Risk-factor analysis of poor graft function after allogeneic hematopoietic stem cell transplantation

Graft Failure Incidence, Risk Factors, and Outcomes in Patients Undergoing Non-Myeloablative Allogeneic Hematopoietic Cell Transplantation Using Post-Transplant Cyclophosphamide

Graft failure (GF) is a major complication of allogeneic hematopoietic cell transplantation (alloHCT) that results in significant morbidity and mortality. Post-transplant cyclophosphamide (PTCy)-based graft-versus-host disease (GVHD) prophylaxis has emerged as an effective regimen across the spectrum of donor-match settings, but few studies have investigated the characteristics of GF in the setting of PTCy-based GVHD prophylaxis. The objective was to detail the incidence, clinical features, risk factors, and outcomes for patients with primary graft failure (PGF) and secondary graft failure (SGF). In this retrospective study at a single institution, 958 consecutive patients undergoing first nonmyeloablative (NMA) alloHCT with PTCy-based GVHD prophylaxis were analyzed. PGF was defined as a failure to achieve an ANC ≥ 500 cells/m3 by day 30 of transplant in the absence of residual disease. SGF was defined as complete loss of donor chimerism after initial engraftment. The incidences of PGF and SGF were 3.8% (n = 37) and 1.8% (n = 17), respectively. Neither PGF nor SGF were associated with HLA disparity. In a multivariate analysis, risk factors for PGF in this cohort included age ≥ 65 (OR 2.4, 95% CI 1.2 to 4.8, P = .0120), an underlying diagnosis of MDS, MPN, or MDS/MPN overlap (OR 2.8, 95% CI 1.4 to 5.7, P = .0050), post-transplant viremia with HHV-6 (OR 2.9, 95% CI 1.5 to 5.7, P = .0030), and low CD34+ dose (OR 0.7, 95% CI 0.5 to 0.9, P = .0080). Patients with PGF had poor overall survival, driven primarily by a high rate of nonrelapse mortality (59% at 36 months). SGF was associated with use of a bone marrow graft source and a diagnosis of Hodgkin lymphoma. Patients with SGF had excellent clinical outcomes with only one of seventeen patients experiencing relapse and relapse-related mortality. The incidence of PGF and SGF in patients receiving NMA conditioning and PTCy is low and is not impacted by HLA disparities between donors and recipients. PGF is more common in recipients with age ≥ 65, a diagnosis of MDS, MPN, or MDS/MPN-overlap, post-transplant HHV-6 viremia, and low CD34+ cell dose. Low total nucleated cell dose is also a risk factor for PGF in patients receiving a bone marrow graft source. Patients who experience PGF have poor outcomes due to high rates of nonrelapse mortality, whereas patients who experience SGF have excellent long-term outcomes.

The indirect effects of CMV reactivation on patients following allogeneic hematopoietic stem cell transplantation: an evidence mapping

Cytomegalovirus (CMV) reactivation following allogeneic hematopoietic stem cell transplantation (allo-HSCT) remains a challenging problem, and the impact on the risk of overall mortality (OM) and non-relapse mortality (NRM) in patients following allo-HSCT is still controversial. Utilizing the evidence mapping method, we aimed to assess the effect of CMV infection on outcomes of patients post-transplantation and identify research gaps through systematic reviews (SRs) and clinical studies. PubMed, EMBASE, Web of Science, and Cochrane library databases were searched from inception until 5 July 2022 to identify relevant literature. After systematic literature screening and data extraction, evidence mapping of the effects of CMV reactivation on patients post-allo-HSCT was conducted. Three SRs and 22 clinical studies were included. In one SR, CMV reactivation was associated with an increased risk of mortality (HR 1.46; 95% CI, 1.24-1.72; P ≤ 0.001). In two SRs, CMV reactivation was associated with NRM. One SR reported CMV reactivation was potentially associated with significant protection against relapse in patients with acute myelocytic leukemia (AML), but no significant correlation with graft-versus-host disease (GVHD) was found. Lastly, in one SR CMV reactivation significantly increased the risk of invasive fungal disease (IFD). Most clinical articles reported that CMV reactivation increased the risk of renal dysfunction, poor graft function, re-hospitalization, and bacterial infections. CMV reactivation following allo-HSCT is associated with an increased risk of OM, NRM, IFD, and renal dysfunction, as well as a reduced risk of relapse in patients with AML.

