Yield Of CD34 Research Articles

Effective Primary Mobilization of Autologous Peripheral Blood Stem Cells with Granulocyte Colony-Stimulating Factor and Plerixafor in Lenalidomide-Treated Patients with Multiple Myeloma

AbstractAbstract 2254 Background:Lenalidomide (LEN) is extensively used in combination with dexamethasone (DEX), with or without bortezomib (BOR), for initial treatment of multiple myeloma (MM). However, several studies have shown that previous exposure to LEN is associated with impaired collection of autologous peripheral blood stem cells (PBSCs) after mobilization with either granulocyte-colony stimulating factor (G-CSF) or chemotherapy plus G-CSF. The effects of previous exposure to LEN on the collection of autologous PBSCs after mobilization with G-CSF plus plerixafor (PLX; Mozobil®) are not well described. Methods:We evaluated the outcomes of autologous PBSC mobilization and collection in 15 consecutive patients (pts) with MM who received previous treatment with at least 2 21-day cycles of LEN in combination with either DEX (10 pts) or DEX and BOR (5 pts) and who underwent initial autologous PBSC mobilization with G-CSF (10 micrograms/kg/dose subcutaneously daily × 4 days) and PLX (0.24 mg/kg/dose subcutaneously, after fourth dose of G-CSF), with additional doses of G-CSF and PLX for subsequent apheresis sessions. Results:Median age of pts was 58 yr (range, 35–67). Patients received a median of 5 cycles (range, 2–12) of LEN. The median number of apheresis sessions was 1 (range, 1–2). The median level of CD34+ cells in the peripheral blood at day 1 of apheresis was 84.36 per microliter (range, 12.46–167.37), and the median yield of CD34+ cells was 6.52 × 106/kg (range, 1.43–17.11) after day 1 of apheresis and 7.46 × 106/kg (range, 2.32–17.11) after day 2 of apheresis. No LEN-treated pts failed mobilization (defined as collection of less than 2 × 106 CD34+ cells/kg). Eleven pts (73.3%) collected at least 6 × 106/kg CD34+ cells (i.e., sufficient for 2 transplants) after 1 or 2 aphereses, with 8 pts (53.3%) reaching that target after 1 apheresis. Of the 4 pts (26.7%) in whom fewer than 6 × 106/kg CD34+ cells were collected after 2 aphereses, 3 pts collected at least 4 × 106 CD34+ cells/kg, and only 1 pt (who received only 2 cycles of LEN) collected 2.32 × 106/kg CD34+ cells. The number of cycles of LEN did not correlate with concentration of CD34+ cells in peripheral blood on day 1 of apheresis (r2=0.099), yield of CD34+ cells on day 1 of apheresis (r2=0.108), or total yield of CD34+ cells after 2 days of apheresis (r2=0.067). Pts who received 4 or fewer cycles of LEN had higher median circulating CD34+ cells on apheresis day 1, higher median CD34+ cell yield with day 1 apheresis and higher total CD34+ cell yield after 2 aphereses than pts who received more than 4 cycles of LEN (Table). Five of 6 pts who received 4 or fewer cycles of LEN collected at least 6 × 106 CD34+ cells/kg after 1 apheresis, compared with 3 of 9 pts who received more than 4 cycles. However, none of these differences were statistically significant (Table). Conclusions:Previous treatment with LEN does not impair collection of autologous PBSCs after initial mobilization with G-CSF and PLX. However, there was a trend to more robust autologous PBSC collections and decreased need for second aphereses in pts who received fewer cycles of LEN. These findings are consistent with the recommendation of the International Myeloma Working Group to collect autologous PBSCs from MM pts after 4 or fewer cycles of LEN-containing regimens. As mobilization with G-CSF with or without chemotherapy leads to inconsistent autologous PBSC collection in LEN-treated MM pts, our experience supports the use of G-CSF plus PLX as an upfront mobilization strategy for these pts. Disclosures:No relevant conflicts of interest to declare.

Influence of Different Dosages of Cyclophosphamide on Stem Cell Mobilization and Engraftment In Newly Diagnosed Multiple Myeloma Patients Treated with a Thalidomide Containing Regimen.

AbstractAbstract 3494 Introduction:Treatment of multiple myeloma (MM) patients (<65 yrs) consists of induction chemotherapy for 3–6 months followed by peripheral blood stem cell collection and transplantation. Both high dose cyclophosphamide (HD-C, 2 gr/m2/day, on days 1–2) and lower dosage of cyclophosphamide (1 gr/m2/i.v.on day 1) combined with doxorubicin (15 mg/m2/day, on days 1–4) and dexamethason 40 mg orally, days 1–4 (LD-C) are used, in combination with G-CSF, to mobilize hematopoietic stem/progenitor cells. A great variability was observed in the engraftment of different hematopoietic lineages post-ASCT. Therefore we questioned whether the dose of cyclofosfamide as mobilizing agent might affect the neutrophil and platelet recovery post-ASCT. The studied MM patients were treated with VAD or TAD (Blood 2010;11:115). Peripheral blood stem cells were collected after LD-C and HD-C with the Cobe Spectra; in each collection, 10 – 12 L of blood was processed in 3 – 4 hours. The target yield was 10 × 106/kg CD34+ cells. Results:92 patients were treated according to VAD and 41 patients with TAD. In the VAD arm 89% of the patients reached the target yield of CD34+ cells after 1 collection compared to 61% in patients treated with TAD (p = 0.0003). The number of CD34+ cells collected at the first day and the total CD34 yield after HD-C or LD-C was significantly higher in patients treated with VAD compared with TAD: 16.6 ± 11.6 × 106/kg vs. 10.4 ± 9.3 × 106/kg (p=0.003), and 16.9 ± 11.1 × 106/kg vs 12.3 ± 8.6 × 106/kg (p=0.02). No significant difference was observed in the total yield of collected CD34+ cells in the VAD arm or TAD arm between HD-C vs. LD-C.In all patients high dose melphalan (200 mg/m2) was used as conditioning regimen followed by reinfusion of peripheral blood stem cells. In the VAD arm no difference in neutrophil and platelet engraftment (absolute neutrophil count > 0.5 × 109/L and platelet count > 20 × 109/L without platelet transfusions) was noticed between patients mobilized with LD-C (22 ±12 days and 23 ±13 days) or HD-C (18 ± 5 (p=0.1) and 21 ±11 days (p=0.5)); in contrast a significant difference was demonstrated in neutrophil and platelet engraftment between patients treated according the TAD arm and mobilized with LD-C (20 ± 8 days and 20 ±19 days) or HD-C (34 ± 11 days (p<0.0001) and 43 ±22 days (p=0.001)). These differences could not be ascribed to differences in the number of infused CD34+ cells: VAD arm: LD-C: 5.7 ± 2.6 × 106/kg, HD-C: 5.7 ± 2.5 × 106/kg: TAD arm: LD-C: 5.2 ± 2.5 × 106/kg and TAD-HD-C 6.4 ± 2 × 106/kg. It might be assumed that the higher dosage of cyclophosphamide had a positive effect on tumor response. However the impaired engraftment was not associated with differences in relapse free survival between the different arms (p = 0.2). In summary these data demonstrate that thalidomide containing regimen in MM patients impair mobilization of stem/progenitor cells and that a mobilization with high dose cyclophosphamide and not low dose cyclophosphamide after treatment with thalidomide prolong the engraftment post-transplantation. Disclosures:No relevant conflicts of interest to declare.

