Peripheral blood progenitor cell or bone marrow transplantation: controversy remains

Analysis of laboratory parameters for optimal autologous peripheral blood stem cell collection from lymphoma and myeloma patients

BACKGROUND

Peripheral blood stem cell (PBSC) collection is important for successful hematopoietic stem cell transplantation. This study aimed to investigate the laboratory parameters associated with the optimal timing of autologous PBSC collection from lymphoma and multiple myeloma patients.

METHODS

We retrospectively evaluated data from 1105 PBSC apheresis procedures performed on 379 adult patients at the National Cancer Center between June 2005 and December 2019. Laboratory parameters, including cutoff values for the number of hematopoietic progenitor cells (HPCs) and circulating CD34+ cells, were analyzed to determine their association with CD34+ cell yield.

RESULTS

The pre-apheresis HPC and CD34+ cell count were statistically significant variables associated with harvested CD34+ cell in lymphoma and MM patients. The optimal cutoff values were 18 × 10⁶ /L for pre-HPC count (66.8% sensitivity, 66.4% specificity) and 11/μL for pre-CD34+ cell count (85.8% sensitivity, 87.2% specificity), to achieve CD34+ cell yields ≥ 1.0 × 10⁶ /kg for each apheresis procedure. Moreover, the optimal cutoff values were 23 × 10⁶ /L for pre-HPC count (71.0% sensitivity, 69.0% specificity) and 18/μL for pre-CD34+ cell count (87.5% sensitivity, 86.3% specificity) to achieve CD34+ cell yields ≥ 2.0 × 10⁶ /kg for each apheresis procedure.

CONCLUSION

HPC count is a potential surrogate marker for monitoring the starting time for PBSC collection. Applying cutoff values for the number of HPC and CD34+ cells may be clinically useful for optimizing the timing of PBSC collection.

A study to compare Hematopoietic Progenitor Cell count determined on a next-generation automated cell counter with flow cytometric CD34 count in peripheral blood and the harvested peripheral blood stem cell graft from autologous and allogenic donors

INTRODUCTION

A successful bone marrow transplant requires a minimum of 2-4 × 10⁶ cells/kg patient body weight of CD 34+ cells to be transfused, where peripheral blood CD34+ cell count being and ideal predictor. We compared the correlation and predictive capacity of both hematopoietic progenitor cell count (HPC) determined on the Sysmex XN-9000 and flow cytometric CD34 in autologous and allogenic donors.

METHODS

Autologous and allogenic donors were taken as per criteria. TLC (Total Leukocyte Count), MNC (Mononuclear cell count), HPC, and CD34 assay were done in both the peripheral blood prior to apheresis, and the harvest product postapheresis. Sysmex XN-9000 was used for TLC, MNC, and HPC tests, and a modified ISH-AGE protocol was used to enumerate CD34 by flow cytometry. Statistical analysis was done using SPSS 16.0.

RESULTS

Sixty-seven allogenic and 35 autologous donors were enrolled. 45% were females, and 55% were males. Correlation between HPC and CD34 was found to be 0.887 with P value < .01 in peripheral blood and 0.847 with P value < .01 in the harvested product. On the other hand, TLC had a correlation of 0.424 and 0.520 in peripheral blood and harvested, respectively. MNC had a weak association. The cutoff value for a target dose of 2 × 10⁶ CD34 cells/kg was 37 × 10⁶ /L for pre-HPC. For a target of 4 × 10⁶ CD34 cells/kg, the cutoff value calculated to be 54 × 10⁶ /L (Sensitivity: 85%, Specificity: 89%) for peripheral blood HPC.

CONCLUSION

We conclude that HPC is comparable to CD34 in predicting harvest product's adequacy.

Identification of cell morphology parameters from automatic hematology analyzers to predict the peripheral blood CD34-positive cell count after mobilization

