Poor mobilizer: a retrospective study on proven and predicted incidence according to GITMO criteria

The impact of diabetes mellitus on hematopoietic stem cell mobilization, a-single center cohort study

BACKGROUND

Factors such as age, underlying hematological disease, chemotherapy and radiotherapy used, and bone marrow infiltration may cause mobilization failure. Several preclinical observed that diabetes mellitus (DM) leads to profound remodeling of the hematopoietic stem cell (HSC) niche, resulting in the impaired release of HSCs. We aim to examine the effect of DM on HSC mobilization and to investigate whether there is a relationship between complications developing in the DM process and drugs used to treat DM and mobilization failure.

METHODS

In Erciyes University Bone Marrow Transplantation Unit, 218 patients who underwent apheresis for stem cell mobilization between 2011 and 2021 were evaluated retrospectively. One hundred and nine patients had a diagnosis of DM, and 109 did not.

RESULTS

Mobilization failure developed in 17 (15.6 %) of the patients in the DM group, while it developed in 7 (6.4 %) patients in the non-DM group (p = 0.03). CD34+ stem cell count was 8.05 (1.3-30.2) × 106/kg in the DM group, while it was 8.2 (1.7-37.3) × 106/kg in the other group (p = 0.55). There was no statistically significant relationship between glucose and hemoglobin A1c levels and the amount of CD34+ cells (p = 0.83 and p = 0.14, respectively). Using sulfonylurea was the only independent predictor of mobilization failure (OR 5.75, 95 % CI: 1.38-24.05, p = 0.02).

CONCLUSION

DM should be considered a risk factor for mobilization failure. Further research is needed fully to understand the mechanisms underlying the mobilization failure effects of sulfonylureas and to develop strategies to improve stem cell mobilization in diabetic patients.

Stem cell mobilization in multiple myeloma: challenges, strategies, and current developments

Among hematological malignancies, multiple myeloma (MM) represents the leading indication of autologous hematopoietic stem cell transplantation (auto-HCT). Auto-HCT is predominantly performed with peripheral blood stem cells (PBSCs), and the mobilization and collection of PBSCs are essential steps for auto-HCT. Despite the improved success of conventional methods with the incorporation of novel agents for PBSC mobilization in MM, mobilization failure is still a concern. The current review comprehensively summarizes various mobilization strategies for mobilizing PBSCs in MM patients and the evolution of these strategies over time. Moreover, existing evidence substantiates that the mobilization regimen used may be an important determinant of graft content. However, limited data are available on the effects of graft characteristics in patient outcomes other than hematopoietic engraftment. In this review, we discussed the effect of graft characteristics on clinical outcomes, mobilization failure, factors predictive of poor mobilization, and potential mobilization regimens for such patients.

Threshold for optimal administration of plerixafor in autologous peripheral blood stem cell collections through CD34+ cell monitoring based on the experience from two Japanese university hospitals

Plerixafor was introduced to Japan in 2017 as a stem cell mobilization enhancement reagent, but the threshold for its use remains unclear. In this study, we assessed 57 patients treated with plerixafor (33 patients with multiple myeloma (MM) and 24 with malignant lymphoma (ML) and 152 patients without plerixafor administration. When CD34+ cell pre-counts were between 5.5 and 20 cells/μL in MM or 6 and 21 cells/μL in ML, the CD34+ cell count increased significantly, attaining the highest yield in response to plerixafor (achievement rate by one leukapheresis is 93.3% and 91.7% in MM and ML, at P < .001 and P = .012, respectively). In case the CD34+ cell pre-count was less than 5.5 cells/μL, an increase of at least 7 cells/μL from baseline by plerixafor was the necessary condition to achieve successful collection through a two-time leukapheresis. Monitoring CD34+ cell numbers might improve the collection efficiency and reduce the cost.

Impact of CD34+ pre-counting and plerixafor on autologous peripheral blood stem cell collection in Japanese university hospitals in eight years

OBJECTIVE

Over the past decade, there have been two major advancements in autologous peripheral blood stem cell (PBSC) collection, namely enumeration of CD 34+ cells for apheresis prediction and use of plerixafor to assist mobilization of PBSC. This study aimed to investigate changes in the efficacy of PBSC collection from two Japanese university hospitals over an eight-year period.

STUDY DESIGN AND METHODS

A series of 399 PBSC collection procedures from 239 patients with solid malignant tumors (ST, n = 42), malignant lymphoma (ML, n = 91), multiple myeloma (MM, n = 99), and others (amyloidosis and leukemia, n = 7) from two university hospitals from 2011 to 2018 were retrospectively analyzed. We also analyzed the effects of CD34+ pre-counting and plerixafor administration in improving CD34+ cell yield.

