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

The effect of preemptive use of plerixafor on stem cell mobilization in patients with lymphoma and multiple myeloma

ABSTRACT Objective: The aim of this study is to investigate the effect of the preemptive use of plerixafor in patients with lymphoma and multiple myeloma which was administered as a preemptive single dose to the patients who were determined to have a CD34+ cell count of

Radiation Therapy Can Be Safely Incorporated into Pretransplantation Treatment Regimens for Patients with Multiple Myeloma

Primary treatment of multiple myeloma (MM) often involves systemic induction therapy (SIT) followed by autologous stem cell transplantation (ASCT). Radiation therapy (RT) is sometimes used for palliation; however, many practitioners avoid RT out of concern that future peripheral blood progenitor cell (PBPC) collection required for ASCT may be compromised. In this study, we retrospectively examined the possible effect of RT on PBPC collection. We reviewed the charts of 732 patients with MM treated with RT at our institution from 1999 to 2017, including patients who received RT prior to PBPC collection for planned ASCT. RT plans (both MM and non-MM RT) were reviewed to estimate the percentage of bone marrow (BM) treated using published estimates of skeletal BM distribution. Statistics were performed using Pearson correlation and the t-test. The 732 MM patients included 485 planned for ASCT; of these, 223 received RT prior to PBPC collection and were included in the final cohort. The median age at PBPC collection was 59 years (range, 33 to 80 years). For SIT, patients received combination regimens including the following agents: bortezomib (142 patients; 64%), lenalidomide (111 patients; 50%), and alkylators (46 patients; 21%). Nine patients (4%) received dexamethasone alone. The median cumulative %BM treated per patient was 6.7 (range .0 to 47.4). The median RT dose was 24 Gy (range, 10.0 to 75.6 Gy). Mobilization was performed using granulocyte-colony stimulating factor (G-CSF) alone (189 patients; 85%), G-CSF with plerixafor (15 patients; 7%), or chemotherapy (19 patients; 9%). A median of 7.8 × 106 CD34+/kg PBPCs (range, .5 to 54.8× 106 CD34+/kg) were collected in a median of 3 (range, 1 to 9) apheresis procedures. One hundred ninety-six patients (99%) collected ≥2.0 × 106 CD34+/kg PBPCs, and 166 (83%) collected >5.0 × 106 CD34+/kg PBPCs. The number of PBPCs collected was not associated with %BM treated (P = .15) or RT dose (P = .56). The number of apheresis procedures performed was not associated with %BM treated (P = .54) or RT dose (P = .85). The amount of PBPCs collected did not differ significantly between patients receiving RT to the pelvis/sacrum (P = .20) and those receiving RT to the spine (P = .13). The time to platelet engraftment was longer for patients with higher %BM treated (P = .02). Eleven patients did not undergo a confirmed ASCT, owing to patient preference (3 patients), trial therapy (1 patient), comorbidities (1 patient), election for hospice (1 patient), inadequate collection (4 patients), or inadequate follow-up (1 patient). In our study cohort, RT prior to ASCT did not impair successful ASCT. RT must be carefully planned and delivered to ensure safe incorporation into pre-ASCT treatment regimens.

Plerixafor as preemptive strategy results in high success rates in autologous stem cell mobilization failure

Plerixafor in combination with granulocyte-colony stimulating factor (G-CSF) is approved for autologous stem cell mobilization in poor mobilizing patients with multiple myeloma or malignant lymphoma. The purpose of this study was to evaluate efficacy and safety of plerixafor in an immediate rescue approach, administrated subsequently to G-CSF alone or chemotherapy and G-CSF in patients at risk for mobilization failure. Eighty-five patients mobilized with G-CSF alone or chemotherapy were included. Primary endpoint was the efficacy of the immediate rescue approach of plerixafor to achieve ≥2.0 × 10⁶ CD34⁺ cells/kg for a single or ≥5 × 10⁶ CD34⁺ cells/kg for a double transplantation and potential differences between G-CSF and chemotherapy-based mobilization. Secondary objectives included comparison of stem cell graft composition including CD34⁺ cell and lymphocyte subsets with regard to the mobilization regimen applied. No significant adverse events were recorded. A median 3.9-fold increase in CD34⁺ cells following plerixafor was observed, resulting in 97% patients achieving at least ≥2 × 10⁶ CD34+ cells/kg. Significantly more differentiated granulocyte and monocyte forming myeloid progenitors were collected after chemomobilization whereas more CD19⁺ and natural killer cells were collected after G-CSF. Fifty-two patients underwent transplantation showing rapid and durable engraftment, irrespectively of the stem cell mobilization regimen used. The addition of plerixafor in an immediate rescue model is efficient and safe after both, G-CSF and chemomobilization and results in extremely high success rates. Whether the differences in graft composition have a clinical impact on engraftment kinetics, immunologic recovery, and graft durability have to be analysed in larger prospective studies.