Carbohydrate-mediated inhibition of ice recrystallization in cryopreserved human umbilical cord blood

Cryopreservation of human umbilical cord blood (UCB) typically involves the cryoprotectant dimethylsulfoxide (DMSO), however, infusional toxicity and reductions in cell viability remain a concern. Ice recrystallization (IR) is an important source of cryopreservation-induced cellular injury and limits the stem cell dose in UCB units. Carbohydrates have wide-ranging intrinsic IR inhibition (IRI) activity related to structural properties. We investigated the impact of carbohydrate IRI on cell viability, induction of apoptosis and hematopoietic progenitor function in cryopreserved UCB. Mononuclear cells (MNCs) from UCB were cryopreserved in storage media containing specific carbohydrates (200 mM) and compared to 5% DMSO. Samples were analyzed under conditions of high IR (‘slow’ thaw) and low IR (‘fast’ thaw). Thawed samples were analyzed for viability and apoptosis by flow cytometry and hematopoietic function using colony-forming unit (CFU) assays. IRI of carbohydrate solutions was determined using the ‘splat cooling’ assay. Greater IRI capacity of carbohydrates correlated with increased yield of viable MNCs ( r 2 = 0.92, p = 0.004) and CD34(+) cells ( r 2 = 0.96, p = 0.019) after thawing under conditions of high IR. The correlations were less apparent under conditions of low IR. Carbohydrates with greater IRI modulate the induction of early apoptosis during thawing, especially in CD34+ cells ( r 2 = 0.96, p = 0.0001) as compared to total mononuclear cells ( p = 0.006), and preserve CFU capacity in vitro ( r 2 = 0.92, p = <0.0001). Our results suggest that carbohydrates with potent IRI increase the yield of non-apoptotic and functional hematopoietic progenitors and provide a foundation for the development of novel synthetic carbohydrates with enhanced IRI properties to improve cryopreservation of UCB.

Predicting PBSC harvest failure using circulating CD34 levels: developing target-based cutoff points for early intervention

Peripheral Blood Stem Cells (PBSC) are usually mobilized using granulocyte colony stimulating factor (G-CSF) with or without chemotherapy. With the emergence of newer mobilizing agents, predicting poor mobilization may allow early intervention and prevent the costs and complications associated with remobilization. We retrospectively evaluated a cohort of 1556 patients seen between January 2000 and December 2008 with Multiple Myeloma (MM) (565; 36%), Non-Hodgkin’s Lymphoma (NHL) (562; 36%), Amyloidosis (345; 22%) or Hodgkin’s disease (HD) (94; 6%) initially mobilized with single agent G-CSF. Sensitivity-specificity analysis was used to identify ideal peripheral blood CD34 count (PB-CD34) cut-points that predicted successful collection. In patients with plasma-cell disorders a PB-CD34 of 11/uL, 17/uL, 21/uL, and 28/uL by day 4 or 5 were required to collect a target of 2, 4, 8 or 12 million/kg respectively. A CD34 yield <0.8 million cells/kg on first apheresis also predicted for <2 million CD34/kg. For patients with NHL or HD, a PB-CD34 <6/uL and <15/uL on day 4 or 5 predicted failure to achieve a target collection of 2 and 4 million/kg respectively. This study suggests that PB-CD34 thresholds should be based on collection target to allow for early intervention and prevent collection failures.

PBPC collections: Management, techniques and risks

We evaluated the efficiency, safety and risks of three techniques which were used for autologous PBPC collections: (a) large-volume leukapheresis (LVL), (b) standard collections, and (c) a new modified technique which was named as “Mixed” collections. In spite of the fact that the standard and LVL collection techniques are used routinely, there may occur special conditions in which the procedures cannot be recommended. Some patients may suffer from serious clinical complications and they cannot tolerate either standard procedures with administration of higher doses of ACD-A, or the high extent of procedure in the course of LVL. We tried to find the safe and efficient collection technique which could help this group of patients to overcome their problems. The “Mixed” collection technique could be such a choice. The numbers of 136 autologous PBPC collections were performed in 98 patients who suffered from hemato-oncological diseases. We evaluated the results of (a) 93 LVL (more than 3 TBV, total blood volumes of the patients were processed; anticoagulation: ACD-A and Heparin), (b) 16 Standard procedures (less than 3 TBV were processed; anticoagulation: ACD-A), and (c) 27 “Mixed” collections (less than 3 TBV of patients were processed; anticoagulation: ACD-A+ Heparin). Collections were performed by the use of separator Cobe Spectra, Caridian. In patients (a) with a good effect of mobilization (precollection CD 34+ cells in blood higher than 20 × 10 3/mL) we prepared almost the same median dose of CD 34+ cells from the standard and “Mixed” collections, 3.8 and 4 × 10 6/kg, respectively. In LVL the median yield of CD 34+ cells was 8.2 × 10 6/kg. In patients (b) who were mobilized weakly (precollection CD 34+ cells in blood lower than 20 × 10 3/mL), LVL enabled to prepare 1.5 × 10 6 of CD 34+/kg from one collection, while the median yield of CD 34+ cells from the standard and “Mixed” collections was 0.9 and 1.2 × 10 6/kg. All the standard, LVL and “Mixed” procedures were tolerated well without any serious adverse reactions. We detected 22 adverse reactions, but only three reactions were associated directly with the procedure. Mild hypocalcemia (2) and hypotensive reaction (1) were transient and treated efficiently. Procedures could continue and were finished according to the planned programme. Other reactions were related either to the insufficient function of central venous catheter or to the poor clinical condition of the patients. LVL enabled to get a higher yield of CD 34+ cells than the Standard and “Mixed” collections in well mobilized patients as well as in weakly mobilized patients. We observed the similar efficiency in standard and “Mixed” collections in well mobilized and weakly mobilized patients. We can recommend LVL in all patients who can tolerate it due to a greater chance of collecting higher yields of progenitor cells. In the weakly mobilized patients LVL offers a greater chance of collecting at least a minimum amount of CD 34+ cells needed for transplantation. “Mixed” collections may be used as an alternative technique under the circumstances in which standard or LVL cannot be recommended – like in patients who do not tolerate a high amount of citrate or a high extent of the procedure, e.g. patients with cardiac arrhytmia, impaired liver or renal function or unstable vital signs.