Sirolimus Is an Acceptable Alternative to Tacrolimus for Graft-versus-Host Disease Prophylaxis after Haploidentical Peripheral Blood Stem Cell Transplantation with Post-Transplantation Cyclophosphamide

Graft-versus-host disease (GVHD) prophylaxis with post-transplantation cyclophosphamide (PTCy), tacrolimus (Tac), and mycophenolate mofetil (MMF) for allogeneic haploidentical donor (haplo) hematopoietic cell transplantation (HCT) results in comparable outcomes to matched unrelated donor HCT. A phase II study from the Moffitt Cancer Center substituting sirolimus (Siro) for Tac in this prophylactic regimen reported comparable rates of grade II-IV acute GVHD (aGVHD). Many centers have substituted Siro for Tac in this setting based on a preferable side effect profile, although comparative data are limited. In this study, we retrospectively compared outcomes in haplo-HCT with PTCy/Siro/MMF versus haplo-HCT with PTCy/Tac/MMF. The study cohort included all consecutive patients receiving haploidentical donor T cell-replete peripheral blood stem cell (PBSC) HCT for hematologic malignancies at Moffitt Cancer Center or the City of Hope National Medical Center between 2014 and 2019. A total of 423 patients were included, of whom 84 (20%) received PTCy/Siro/MMF and 339 (80%) received PTCy/Tac/MMF. The median age for the entire cohort was 54 years (range, 18 to 78 years), and the median follow-up was 30 months. The Siro group had a higher proportion of patients age ≥60 years (58% versus 34%; P < .01), and the groups also differed in diagnosis type, conditioning regimen, and cytomegalovirus serostatus. There were no significant differences in the rates of grade II-IV aGVHD (45% versus 47%; P = .6) at day +100 or chronic GVHD (cGVHD) (47% versus 54%; P = .79) at 2 years post-HCT. In multivariate analysis, neutrophil engraftment at day +30 was significantly better in the Tac group (odds ratio, .30; 95% confidence interval, .1 to .83; P = .02), with a median time to engraftment of 17 days versus 18 days in the Siro group, but platelet engraftment was similar in the 2 groups. Otherwise, in multivariate analysis, GVHD prophylaxis type had no significant influence on aGVHD or cGVHD, nonrelapse mortality, relapse, GVHD-free relapse-free survival, disease-free survival, or overall survival after PBSC haplo-HCT. These findings suggest that Siro is a comparable alternative to Tac in combination with PTCy/MMF for GVHD prophylaxis, with overall similar clinical outcomes despite delayed engraftment after peripheral blood stem cell haplo-HCT. Although Tac remains the standard of care, Siro may be substituted based on the side effect profile of these medications, with consideration of patient medical comorbidities at HCT.

Definitions, incidence and outcome of poor graft function after hematopoietic cell transplantation: A systematic review and meta-analysis

