirements for transfusion of RBCs or PLTs. Duration of hospitalization was 16 days for the 100 microg per day group and 17 days for the 250 microg per day group. Daily lenograstim dose per patient's body weight and total amount of lenograstim used during ASCT were both significantly lower in the 100 microg per day group.

CONCLUSION

Administration of 100 microg per day of lenograstim showed comparable clinical efficacy to 250 microg per day lenograstim for immediate hematopoietic recovery after ASCT. Use of the lower dose was associated with lower overall lenograstim usage and lower cost.

Collection of peripheral blood progenitor cells: analysis of factors predicting the yields

We retrospectively analyzed data on 628 leukapheresis from 160 consecutive patients with hematologic or solid malignancies to identify predictive factors affecting the achievement of optimal peripheral blood progenitor cell (PBPC) collection, which was defined as > or = 5x10(6) CD34+ cells/kg. In univariate analysis, a diagnosis of multiple myeloma, no prior axial skeletal radiotherapy, absence of exposure to alkylating agents and cisplatin, fewer cycles of chemotherapy, and fewer number of previous chemotherapy regimens favored the achievement of target number of PBPC. In multivariate analysis, the absence of prior exposure to alkylating agents, especially cyclophosphamide, (P=0.003, RR=2.08) and cisplatin (P=0.015, RR=2.50) were independent predicting factors affecting the probability of achieving the target PBPC and the time to reach the target PBPC collection. In addition, the total dose of cyclophosphamide the patient received significantly alters the mobilization.

Predictive value of circulating immature cell counts in peripheral blood for timing of peripheral blood progenitor cell collection after G-CSF plus chemotherapy-induced mobilization

BACKGROUND

Enumeration of CD34+ cells in peripheral blood (PB) before apheresis predicts the number of CD34+ cells collected, although flow cytometric techniques used are complex and expensive. In an attempt to determine the optimal timing for peripheral blood progenitor cell (PBPC) collection, the usefulness of circulating immature cell (CIC) counts in PB was evaluated.

STUDY DESIGN AND METHODS

CIC counts in PB and CD34+ cell counts in the apheresis product from 249 collections were assessed, and the relationship between these two parameters was evaluated by with the Pearson rank correlation analysis, the Fisher exact test, and the U-test.

RESULTS

CIC counts were correlated significantly with the number of CD34+ cells per kg of patient's body weight in the apheresis product (Pearson rank correlation analysis: r = 0.635, p < 0.0001). When a level of 1 x 10(9) CICs per L was selected as a cutoff value, the sensitivity and specificity for collecting more than 1 x 10(6) CD34+ cells per kg of body weight were 75.7 and 85.5 percent, respectively.

CONCLUSION

The present study strongly suggests that the number of CICs in PB may estimate the number of CD34+ cells collected. The data indicate that CIC counts above 1 x 10(9) per L can be used as a good predictor for PBPC collections containing more than 1 x 10(6) CD34+ cells per kg of body weight in a single apheresis procedure.