Optimal timing of apheresis initiation is important for maximizing the hematopoietic stem cell (HSC) yield. This study aimed to identify useful parameters from automatic hematology analyzers for predicting the peripheral blood CD34+ cell count after mobilization. We prospectively enrolled 53 healthy donors and 72 patients, and evaluated 43 cell morphology parameters from Unicel DxH800 (Beckman Coulter, USA) and Advia 2120i (Siemens Healthcare Diagnostics, USA). The correlation of each parameter with the CD34+ cell count in pre-apheresis blood samples was analyzed. The delta neutrophil index (DNI) from Advia 2120i, standard deviation of volume of neutrophils and monocytes (SD-V-NE and SD-V-MO), standard deviation of conductivity of neutrophils and monocytes (SD-C-NE and SD-C-MO), mean conductivity of neutrophils and monocytes (MN-C-NE and MN-C-MO), and standard deviation of axial light loss of neutrophils and monocytes (SD-AL2-NE and SD-AL2-MO) from DxH800 showed significant correlations with the CD34+ cell count. SD-V-NE, SD-C-NE, and SD-C-MO showed good or fair area under the curve values for the prediction of the CD34+ cell count. SD-V-NE, SD-C-NE, and SD-C-MO from DxH800 will provide rapid, useful information for the initiation of apheresis after mobilization.

Optimal graft source for allogeneic hematopoietic stem cell transplant: bone marrow or peripheral blood?

Peripheral blood (PB), compared with bone marrow graft, has higher stem cell content, leads to faster engraftment and is more convenient for collection. Consequently, the use of PB graft has significantly increased in recent years. Although the use of PB graft is acceptable or even preferred to bone marrow graft in matched related donor allogeneic transplant due to a possibility of improved survival, PB graft increases the risk of chronic graft-versus-host disease and associated long-term toxicities in the setting of matched unrelated donor allogeneic transplant. In haploidentical transplant, mitigation of graft-versus-host disease with the use of post-transplant cyclophosphamide is a hypothesis-generating possibility; however, available studies have significant limitations to draw any definite conclusion.

Allogeneic stem cell transplantation in acute myeloid leukemia

We report a case series of 12 patients with acute myeloid leukemia who underwent allogeneic stem cell transplant with a matched related donor. Male to female ratio was 1:1. The main complication post-transplant was graft-versus-host disease (n=7 patients). Transplant-related mortality involved one patient; cause of death was multi-organ failure. After a median follow up of 36.0±11.3 months, overall survival was 16%.

Mobilized peripheral blood stem cells compared with bone marrow from HLA-identical siblings for reduced-intensity conditioning transplantation in acute myeloid leukemia in complete remission: a retrospective analysis from the Acute Leukemia Working Party of EBMT

Reduced-intensity conditioning (RIC)-alloSCT is increasingly used for acute myelogenous leukemia. Limited data are available for the comparison of peripheral blood stem cells with bone marrow for RIC-alloSCT. We used the European Group for Blood and Marrow Transplantation (EBMT) ALWP data to compare the outcome of mobilized peripheral blood stem cells (PBSC) (n = 1430) vs. bone marrow (BM) (n = 107) for acute myelogenous leukemia (AML) patients with complete remission that underwent RIC-alloSCT from compatible sibling donors. The leukemia features, the disease status, and the time from diagnosis were similar between the two groups. Engraftment was achieved in 99% and 93% in the PBSC and BM groups, respectively (P < 0.0001). The day of engraftment was significantly earlier for the PBSC vs. the BM group, 15 (1-59) and 19 (5-69), respectively (P < 0.001). Acute GVHD, severe GVHD (grade III-IV) and chronic GVHD did not differ between the groups. leukemia-free survival (LFS), relapse, and non-relapsed mortality (NRM) were 51 ± 2%, 32 ± 1%, and 17 ± 1% vs. 50 ± 6%, 38 ± 6%, and 12 ± 3% for the PBSC and BM groups, respectively. Our results indicate faster engraftment, but no difference in GVHD, LFS, relapse, and NRM when comparing PBSC to BM grafts from sibling donors following RIC conditioning. This is the first study comparing PBSC to BM grafts in the RIC setting, analyzing a homogeneous population of patients with AML in remission. Whether PBSC should be preferred for advanced phases of the disease, where the outcome is dominated by relapse incidences, needs further investigation.

Decreased soluble TGF-β1, Tie-2, and angiopoietins serum levels in bone marrow after treating healthy donors with granulocyte colony-stimulating factor

The goal of this study was to investigate the effect of granulocyte colony-stimulating factor (G-CSF) on Tie-2, angiopoietins, VEGF, and TGF-β1 in bone marrow (BM) of healthy donors. Soluble Tie-2, angiopoietins, VEGF, and TGF-β1 levels in the BM were determined via ELISA in 25 healthy donors before and after G-CSF treatment. The results showed that treating healthy donors with G-CSF significantly decrease serum levels of Tie-2, angiopoietin-1, angiopoietin-2, and TGF-β1. In contrast, median VEGF level in the G-CSF-primed BM was significantly higher than steady-state BM. Our results suggest that decreased soluble TGF-β1, Tie-2, and angiopoietins levels in the BM could be related to stem cell mobilization.