Current role of radiation therapy for multiple myeloma

Background: Radiation therapy (RT) is a treatment modality traditionally used in patients with multiple myeloma (MM), but little is known regarding the role and effectiveness of RT in the era of novel agents, i.e., immunomodulatory drugs and proteasome inhibitors.

Methods: We retrospectively reviewed data from 449 consecutive MM patients seen at our institute in 2010–2012 to assess indications for RT as well as its effectiveness. Pain response was scored similarly to RTOG 0631 and used the Numerical Rating Pain Scale.

Results: Among 442 evaluable patients, 149 (34%) patients and 262 sites received RT. The most common indication for RT was palliation of bone pain (n = 109, 42%), followed by prevention/treatment of pathological fractures (n = 73, 28%), spinal cord compression (n = 26, 10%), and involvement of vital organs/extramedullary disease (n = 25, 10%). Of the 55 patients evaluable for pain relief, complete and partial responses were obtained in 76.4 and 7.2%, respectively. Prior RT did not significantly decrease the median number of peripheral blood stem cells collected for autologous transplant, even when prior RT was given to both the spine and pelvis. Inadequacy of stem cell collection for autologous stem cell transplant (ASCT) was not significantly different and it occurred in 9 and 15% of patients receiving no RT and spine/pelvic RT, respectively. None of the three cases of therapy-induced acute myelogenous leukemia/MDS occurred in the RT group.

Conclusion: Despite the introduction of novel effective agents in the treatment of MM, RT remains a major therapeutic component for the management in 34% of patients, and it effectively provides pain relief while not interfering with successful peripheral blood stem cell collection for ASCT.

Factors determining pbsc mobilization efficiency and nonmobilization following ICE with or without rituximab (R-ICE) salvage therapy for refractory or relapsed lymphoma prior to autologous transplantation

ICE/R-ICE (ifosfamide, carboplatin, and etoposide without or with rituximab) chemotherapy followed by autologous stem cell transplantation is an established regimen in refractory/relapsed lymphoma. Few studies have addressed which factors are important in determining peripheral blood stem cell (PBSC) mobilization efficiency or nonmobilization following ICE/R-ICE. Between 2004 and 2013, 88 patients with refractory/relapsed lymphoma who received ICE/R-ICE salvage-chemotherapy prior to granulocyte colony stimulating factor (G-CSF) stimulated PBSC mobilization at a single center were identified. Mobilization efficiency was assessed by time from ICE/R-ICE to day of harvest, duration of G-CSF use, days to peripheral blood (PB) CD34(+) ≥15/µL, PB CD34(+) number on harvest day, CD34(+) yield and nonmobilization rate. Median PB CD34(+) at harvest were 54/μL (7-524); median days to first apheresis was 15 (11-30); median harvested total CD34(+) were 5.46 × 10(6) /kg (0.96-44.36); 71 patients (80.7%) successfully mobilized; 20 (22.7%) patients were poor mobilizers; 14 (15.9%) patients were considered nonmobilizers with maximal PB CD34(+) <7/µL and did not proceed to apheresis. Six of 20 poor mobilizers were apheresed with PB CD34(+) 7-12/µL, 50% were successfully harvested. No differences were found between ICE and R-ICE regimens. Impaired mobilization efficiency was associated with age, remission status, >1 line of induction chemotherapy, four cycles ICE/R-ICE and grade 4 neutropenia. Prior bone marrow (BM) involvement was associated with nonmobilization. The majority of patients can be successfully mobilized with ICE/R-ICE. Prior BM involvement is associated with high rates of nonmobilization following ICE/R-ICE. Such patients may benefit from novel mobilization agents and/or alternative salvage regimens to ICE/R-ICE.

