Preapheresis peripheral blood CD34+ mononuclear cell counts as predictors of progenitor cell yield

BACKGROUND: Peripheral blood progenitor cells, harvested by apheresis after mobilization, provide rapid hematologic recovery after high-dose chemotherapy. However, because harvesting these cells is expensive and time-consuming, there has been much interest in optimizing collection protocols. An investigation was made to determine whether, in this clinical setting, peripheral blood progenitor cell yields may be predicted from preapheresis progenitor cell counts, allowing the length of each procedure to be "fine tuned" to achieve specific target goals. STUDY DESIGN AND METHODS: Preapheresis peripheral blood CD34+ cell and total colony-forming cell counts were assessed before 78 peripheral blood progenitor cell collections from 13 consecutive patients were performed. Preapheresis counts were correlated with actual progenitor cell yields. Factors affecting this correlation were analyzed. RESULTS: With the use of linear regression analysis preapheresis progenitor cell counts were found to correlate significantly but weakly with actual yields per kg of body weight per liter of blood processed (CD34+ cells: r = 0.43; colony-forming cells: r = 0.56). Further analysis revealed two possible causes: 1) circulating progenitor cell concentrations fluctuate widely during harvest, which implies that preapheresis counts are not representative of actual concentrations during apheresis, and 2) the efficiency with which apheresis machines extract mononuclear cells varies greatly between procedures. CONCLUSION: Preapheresis CD34+ and colony-forming cell counts correlated poorly with subsequent yields in this clinical setting, which suggests that it is not practical to use such counts to predict with certainty the length of apheresis needed to achieve a target yield.     

Concentration of citrate anticoagulant in peripheral blood progenitor cell collections

BACKGROUND: Peripheral blood progenitor cell (PBPC) collection by hemapheresis has become widely used in recent years. For anticoagulation during cytapheresis, citrate solutions, commonly ACD-A, are used, at a recommended anticoagulant-to-whole blood ratio of 1:11 to 1:12. Although the apheresis procedure is generally well tolerated, the most common patient complaints are attributable to transient hypocalcemia, which is a side effect of the citrate anticoagulant. Patients experiencing discomfort due to hypocalcemia are sometimes managed by a decrease in the flow rate of the anticoagulant. CASE REPORTS: Two cases are reported in which seemingly minor reductions in the anticoagulant: whole blood ratio appeared to cause gelation of freezing solution prepared from plasma that was collected in addition to PBPCs for use in the cryopreservation of cells. In both cases, the final ratio of citrate anticoagulant to whole blood was less than 1:12. Gelation occurred when plasma collected under these conditions was used to prepare freezing solution. CONCLUSION: The addition of heparin to this plasma, or the addition of ACD-A to correct the anticoagulant:whole blood ratio, prevented the gelation of freezing solution, which suggests that coagulation activation in the autologous plasma specimen was implicated in the subsequent gelation. During cytapheresis for PBPC collection, citrate-containing anticoagulants should be used at the recommended ratio of 1:12, or with more anticoagulant than usual. Tolerance for a reduced concentration of citrate may be more limited than is generally appreciated. When plasma is collected in addition to PBPCs, heparin should be added to both the cells and the plasma as soon as possible after the collection. Patients undergoing PBPC and stem cell collection should be given supplemental calcium, rather than less anticoagulant, to alleviate the discomfort associated with citrate.     

Transient respiratory disturbance by granulocyte-colony-stimulating factor administration in healthy donors of allogeneic peripheral blood progenitor cell transplantation

BACKGROUND: Allogeneic peripheral blood progenitor cell (PBPC) transplantation requires granulocyte-colony-stimulating factor (G-CSF) administration to mobilize PBPCs in healthy donors. The effects of G-CSF on pulmonary functions, however, have not been clearly elucidated in PBPC donors. STUDY DESIGN AND METHODS: Respiratory status by measurements of arterial blood gas was prospectively evaluated serially in 25 healthy donors (9 men, 16 women; age, 18-61 years) administered a dose of 10 microg per kg for 5 days. RESULTS: White blood cell (WBC) counts increased in all the subjects after G-CSF administration; means on Days 0, 3, and 5 were 6 x 10(9), 33.4 x 10(9), and 33.6 x 10(9) per L, respectively. The mean PaO(2) values on the respective days were 93.1, 85.8, and 81.8 mmHg, and these changes were significant (p < 0.0001), remaining significant after adjustment for the WBC count. Levels of both PaCO(2) and AaDO(2) were significantly higher after G-CSF administration than those before G-CSF administration (p < 0.0001 and p = 0.0004, respectively). SaO(2) was significantly decreased after G-CSF administration (p = 0.0002). Age was identified as a significant predictive factor for the increase of AaDO(2) and PaO(2) decline. These observations clearly indicate that the gas exchange was significantly affected during G-CSF administration in healthy PBPC donors. CONCLUSION: Considering an increasing use of PBPC mobilization by G-CSF, careful monitoring of the respiratory status is important to ensure safety of PBPC donors, especially elderly donors.     