Mobilized peripheral blood stem cells compared with bone marrow as the stem cell source for unrelated donor allogeneic transplantation with reduced-intensity conditioning in patients with acute myeloid leukemia in complete remission: an analysis from the Acute Leukemia Working Party of the European Group for Blood and Marrow Transplantation

Reduced-intensity conditioning allogeneic stem cell transplant (RIC-alloSCT) is being increasingly used for patients with acute myelogenous leukemia (AML) with comorbidities. Few published data are currently available regarding for the use of peripheral blood stem cells (PBSCs) compared to bone marrow (BM) in the RIC-alloSCT using unrelated donors (URDs). This retrospective report compared the outcomes of PBSC versus BM RIC-alloSCT. Between 2000 and 2007, 602 patients with AML in complete remission (CR) underwent RIC-alloSCT from URDs with PBSC (508) or BM (94) grafts. Recipient's age was higher in the PBSC versus BM groups 57 (range, 17-77 years) and 51 (range, 17-76 years), respectively (P < .0001). Leukemia features and disease status at RIC-alloSCT were also comparable between the PBSC versus BM groups. Engraftment was achieved in 97% and 96% with BM versus peripheral blood (PB), respectively. Acute graft-versus-host disease (aGVHD) grade >II was significantly higher in the PBSC group: 27% versus 12% in the BM group (P < .002). Similarly, chronic graft-versus-host disease (cGVHD; at 2 years) was somewhat higher in the PBSC group with 43% ± 3% versus 35% ± 6% in the BM group, respectively (P = .04). The 2-year probabilities of leukemia-free survival (LFS) were 46% ± 3% for the PBSC group in comparison to 43% ± 6% for the BM transplant group (P = NS), whereas relapse incidence was significantly higher in the BM versus the PB transplant group: 46% ± 6% versus 32% ± 3%, respectively (P = .014). Non-relapse mortality (NRM) was significantly higher for the PBSC versus the BM group: 28% ± 2% versus 13% ± 4%, respectively (P = .004). In multivariate analysis, after adjustment for differences between both groups, the PBSC group was associated with a higher incidence of aGVHD (grade II-IV; hazard ratio [HR] = 2.33; P = .06), higher NRM (HR = 2.3; P = .015), and a decreased relapse incidence (HR, 0.61; P = .02) with no statistical difference of LFS between the 2 groups (P = .88). In conclusion, our results indicate significantly higher incidence of aGVHD and NRM and a lower incidence of relapse but not statistically different LFS comparing unrelated PBSC to BM grafts after RIC-alloSCT.

Intensification of GVHD prophylaxis with low-dose ATG-F before allogeneic PBSC transplantation from HLA-identical siblings in adult patients with hematological malignancies: results from a retrospective analysis

Several studies have shown that chronic GVHD (cGVHD) is more frequent in patients receiving transplants from PBSC than in those receiving BM. In the setting of PBSC-unrelated transplants, the addition of anti-T-cell globulin (ATG) has shown a significant decrease in incidence/severity of cGVHD, without an increase in relapses or infections. However, no prospective data are yet available in the sibling setting. We retrospectively analyzed the effects of intensification of standard GVHD prophylaxis (CsA+MTX) by the addition of low-dose ATG in 245 patients receiving a transplant from HLA-identical sibling. From 1996 to 2001, patients received PBSC as the preferred source (group 2), and then ATG was added before transplant (group 3) because of a high cGVHD rate. Patients receiving BM in the same time period were analyzed as a control group (group 1). The incidence of grade III-IV acute GVHD and cGVHD was not significantly different in the three groups, but extensive cGVHD was highest in group 2 (38%) compared with group 3 (21%) or group 1 (28%; P=0.03). OS, TRM and time to relapse/progression were similar in the three groups. Our analysis shows that adding ATG to PBSC sibling allogeneic transplants can lower cGVHD, without an increase of relapse. Further prospective studies are needed to confirm these findings.