Efficacy and safety of gemcitabine, carboplatin, dexamethasone, and rituximab in patients with relapsed/refractory lymphoma: a prospective multi-center phase II study by the Puget Sound Oncology Consortium

We conducted a multi-center phase II trial of gemcitabine (G), carboplatin (C), dexamethasone (D), and rituximab (R) in order to examine its safety and efficacy as an outpatient salvage regimen for lymphoma. Fifty-one patients received 2–4 21-day cycles of G (1000 mg/m2, days 1 and 8), C (AUC = 5, day 1), D (40 mg, daily days 1–4), and R (375 mg/m2, day 8 for CD20-positive disease) and were evaluable for response. Characteristics included: median age 58 yeas (19–79 years), stage III/IV 88%, elevated LDH 33%, median prior therapies 2, prior stem cell transplant 12%, chemoresistant 62%, median prior remission duration 2.5 months. The overall and complete response rates were 67% (95% confidence interval [CI] 54–80%) and 31% (95% CI 19–44%), respectively, with activity seen in a broad variety of histologies. Responses occurred in 16 of 17 (94%, 95% CI 83–100%) transplant-eligible patients and 15 of 28 (54%, 95% CI 34–71%) with chemoresistant disease. The median CD34 yield in patients attempting peripheral blood stem cell (PBSC) collection following this regimen was 10.9 × 106 CD34+ cells/kg (range 5.0–24.1 × 106). Hematologic toxicity was common, but febrile neutropenia (2.5%) and grade 4 non-hematologic adverse events (n = 2) were rare, with no treatment-related deaths. GCD(R) is a safe and effective outpatient regimen for relapsed lymphoma, and successfully mobilizes PBSCs.

Collection of Autologous Peripheral Blood Stem Cells Using the COBE Spectra Is Associated with Higher CD34+ Yields and Requires Less Collection Time Than the Fresenius AS104 Cell Separator.

Abstract 2158Poster Board II-135We retrospectively analyzed yields and characteristics of autologous peripheral blood stem cell (PBSC) products collected using either a COBE Spectra (CS) or Fresenius AS104 (F) cell separator. CS and F collections were performed according to manufacturer's protocol.One hundred and fifty nine adult patients (pts) collected between January 2006 and July 2009 at our center were randomly selected for analysis. Eighty nine pts had multiple myeloma (MM) and 72 pts other cancers, including non-Hodgkin's lymphoma (n=42), Hodgkin's disease (n=20), testicular cancer (n=5), neuroblastoma (n=1), acute lymphocytic leukemia (n=1), or acute promyelocytic leukemia (n=1). Pts were collected on either CS (n=85) or F (n=74), and mobilized with G-CSF alone (n=47), G-CSF and Plerixafor (P) (n=26), or G-CSF and Chemotherapy (Ch) (n=66). Data from pts who failed to mobilize were not included in the analysis. Results are summarized in table. All p-values were calculated using two-tailed, heteroscedastic student T-test; statistical significance was defined as p < 0.05.COBE MediansStandard DeviationFresenius MediansStandard DeviationNumber of Products165180Number of Patients8574Weight at Collection (kg)82.7±18.079.6±16.0p = 0.459Volume Processed (L)18.00±2.4018.05±2.75p = 0.488Volume Collected (ml)241±56.8402±72.0p < 0.001Product WBC (K/μl)163.3±136.0155.85±29.39p < 0.001Total Cells4.07E+10±3.98E+102.17E+10±1.26E+10p < 0.001% MNC75±2385±11p < 0.001Peripheral CD34 / μl24±4425±79p = 0.050Absolute Product CD34 / μl726.73±1325.94264.63±781.01p < 0.001Product / Peripheral CD34 Ratio24.87±10.9010.91±6.64p < 0.001Product CD34/kg (10 6)2.02±4.671.40±4.15p = 0.152Hours per collection4.25±0.655.20±0.88p < 0.001Number of Collections / pt2±12±1p = 0.550CD34 cells/kg × 106infused3.85±3.203.85±2.24p = 0.273CD34 yields are calculated as the ratio of the absolute CD34 count/μl of the PBSC product to the pt's peripheral blood CD34 / μl count taken on the day of collection. Pt age, weight on day of collection, number of collections per pt, volume processed per collection, disease type (MM versus other) and mobilization strategy did not differ between patients collected with CS or F. Products collected on the CS had significantly higher total WBC when compared to the F (163.3 ± 136 K/μl vs. 55.7 ± 29.2 K/μl, p < 0.001), but had lower percentages of mononuclear cells (75% ± 23% vs. 85% ± 11%, p < 0.001); this relationship persisted when patients were divided by disease type or mobilization strategy. CD34 / kg counts of PBSC products were not significantly different in any cohort, but absolute CD34 count of the PBSC product was significantly higher in every disease type and mobilization strategy on the CS (all pts, 727 ± 1326 cells/μl vs. 265 ± 789 cells/μl, p < 0.001). CD34 yields were also significantly higher on the CS than the F across all disease types and mobilization strategies (all pts, 24.9 ± 10.9 vs. 11.2 ± 7.4, p < 0.001). Analysis of peripheral blood CD34 counts/ μl and product CD34 count/ μl showed a stronger correlation in pts mobilized with G-CSF + P (R2 = 0.8735) versus G-CSF + Ch (R2 = 0.5492) or G-CSF alone (R2 = 0.5). Hours for collection were lower on the CS than the F, regardless of disease type (4.25 ± 0.65 hrs vs. 5.2 ± 0.98 hrs, p < 0.001). No difference in WBC or platelet engraftment after transplantation was observed between the cell separators. Adverse effects on infusion were similar except, 3 of 169 pts experienced seizures upon infusion of PBSC product; all three were collected on the CS and all three had product WBC counts of 590 K/μl or above (compared to a median of 163.3 K/μl for the total MM/CS population).In conclusion, collection of PBSC using the CS is associated with higher CD34 yields and requires less collection time than collections with the F cell separator. Disclosures:No relevant conflicts of interest to declare.

Appropriate Timing of G-CSF Use After Mobilization Chemotherapy Significantly Increases the Yield ofCD34+ Cells in autoPBSCT.