Poor graft function (PGF) after allogeneic hematopoietic stem cell transplantation (HCT) is a serious complication with high morbidity and mortality. The reported incidence of PGF, its risk factors and outcome vary substantially between studies. This variability may be explained by heterogeneity in patient cohorts and HCT strategies, differences in the underlying causes of cytopenia, as well as by differences in PGF definition. In this systematic review and meta-analysis, we provide an overview of the various PGF definitions used and determined the impact of this variability on the reported incidence and outcome. We searched MEDLINE, EMBASE and Web of Science up to July 2022, for any study on PGF in HCT recipients. We performed random-effect meta-analyses for incidence and outcome and subgroup analyses based on different PGF criteria. Among 69 included studies (14.265 HCT recipients), we found 63 different PGF definitions, using various combinations of 11 common criteria. The median incidence of PGF was 7% (IQR: 5-11%, 22 cohorts). The pooled survival of PGF patients was 53% (95% CI: 45-61%, 23 cohorts). The most commonly reported risk factors associated with PGF were history of cytomegalovirus infection and prior graft-versus-host disease. Incidence was lower in studies with strict cytopenic cutoffs, while survival was lower for primary compared to secondary PGF. This work indicates that a standardized, quantitative definition of PGF is needed to facilitate clinical guideline development and to advance scientific progress.

Poor graft function after haploidentical stem cell transplantation with post-transplant cyclophosphamide

This is a retrospective cohort study of consecutive adult patients who received a haploidentical-SCT (haplo-SCT) with post-transplant cyclophosphamide (PT-Cy) in a single centre. Poor graft function (PGF) was defined as the occurrence of either persistent neutropenia (ANC < 0.5 × 10⁹/µL) with poor response to granulocyte colony-stimulating factors (G-CSF) and/or thrombocytopenia (platelets < 20 × 10⁹/L) with transfusion dependence, with complete donor chimerism and without concurrent severe GVHD or underlying disease relapse, during the first 12 months after transplantation. Forty-four (27.5%) out of 161 patients were diagnosed with PGF. Previous CMV reactivation was significantly more frequent in patients with PGF (88.6% versus 73.5%, p = 0.04) and the number of reactivations was also higher in these patients. Besides, early CMV reactivations in the first 6 months post-SCT were also significantly more frequent among patients with PGF (88.6% versus 71.8% p = 0.025). Thirty-two percent of patients with PGF were treated with increasing doses of thrombopoietin-receptor agonists (TRA) and 7 patients were treated with a donor CD34 + selected boost. In total, 93.2% of patients reached adequate peripheral blood counts in a median time of 101 days (range 11-475) after diagnosis. PGF is a frequent complication after haplo-SCT with PT-Cy. CMV reactivation might be the most relevant factor associated to its development. Even when most patients recover peripheral counts with support therapy, there is a group of patients with persistent cytopenias who can effectively be treated with TRA and/or a boost of CD34 + selective cells.

Cost analysis of childhood hematopoietic stem cell transplantation in Sichuan, China

Objective

To analyze the inpatient cost of hematopoietic stem cell transplantation (HSCT) in children, so as to support clinical decision-making.

Methods

Study population were children who received HSCT in a tertiary children's hospital (Sichuan, China) between 1st January 2020 and 31st December 2021. The median and interquartile range (IQR) of total cost at 100 days post transplantation were calculated. Subgroup analyses were conducted based on age, gender, transplantation types, and post-transplant complications. The cost differences between subgroups were analyzed to determine whether it had an impact on the total costs.

Results

A total of 142 pediatric patients were included in the study with a total cost of 250721.78 yuan (197019.16-315740.52, 1 yuan equals to around 0.15 US dollars). Drug costs accounted for 51.85% of the total cost, followed by medical service costs (12.57%) and treatment expenses (12.24%). In terms of transplantation types, the cost of autologous transplantation was lower than that of allogeneic transplantation (115722.98 yuan vs. 256043.99 yuan, p < 0.05), and the cost of human leukocyte antigen (HLA) complete matched was lower compared with that of partial matched (213760.88 yuan vs. 294044.84 yuan, p < 0.05). As for post-transplant complications, cases with <3 types of complications cost less than those with ≥3 types (212893.25 yuan vs. 286064.60 yuan, p < 0.05), and those with severity ≤ grade 2 cost less than those > grade 2 (235569.37 yuan vs. 280061.58 yuan, p < 0.05). Age and gender of patients did not lead to statistical differences in the total cost, while the transplantation types and post-transplant complications influenced the total cost.

