Anemia associated with impaired erythropoietin secretion after allogeneic stem cell transplantation: incidence, risk factors, and response to treatment

Outcomes with CD34-Selected Stem Cell Boost for Poor Graft Function after Allogeneic Hematopoietic Stem Cell Transplantation: A Systematic Review and Meta-Analysis

Poor graft function (PGF) is a life-threatening complication after allogeneic hematopoietic stem cell transplantation (allo-HSCT) characterized by multilineage cytopenia in the absence of mixed donor chimerism (<95% donor), relapse, or severe graft-versus-host disease (GVHD). We present a systemic review and meta-analysis aimed at assessing the outcomes with CD34-selected stem cell boost (SCB) for PGF in adult allo-HSCT recipients. We screened a total of 1753 records identified from 4 databases (PubMed, Embase, Cochrane, and ClinicalTrials.gov) following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines, using the search terms "hematological malignancies," "hematopoietic stem cell transplantation," "CD34 antigen(s)," "graft failure," and "poor graft function," from the date of inception to January 2021. After excluding review, duplicate, and nonrelevant articles, we included 7 studies reporting outcomes following administration of CD34-selected SCB for PGF after allo-HSCT, including hematologic complete response (CR) and overall response rate (ORR), GVHD, and overall survival (OS). Quality evaluation was done using the National Institutes of Health quality assessment tool. Pooled analysis was done using the R 'meta' package, and proportions with 95% confidence intervals (CIs) were computed. The inter-study variance was calculated using the Der Simonian-Laird estimator. We identified 209 patients who received CD34-selected SCB for PGF after allo-HSCT. The median age was 49 years (range, 18 to 69 years), and 61% were men. Primary graft sources included peripheral blood stem cells (72%) and bone marrow (28%). Donor types were matched sibling (37%), matched unrelated (36%), mismatched unrelated (22%), and haploidentical donors (5%). The median time from allo-HSCT to SCB was 138 days (range, 113 to 450 days). The median SCB dose was 3.45 × 10⁶ CD34 cells/kg (range, 3.1 to 4.9 × 10⁶ cells/kg). CR and ORR were 72% (95% CI, 63% to 79%; I² = 26%) and 80% (95% CI, 74% to 85%; I² = 0%), respectively. After a median follow-up of 42 months (range, 30 to 77 months), the actuarial survival rate was 54% (95% CI, 47% to 61%; I² = 0%). OS ranged from 80% at 1 year to 40% at 9 years. The incidences of acute and chronic GVHD after SCB were 17% (95% CI, 13% to 23%; I² = 0%) and 18% (95% CI, 8% to 34%; I² = 76%), respectively. Nonrelapse mortality was reported in 42 patients, with a pooled rate of 27% (95% CI, 17% to 40; I² = 59%), and death due to relapse was reported in 25 patients, with a pooled rate of 17% (95% CI, 11% to 23%; I² = 0%). Our data show that CD34-selected SCB improves outcomes after PGF post allo-HSCT with an acceptable toxicity profile. The literature lacks high-quality randomized evidence, and there remains an unmet need for prospective studies to address the optimal dosing and manipulation of SCB. © 2021 American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc.

A matched-pair analysis reveals marginally reduced CD34+ cell mobilization on second occasion in 27 related donors who underwent peripheral blood stem cell collection twice at the same institution

BACKGROUND

In a small proportion of cases, hematopoietic function is insufficient after allogeneic hematopoietic stem cell transplantation, as a result of poor graft function or graft failure. These complications are common indications of re-mobilization of the initial donor, either for a second allograft or for an infusion of CD34+ Selected stem Cell Boost (SCB).

METHODS AND MATERIALS

We retrospectively reviewed the results of two cycles of CD34+ cell mobilization and collection. CD34+ cells mobilized and collected at each cycle were compared. When CD34+ cell selection from the collected allogeneic mononuclear cells was indicated, it was performed with the Clinimacs Plus® medical device, and results from in-process and final quality checks were analyzed. To assess the efficacy of CD34+ SCB, transfusion needs before and after the infusion of selected CD34+ cells were calculated.