Abstract 2144Poster Board II-121The yield of CD34+ cells collected by apheresis for autologous peripheral blood stem cell (PBSC) transplantation was greatly increased when the appropriate timing was determined to begin using G-CSF after COAEP mobilization. 29 patients with lymphoma or multiple myeloma (MM) received the same mobilization chemotherapy, including CTX 400mg/m2 d1; VDS 2 mg/ m2 d1; Ara-C 60 mg/m2 ×5d; vp-16 60 mg/m2 ×5d; and prednisone 40 mg/m2 ×5d. The control group (12 cases) received subcutaneous G-CSF (filgrastim) at the first restoration after the initial nadir of the peripheral WBC count. The experimental group (17 cases) received G-CSF during the steady rise of the WBC count (end of fluctuating after initial nadir). G-CSF was given in a single daily subcutaneous dose of 300μg until the final PBSC apheresis.When the peripheral WBC and mononuclear cell (MNC) counts reached 10.0×109/Land 1.0×109/L, respectively, leukapheresis was carried out using the COBE Spectrablood cell separator. Despite comparable treatment with alkylating agents, a significantly increased yield of CD34 positive cells was observed in the experimental group (32.0×106/kg) compared to the control group (3.1×106/kg) (P=0.0182). This result indicates the importance of appropriate timing for the use G-CSF after mobilization chemotherapy to increase the CD34+ cell yield. Disclosures:No relevant conflicts of interest to declare.

High CD34 Yield Not Impaired by Melphalan 10mg/m2 Test-Dosing for Pharmacogenomics in M-VTD-PACE as Induction Therapy in Total Therapy 4 (TT4) for Low-Risk and Total Therapy 5 (TT5) for High-Risk Newly Diagnosed Multiple Myeloma (MM).

Abstract 3411Poster Board III-299 Introduction:Based on profound outcome differences in Total Therapy 3 (TT3) among patients with gene expression profiling (GEP)-defined low- and high-risk groups, TT4 for low-risk MM randomizes patients between standard and light version of TT3, whereas TT5 for high-risk MM applies dose-dense treatment sequences. Both trials employ M-VTD-PACE combination therapy for induction followed by HPC collection with the objective of collecting a minimum of 20 × 106 CD34 cells per kg body weight. The M-VTD-PACE regimen includes M (melphalan, 10mg/m2) as a test-dose after a preceding bortezomib test-dose (1.0mg/m2), each of which is followed 48hr later by GEP studies to examine prognostically relevant and drug-unique GEP alterations. There was obvious concern that the M test-dose might interfere with HPC collection. Here, we examined the CD34 yield and the days required in the first 84 patients in comparison to predecessor TT3 protocols. Methods:Box-plots were used to display the total CD34 collections and the CD34 collection days. Comparisons were made using the Wilcoxon Rank Sum Test. Results:As is evident from the appended Figure, the addition of M did not adversely affect CD34 total yield or the kinetics of procurement. Results will be presented on the engraftment kinetics and early outcome results for this first personalized medicine trial in MM. Conclusion:We were able to introduce M pharmaco-genomic investigations in this first-in-kind risk-directed front-line protocol for MM without compromising HPC mobilization. [Display omitted] [Display omitted] X 106CD34 / kgDays of collectionProtocolMinimumMedianMeanMaximumMinimumMedianMeanMaximumTT31.4530.0333.99120.112.002.002.469.00TT4/TT58.1032.7337.07126.862.002.002.337.00P-value for medians of totals, 0.133; for medians of days, 0.360 Disclosures:van Rhee:Genzyme Corporation: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding.

Harvesting of Peripheral Blood Stem Cells Using Plerixafor (MOZOBIL) and Granulocyte-Colony Stimulating Factor in Patients Who Had Never Undergone Stem Cell Collection.

Abstract 4236 IntroductionThe collection of peripheral blood stem cells (PBSC) can be tedious and expensive. Moreover, PBSC yields can be severely compromised in patients who previously received chemotherapy. The use of plerixafor (MOZOBIL) for PBSC mobilization has been shown to significantly improve CD34 stem cell yields in patients whom PBSC collections have been adequate. However, this requires the patient to undergo further PBSC harvesting sessions; adding to the patient's inconvenience, exposure to adverse events and costs. We therefore investigated whether using plerixafor at the outset of PBSC mobilization would improve patient acceptability; reduce PBSC collection days and accordingly the patient's costs. Patients and MethodsThree adult patients who had never undergone PBSC harvesting were mobilized using subcutaneous (SC) granulocyte-colony stimulating factor (G-CSF) 10 μg/kg daily starting 4 days prior to PBSC harvesting; plus SC plerixafor 240 μg/kg 10 hours prior to PBSC harvesting. Both G-CSF and plerixafor were continued for as long as was required for PBSC collections. Two patients had multiple myeloma (MM) and were both in stringent complete remission (sCR). The third patient suffered from adult-onset spinomuscular atrophy (SMA) and stem cells were required for possible re-infusion therapy. Importantly, the bone marrows of all 3 patients were assessed to be normal prior to PBSC mobilization and collection. The target PBSC CD34 yield was 2 million CD34 cells/kg per PBSC collection. ResultsAs can be seen, the CD34 yields (expressed as x million CD34 cells/kg) exceeded expectations:PatientDiagnosisCell SeparatorDay 1Day 2Day 3Patient #1MMCOBE Spectra2.794.354.21Patient #2MMCOBE Spectra3.433.12not donePatient #3SMASPECTRA Optia8.105.565.50All patients tolerated the procedure very well and were discharged within 24 hrs of completing the final PBSC collection. The only adverse event was grade 1 restless legs syndrome in Patient #1 following the first injection of plerixafor. It was improved with oral diazepam and did not recur. Both patients with MM reported a sense of “rejuvenation” 2-3 weeks after PBSC collection. All patients were pleased with the relatively complication-free procedure. ConclusionsUpfront collection of PBSCs using G-CSF/plerixafor is both highly effective and safe. There is great patient acceptability as well as much fewer PBSC collection days and an accompanying reduction in procedure costs. The added advantage of using the SPECTRA Optia cell separator is worth further investigations. Disclosures:Off Label Use: Plerixafor (MOZOBIL) - Use in patients who had never undergone stem cell collection..

A Prospective, Randomized Study of Melphalan, Prednisone, Lenalidomide (MPR) versus Melphalan (200 Mg/M2) and Autologous Transplantation (Mel200) in Newly Diagnosed Myeloma Patients: An Interim Analysis.