Unicentric study of cell therapy in chronic obstructive pulmonary disease/pulmonary emphysema

Within the chronic obstructive pulmonary disease (COPD) spectrum, lung emphysema presents, as a primarily histopathologic feature, the destruction of pulmonary parenchyma and, accordingly, an increase in the airflow obstruction distal to the terminal bronchiole. Notwithstanding the significant advances in prevention and treatment of symptoms, no effective or curative therapy has been accomplished. In this context, cellular therapy with stem cells (SCs) arises as a new therapeutic approach, with a wide application potential. The purpose of this study is to evaluate the safety of SCs infusion procedure in patients with advanced COPD (stage IV dyspnea). After selection, patients underwent clinical examination and received granulocyte colony-stimulating factor, immediately prior to the bone marrow harvest. The bone marrow mononuclear cells (BMMC) were isolated and infused into a peripheral vein. The 12-month follow-up showed a significant improvement in the quality of life, as well as a clinical stable condition, which suggest a change in the natural process of the disease. Therefore, the proposed methodology in this study for BMMC cell therapy in sufferers of advanced COPD was demonstrated to be free of significant adverse effects. Although a larger sample and a greater follow-up period are needed, it is possible to infer that BMMC cell therapy introduces an unprecedented change in the course or in the natural history of emphysema, inhibiting or slowing the progression of disease. This clinical trial was registered with ClinicalTrials.gov (NCT01110252) and was approved by the Brazilian National Committee of Ethics in Research (registration no. 14764, CONEP report 233/2009).

Rabbit antithymocyte globulin (thymoglobulin): 25 years and new frontiers in solid organ transplantation and haematology

The more than 25 years of clinical experience with rabbit antithymocyte globulin (rATG), specifically Thymoglobulin, has transformed immunosuppression in solid organ transplantation and haematology. The utility of rATG has evolved from the treatment of allograft rejection and graft-versus-host disease to the prevention of various complications that limit the success of solid organ and stem cell transplantation. Today, rATG is being successfully incorporated into novel therapeutic regimens that seek to reduce overall toxicity and improve long-term outcomes. Clinical trials have demonstrated the efficacy and safety of rATG in recipients of various types of solid organ allografts, recipients of allogeneic stem cell transplants who are conditioned with both conventional and nonconventional regimens, and patients with aplastic anaemia. Over time, clinicians have learnt how to better balance the benefits and risks associated with rATG. Advances in the understanding of the multifaceted mechanism of action will guide research into new therapeutic areas and future applications.

NCI First International Workshop on the Biology, Prevention, and Treatment of Relapse after Allogeneic Hematopoietic Stem Cell Transplantation: report from the Committee on the Epidemiology and Natural History of Relapse following Allogeneic Cell Transplantation

Allogeneic hematopoietic stem cell transplantation (alloHSCT) is increasingly being used for treatment of hematologic malignancies, and the immunologic graft-versus-tumor effect (GVT) provides its therapeutic effectiveness. Disease relapse remains a cause of treatment failure in a significant proportion of patients undergoing alloHSCT without improvements over the last 2-3 decades. We summarize here current data and outline future research regarding the epidemiology, risk factors, and outcomes of relapse after alloHSCT. Although some factors (eg, disease status at alloHSCT or graft-versus-host disease [GVHD] effects) are common, other disease-specific factors may be unique. The impact of reduced-intensity regimens on relapse and survival still need to be assessed using contemporary supportive care and comparable patient populations. The outcome of patients relapsing after an alloHSCT generally remains poor even though interventions including donor leukocyte infusions can benefit some patients. Trials examining targeted therapies along with improved safety of alloHSCT may result in improved outcomes, yet selection bias necessitates prospective assessment to gauge the real contribution of any new therapies. Ongoing chronic GVHD (cGVHD) or other residual post-alloHSCT morbidities may limit the applicability of new therapies. Developing strategies to promptly identify patients as alloHSCT candidates, while malignancy is in a more treatable stage, could decrease relapses rates after alloHSCT. Better understanding and monitoring of minimal residual disease posttransplant could lead to novel preemptive treatments of relapse. Analyses of larger cohorts through multicenter collaborations or registries remain essential to probe questions not amenable to single center or prospective studies. Studies need to provide data with detail on disease status, prior treatments, biologic markers, and posttransplant events. Stringent statistical methods to study relapse remain an important area of research. The opportunities for improvement in prevention and management of post-alloHSCT relapse are apparent, but clinical discipline in their careful study remains important.

Is mobilized peripheral blood comparable with bone marrow as a source of hematopoietic stem cells for allogeneic transplantation from HLA-identical sibling donors? A case-control study

BACKGROUND

Granulocyte colony-stimulating factor mobilized peripheral blood stem cells are increasingly used instead of bone marrow as a stem cell source for transplantation. Whereas this change is almost complete for autologous transplantation, there are some concerns when considering allogeneic transplants.