Automated red blood cell exchange in preparation for filgrastim mobilization of autologous peripheral blood hematopoietic progenitor cells in a patient with sickle cell anemia

Increasing survival of patients with sickle cell anemia (SCA) well into adulthood results in a rising likelihood of developing hematological malignancy. High‐dose chemotherapy with autologous hematopoietic progenitor cell (HPC) rescue is standard of care for several hematological malignancies, but the risk of severe or life‐threatening vaso‐occlusive phenomena during filgrastim mobilization of HPC for collection poses a potential barrier to this approach. We report the use of automated red cell exchange in preparation for filgrastim mobilization in a patient with homozygous SCA. Red cell exchange was repeated just prior to high‐dose chemotherapy to mitigate the need for red cell transfusion during bone marrow reconstitution. The patient experienced no vaso‐occlusive phenomena throughout the entire episode of care and did not become iron overloaded. This approach should be considered for all patients with homozygous or compound heterozygous sickle cell disease who are candidates for auto‐HPC rescue therapy.     

Plerixafor and granulocyte-colony-stimulating factor (G-CSF) in patients with lymphoma and multiple myeloma previously failing mobilization with G-CSF with or without chemotherapy for autologous hematopoietic stem cell mobilization: the Austrian experience on a named patient program

BACKGROUND: Plerixafor in combination with granulocyte–colony‐stimulating factor (G‐CSF) has been shown to enhance stem cell mobilization in patients with multiple myeloma, non‐Hodgkin's lymphoma, and Hodgkin's disease who demonstrated with previous mobilization failure. In this named patient program we report the Austrian experience in insufficiently mobilizing patients. STUDY DESIGN AND METHODS: Twenty‐seven patients from eight Austrian centers with a median (range) age of 58 (19‐70) years (18 female, nine male) were included in the study. Plerixafor was limited to patients with previous stem cell mobilization failure and was given in the evening of Day 4 of G‐CSF application. RESULTS: A median increase of circulating CD34+ cells within 10 to 11 hours from administration of plerixafor by a factor of 4.7 over baseline was noted. Overall, 20 (74%) patients reached more than 10 × 10⁶ CD34+ cells/L in the peripheral blood, resulting in 17 (63%) patients collecting at least 2 × 10⁶ CD34+ cells/kg body weight (b.w.; median, 2.6 × 10⁶ CD34+ cells/kg b.w.; range, 0.08 × 10⁶‐8.07 × 10⁶). Adverse events of plerixafor were mild to moderate and consisted of gastrointestinal side effects and local reactions at the injection site. Thirteen (48%) patients underwent autologous transplantation receiving a median of 2.93 × 10⁶ CD34+ cells/kg (range, 1.46 × 10⁶‐5.6 × 10⁶) and showed a trilinear engraftment with a median neutrophil recovery on Day 12 and a platelet recovery on Day 14. CONCLUSION: Our study confirms previous investigations showing that plerixafor in combination with G‐CSF is an effective and well‐tolerated mobilization regimen with the potential of successful stem cell collection in patients with previous mobilization failure.     

Rapid succession of peripheral blood progenitor cell mobilization cycles in patients with chronic heart failure: effects on the hematopoietic system

