Multiple myeloma patients receiving large volume leukapheresis efficiently yield enough CD34+ cells to allow double transplants

Expression of adhesion molecules on CD34+ cells from steady-state bone marrow before and after mobilization and their association with the yield of CD34+ cells

Background

Cell adhesion molecules (CAMs) expressed on hematopoietic progenitor cells (HPCs), endothelial cells, and stromal cells play a pivotal role in the mobilization of CD34+ cells. Herein, we conducted a non-randomized peripheral blood stem cell (PBSC) mobilization study aimed to compare the potential differences in the expressions of several CAMs and chemokines on CD34+ cells obtained from bone marrow aspirate before and after HPC mobilization from patients with hematologic malignancies and healthy donors.

Methods

Three-color cytofluorometric analysis was used to compare the expressions of CAMs and chemokines in the bone marrow before and after mobilization.

Results

For all studied groups, CAM expression among those with good and poor yields of CD34+ cells was significantly correlated with VCAM-1 (P=0.007), CD44 (P=0.027), and VLA-4 (P=0.014) expressions. VCAM-1 (P=0.001), FLT-3 (P=0.001), CD44 (P=0.011), VLA-4 (P=0.001), and LFA-1 (P=0.001) expressions were higher before HPC mobilization than after HPC mobilization. By contrast, the expression of CXCR4 significantly varied before and after mobilization only among those with successful PBSC mobilization (P=0.002).

Conclusion

We attempted to identify particular aspects of CAMs involved in CD34+ cell mobilization, which is a highly complex mechanism that involves adhesion molecules and matrix metalloproteases. The mechanism by which CD34+ cell mobilization is activated through proteolytic enzymes is not fully understood. We believe that CXCR4, VLA-4, CD44, and VCAM-1 are the most important molecules implicated in HPC mobilization, particularly because they show a correlation with the yield of CD34+ cells collected via large volume leukapheresis.

Large volume leukapheresis is efficient and safe even in small children up to 15 kg body weight

BACKGROUND

The collection of peripheral blood stem cells, although now a routine procedure, is still a challenge in low body weight children because of specific technical and clinical issues. For paediatric patients it is crucial to obtain an adequate number of CD34+ cells with the minimum number of procedures: this can be done using large volume leukapheresis (LVL).

MATERIALS AND METHODS

We analysed the efficacy and safety of 54 autologous LVL performed in 50 children (33 [66%] males and 17 [34%] females), median age 2 years (range, 1-5) and median body weight 12 kg (range, 6-15). The procedures were performed with a COBE Spectra previously primed with red blood cells; ACD-A solution and heparin were used as anticoagulants.

RESULTS

The target CD34+ cell dose (≥5×10/kg body weight) were collected with one LVL in 46 (92%) patients, while four (8%) patients needed another procedure. All our LVL were well tolerated. Side effects were observed in five (9.2%) patients and one procedure had to be discontinued because of catheter-related haemorrhage. The platelet count decreased significantly (p<0.001) after each procedure but without bleeding or need for transfusion support.

DISCUSSION

Our experience confirms that LVL is efficient and safe even in small children, if the procedure is adjusted considering the weight and age of child. The most important factors are good venous access, adequate preparation of the child's electrolyte status, and surroundings in which the small child as well as parents feel comfortable, and can tolerate the procedure better. Although a median platelet loss of 50% can be expected, LVL is safe and reduces the overall number of procedures required. It can be recommended for peripheral blood stem cell collection even in small body weight children with malignant diseases, particularly those who mobilise low numbers of CD34+ cells.

Hematopoietic stem cells from poor and good mobilizers are qualitatively equivalent

BACKGROUND

Marrow damage from chemo- and radiation therapies has been suggested to affect quality and quantity of hematopoietic stem cell (HSC) products. We tested the hypothesis that CD34+ cells (HSCs) from low mobilizers are qualitatively inferior to HSCs from high mobilizers.

STUDY DESIGN AND METHODS

HSC quality was defined by proportion of primitive HSC subsets (CD34+CD38-, CD34+HLA-DR-, and CD34+ in G0 stage of cell cycle), the proportion of HSCs that express CXCR4 and CD26 homing proteins, and days to neutrophil and platelet (PLT) engraftments after transplant. HSC content and CD34 subsets analyses were performed using flow cytometry following the ISHAGE protocol. We evaluated the HSC quantity and quality of 139 autologous filgrastim-mobilized HSC products. Patients were categorized into low, moderate, and high mobilizers if their total HSC collection was less than 3 × 10(6), 3 × 10(6) or more and less than 5 × 10(6), and 5 × 10(6)/kg or more, respectively.

RESULTS

The median number of primitive CD34 subsets increases with increasing HSC numbers and this association was significant (p = 0.001). However, when the ratios of the primitive CD34 subsets to total HSC counts were compared among the mobilization groups, the ratios were not significantly different. Coexpression of neither CD26 nor CXCR4 with CD34 antigen correlated with HSC mobilization. Evaluation of days to neutrophil engraftment among the mobilization groups did not show a significant difference (p = 0.1). However, days to PLT engraftment among the mobilization groups was significantly different (p = 0.05).

CONCLUSION

The quality of HSCs from low mobilizers was comparable to HSCs from high mobilizers.

Efficacy and cost-benefit analysis of risk-adaptive use of plerixafor for autologous hematopoietic progenitor cell mobilization

BACKGROUND

Plerixafor (P) reduces mobilization failure rates but it is very expensive. For better utilization of P, we employed a risk-adaptive strategy of using it only in patients who are at high risk of mobilization failure, defined by peripheral blood (PB) CD34+ cell count of fewer than 10×10(6)/L after 4 days of filgrastim (F) alone.