RESULTS

Using CD34+ pre-count as a reference, the frequency of apheresis was reduced and the yield of CD34+ cells increased in patients with ST. When administrating plerixafor, especially with a CD34+ pre-count <20/μL, the yield of CD34+ cells was significantly increased in patients with ML (p = 0.02) and MM (p = 0.03).

CONCLUSIONS

We verified that CD34+ cell counting and plerixafor administration contributed to effective PBSC collections in our hospitals for the eight-year study period. In patients with ST, CD34+ pre-count threshold for starting apheresis was ≥10/μL. CD34+ pre-count (<20/μL) was useful to select appropriate patients for plerixafor administration among the patients with ML and MM.

Diabetes mellitus as a poor mobilizer condition

Hematopoietic stem cell (HSC) transplantation in an effective and curative therapy for numerous hematological malignancies. Mobilization of HSCs from bone marrow (BM) to peripheral blood (PB) followed by apheresis is the gold standard for obtaining HSCs for both autologous and allogeneic stem cell transplantation. After administration of granulocyte-colony stimulating factor (G-CSF), up to 30% of patients fail to mobilize "optimal" numbers of HSCs required for engraftment. This review summarizes the current experimental and clinical evidence that diabetes mellitus is a risk factor for poor mobilization. Diabetes causes a profound remodeling of the HSC niche, resulting in impaired release of HSCs. Experimental studies indicate that hyperglycemia hampers regulation of CXCL12 and clinical studies suggest that diabetes impairs HSC mobilization especially in response to G-CSF, but less to plerixafor. Understanding further the biochemical alterations in the diabetic BM will provide insights into future therapeutic strategies to reverse the so-called "diabetic stem cell mobilopathy".

Modified CVAD and modified CBAD compared to high-dose cyclophosphamide for peripheral blood stem cell mobilization in patients with multiple myeloma

BACKGROUND

The optimal regimen for peripheral blood stem cell (PBSC) mobilization in patients with multiple myeloma undergoing autologous hematopoietic stem cell transplantation (auto-HCT) has not been established. Experience at The University of Texas MD Anderson Cancer Center suggests in addition to single-agent cyclophosphamide (Cy), modified cyclophosphamide, vincristine, doxorubicin, and dexamethasone (mCVAD), and modified cyclophosphamide, bortezomib, doxorubicin, and dexamethasone (mCBAD) may be successful chemomobilization regimens.

METHODS

This retrospective review included 167 patients (66 with Cy, 74 with mCVAD, and 27 with mCBAD) with multiple myeloma undergoing mobilization for auto-HCT between January 1, 2006 and September 30, 2013. The primary objective was to evaluate and compare the successful mobilization of CD34+ cells among high-dose Cy, mCVAD or mCBAD.

RESULTS

Successful mobilization (≥2×10⁶ CD34+ cells/kg) was achieved in all patients, while 65 (98%), 72 (97%), and 27 (100%) patients achieved an optimal mobilization (≥4×10⁶ CD34+ cells/kg) in the Cy, mCVAD, and mCBAD groups, respectively. There was no significant difference in the number of apheresis sessions (P=.63), incidence of febrile neutropenia (P=.57), or hospital admission rates (P=.55).

CONCLUSION

Either Cy, mCVAD, or mCBAD can yield successful PBSC mobilization in patients with multiple myeloma undergoing auto-HCT.

Circulating hematopoietic progenitors and CD34(+) cells predicted successful hematopoietic stem cell harvest in myeloma and lymphoma patients: experiences from a single institution

Background

Previous studies have shown that the numbers of both circulating hematopoietic progenitor cell (HPC) and CD34⁺ cell are positively correlated with CD34⁺ cell harvest yield. However, the minimal numbers of both circulating HPCs and CD34⁺ cells required for performing an efficient hematopoietic stem cell (HSC) harvest in lymphoma and myeloma patients have not been defined in our institution.

Patients and methods

Medical records of 50 lymphoma and myeloma patients undergoing peripheral blood HSC harvest in our institution were retrospectively reviewed. The minimal and optimal HSC harvest yield required for the treatment was considered to be ≥2×10⁶ CD34⁺ cells/kg and ≥5×10⁶ CD34⁺ cells/kg, respectively.