RESULTS

The median peripheral blood concentration of CD34+ cells/μL was marginally reduced during the second cycle (35.6 vs 33.8, p < 0.05); results revealed a strong correlation between paired values (r = 0.85). The cumulative number of collected CD34+ cells were similar for both cycles; the total processed blood volume was higher during the second cycle (p = 0.023). For CD34+ immune-selection procedures, CD34+ cell recovery and purity were respectively 57% and 95%, with a median T-cell depletion of 6.7 log. Recipients' needs for platelet and red blood cell transfusions were significantly reduced after CD34+ SCB.

CONCLUSION

This study confirms the feasibility of a second cycle of mobilization in healthy related donors and the benefits of CD34+ SCB on hematopoietic reconstitution.

[Effects of CD34(+) selected stem cells for the treatment of poor graft function after allogeneic stem cell transplantation]

目的

观察输注纯化供者CD34⁺细胞治疗单倍型造血干细胞移植后移植物功能不良的疗效和安全性。

方法

对2014年1月至2018年3月期间接受供者纯化CD34⁺细胞治疗的12例单倍型造血干细胞移植后移植物功能不良患者进行回顾性分析。

结果

12例患者中男9例、女3例，中位年龄26（14~54）岁；急性淋巴细胞白血病4例，急性髓系白血病5例，慢性髓性白血病2例，慢性粒-单核细胞白血病1例。分选产物CD34⁺细胞纯度为92.0%（44.0%~97.0%），回收率为55.0%（45.0%~96.7%），回输CD34⁺细胞的中位数为1.9（0.9~4.4）×10⁶/kg，CD3⁺细胞中位数为0.6（0.3~2.0）×10⁴/kg。中性粒细胞恢复中位时间为18（14~39）d，血小板恢复中位时间为29（16~153）d，红细胞恢复中位时间为60（9~124）d。12例患者输注过程中未发生严重不良反应，10例获得完全缓解，1例患者获得部分缓解，1例患者无效，未发生重症感染和重度GVHD。

结论

回输供者纯化CD34⁺细胞是单倍型造血干细胞移植后植入功能不良的一种安全、有效治疗方法。

Optimizing peripheral blood stem cells transplantation outcome through amend relapse and graft failure: a review of current literature

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) has been considered as a valuable approach in treatment of numerous malignant and none malignant hematologic disorders. However, relapse and poor graft function (PGF) after allo-SCT remain to be controversial issues which may affect the transplantation outcome. Relevant articles were searched in MEDLINE database (2000–2016) using keywords and phrases: donor lymphocyte infusions, allogeneic stem cells transplantation, relapsed hematologic malignancies, booster schedules, cell dose, laboratory monitoring protocols and technical aspects of apheresis. Relapse of disease and PGF could be reduced via noting some main points such as choosing the suitable time and patient for donor lymphocyte infusion (DLI) and also determination of patients who ought to candidate for second allogeneic HSCT or for the use of stem cell boost. DLI and stem cell booster are promising treatment strategies noted in this review. Finally, this paper discusses indications and technical aspects of DLI and stem cell booster in hematological malignancies and emphasizes their therapeutic or pre-emptive potentials.

Fresh or Cryopreserved CD34+-Selected Mobilized Peripheral Blood Stem and Progenitor Cells for the Treatment of Poor Graft Function after Allogeneic Hematopoietic Cell Transplantation