Conclusion

The total cost at 100 days post transplantation associated with HSCT treatment were substantial for pediatric patients. The HLA compatibility between donors and recipients, and post-transplant complications were important factors affecting the total cost.

Recent Advancements in Poor Graft Function Following Hematopoietic Stem Cell Transplantation

Poor graft function (PGF) is a life-threatening complication that occurs after transplantation and has a poor prognosis. With the rapid development of haploidentical hematopoietic stem cell transplantation, the pathogenesis of PGF has become an important issue. Studies of the pathogenesis of PGF have resulted in some success in CD34⁺-selected stem cell boosting. Mesenchymal stem cells, N-acetyl-l-cysteine, and eltrombopag have also been investigated as therapeutic strategies for PGF. However, predicting and preventing PGF remains challenging. Here, we propose that the seed, soil, and insect theories of aplastic anemia also apply to PGF; CD34⁺ cells are compared to seeds; the bone marrow microenvironment to soil; and virus infection, iron overload, and donor-specific anti-human leukocyte antigen antibodies to insects. From this perspective, we summarize the available information on the common risk factors of PGF, focusing on its potential mechanism. In addition, the safety and efficacy of new strategies for treating PGF are discussed to provide a foundation for preventing and treating this complex clinical problem.

Hematopoiesis reconstitution and anti-tumor effectiveness of Pai-Neng-Da capsule in acute leukemia patients with haploidentical hematopoietic stem cell transplantation

BACKGROUND

With the rapid development of haploidentical hematopoietic stem cell transplantation (haplo-HSCT), primary poor graft function (PGF) has become a life-threatening complication. Effective therapies for PGF are inconclusive. New Chinese patent medicine Pai-Neng-Da (PND) Capsule exerts dual effect in promoting hematopoiesis recovery and regulating immunity. Still, the application of PND capsule in hematopoietic stem cell transplantation, especially in the haplo-HSCT setting, has not yet been reported.

AIM

To evaluate the role of PND capsule in acute leukemia patients with haplo-HSCT.

METHODS

We retrospectively collected data of acute leukemia patients who underwent haplo-HSCT at the Affiliated People’s Hospital of Ningbo University between April 1, 2015 and June 30, 2020. Twenty-nine consecutive patients received oral PND capsule from the sixth day to the first month after haplo-HSCT were included in the PND group. In addition, 31 patients who did not receive PND capsule during haplo-HSCT were included in the non-PND group. Subsequently, we compared the therapeutic efficacy according to the western medical evaluation indexes and Chinese medical symptom scores, and the survival between the PND group and the non-PND group, using the chi-square test, Fisher’s exact test, and the Kaplan–Meier method.

RESULTS

The duration of platelet engraftment was shorter in the PND group than in the non-PND group (P = 0.039). The PND group received a lower frequency of red blood cells and platelet transfusions than the non-PND group (P = 0.033 and P = 0.035, respectively). In addition, PND capsule marginally reduced the rate of PGF (P = 0.027) and relapse (P = 0.043). After 33 (range, 4-106) months of follow-up, the 3-year relapse-free survival (P = 0.046) and progression-free survival (P = 0.049) were improved in the PND group than in the non-PND group. Also, the therapeutic efficacy of the PND group according to Chinese medical symptom scores was significantly better than that of the non-PND group (P = 0.022). Moreover, the adverse events caused by PND capsule were mild. Nevertheless, there were no significant differences in the duration of neutrophil engraftment, the risk of infection within 100 days after haplo-HSCT, the acute graft-versus-host disease, or the 3-year overall survival between the two groups.

CONCLUSION

PND capsule could promote hematopoiesis reconstitution, improve the therapeutic efficacy of Chinese medical symptom scores, present anti-tumor effectiveness, and prolong the survival of acute leukemia patients with haplo-HSCT.