Results

The minimally required or optimal HSC yield obtained was not influenced by age (≥60 years), sex, underlying malignancies, disease status, multiple rounds of chemotherapy, or history of radiotherapy. The numbers of both circulating HPC and CD34⁺ cell were higher in patients with minimally required HSC yields (P=0.000 for HPC and P=0.000 for CD34⁺ cell) and also in patients with optimal HSC yields (P=0.011 for HPC and P=0.006 for CD34⁺ cell). The cell count cutoff for obtaining minimally required HSC harvest was determined to be 20/mm³ for HPCs and 10/mm³ for CD34⁺ cells. Furthermore, the cell count cutoff for obtaining optimal HSC harvest was determined to be 60/mm³ for HPCs and 35/mm³ for CD34⁺ cells.

Conclusion

A total of 60/mm³ of HPCs and 35/mm³ of CD34⁺ cells in peripheral blood predicted optimal HSC harvest in lymphoma and myeloma patients.

Targeting stem cell niche can protect hematopoietic stem cells from chemotherapy and G-CSF treatment

INTRODUCTION

Hematopoietic stem/progenitor cells (HSPCs) reside in a tightly controlled local microenvironment called bone marrow niche. The specialized microenvironment or niche not only provides a favorable habitat for HSPC maintenance and development but also governs stem cell function.

METHOD

We investigated the effect of cytotoxic drugs on bone marrow niche. To mimic the multiple rounds of chemotherapy followed by autologous hematopoietic stem cells (HSCs) transplantation in a clinical setting, we further verified the hypothesis that targeting the niche might improve stem cell-based therapies in mouse models.

RESULTS

We found that multiple rounds of cytotoxic drug treatment significantly disrupted niche and serum osteocalcin level was significantly reduced after treatment in autologous HSPCs transplanted patients (P = 0.01). In mouse models, the number of CD45(-)Ter119(-)OPN(+) osteoblasts was significantly reduced after multiple rounds of chemotherapies and granulocyte colony stimulating factor (G-CSF) treatment (P < 0.01). Parathyroid hormone (PTH) or receptor activator of nuclear factor kappa-B ligand (RANKL) treatment significantly increased the number of HSCs mobilized into peripheral blood (PB) for stem cell harvesting and protected stem cells from repeated exposure to cytotoxic chemotherapy. Treatments with G-CSF and PTH significantly increased the preservation of the HSC pool (P < 0.05). Moreover, recipient mice transplanted with circulation HSPCs that were previously treated with PTH and RANKL showed robust myeloid and lymphatic cell engraftment compared to the mice transplanted with HSCs after chemotherapy or G-CSF treatment.

CONCLUSION

These data provide new evidence that the niche may be an important target for drug-based stem cell therapy.

Predicting poor peripheral blood stem cell collection in patients with multiple myeloma receiving pre-transplant induction therapy with novel agents and mobilized with cyclophosphamide plus granulocyte-colony stimulating factor: results from a Gruppo Italiano Malattie EMatologiche dell'Adulto Multiple Myeloma Working Party study

INTRODUCTION

A still not well defined proportion of patients with multiple myeloma (MM) and eligible for autologous stem cell transplantation (AuSCT) fails to mobilize CD34+ peripheral blood stem cells (PBSC) at all or to collect an adequate number for a safe procedure or sufficient for multiple transplants. These so-called "poor-mobilizers" are difficult to be predicted, due to marked difference across previous heterogeneous studies.

METHODS

We aimed to develop a method based on simple clinical parameters for predicting unsuccessful (<2×10(6)/kg) or sub-optimal (<5×10(6)/kg) collections of CD34+ PBSC in newly diagnosed MM patients eligible for AuSCT, treated with novel agents and receiving an homogeneous mobilizing therapy with cyclophosphamide and granulocyte-colony stimulating factor (G-CSF). To this purpose, 1,348 patients enrolled in five consecutive Italian clinical trials were retrospectively analysed. Age, baseline low peripheral blood cell counts, use of lenalidomide, and haematological toxicity developed during induction were taken into account as possible factors associated with poor mobilization.

RESULTS

Overall, 280 patients (20.8%) showed either sub-optimal (167 patients, 12.4%) or unsuccessful (113 patients, 8.4%) collections. All analysed parameters negatively influenced the procedure, but only age and haematological toxicity during induction maintained their significance at multivariate analysis. Based on ordinal logistic regression model, we constructed a risk heat-map where the four parameters were pooled and weighted according to their relevance as single or combined variables. This model was predictive for different probabilities of failure, suboptimal or optimal outcomes.

CONCLUSIONS

We found that about one fifth of newly diagnosed MM fails to collect an adequate number of PBSC. Our model, based on a large group of patients treated frontline with novel agents and receiving the most popular mobilizing approach currently employed in Europe, is applicable in individual subjects and may contribute to the early identification of "poor mobilizer" phenotypes.