BACKGROUND: Circulating hematopoietic peripheral blood progenitor cells (PBPCs) may contribute to the regeneration of nonhematopoietic organs. An increase in circulating PBPC numbers may enhance this process. Therefore, an exploratory trial of repeated PBPC mobilization in patients with chronic heart failure was conducted. The safety and cardiovascular efficacy data have been described elsewhere. In the hematopoietic system, the trial offered an opportunity to study several new aspects of granulocyte-colony-stimulating factor (G-CSF) action. STUDY DESIGN AND METHODS: Fourteen male patients with chronic heart failure were treated successively with G-CSF (four 10-day treatment periods interrupted by treatment-free intervals of equal length; daily dose adjustment to maintain a white blood cell [WBC] count of 45 x 10(9)-50 x 10(9)/L). RESULTS: G-CSF induced a rapid increase in cells of all WBC lineages with return to levels equal to (neutrophilic, eosinophilic, and basophilic granulocytes) or lower than those before treatment (monocytes, lymphocytes) during the treatment-free intervals. Red cell counts remained unchanged, but platelet counts decreased followed by rebound thrombocytosis. The extent of CD34+ cell mobilization was highly variable. For each patient, the changes induced were identical through all cycles, but the G-CSF dose required in the first cycle was significantly higher than in subsequent cycles. In the cohort of patients, an inverse correlation was observed between the WBC level reached and the dose of G-CSF administered. CONCLUSIONS: Rapid alternation between PBPC mobilization and recovery periods is feasible, with identical alterations in all treatment cycles. G-CSF responsiveness varies among patients and is increased by pretreatment with G-CSF.     

Harvesting peripheral blood progenitor cells from healthy donors with a short course of recombinant human granulocyte-colony-stimulating factor

A short-course administration of non-glycosylated granulocyte-colony-stimulating factor (G-CSF) was investigated in 68 healthy donors (HDs) in order to collect > or = 4 x 10(6) CD34+ cells per kilogram of recipient's body weight. G-CSF was given at 10 microg/kg per day administered in two divided doses for 3 days. Leukapheresis was scheduled on day 4, 12 h after the last dose of G-CSF. A median of 35.6 circulating CD34+ cells microL(-1) (range, 3.1-185) was found on the day of leukapheresis. This allowed a median collection of CD34+ cells of 4.2 x 10(6) per kilogram of recipient's weight (range, 1.0-17.4). One single procedure was sufficient to reach the target level of CD34+ cells in 36 (53%) of 68 donors; significant correlations were found between the number of CD34+ cells collected on day 4 and the patient's sex, body-weight and volume of blood processed. A retrospective analysis was made with a historical group of HDs collected on day 5. The day 5 schedule allowed a more consistent achievement of the target cell dose with one leukapheresis (P = 0.005) and resulted in the initial collection of a significantly larger number of CD34+ cells (P = 0.006).     

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.     

Microbiologic contamination of peripheral blood progenitor cells collected for hematopoietic cell transplantation

BACKGROUND: Peripheral blood progenitor cells (PBPCs) rather than bone marrow are used increasingly to provide hematologic reconstitution when transfused after marrow-ablative chemotherapy. PBPCs often are collected via central venous catheters that have remained in place for long periods of time and that may become infected. STUDY DESIGN AND METHODS: The investigators reviewed their 5-year experience in collecting PBPCs for the prevalence of bacterial contamination. Except for cotrimoxazole therapy given to prevent Pneumocystis cariini pneumonia, patients were not given antibiotic prophylaxis. RESULTS: Each patient underwent a median of 7 (range, 2–21) PBPC collections; 0.2 percent (3/1040 collections) were culture positive for bacteria (two collections contained coagulase-negative staphylococci and one contained Serratia marcescens). All culture-positive collections were discarded; no PBPCs were culture positive at the time of thawing and transfusion. CONCLUSION: This contamination rate is below that previously reported for bone marrow harvests and platelet concentrate collections. Obtaining PBPCs through large-bore central venous catheters has not added to the risk of infection in transplant patients. A program of screening in vitro cultures and strict adherence to sterility techniques can result in very low microbiologic contamination and thus obviates the need for prophylactic antimicrobials in the PBPCs and in the patient.     

Second donation of granulocyte-colony-stimulating factor-mobilized peripheral blood progenitor cells: risk factors associated with a low yield of CD34+ cells