DESIGN AND METHODS

We performed a retrospective case-control study including 820 adult patients who had received an allogeneic stem cell transplant from an HLA-identical sibling donor. Quality of life (QoL) was assessed in 150 patients using the EORTC Quality of Life Questionnaire C30 (QLQ-C30).

RESULTS

There were no statistically significant differences in overall survival at ten years (bone marrow: 48.9% vs. peripheral blood stem cells: 39.8%; p=0.621), transplant-related mortality (bone marrow: 28.9% vs. peripheral blood stem cells: 34.4%; p=0.682) or relapse incidence at 9 years (29.4% vs. 35.2%, respectively; p=0.688). Similar outcomes were maintained independently of the phase of the disease. However, multivariate analysis identified a higher incidence of acute graft-versus-host disease grades II-IV (p: 0.023; Hazard ratio [HR]: 1.41; 95% confidence interval [CI]: 1.05-1.89) and grades III-IV (p: 0.006; HR: 1.89; 95% CI: 1.20-2.98), in the peripheral blood stem cells-stem cell transplant group. As previously described, extensive chronic graft-versus-host disease was also more frequent in the peripheral blood stem cells group (28% vs. 15.6%; p<0.001). Patients transplanted with peripheral blood stem cells had significant impairment of role and social functioning.

CONCLUSIONS

Although overall survival was not affected by the stem cell source, peripheral blood stem cell transplants were associated with a higher risk of both acute and chronic GvHD. Global quality of life was similar in both groups, but patients transplanted with peripheral blood stem cells showed worse role and social functioning scores, probably related to the increased incidence of chronic graft-versus-host disease.

Use of the haematopoietic progenitor cell parameter in optimizing timing of peripheral blood stem cell harvest

BACKGROUND AND OBJECTIVES

Timing of peripheral blood stem cell (PBSC) harvest is typically based on quantification of peripheral blood (PB) CD34+ cells. CD34 enumeration is expensive, requires expertise and takes a minimum of 1-2 h to perform. The Sysmex XE2100 is an automated haematology analyser that can rapidly and inexpensively identify haematopoietic progenitor cell (HPC) populations in PB. The aim of this study was to examine if HPC can be used to optimize timing of PBSC harvest.

MATERIALS AND METHODS

White blood cell (WBC), HPC and CD34 counts were determined in a total of 60 mobilized donors. Data were analysed to examine the utility of WBC and HPC counts in predicting preharvest CD34+ counts.

RESULTS

In adults presenting for autologous collection, a PB HPC threshold of > 30/microl predicts a preharvest CD34+ count of > 20/microl with sensitivity of 86% and positive predictive value (PPV) of 100%. Among paediatric patients with a diagnosis of neuroblastoma, an HPC threshold of > 16/microl yielded sensitivity and PPV of 100%, while in children with other diagnoses, an HPC cut-off of > 44/microl yielded sensitivity and PPV of 67% and 100%, respectively. Eighty per cent of adequately mobilized allogeneic donors were identified using an HPC threshold > 15/microl, with a PPV of 100%. PB WBC can also aid in predicting CD34 counts in most patient groups, albeit with lower sensitivity than HPC.

CONCLUSION

By virtue of being a sensitive and accurate predictor of preharvest CD34+ counts, our data support the use of the HPC parameter in optimizing the timing of PBSC harvest.

[Stem cell transplantation in the treatment of gastrointestinal diseases]

The stem cells with self-renewal ability are capable to form one or more cell types. They will be in the target of cell and gene therapy because of their multipotency and easy retrieval. Application of adult mesenchymal, neuronal, epidermal and haematopoietic stem cell can be favourable in the treatment of cardiac (myocardial infarction), bone (osteoarthritis), neurological (Parkinson's, Alzheimer's) and hematological (hemophilia, thrombocytopenia) disorders. Authors summarize the knowledge in connection with their application in the therapy of gastrointestinal diseases. Haematopoietic stem cell transplantation has been successful for the treatment of refractory Crohn's disease, as well as in selected group of celiac patients. Mesenchymal stem cell transplantation has been proved beneficial in the prevention of liver fibrotic process. It will gain more grounds in the treatment of autoimmune liver diseases: autoimmune hepatitis, primary biliary cirrhosis and primary sclerosing cholangitis in the future. Well-designed, multicentric, prospective studies are needed to confirm the results of case reports and clinical studies with small group of patients.