STUDY DESIGN AND METHODS

Herein, we present the results of efficacy and cost-benefit analysis of this risk-adaptive approach for hematopoietic progenitor cell (HPC) collection. All patients received daily F for 4 days, and P was added for those "at-risk" patients from Day 4 with apheresis commencing the following morning. F and P were continued daily for up to a maximum of 4 days or until more than 5×10(6) CD34+ cells/kg were collected. Forty-two transplant-eligible patients underwent HPC mobilization.

RESULTS

Eighteen patients mobilized with F alone and 24 patients required P with F. Two patients failed adequate HPC mobilization after F+P. Addition of P increased the PB CD34+ count by 6.8-fold with a mean yield of 4.9×10(6) CD34+ cells/kg. Decision-analysis model estimated cost-effectiveness for this risk-adaptive approach of using P with savings of $19,300/patient. Engraftment after HPC infusion was similar among the patients regardless of mobilization regimens.

CONCLUSION

These results suggest that addition of P to F based on a risk-adaptive strategy significantly reduces the frequency of mobilization failures and is also cost-effective.

Mobilization and collection of peripheral blood stem cells in multiple myeloma patients older than 65 years

Over the past 10 years, the incidence of multiple myeloma (MM) has been greater among individuals >65 years old than in younger age groups. This retrospective study of peripheral blood stem cell mobilization and harvesting examined patients of various age groups who were afflicted with this pathology. One group of 17 patients ≥65 years of age with MM (group A) were mobilized between 2002 and 2009 and compared with 33 consecutive patients of younger ages with the same diagnosis treated in 2008 and 2009 (group B). The 2 populations had a similar gender distribution; their median ages were 66 and 52 years, respectively. A successful mobilization was defined as a collection of ≥2.5 × 10(6) CD34+/kg body weight. The mobilization used filgrastim (16 μg/kg/d) with the beginning of the harvest on the fifth day. The median number of outpatient apheresis procedures per patient was 2 in group A and 1 in group B. There were no incidents or serious adverse reactions. Patients in group A collected 4.68 × 10(6) CD34+ cells/kg and for group B 3.30 × 10(6)/kg. The group A patients required a greater number of apheresis procedures to collect the appropriate graft. In conclusion, mobilization with growth factors and PHSP harvest by apheresis was safe with reasonable costs for subjects including those aged ≥65 years, resulting in an option for autologous transplantation.

Critical review of economic evaluations in multiple myeloma: an overview of the economic evidence and quality of the methodology

Continued expansion in the availability of costly alternative therapies in multiple myeloma will enhance the role of economic evaluations in reimbursement decisions and amendments to the treatment guidelines. The quality of economic evaluations should be taken into account by clinicians involved in decision-making. A systematic review and critique of the methodology was performed to assess the trends and quality in economic evaluations in multiple myeloma to date. A literature search was conducted to identify full economic evaluations in multiple myeloma as of December 2009. Details of the economic evaluation methods applied were extracted. Each study underwent a quality assessment based on the Drummond checklist for appraisal of high-quality economic evaluations in health care. Eighteen published economic evaluations were identified. Stem cell transplantation in combination with intensive chemotherapy has been demonstrated to be cost-effective, while interferon alpha is generally ineffective at additional costs. Evaluations have become less frequent in the last decade, especially for newer therapies despite their important contribution to improvements in outcomes. The quality of the methodology applied and its documentation can be improved in many aspects. As users of the results of economic evaluations, clinicians involved in guiding decision-making should be critical of the quality of economic evaluations in multiple myeloma. To ensure access to and identification of high-quality studies, researchers conducting economic evaluations of future advances should strive towards evaluations that fulfil the Drummond criteria and are properly documented.

Peripheral blood stem cell collection in multiple myeloma: a retrospective analysis of 6 years leukapheresis activity in 109 patients treated at the Istituto Nazionale dei Tumori of Milan

Double autologous stem cell transplantation is the standard treatment in newly diagnosed multiple myeloma (MM) patients younger than 65 years; therefore, optimization of leukapheresis is crucial. We performed a retrospective analysis of 297 leukaphereses comparing semiautomated (V4.7 in 20% of collections) versus automated (V6.0 in 80%) Caridian (COBE) Spectra versions and analyzing the influence of M-protein on the outcome. Both methods gave comparable collection efficiencies (CE%) (53.4% vs. 55.7% in V6.0 and V4.7, respectively) with similar leukapheresis time and processed volume. Harvest volume was higher in V4.7 (P < 0.0001) with similar contamination of red blood cells (RBCs) (P = 0.77) and platelets (P = 0.09) when compared with V6.0. In patients with higher peripheral white blood cells (WBCs), V6.0 with adjusted harvest volume (<700 mL), achieved similar CD34(+) CE% (P = 0.39) and better enrichment of nucleated cells (P < 0.0,002) but higher RBCs (P < 0.0,001) and platelets contamination (P = 0.001), when compared with a larger cycle volume in patients with lower WBCs. In hard to mobilize patients, CD34(+) CE% was significantly more efficient with V4.7 than V6.0 (P < 0.0,001). CD34(+) CE% was unaffected by serologic M-protein, but platelet CE% was higher in the absence of M-protein (P = 0.0,003), without any reduction in peripheral patients platelets. We, therefore, conclude that in the setting of MM patients with a high WBCs count and/or low percentage of peripheral CD34(+) cells, collections with V4.7 or adjusted cycle volume V6.0 gave comparable result in CD34(+) CE%. RBCs and platelets contamination is higher if low cycle volume is chosen. In hard to mobilize patients, V4.7 is advisable.