Abstract 350▪▪This icon denotes an abstract that is clinically relevant. Background.The incorporation of new drugs as induction therapy before autologous transplantation appears to produce a high proportion of complete responses, slightly superior to those achieved by conventional chemotherapy with new drugs. Randomized trials are needed to directly compare current best chemotherapeutic approach with best autologous transplantation strategy. Aims.To compare melphalan, prednisone and lenalidomide (MPR) with tandem melphalan (200 mg/m2) (MEL200) in patients younger than 65 years. Methods.As induction, all (N=402) patients received four 28-day cycles of lenalidomide (25 mg days 1-21) and low-dose dexamethasone (40mg days 1,8,15,22) (Rd). Cyclophosphamide (4 g/m2) plus granulocyte-colony stimulating factor was used to mobilize stem cells. As consolidation, patients (N=202) randomized to MPR received six 28-day cycles of melphalan (0.18 mg/kg days 1-4), prednisone (2 mg/kg days 1-4) and lenalidomide (10mg days 1-21); patients (N=200) randomized to MEL200 received tandem melphalan 200 mg/m2 with stem-cell support. All patients were also randomized to receive either aspirin or low-molecular weight heparin (enoxaparin) as thromboprophylaxis. Primary end point was progression-free survival; data were analyzed in intention-to-treat. Results.Patient characteristics were similar in both groups, median age was 58 years. After Rd induction, at least partial response (PR) rate was 84%, at least very good partial response (VGPR) was 32% including 5% complete response (CR). The median yields of CD34+ cells harvested was 10 ×106 CD34+ cells/Kg; 94% of patients collected the minimum dose of 2×106/kg CD34+ cells. After 3 cycles of MPR, at least VGPR rate was 51% and CR 11%. After the first MEL200, at least VGPR rate was 56% and CR 14%. No difference in responses were reported according to cytogenetic abnormalities, such as del13, t(4;14) and t(14;16). After a median follow-up of 12 months, 1-year progression-free survival was 96% for MPR and 94% for MEL200 (p=.92) 1-year overall survival was 98% for MPR and 99% for MEL200 (p=.94). During Rd induction, the most frequent grade 3-4 adverse events were neutropenia (9%), anemia (8%), infections (4%), skin rash (4%), fatigue (2%) and thromboembolic events (1%). During consolidation, the incidence of grade 3-4 neutropenia (97% vs 34%, p <.001) thrombocytopenia (97% vs 16%, p<.001), infections (21% vs 3%, p<.001) and gastrointestinal (17% vs 1%, p<.001) complications was higher in MEL200 patients The incidence of thromboembolic events was similar in patients randomized to receive aspirin (2%) or enoxaparin (1%) as thromboprophylaxis (p=.42). Conclusion.Rd is an effective and safe induction regimen. Both MPR andMEL200 improved the quality of response, achieved by Rd induction. At present, progression-free and overall survival are not significantly different in the two groups, but longer follow-up is needed. Both aspirin and enoxaparin were equally effective as thromboprophylaxis. These data will be updated at the meeting. Disclosures:Palumbo:CELGENE: Honoraria. Cavallo:CELGENE: Honoraria. Patriarca:CELGENE: Honoraria. Caravita:CELGENE: CONSULTANCY. Boccadoro:CELGENE: CONSULTANCY, ADVISORY COMMITTEES, Research Funding.

Limitations of G-CSF Mobilization in Splenectomized Patients with Beta-Thalassemia Major: Implications for Thalassemia Gene Therapy.

Abstract 2150Poster Board II-127For gene therapy (GT) of thalassemia (TH), high numbers of genetically-modified hematopoietic stem cells (HSCs) are required to effectively compete for niche space in the hypercellular thalassemic bone marrow (bm). Mobilized peripheral blood is the preferable source of HSCs for thalassemia GT due to higher yields of CD34+cells compared to bm harvest. There is limited information on the mobilization efficacy of adult patients with major β-TH as well as on the safety of the procedure in a condition of splenomegaly and extramedullary hemopoiesis. Rare events of splenic rupture or thrombosis with G-CSF in normal donors raise safety concerns for its use in TH where chronic splenomegaly and hypercoagulability exist. Pretreatment of patients with hydroxyurea (HU) could reduce the risk of splenic rupture or thrombosis by decreasing the splenic hemopoiesis and thereby the spleen size in the non-splenectomized (non-SPL), and the circulating cells in the splenectomized (SPL) patients before G-CSF. In an on going mobilization study, we aim to assess the safety and efficacy of G-CSF mobilization with or without HU pretreatment in adult patients with β-TH major. Sufficient mobilization is considered to be the yield of ≥2×106CD34+cells/kg/2aphereses. Sixteen patients have been enrolled so far, 9 SPL and 7 non-SPL. One non-SPL patient withdrew during the study. Six SPL and 4 non-SPL patients received HU pretreatment (20mg/kg/d the non-SPL, 25-30mg/kg/d the SPL) for 1 month before G-CSF. There was a 1-2 weeks' interval between HU cessation and G-CSF initiation. No severe adverse events were observed. In non-SPL patients, HU decreased the spleen volume over baseline (306cm3 vs 536cm3, p=0,03) resulting in 9% max increase during mobilization compared to 45% size increase in patients w/o HU pretreatment. In non-SPL patients, HU negatively affected the CD34+yield when the ‘wash-out' period before G-CSF was 8 days (mean CD34+cells 1,86±0,76×106/kg/2aphereses, n=2). However, when the interval period from the HU stop to the G-CSF initiation increased up to 18 days allowing for bm recovery after the myelosuppressive effect of HU, mobilization was successful (P12:CD34+cells 6,5×106/kg/2aph). Non-SPL patients w/o HU pretreatment (n=3) yielded adequate numbers of HSCs (CD34+cells:5,8±3,89×106/kg/2aph). Surprisingly, CD34+cell yields were very low in the first 2 non-HU pretreated SPL patients (CD34+cells:0,98±0,14×106/kg/2aph). This was due to the development of early excessive leukocytosis (mean max WBCs 81×109/l, day 3) with the regular 10mcg/kg/d G-CSF dose, which necessitated dose hold or therapeutic leukapheresis and resulted in loss of the CD34+cell peak in blood. However, when mobilization started with lower (2,5mcg/kg/d) and adjusted to the WBCs doses of G-CSF (mean daily dose 3,21mcg/kg) and aphereses were initiated later (day6), CD34+cell yield markedly improved (P15:4,5×106/kg/2aph) without inducing early excessive leukocytosis (max WBCs 67×109/l, day 5). In SPL patients, HU was shown to decrease the high PLT and WBC numbers before G-CSF (PLTs:from 640±132×109/l at baseline to 240±53×109/l, p=0,0002 / WBCs:from 20,23±15,8×109/l at baseline to 11,47±6,11×109/l, p=0,23) potentially reducing the risk of thrombosis and partially preventing excessive leukocytosis during mobilization (max WBCs SPL-HU:51,68±29,37×109/l vs SPL-no HU:74,77±8,78×109/l, p=0,23). HU pretreatment negatively affected the yield in SPL patients when the ‘wash-out' period before G-CSF was 7-10 days (mean CD34+yield 0.62±0,41×106/kg/2aph, n=5). However, when the interval period from HU stop to G-CSF initiation increased up to 12 days, mobilization was successful (P16:CD34+cells 3,8×106/kg/2aphereses). G-CSF dose adjustment was also needed in HU-pretreated SPL patients with WBCs≥14,6×109/l before G-CSF (P9,P16). Overall, it seems that mobilization of SPL thalassemic patients is challenging. Mobilization is not inherently inefficient in SPL patients but it results from mandatory G-CSF-dose modifications to avoid hyperleukocytosis. Patient-tailored schemes of G-CSF mobilization or alternative ways of mobilization (ie AMD 3100) will be required in order to obtain high numbers of HSCs from SPL patients. HU seems to play a safety role as pretreatment before mobilization, especially in the SPL patients, however the time to G-CSF initiation after HU cessation is critical for a sufficient CD34+cell yield. Disclosures:No relevant conflicts of interest to declare.