Remobilization of hematopoietic stem cells with high-dose methotrexate and cytarabine in patients with non-Hodgkin's lymphoma and multiple myeloma after failure to mobilize with chemotherapy and cytokines

BACKGROUND

High-dose chemotherapy supported by autologous stem cell transplantation is an effective treatment for patients with relapsed or refractory non-Hodgkin's lymphomas (NHLs) and fit patients with multiple myeloma (MM). However, failure rates of hematopoietic stem cell mobilization are estimated to be between 5 and 30%, respectively. Thus, we investigated the efficacy of the combination chemotherapy of high-dose methotrexate (MTX) and cytarabine with granulocyte-colony-stimulating factor (G-CSF) as a remobilization method in those who failed a prior mobilization and collection with chemotherapy and G-CSF.

STUDY DESIGN AND METHODS

Mobilization failure was defined as a collection of fewer than 5 × 10(6) CD34+ cells after three to five apheresis procedures. MTX (3500 mg/m(2) in a 120-min infusion) on Day 1 and cytarabine (3000 mg/m(2) infusion for 120 min) on Day 4 and Day 5 were followed by G-CSF (10 μg/kg daily).

RESULTS

A total of eight patients (six NHL and two MM; median age, 55 years) who had failed in prior mobilization with conventional chemotherapy and G-CSF underwent the second mobilization as described in the method. Successful collection of CD34+ cells (> 5 × 10(6) /kg) was achieved in six patients (75%) with three to five apheresis procedures. The total yield of CD34+ cells/kg body weight was 6.28 × 10(6) /kg (median; range, 1.53 × 10(6) -10.09 × 10(6) /kg).

CONCLUSIONS

This preliminary result warrants further investigation of high-dose MTX and cytarabine plus G-CSF as a means to remobilize stem cells in those with prior failure to mobilize stem cells with chemotherapy and G-CSF.

Being underweight may reduce your ability to mobilise peripheral blood stem cells

Being underweight is associated with a poorer outcome after haematopoietic stem cell transplantation (HSCT). We investigated whether nutritional status affects a patient's ability to mobilise stem cells. Weights, heights, peripheral blood CD34 counts and total collected stem cells were collected on 305 patients. Those patients who were underweight had a lower median peripheral blood CD34 count than those who were not underweight (36.0 vs. 53.0 × 10(6)/L (p = 0.0047)). However, the proportion of patients achieving a collection containing the minimum number of CD34 cells required to define a successful stem cell collection was similar in those who were underweight and those who were not. Therefore being underweight may reduce a patient's ability to mobilise peripheral blood stem cells and, if confirmed, improving nutritional status may reduce the number of patients who fail to mobilise.

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.

Poor hematopoietic stem cell mobilizers in multiple myeloma: a single institution experience

In a single institution, in a group of 28 myeloma patients deemed eligible for autologous transplant, stem cell mobilization was attempted using filgrastim: 26 individuals were given 31 autografts employing 1-4 (median three) apheresis sessions, to obtain a target stem cell dose of 1 x 10(6) CD34 +ve viable cells / Kg of the recipient. The median number of grafted CD34 cells was 7.56 x 10(6) / Kg of the recipient; the range being 0.92 to 14.8. By defining as poor mobilizers individuals in which a cell collection of < 1 x 10(6) CD34 viable cells / Kg was obtained, a subset of eight poor mobilizers was identified; in two patients the autograft was aborted because of an extremely poor CD34 +ve cell yield (< 0.2 x 10(6) CD34 +ve viable cells / Kg of the recipient) after four apheresis sessions. The long-term overall survival of the patients grafted with > 1 x 10(6) CD34 +ve viable cells / Kg was better (80% at 80 months) than those grafted with < 1 x 10(6) CD34 +ve viable cells / Kg (67% at 76 months). Methods to improve stem cell mobilization are needed and may result in obtaining better results when autografting multiple myeloma patients.

Comparison of unmobilized and mobilized graft characteristics and the implications of cell subsets on autologous and allogeneic transplantation outcomes

Autologous and allogeneic hematopoietic stem cell transplantation (HSCT) are considered the standard of care for many malignancies, including lymphoma, myeloma, and some leukemias. In many cases, mobilized peripheral blood has become the preferred source of hematopoietic stem cells. The efficacy of different mobilization regimens and transplantation outcomes based on cell doses has been well studied; however, the characteristics of the stem cell graft may be of equal importance with respect to patient outcomes following autologous or allogeneic HSCT. This review summarizes available preclinical and clinical data for bone marrow and mobilized peripheral blood HSCT characteristics, defined as the cell types found in the graft as well as their gene expression profiles. It also explores how graft characteristics can affect bone marrow homing, engraftment, immune reconstitution, and other posttransplantation outcomes in both the allogeneic and autologous HSCT settings.