BACKGROUND: There are still limited data on the efficacy and safety of repeated donations of granulocyte-colony-stimulating factor (G-CSF)-mobilized peripheral blood progenitor cells (PBPCs) for allogeneic transplantation. STUDY DESIGN AND METHODS: Sixty-seven healthy donors undergoing two consecutive mobilizations of PBPCs within a median interval of 5 months (range, 0.1-47 months) were investigated. For both first mobilization (FM) and second mobilization (SM), G-CSF (lenograstim) at 7.5 microg per kg per day was administered. RESULTS: The nonhematologic side effects were comparable between both mobilizations. A significantly lower yield of CD34+ cells x 10(6) per kg of donor weight was obtained on Day 5 of SM in female (n = 31; FM, 5.0; SM, 3.23; p = 0.008) but not in male (n = 36; FM, 5.96; SM, 5.36; p = 0.24) donors. Multivariate analysis identified a lower CD34+ blood concentration on Day 5 of FM (p < 0.001) as well as female sex (p = 0.015) as independent risk factors for a lower yield of progenitor cells, whereas donor age and body mass index, interval between donations, and schedule of G-CSF application showed no significant impact. CONCLUSION: The identified risk factors allow the estimation of the efficacy of a SM in an individual donor before G-CSF administration, thus avoiding distress to both the donor and the recipient.     

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 randomized clinical trial comparing granulocyte-colony-stimulating factor administration sites for mobilization of peripheral blood stem cells for patients with hematologic malignancies undergoing autologous stem cell transplantation

BACKGROUND: A study was undertaken to investigate whether granulocyte–colony‐stimulating factor (G‐CSF) injection in lower adipose tissue–containing sites (arms and legs) would result in a lower exposure and reduced stem cell collection efficiency compared with injection into abdominal skin. STUDY DESIGN AND METHODS: We completed a prospective randomized study to determine the efficacy and tolerability of different injection sites for patients with multiple myeloma or lymphoma undergoing stem cell mobilization and apheresis. Primary endpoints were the number of CD34+ cells collected and the number of days of apheresis. Forty patients were randomly assigned to receive cytokine injections in their abdomen (Group A) or extremities (Group B). Randomization was stratified based on diagnosis (myeloma, n = 29 vs. lymphoma, n = 11), age, and mobilization strategy and balanced across demographic factors and body mass index. RESULTS: Thirty‐five subjects were evaluable for the primary endpoint: 18 in Group A and 17 in Group B. One evaluable subject in each group failed to collect a minimum dose of at least 2.0 × 10⁶ CD34+ cells/kg. The mean numbers of CD34+ cells (±SD) collected were not different between Groups A and B (9.15 × 10⁶ ± 4.7 × 10⁶/kg vs. 9.85 × 10⁶ ± 5 × 10⁶/kg, respectively; p = NS) after a median of 2 days of apheresis. Adverse events were not different between the two groups. CONCLUSION: The site of G‐CSF administration does not affect the number of CD34+ cells collected by apheresis or the duration of apheresis needed to reach the target cell dose.     

The role of diagnosis in patients failing peripheral blood progenitor cell mobilization

BACKGROUND: Failure to mobilize PBPCs for auto-logous transplantation has mostly been attributed to previous therapy and poses therapeutic problems. STUDY DESIGN AND METHODS: The role of underlying disease was analyzed in 17 of 73 (23%) patients with PBPC mobilization failure, and secondary mobilization with high-dose filgrastim was attempted. RESULTS: Of 16 patients with acute leukemia, 13 (81%) mobilized poorly. In contrast, of 57 patients with non-Hodgkin's lymphoma, Hodgkin's lymphoma, multiple myeloma, and solid tumor, 53 (93%, p < 0.001) showed good PBPC mobilization. Relapsed disease did not predispose to poor mobilization. As secondary mobilization attempt, 7 patients received 25 micro g per kg per day filgrastim without chemotherapy leading to a 3.7 +/- 2.8-fold (SD) increase in the maximum number of circulating CD34+ cells (p = 0.104). PBPC apheresis yielded 3.3 (+/-0.5) x 10(6) CD34+ cells per kg of body weight in 5 patients. Four poor mobilizers received 50 micro g per kg per day filgrastim as second or third mobilization attempt. Circulating CD34+ cells in these patients increased by 1.5 (+/-0.7) compared with the primary G-CSF application. CONCLUSION: Selective PBPC mobilization failure was seen in patients with acute leukemia whereas remarkably good mobilization was seen in other malignancies. Increasing the filgrastim dose to 25 micro g per kg per day may allow PBPC collection in patients failing PBPC mobilization.     