Mobilization of Allogeneic Peripheral Blood Stem Cells in Family Donors with Single-Dose Pegfilgrastim.

Abstract 2148Poster Board II-125 Introduction:The standard procedure for obtaining peripheral blood stem cells (PBSC) is donor mobilization with G-CSF. Pegfilgrastim is a covalently bound conjugate of filgrastim and monomethoxypolyethylene glycol with longer half-life elimination due to decreased plasma clearance and could represent an alternative approach for PBSC mobilization in healthy donors. Design and Methods:From July 2006 till August 2009 28 related healthy donors (50% male, 50% female) were treated with single dose of 12 mg pegfilgrastim for mobilization of allogeneic PBSC. The harvests were performed as large-volume, continuous-flow collections using a Cobe Spectra blood cell separator on day 4 and if necessary on day 5 of the mobilization regimen. In case of inadequate CD34+ counts (less than 4×106/kg body weight of recipient on day 5), stimulation was continued with filgrastim. In addition, the serum level of filgrastim was determined twice daily. Results:We present the results of 27 donors (the results of the 28th donor are still pending). In all 27 cases the harvests were successful. In 22 out of 27 donors (82%) only a single apheresis was needed to reach the target. Two of the donors required additional treatment with non-pegylated filgrastim.The maximal concentration of circulating CD34+ cells was achieved on day 4 (median 74.3/μl; range 24.6-136.6). The median yield of CD34+ cells was 5.9×106/kg of the recipients body weight (range 3-14.5), and the median CD3+ count was 9.1×108/kg of the recipient body weight (range 1.4-6.2). Serum filgrastim level peak was on day 2 of the mobilization regimen with a median level of 226 ng/ml (range 35 to 1123 ng/ml), thus preceding the increase of CD34+ cells in blood. The main adverse events were WHO grade 1 and included headaches, bone pain and transient elevations of alkaline phosphatase and lactate dehydrogenase. Conclusion:PBSC mobilization with a single dose of pegfilgrastim is feasible for healthy donors. The graft composition was comparable to that obtained with the conventional regimen of short-term G-CSF. Long-term follow-up of healthy donors treated with pegfilgrastim should be further investigated. Disclosures:No relevant conflicts of interest to declare.

Predicting Poor Peripheral Blood Stem Cell Mobilization Using Initial Peripheral CD34 Counts in Patients with Lymphoma.

Abstract 4228 BackgroundPeripheral blood stem cells (PBSC) are the preferred graft type for autologous stem cell transplantation (ASCT) and mobilization is typically done using growth factor (GF) alone or a combination of chemotherapy (CTX) and GF. The success of mobilization is influenced by several factors such as prior therapy, mobilization strategy, underlying disease, among others. Patients (Pts) failing to mobilize successfully often have GF dose increased and if unsuccessful, mobilization is reattempted with chemotherapy + GF or G-CSF (Granulocyte Colony-Stimulating factor) + GM-CSF (Granulocyte–Macrophage Colony-Stimulating factor). More recently, plerixafor, a CXCR4 inhibitor, has been found to enhance G-CSF based collection allowing potential early intervention in poor mobilizers. However, this approach requires valid cut-points for peripheral CD34 counts (pCD34) for cost efficient use. MethodsWe studied 656 first time, G-CSF based PBSC mobilizers with Non-Hodgkin Lymphoma (562; 86%), or Hodgkin's Disease (94; 14%). Salvage attempts were excluded, as were first attempts using CTX+GCSF, plerixafor or GF combinations. Sensitivity-specificity analysis (Receiver operating characteristic) was used to define ideal cut-points for predefined outcomes. We used a CD34 yield of 2 million/kg as the minimum required collection and 5 million/kg as the ideal collection for the current analysis. Our current practice is to initiate collection at a pCD34 of 10/uL. ResultsWe first determined the best day 1 pCD34 cutoff for being able to collect at least 2 million/kg PBSC to be 9/uL. Among those with ≥9/uL, only 6.6 % failed to collect at least 2 million compared to 55% among the rest (P < 0.001). These numbers were 6.3% and 50% respectively using the traditional cutoff of 10/uL. We then examined how the pCD34 on day 2 predicted collection, among those failing to reach the current threshold of 10/uL. Among this group, a pCD34 on day 2 of 9.1/uL was the best cutoff to predict a collection of 2 million/kg. Among those with >=9.1/uL, only 22% failed to collect at least 2 million compared to 79% among the rest (P < 0.001). Among those with day 1 pCD34 < 10, 49% achieved a count of 9.1/uL on day 2. We then examined what pCD34 on day 1 can best predict a pCD34 ≥ 9.1 on day 2 and found this to be 5.2/uL. Among those with day 1 pCD34 ≥ 5.2/uL, 79% reached day 2 pCD34 ≥ 9.1 compared to 24% among the rest (P < 0.001).We then determined cutoffs based on ideal targets using only those patients achieving pCD34 count > 10/uL by day 2, since these patients would have started collection without any change in the mobilization technique. We used a maximum of 5 collections to achieve the goal as being ideal, taking into account the most commonly used practice of collecting during weekdays. We examined cutoffs for a target of 5 million/kg for one transplant. The best day 1 or day 2 pCD34 predicting a 5 million/kg yield in 5 collections was 17/uL. Among those with day 1or 2 pCD34 ≥ 17/uL, 4% failed to reach 5 million in ≤ 5 days compared to 96% among the rest (P < 0.001). ConclusionsThis study provides an estimate of optimal pCD34 count thresholds for early identification of patients with lymphoma at high risk of collection failure. It is reasonable to use the first or second day pCD34 count, since a substantial proportion of patients will achieve the threshold value by day 2 and these patients appear to have similar outcome as those reaching the threshold by day 1. Based on the results here, interventions such as addition of plerixafor can be considered if pCD34 count is < 6/uL on day 1 or < 10/uL by day 2, to achieve the minimum collection of 2 million/kg. However, in order to achieve the ideal targets, a higher threshold should be considered and the recommendation based on the current study would be 17/uL for a target of 5 million. Such a target-adapted strategy may be more appropriate. Disclosures:Kumar:Celgene,Genzyme,Millenium,Novartis,Bayer,: Honoraria, Research Funding. Gertz:Genzyme: Research Funding. Micallef:Genzyme: Research Funding.