CD34⁺-selected stem cell boost (SCB) without conditioning has recently been utilized for poor graft function (PGF) after allogeneic hematopoietic stem cell transplantation with promising results. Unfortunately, many patients have been unable to receive the boost infusion as their donors were unwilling or unable to undergo an additional stem cell collection. Therefore, we conducted this study utilizing either fresh or cryopreserved peripheral blood stem cell products to create CD34⁺-selected boost infusions for the treatment of PGF. Additionally, to explore relationship of CD34⁺ dose and response, we included a cohort of donors mobilized with plerixafor in addition to the standard granulocyte colony-stimulating factor (G-CSF). Twenty-six patients with PGF were included in this study. Seventeen donor-recipient pairs were enrolled onto the prospective study; an additional 9 patients treated off protocol were reviewed retrospectively. Three different donor products were used for CD34⁺ selection: (1) fresh mobilized product using G-CSF only, (2) fresh mobilized products using G-CSF and plerixafor, and (3) cryopreserved cells mobilized with G-CSF. CD34⁺ cell selection was performed using a CliniMACS. The infusion was not preceded by administration of any chemotherapy or conditioning regimen. The primary objective was hematologic response rate and secondary objectives included CD34⁺ yields, incidence and severity of acute and chronic graft-versus-host disease (GVHD), overall survival (OS), and relapse-free survival (RFS). The median post-selection CD34⁺ counts per kilogram of recipient weight were 3.1 × 10⁶, 10.9 × 10⁶, and 1 × 10⁶ for G-CSF only, G-CSF plus plerixafor, and cryopreserved products, respectively. The median CD34⁺ yields (defined as the number of CD34⁺ cells after selection/CD34⁺ cells before CD34⁺ selection) were 69%, 66%, and 28% for G-CSF only, G-CSF plus plerixafor, and cryopreserved products, respectively. After SCB, 16 of the 26 recipients (62%) had a complete response, including 5 of 8 (63%) who received cryopreserved products. Five had a partial response (19%), resulting in an overall response rate of 81%. One-year RFS and OS were 50% and 65%, respectively. There was no treatment-related toxicity reported other than GVHD: 6 (23%) developed acute GVHD (2 grade I and 4 grade II) and 8 (31%) developed chronic GVHD (2 limited and 6 extensive). Cryopreserved products are viable alternatives to create SCB for the treatment of PGF. When collecting fresh products is an option, the addition of plerixafor increases CD34⁺ yield over G-CSF alone; however, it is currently unclear if the CD34⁺ cell dose impacts the efficacy of the SCB.

Erythropoiesis-stimulating agents in allogeneic and autologous hematopoietic stem cell transplantation

INTRODUCTION

Erythropoiesis-stimulating agents (ESAs) are used in treating cancer- and chemotherapy-induced anemia with the aim of accelerating the recovery of red blood cells (RBCs), reduce the risks associated with RBC transfusions and improve quality of life.

AREAS COVERED

A systematic review has been conducted to examine the current evidence for the efficacy and safety of using ESAs in hematopoietic stem cell transplants (HSCTs).

EXPERT OPINION

Despite the international recommendations for the use of ESAs in treating different malignancies, there is a lack of guidelines for their use in patients undergoing HSCT. An evaluation of published clinical trials shows that there are no available powerful studies concerning the use of ESAs in this setting, with only heterogeneous and small numbers of patients reported so far. Nevertheless, the more robust and intriguing of these data suggest that the ESA's administration at an appropriate time after the infusion of stem cells may be effective both in autologous and allogeneic HSCTs. New guidelines are required, overseen by an expert in the in the field of stem cell transplantation.

Erythropoietin therapy after allogeneic hematopoietic cell transplantation: a prospective, randomized trial

Erythropoietin therapy can be effective to hasten erythroid recovery and reduce transfusion requirements after allogeneic HCT.

Erythropoietin Receptor Signaling Through STAT3 Is Required For Glioma Stem Cell Maintenance

Recombinant erythropoietin (EPO) is a growth factor used in the treatment of chemotherapy-induced anemia, but recent studies suggest that EPO may accelerate cancer growth. Although several cancers express EPO receptors (EPORs), the mechanism by which EPOR promotes tumor growth remains poorly understood. Glioblastomas display a cellular hierarchy of self-renewal and tumor propagation restricted to glioma stem cells (GSCs). We find that GSCs express higher levels of EPOR than matched non-stem glioma cells. Prospective enrichment for EPOR on GSCs increased neurosphere formation, suggesting that EPOR can select for a subset of GSCs with increased self-renewal capacity. Targeting EPOR expression with lentiviral mediated short hairpin RNA (shRNA) reduced GSC growth, survival, and neurosphere formation capacity, defining a crucial role for EPOR in GSC maintenance. We further find that STAT3 is an important mediator of EPOR signals in GSCs. EPOR knockdown attenuated the basal activation of STAT3 present in GSCs, and a small molecule inhibitor of STAT3 reduced GSC growth and survival. EPOR signaling was critical for survival in vivo, as targeting EPOR expression decreased GSC tumorigenic potential. Elevated EPOR expression also associated with poor patient outcome. Thus, EPOR on GSCs promotes tumor growth and may explain the poor survival of cancer patients treated with EPO.