Changes in serum osteocalcin and bone-specific alkaline phosphatase are associated with bone pain in donors receiving granulocyte-colony-stimulating factor for peripheral blood stem and progenitor cell collection

BACKGROUND: Granulocyte-colony-stimulating factor (G-CSF) has been used to increase the number of CD34+ peripheral blood stem and progenitor cells collected by apheresis for use in autologous or allogeneic progenitor cell transplantation. The most frequent side effect of G-CSF treatment is bone pain, which occurs in over 80 percent of healthy progenitor cell donors. STUDY DESIGN AND METHODS: The possible mechanism of bone pain was investigated by measuring serum levels of osteocalcin (OC), bone-specific alkaline phosphatase (BAP), acid phosphatase (ACP), and tartrate-resistant acid phosphatase (TRAP) in seven healthy progenitor cell donors treated with human recombinant G-CSF administered subcutaneously for 5 consecutive days. RESULTS: All seven patients experienced bone pain during the treatment period. Serum levels of OC, BAP, ACP, and TRAP were measured in blood samples drawn on Days 0, 4, 5, 6, and 14. Levels of BAP were increased (p<0.05) over baseline on Days 4, 5, and 6, while those of OC decreased on Days 4, 5, and 6 (p<0.05). No significant changes occurred in ACP or TRAP levels. OC and BAP are considered markers of bone formation (osteoblast activity), and they correlate in many patients with metabolic bone disorders. The pattern of increased BAP and decreased OC has been reported in patients with osteolytic bone metastases. CONCLUSION: G-CSF treatment in healthy stem and progenitor cell donors may affect osteoblastic activity, and this activity may be associated with bone pain.     

The influence of blood group differences in allogeneic hematopoietic peripheral blood progenitor cell transplantation

BACKGROUND: Severe immunohematologic complications after ABO-mismatched allogeneic blood peripheral blood progenitor cell (PBPC) transplantation (PBPCT), including pure red cell aplasia and immune hemolysis, have been described. Although several studies have addressed this issue, the clinical influence of blood group differences on transfusion requirements and survival is still discussed controversially, especially in the case of PBPCT. STUDY DESIGN AND METHODS: This single-center study is based on 143 patients receiving PBPCT after standard or reduced-intensity conditioning. The influence of blood group differences in the ABO, Rh, and Kell systems on red blood cell, platelet, and plasma transfusion requirements; length of hospitalization in transplantation unit; survival; and occurrence of graft-versus-host disease was investigated. Additionally, the influence of the conditioning regimen and irregular antibodies on the measures mentioned above was analyzed. RESULTS: Multivariate analysis demonstrated that minor and bidirectional ABO mismatch (p = 0.028) and Rh difference (p = 0.020) independently led to poorer survival. The Kell difference did not show significant influences on the measures mentioned above. A clinically relevant influence of blood group differences on transfusion requirements could not be demonstrated. Irregular antibodies also did not show significant influences. CONCLUSION: These findings indicate an influence of blood group differences in PBPCT on survival and must be studied in further detail.     

Evaluation of an algorithm based on peripheral blood hematopoietic progenitor cell and CD34+ cell concentrations to optimize peripheral blood progenitor cell collection by apheresis

BACKGROUND: Quantification of peripheral blood (PB) CD34+ cells is commonly used to plan peripheral blood progenitor cell (PBPC) collection but is time-consuming. Sysmex has developed a hematology analyzer that can quickly identify a population of immature hematopoietic cells (HPCs) according to cell size, cell density, and differential lysis resistance, which may indicate the presence of PBPCs in PB. This prospective study has evaluated the potential of such method to predict the PBPC mobilization. STUDY DESIGN AND METHODS: A total of 141 patients underwent PBPC mobilization. PB HPCs and PB CD34+ cells were simultaneously quantified with a hematology analyzer (SE2100, Sysmex) and flow cytometry, respectively. The number of blood volumes processed was then based on PB CD34+ cell concentration. RESULTS: The optimal PB HPC level able to predict a minimal level of 10 x 10(6) PB CD34+ cells per L was 5 x 10(6) per L with positive and negative predictive values of 0.93 and 0.36 percent, respectively. For this cutoff point, sensitivity and specificity were 0.81 and 0.65, respectively. The median number of blood volumes processed according to the PB CD34+ cell count allowed us to perform only one apheresis procedure for a majority of patients. CONCLUSION: PB HPC quantification is very useful to quickly determine the initiation of PBPC apheresis especially for patients with higher concentrations. For patients exhibiting a lower HPC count (<5 x 10(6)/L), other parameters such as a CD34 test may be needed. Such a policy associated with a length of apheresis adapted to the richness in the PB CD34+ cells allows for optimizing the organization of centers with an improvement in patient comfort and economical savings.