Predicting Poor Peripheral Blood Stem Cell Mobilization in Multiple Myeloma (MM) Using Initial Peripheral CD34 Counts: Developing Target-Based Cut-Points for Early Intervention.

Abstract 3231Poster Board III-168 BackgroundPeripheral blood stem cells (PBSC) are the preferred graft type for autologous stem cell transplantation (ASCT) and mobilization is typically done using growth factor (GF) alone or a combination of chemotherapy (CTX) and GF. The success of mobilization is influenced by several factors such as prior therapy and mobilization strategy. Patients (Pts) failing to mobilize successfully often have GF dose increased and if unsuccessful, mobilization reattempted with chemotherapy + GF or G-CSF (Granulocyte Colony-Stimulating Factor) + GM-CSF (Granulocyte-Macrophage Colony-Stimulating Factor). More recently, plerixafor, a CXCR4 inhibitor, has been found to enhance G-CSF based collection allowing potential early intervention in poor mobilizers. However, this approach requires valid cut-points for peripheral CD34 counts (pCD34) for cost efficient use. MethodsWe studied 910 first time, G-CSF based PBSC mobilizers with MM (565; 62%), or light chain amyloidosis (345; 38%). Salvage attempts were excluded, as were first attempts using CTX+GCSF, plerixafor or GF combinations. Sensitivity-specificity analysis (ROC) was used to define ideal cut-points for predefined outcomes. We used a CD34 yield of 2 million/kg as the minimum required collection and 4 million/kg as the ideal collection for this analysis. Our current practice is to initiate collection at a pCD34 of 10/uL. ResultsWe first determined the best day 1 pCD34 cutoff for being able to collect at least 2 million/kg PBSC to be 9.2/uL. Among those with ≥9.2/uL, only 1.6% failed to collect at least 2 million compared to 27% among the rest (P < 0.001). These numbers were 1.7% and 25% respectively using the traditional cutoff of 10/uL. We then examined how the pCD34 on day 2 predicted collection, among those failing to reach the current threshold of 10/uL. Among this group, a pCD34 on day 2 of 8/uL was the best cutoff to predict a collection of 2 million/kg. Among those with >8/uL, only 9% failed to collect at least 2 million compared to 48% among the rest (P < 0.001). Among those with day 1 pCD34 < 10, 65% achieved a count of 8/uL on day 2. We then examined what pCD34 on day 1 can best predict a pCD34 ≥ 8 on day 2 and found this to be 5/uL. Among those with day 1 pCD34 ≥ 5/uL, 92% reached day 2 pCD34 ≥ 8 compared to 36% among the rest (P < 0.001).We then determined cutoffs based on ideal targets using only those patients achieving pCD34 count > 10/uL by day 2, since these patients would have started collection without any change in the mobilization technique. We used a maximum of 5 collections to achieve the goal as being ideal, taking into account the most commonly used practice of collecting during weekdays. We examined cutoffs both for a target of 4, 8 and 12 million/kg for one, two or three transplants respectively. Among those with a day 1 or day 2 pCD34 > 10/uL 98% collected 4 million/kg in 5 collections. The best day 1 or day 2 pCD34 predicting a 8 million/kg yield in 5 collections was 21.4/uL and a 12 million/kg yield was 27.9/uL. Among those with day 1or 2 pCD34 ≥ 21.4/uL, 90% collected 8 million compared to 54% among those with pCD34 < 21.4/uL. Similarly, among those with day 1 or 2 pCD34 ≥ 27.9/uL, 79% reached 12 million in ≤ 5 days compared to 17% among those with pCD34 < 27.9/uL (P < 0.001).Finally we examined if poor collection on first day, despite a pCD34 > 10 predicts for poor overall yield. A ratio of day 1 collection (million/kg) to pCD34 day 1 or 2 < 5×104 was highly predictive of failure to get eventual yield of 2 million/kg, with 38% below the cutoff failing to reach the goal compared to 2% for those above the cutoff. ConclusionsThis study provides an estimate of optimal pCD34 count thresholds for early identification of patients at high risk of collection failure. It is reasonable to use the first or second day pCD34 count, since a substantial proportion of patients will achieve the threshold value by day 2 and have similar outcome as those reaching the threshold by day 1. Based on the results here, interventions such as plerixafor can be considered if pCD34 count is < 5/uL on day 1 or < 9/uL by day 2, to achieve the minimum collection of 2 million/kg. However, in order to achieve the ideal targets, a higher threshold should be considered and the recommendation would be 17/uL, and 28/uL for target of 8 or 12 million respectively. Finally, identification of poor mobilizers after start of collection potentially provides another time point for early intervention, and this needs to be prospectively studied. DisclosuresMicallef:Genzyme: Research Funding. Gertz:Genzyme: Research Funding. Kumar:Celgene,Genzyme,Millenium,Novartis,Bayer,: Honoraria, Research Funding.

Successful Stem Cell Remobilization Using Plerixafor (Mozobil) Plus Granulocyte Colony-Stimulating Factor in Patients with Non-Hodgkin Lymphoma: Results from the Plerixafor NHL Phase 3 Study Rescue Protocol

In a phase 3 multicenter, randomized, double-blinded, placebo-controlled study of 298 patients with non-Hodgkin lymphoma (NHL), granulocyte colony-stimulating factor (G-CSF) plus plerixafor increased the proportion of patients who mobilized >or=5 x 10(6) CD34(+) hematopoietic stem cells (HSCs)/kg compared with placebo plus G-CSF (P < .001). Patients in either study arm who failed mobilization (< 0.8 x 10(6) CD34(+) cells/kg in 2 collections or <2 x 10(6) CD34(+) cells/kg in 4 collections) were eligible to enter the opened-label rescue protocol. Following a 7-day minimum rest period, these patients received G-CSF (10 microg/kg/day) for 4 days, followed by daily plerixafor (0.24 mg/kg) plus G-CSF and apheresis for up to 4 days. Of the 68 patients failing initial mobilization (plerixafor, n = 11; placebo, n = 57), 62 patients (91%) entered the rescue procedure (plerixafor, n = 10; placebo, n = 52). Four of 10 patients (40%) from the plerixafor group and 33 of 52 (63%) from the placebo group mobilized sufficient CD34(+) cells (>or= 2 x 10(6) cells/kg) for transplantation from the rescue mobilization alone (P = .11). Engraftment of neutrophils (11 days) and platelets (20 days) was similar to that in patients who did not fail initial mobilization, and all patients had durable grafts at the 12-month follow-up. Common plerixafor-related adverse events (AEs) included mild gastrointestinal (GI) effects and injection site reactions. There were no drug-related serious AEs. These data support that plerixafor plus G-CSF can safely and effectively remobilize patients with NHL who have failed previous mobilization.