The Incidence, Outcomes, and Risk Factors of Secondary Poor Graft Function in Haploidentical Hematopoietic Stem Cell Transplantation for Acquired Aplastic Anemia

Secondary poor graft function (sPGF) increases the risk of life-threatening complications after hematopoietic stem cell transplantation (HSCT). The incidence, clinical outcomes, and risk factors of sPGF have not been elucidated in haploidentical (haplo-) HSCT for acquired aplastic anemia (AA) patients. We retrospectively reviewed 423 consecutive AA patients who underwent haplo-HSCT between January 2006 and December 2020 and report a 3-year cumulative incidence of 4.62% (95% confidence interval [CI]: 3.92%-10.23%) of sPGF. While no primary PGF occurred. The median time to sPGF was 121 days (range 30-626 days) after transplantation. To clarify the risk factors for sPGF, 17 sPGF cases and 382 without PGF were further analyzed. Compared to patients without PGF, the 2-year overall survival was significantly poorer for sPGF patients (67.7% vs 90.8%, p =.002). Twelve sPGF patients were alive until the last follow-up, and 7 achieved transfusion independency. The multivariable analyses revealed that later neutrophil engraftment (OR 2.819, p=.049) and a history of refractory cytomegalovirus viremia (OR=7.038, p=.002) post-transplantation were associated with sPGF. There was weak evidence that a history of grade 3-4 acute graft-versus-host disease increased the risk of sPGF (p=.063). We advocated better post-transplantation strategies to balance the risk of immunosuppression and viral reactivation for haplo-HSCT in AA patients.

Clinical features, pathophysiology, and therapy of poor graft function post-allogeneic stem cell transplantation

Poor graft function (PGF), defined by the presence of multilineage cytopenias in the presence of 100% donor chimerism, is a serious complication of allogeneic stem cell transplant (alloSCT). Inducers or potentiators of alloimmunity such as cytomegalovirus reactivation and graft-versus-host disease are associated with the development of PGF, however, more clinical studies are required to establish further risk factors and describe outcomes of PGF. The pathophysiology of PGF can be conceptualized as dysfunction related to the number or productivity of the stem cell compartment, defects in bone marrow microenvironment components such as mesenchymal stromal cells and endothelial cells, or immunological suppression of post-alloSCT hematopoiesis. Treatment strategies focused on improving stem cell number and function and microenvironment support of hematopoiesis have been attempted with variable success. There has been limited use of immune manipulation as a therapeutic strategy, but emerging therapies hold promise. This review details the current understanding of the causes of PGF and methods of treatment to provide a framework for clinicians managing this complex problem.

Primary graft failure following allogeneic hematopoietic stem cell transplantation: risk factors, treatment and outcomes

OBJECTIVES

Graft failure (GF) is an intractable complication of transplantation, which can severely affect the efficacy of the graft; however, the characteristics, incidence, and risk factors of primary GF have not been well described. This study aimed to analyze the risk factors and outcomes of primary GF to swiftly identify high-risk patients for GF.

METHODS

We performed a case-control study with a case-control ratio of 1:4 with 869 patients who underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT) between January 2015 and December 2019 at our center.

RESULTS

Nineteen (2.19%) patients experienced primary poor graft function (PGF), while eleven (1.27%) patients developed primary graft rejection (GR). Univariate and multivariate logistic analyses identified two independent risk factors for primary PGF: splenomegaly [P = 0.030; odds ratio (OR), 3.486; 95% confidence interval (CI), 1.139 to 13.109], and donor type [non-matched sibling donor (non-MSD)] (P = 0.018; OR, 4.475; 95% CI, 1.289 to 15.537). However, only donor type (non-MSD) was statistically significant (P = 0.020; OR, 19.432; 95% CI, 1.595 to 236.691) for primary GR. The overall survival was significantly lower in the primary PGF (P = 0.001) and GR group (P = 0.000), respectively, compared to the control group.