Peripheral blood progenitor cell mobilization with intermediate-dose cyclophosphamide, sequential granulocyte-macrophage-colony-stimulating factor and granulocyte-colony-stimulating factor, and scheduled commencement of leukapheresis in 225 patients undergoing autologous transplantation

BACKGROUND

Interpatient variability in the kinetics of peripheral blood progenitor cell (PBPC) mobilization is commonly seen with conventional chemotherapy-based mobilization regimens. This necessitates the availability of leukapheresis (LP) facilities 7 days a week.

STUDY DESIGN AND METHODS

The efficacy of an approach where LP was invariably commenced on Day 11 after intermediate-dose cyclophosphamide followed by sequential administration of granulocyte-macrophage-colony-stimulating factor (CSF) and granulocyte-CSF (Cy/GM/G) was retrospectively analyzed in 225 consecutive, unselected patients undergoing autologous hematopoietic stem cell transplantation for all diagnoses other than acute leukemia at our center. Cy/GM/G was scheduled to avoid weekend LP.

RESULTS

After Cy/GM/G, a CD34+ cell yield of at least 2.0x10(6) per kg was achieved in 90.7 percent of patients. Optimal yield (OY; >or=5x10(6) or 10x10(6) CD34+ cells/kg depending on diagnosis) was achieved in 67.6 percent of patients. Only three patients (1.3%) required LP on Saturday or Sunday. Febrile neutropenia (FN) was encountered in 5.3 percent. PBPC yield was highest on Day 1 of LP (p<0.001). In multivariate analyses, platelet (PLT) count on Day 1 of LP (PLT-D1LP) was positively associated with achievement of OY (p<0.001). PLT-D1LP and diagnosis of myeloma were associated with a shorter time to achieve a CD34+ cell yield of at least 5x10(6) per kg (p<0.001 and p=0.002, respectively).

CONCLUSION

Cy/GM/G with scheduled LP commencement on Day 11 enables optimal CD34+ cell yields in most patients undergoing autologous transplantation, despite a low risk of FN and avoidance of weekend LP.

An antecedent diagnosis of refractory anemia with excess blasts has no influence on mobilization of peripheral blood stem cells and hematopoietic recovery after autologous stem cell transplantation in acute myeloid leukemia

Several studies have reported data on factors influencing mobilization of peripheral blood stem cells (PBSC) in non-myeloid malignancies. On the contrary, data from patients with acute myeloid leukemia (AML) are very limited, in particular, as the impact of an antecedent diagnosis of refractory anemia with excess blasts (RAEB) on mobilization of PBSCs as well as hematopoietic recovery after autologous stem cell transplantation (ASCT) is concerned. We retrospectively analyzed a cohort of 150 consecutive AML patients in first complete remission in order to make a comparison between patients with de novo AML and secondary AML (s-AML) in terms of CD34 positive (CD34+) cells mobilization and number of leukapheresis needed to collect at least one single stem cell graft. Data concerning hematopoietic recovery after ASCT were also compared. The successful mobilization rate (>2 x 10(6) CD34+ cells/kg) was comparable between de novo AML patients (87%) and those with s-AML (76%), P:0.21. No statistically significant difference was found in terms of either median number of CD34+ cells collected (P:0.44) or CD34+ cells peak in peripheral blood (P:0.28). Both groups of patients needed a median of two apheresis (P:0.45) and no difference was found on the median number of CD34+ cells collected per single apheresis (P:0.59). Finally, neutrophil and platelet recovery after ASCT were comparable between the two groups. An antecedent diagnosis of RAEB has no impact on mobilization and collection of PBSCs in AML as well as on hematopoietic recovery after ASCT.

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.