Peripheral blood stem cell mobilisation by granulocyte-colony stimulating factor in patients with acute and old myocardial infarction for intracoronary cell infusion

Background/aims:Peripheral blood stem cells (PBSC) are one of the most promising stem cell sources for treatment of ischaemic heart disease. However, the experience of mobilisation and collection of PBSC using...

Plerixafor (P) plus G-CSF (G) in previous peripheral blood progenitor cell (HPC) mobilization failures (MF)

7095 Background: Successful autologous stem cell transplantation (AT) requires harvesting sufficient HPC to ensure reliable engraftment, which cannot be accomplished in ∼10% of previously treated patients. Methods: MF was defined as the inability to collect at least 2 x106 CD34+ cells/kg with growth factor alone (GF) (n=38) or in combination with chemotherapy (GF-CT) (n=27). Of 65 patients reported here, 45 were enrolled in a compassionate use program and 20 were part of a clinical trial (AMD3100–2102); 55 had MM, 9 had lymphoma and 1 had primary amyloidosis. All patients had been treated previously and included prior AT in 26 patients, 15 of whom had 2 AT and 2 had ≥3 AT. The P+G regimen started with G (10 μg/kg) for 4 days, P (240 μg/kg) was added on the evening of day 4; both P and G were continued until completion of collection. In the case of MM, all collected products were analyzed for tumor contamination by DNA/cIg flow cytometry. Results: Of all 65 patients, 63 initiated apheresis which yielded a median 3.6x106 CD34/ kg (range, 0.3–17.8) during a median of 5 days (d) of collection (range, 2–7), with successive median daily CD34 yields of 1.1, 0.9, 0.6, 0.5, 0.3, 0.4 and 0.5 x106/kg. MM cells were mobilized in only 2/55 patients. Additional collection was undertaken in 25 patients, using GF or GF-CT in 19 (median, 3.2x106 CD34 cells; range, 0–8.5), further P+G in 5 (median, 1.7x106 CD34 cells/kg; range, 0.9–3.5), and 1 patient received P+G on a third occasion (2.2x106 CD34 cells /kg). Of 63 patients, 51 (81%) and 24 (38%), respectively, collected ≥2.0 and ≥5.0x106 CD34 /kg. AT was supported with P+G derived products in 43 patients including 7 who received 2 AT. With median infused CD34+cells of 3.6x106 / kg (range, 1.0–7.7), the median times to neutrophils &gt; 500/μl and platelets &gt;20,000/ μl were 14 d (range, 11–35) and 15 d (range, 9–253). Conclusions: P+G ensures collection of an adequate HPC product after MF in 81% that affords durable engraftment even though 40% had prior AT. [Table: see text]

Analyzing white blood cell subpopulation for quick and simple predictors for autologous stem cell collection

7101 Background: For patients undergoing peripheral stem cell harvesting, the current standard predictor for successful harvest is the peripheral blood (PB)CD34 count, which may have a slow turn-around time. Daily monitoring of CD34 count may not be cost-effective. This study aims to identify simple hematological parameters that can be used to predict for a single day CD 34+ stem cell yield of at least 1 x 10(6)/kg. Methods: 57 patients with lymphoproliferative malignancies who underwent autologous stem cell (ASC) harvesting were studied following DHAP, ICE or ESHAP chemotherapy. Eight main parameters were investigated to predict for a single day CD34 stem cell yield above 1x10(6)/kg: PB CD34+ cells, absolute monocyte count (AMC), AMC ratio, total white count (WBC), absolute lymphocyte count (ALC), ALC ratio, immature granulocyte count (IMC), IMC ratio and non-neutrophil cells (NNC). NNC was calculated by subtracting absolute neutrophil count from the total white count. The ratios were calculated by dividing the respective values on the first day of harvest with the values on the day before mobilizing chemotherapy started. Results: Linear regression showed a strong correlation between stem cell yield and CD34+ cells (R2=0.79, p&lt;0.001), IMC ratio (R2=0.51, p&lt;0.001) and AMC ratio (R2= 0.46, P&lt;0.001). WBC and AMC showed a wide dispersion of results and were not reliable predictors of CD34 yield. On multivariate analysis, an IMC &gt; 1 (p=0.03) and AMC ratio &gt; 1 (p=0.002), ALC ratio &gt; 1 (p=0.03) were independently predictive of a single day CD34 stem cell yield exceeding 1x10(6)/kgConclusions: Incorporating simple, routine hematolgic indices such as ALC and AMC ratio into a simple formula can be used to predict for ASC collection in addition to CD34+ count. This may be particularly useful when the turn-around-time to attain enumeration of CD34+ cells is slow or delayed on the same day of collection. No significant financial relationships to disclose.

Plasma levels of FL and SDF-1 and expression of FLT-3 and CXCR4 on CD34+ cells assessed pre and post hematopoietic stem cell mobilization in patients with hematologic malignancies and in healthy donors

Peripheral blood stem cells (PBSC) became the main source of cells for autologous transplantation. Alterations in the expression of adhesion molecules are essential in the CD34+ cells mobilization process. These molecules are involved in the interaction between hematopoietic and stromal cells and they have been disclosed as a considerable factor to the trafficking and homing of the CD34+ progenitor cells. This is a non-randomized PBSC mobilization study designed to evaluate the influence and behavior of FL and SDF-1 and their receptors in two different moments, prior and after HPCs mobilization, with the yield of CD34+ cells collected by apheresis. There was higher concentration of FL and lower of SDF-1 plasma level at post than pre PBSC mobilization ( p = 0.001 and p = 0.012, respectively) regarding all individuals searched, but without any correlation with a good yield of CD34+ cells. However, CXCR4 expressions on the CD34+ cells from bone marrow aspirates (BMA), at pre and post mobilization showed a difference statistical significant for those individuals with good yield of CD34+ cells ( p = 0,036), but not achieved for poor yield ( p = 0,156). There was a higher expression of CXCR4 in steady-state for the successfully individuals than for those unsuccessfully (529.84 ± 54.68 and 496.31 ± 97.51, respectively). In conclusion, we confirmed the important role of CXCR4/SDF-1 axis in the process of PBSC mobilization.