CONCLUSION

GF can significantly affect the overall survival of patients who underwent allo-HSCT, despite its considerably low incidence. A human leukocyte antigen-matched sibling donor should be the first choice for patients undergoing allo-HSCT for the prevention of GF. Moreover, splenomegaly is an independent risk factor for PGF, and caution must be exercised while treating such patients.

Haploidentical donor transplant is associated with secondary poor graft function after allogeneic stem cell transplantation: A single-center retrospective study

Background

Secondary poor graft function (sPGF) is a serious complication after allogeneic hematopoietic stem cell transplantation (allo‐HSCT) related to poor outcome. We aimed to retrospectively evaluate the morbidity and hazard elements of sPGF after allo‐HSCT.

Methods

Eight hundred and sixty‐three patients who achieved initial engraftment of both neutrophils and platelets were retrospectively reviewed in this study.

Results

Fifty‐two patients developed sPGF within 180 days post‐transplants, with the median onset time was 62 days (range, 34–121 days) post‐transplants. The overall cumulative incidence of sPGF within 180 days post‐transplantation was 6.0%, with 3.4%, 3.4%, and 10.1%, respectively, in matched sibling donor (MSD), matched unrelated donor (MUD), and haploidentical donor (HID) transplant (p < 0.0001). Multivariable analysis showed that HID (HID vs. MSD: hazard ratio [HR] 2.525, p = 0.004; HID vs. MUD: [HR] 3.531, p = 0.017), acute graft versus host disease (aGVHD) within +30 days ([HR] 2.323, p = 0.003), and cytomegalovirus (CMV) reactivation ([HR] 8.915, p < 0.0001) within +30 days post‐transplants were hazard elements of sPGF. The patients with sPGF had poorer survival than good graft function (51.7±8.1% vs. 62.9±1.9%, p < 0.0001). Our results also showed that only CMV reactivation was the hazard element for the development of PGF in HID transplant ([HR] 12.521 p < 0.0001).

Conclusion

HID transplant is also an independent hazard element of sPGF except for aGVHD and CMV reactivation.

Hematopoietic Dysfunction during Graft-Versus-Host Disease: A Self-Destructive Process?

Graft-versus-host disease (GvHD) is a major complication of allogeneic hematopoietic (stem) cell transplantation (HCT). Clinically, GvHD is associated with severe and long-lasting hematopoietic dysfunction, which may contribute to the high mortality of GvHD after HCT. During GvHD, excessive immune activation damages both hematopoietic stem and progenitor cells and their surrounding bone marrow niche, leading to a reduction in cell number and functionality of both compartments. Hematopoietic dysfunction can be further aggravated by the occurrence—and treatment—of HCT-associated complications. These include immune suppressive therapy, coinciding infections and their treatment, and changes in the microbiome. In this review, we provide a structured overview of GvHD-mediated hematopoietic dysfunction, including the targets in the bone marrow, the mechanisms of action and the effect of GvHD-related complications and their treatment. This information may aid in the identification of treatment options to improve hematopoietic function in patients, during and after GvHD.

A concise review on factors influencing the hematopoietic stem cell transplantation main outcomes

BACKGROUND AND AIMS

As a curative procedure, hematopoietic stemcell transplantation (HSCT) is an approved treatment for many malignant orbenign hematologic and non-hematologic diseases. There are different outcomes of HSCT, as well as several parameters influencing these outcomes.

METHODS

We had searched scientific sources like Web ofScience and PubMed with a combination of keywords such as HSCT, engraftment,survival, outcomes, etc. Totally, 80 articles were included.

RESULTS

Here we have reviewed the effective factors onmain outcomes of HSCT including engraftment, survival, graft versus hostdisease, and Mobilization. Also, the prediction of hematological reconstitutionand some novel suggestions leading to better outcomes are reviewed.

CONCLUSION

The study will be applicable for improvedmanagement of autologous and allogeneic HSCT process to increase the procedureefficiency.