PBPC collection techniques: standard versus large volume leukapheresis (LVL) in donors and in patients

Transplantations of autologous and allogeneic peripheral blood progenitor cells (PBPC) are able to assure a complete hematopoietic and immunologic reconstitution in patients. PBPC are collected by leukapheresis technique after prior mobilization therapy, but procedures and results remain still highly variable and are poorly characterized. An optimum regimen for PBPC collections has not yet been recommended, but 2-3 total blood volumes (TBV) of the donor or patient are regarded as a standard. Another promising technique is large volume leukapheresis (LVL) with processing of 3-6 TBV of donor or patient. The aim of this paper is to find the most efficient and safe collection technique for an individual donor or patient and, consequently minimize the number of procedures required. Finding the optimal collection procedure would be helpful while considering which method would be preferred in an individual donor or patient with respect to the result of mobilization, health state and required yield of CD 34+ cells for transplantation. We evaluated the results in a total of 134 standard and LVL procedures, which were performed in 21 well mobilized donors (Group I), in 65 well mobilized patients (Group II), and in 14 weakly mobilized patients (Group III) with hemato-oncological diseases. A precollection concentration of CD 34+ cells in peripheral blood higher than 20 x 10(3)/mL was considered to be the criterion for efficient mobilization. Such levels of concentration indicating the start of PBPC collections could be easily reached in Group I of donors and Group II of well mobilized patients. Heavily pretreated patients at advanced stages of disease (Group III) did not respond to mobilization sufficiently and had a concentration of CD 34+ cells lower than 20x10(3)/mL. LVL technique made it possible to obtain higher numbers of CD 34+ cells than in the standard collection in well mobilized donors (Group I), well mobilized patients (Group II), and even in weakly mobilized patients in Group III. In donors and well mobilized patients (Group I and Group II) it was possible to collect sufficient amounts of CD 34+ cells for allogeneic or for autologous transplantation from one LVL collection. The median yield of CD 34+ cells from one LVL collection was 5.5 x 10(6)/kg b.w. in donors, and 6.0 x 10(6)/kg b.w. in well mobilized patients. Due to the linear dependence of the yield of collected CD 34+ cells on the concentration of CD 34+ cells in blood, it can be used as a simple prediction of the success of collection in Group II (correlation coefficient 0.93 for standard procedures, and correlation coefficient 0.88 for LVL). In Group III of weakly mobilized patients the standard collections were usually ineffective and the relationship between the yield of CD 34+ cells/kg in the product and the precollection concentration of CD 34+ cells was much less significant (correlation coefficient 0.56 for standard procedures and correlation coefficient 0.66 for LVL). The median of CD 34+ cells collected from one standard procedure was only 0.7 x 10(6)/kg but using LVL the median increased to 1.4 x 10(6)/kg. Our results prove that the yield of CD 34+ cells in the product can be enhanced by large volume leukapheresis (LVL). Based on the results obtained, we recommend LVL in all donors and patients who can tolerate it due to a greater chance of collecting higher yields of progenitor cells while minimizing adverse reactions. LVL procedures should also be preferred in weakly mobilized patients where it is not possible to collect sufficient amounts of CD 34+ cells for transplantation using the standard regime. In weakly mobilized patients LVL provides a greater chance to at least collect a minimum amount of CD 34+ cells necessary. LVL should be used in circumstances where extremely high doses of CD 34+ cells has to be prepared, e.g. planned "tandem" transplantations or manipulations with a graft in which a significant loss of cells is expected.

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.

A single prior course of BCNU-cisplatin chemotherapy has a significant deleterious effect on mobilization kinetics of otherwise untreated patients

Extensive prior treatment with cytotoxic agents is associated with impaired mobilization of hematopoietic cells. To assess the effect of a single course of standard-dose chemotherapy (CT), we compared the results of filgrastim-induced mobilization among two sequential groups of grade III-IV malignant glioma patients included in a hematopoietic transplantation program. The first group (21 patients) had never been treated with CT until 2 days after surgery, when they received a course of 100 mg/m2 BCNU (i.v.) and 100 mg intracarotid cisplatin for cytoreduction (not for mobilization). At 1 month after this CT, they were mobilized with 12 microg/kg filgrastim. The second group (22 patients) was mobilized with the same dose of filgrastim directly after the surgery, without having ever received any prior CT. The blood level of CD34+ cells was significantly lower in the CT-treated patients, both on the fourth day of filgrastim (15 vs 36 cells x 10(6)/l; P=0.01) and on the fifth (25 vs 58 cells x 10(6)/l; P=0.003), as it was the number of CD34+ cells collected per apheresis (1.3 vs 3.5 x 10(6)/l; P<0.0005). The toxic effect of a single course of BCNU-cisplatin CT led to significant impairment of the filgrastim-induced mobilization response.