Outcome of Patients Treated with Hematopoietic Stem Cell Transplantation: Results from A Single Center

OBJECTIVE

Hematopoietic stem cell transplantation (HSCT) is known as one of the most advanced and modern treatments in the world for various diseases which do not respond well to other therapies. Evaluating outcomes of these patients, especially in newly developed centers, can crucially help in developing and improving the quality of these centers.

METHODS

In a retrospective analytical cohort study, we statistically analyzed all patients treated with HSCT in the Bone Marrow Transplant Unit of the Ali-Asghar Pediatric Hospital affiliated to Iran University of Medical Sciences. The demographic information as well as all information concerning each patient's transplant process was extracted and statistically analyzed using SPSS Version 23.

RESULTS

The mean neutrophilic and platelet engraftment days were, respectively, 16 (range = 12-21) and 22 (range = 15-34) days after HSCT, while the neutrophilic engraftment occurred significantly earlier in allogeneic transplants compared to the autologous ones (P = 0.020). The total event-free survival (EFS) rate of the patients based on the median follow-up of 12 months was 11.50% ± 53.60%. Based on the total follow-up period, the estimated total EFS rate of the patients was calculated as 35.20% ± 13.50%. The estimated EFS rate was found to be better in patients who had undergone allogeneic transplantation than those who received an autologous transplant (P = 0.780).

CONCLUSIONS

The HSCT results at our center are comparable to those at other centers in Iran. We argue that the facility can provide adequate therapy to patients requiring HSCT, on the proviso that some organizational limitations are addressed.

Evaluation of risk factors for and subsequent mortality from poor graft function (PGF) post allogeneic stem cell transplantation

Poor Graft Function (PGF) is defined by multi-lineage cytopenias with complete donor chimerism post allogeneic transplantation, Risk factors for and subsequent mortality from PGF were assessed in our transplant cohort. Non-sibling donor [OR 1.97; 95% CI 1.02-3.70], ICU admission [OR 5.28; 95% CI 2.29-11.88] or blood culture positivity within the first 30 days [OR 1.67; 95% CI 1.07-2.62], grade III-IV acute graft vs host disease (GVHD) [OR 4.082; 95% CI 2.31-7.16] and CMV viremia [OR 2.43; 95% CI 1.53-3.88] and were significantly associated with development of PGF. PGF patients without count recovery had a 2 year OS of 6%. Severe GVHD, thrombocytopenia and anemia portended inferior survival and were used to develop a prognostic score for mortality from PGF. This analysis identifies risk factors predictive of PGF and poor survival in those without recovery.

Advances in the understanding of poor graft function following allogeneic hematopoietic stem-cell transplantation

Poor graft function (PGF) following allogeneic hematopoietic stem-cell transplantation (allo-HSCT) is a life-threatening complication and is characterized by bilineage or trilineage blood cell deficiency and hypoplastic marrow with full chimerism. With the rapid development of allo-HSCT, especially haploidentical-HSCT, PGF has become a growing concern. The most common risk factors illustrated by recent studies include low dose of infused CD34+ cells, donor-specific antibody, cytomegalovirus infection, graft versus host disease (GVHD), iron overload and splenomegaly, among others. Because of the poor prognosis of PGF, it is crucial to uncover the underlying mechanism, which remains elusive. Recent studies have suggested that the bone marrow microenvironment may play an important role in the pathogenesis of PGF. Deficiency and dysfunction of endothelial cells and mesenchymal stem cells, elevated reactive oxygen species (ROS) levels, and immune abnormalities are believed to contribute to PGF. In this review, we also discuss recent clinical trials that evaluate the safety and efficacy of new strategies in patients with PGF. CD34+-selected stem-cell boost (SCB) is effective with an acceptable incidence of GVHD, despite the need for a second donation. Alternative strategies including the applications of mesenchymal stem cells, N-acetyl-l-cysteine (NAC), and eltrombopag have shown favorable outcomes, but further large-scale studies are needed due to the small sample sizes of the recent clinical trials.

Evolution of the role of haploidentical stem cell transplantation: past, present, and future

INTRODUCTION

The accessibility to haplo-donors has led to an increase in the number of haplo-HSCT worldwide. A systematic search of the PubMed database between 2000 to present was performed.

AREAS COVERED

In this review, the authors discussed the most used approaches to perform haplo-HSCT and its results: T-cell depletion (TCD, including Perugia platform and its modifications) and T-cell repleted haplo (TCR, including the high-dose post-transplant cyclophosphamide strategy (Baltimore protocol) and the Beijing protocol). The improvements and modifications made to the different strategies have increased the indications of haplo-HSCT, including both malignant and nonmalignant disorders. Focusing on the Baltimore protocol, the authors review the results of the retrospective studies that have compared it to other donor transplants. The limitations of this strategy in terms of toxicity, graft complications, and GVHD are also discussed in detail. Finally, possible approaches to improve the outcomes of TCR haplo-HSCT are presented.

EXPERT OPINION

The recent advances in the field of haplo-HSCT have allowed a large number of patients with incurable diseases to benefit from this procedure despite not having a matched donor. With all available strategies, virtually no patient who needs an allogeneic transplant should be excluded by the absence of a donor.

A Prospective Pilot Study of Graft-versus-Host Disease Prophylaxis with Post-Transplantation Cyclophosphamide and Ruxolitinib in Patients with Myelofibrosis

INTRODUCTION

This prospective study evaluated a calcineurin inhibitor-free graft-versus-host disease (GVHD) prophylaxis regimen of ruxolitinib in combination with post-transplant cyclophosphamide (PTCy). Patents and Methods: Twenty patients with primary or secondary myelofibrosis were prospectively enrolled. Reduced intensity conditioning was performed, followed by allogeneic stem cell transplantation from related (n = 7) or unrelated (n = 13) donors. GVHD prophylaxis included only PTCy and ruxolitinib (45 mg) from day-7 to day-2, and 15 mg from day+5 to day+100. This trial was registered at www.clinicaltrials.gov as #NCT02806375.

RESULTS

Primary engraftment was documented in 17 patients. One patient experienced primary graft failure and 2 died before engraftment. Eleven patients demonstrated severe poor graft function (SPGF), which required ruxolitinib dose reduction. The regimen was well tolerated, with grade 3-4 non-haematological toxicity in 30%, viral reactivation in 45%, and severe sepsis in 15% of patients. The incidence of acute GVHD grade II-IV was 25%, grade III-IV GVHD was 15%, and moderate chronic GVHD was 20%, with no severe cases. Only 2 patients required systemic steroids. Haematological relapse was documented in 1 patient. Two-year non-relapse mortality was 15%, 2-year overall survival was 85%, and 2-year event-free survival was 72%.

CONCLUSION

GVHD prophylaxis with PTCy and ruxolitinib is associated with low toxicity, good acute and chronic GVHD control, and low relapse incidence. However, the relatively high rate of SPGF should be taken into account. SPGF could possibly be mitigated by ruxolitinib dose reduction.

Donor-Derived CD123-Targeted CAR T Cell Serves as a RIC Regimen for Haploidentical Transplantation in a Patient With FUS-ERG+ AML

Background: Allogeneic hematopoietic stem cell transplantation (allo-HSCT) following chemotherapy is part of standard treatment protocol for patients with acute myeloid leukemia (AML). FUS-ERG+ AML is rare but has an extremely poor prognosis even with allo-HSCT in remission, possibly due to its a leukemia stem cell (LSC)-driven disease resulting in chemotherapy resistance and a novel therapy is urgently required. It has been reported that FUS-ERG-positive AML expresses CD123, a marker of LSC, in some cases. CD123-targeted CAR T cell (CART123) is promising immunotherapy, but how to improve the complete remission (CR) rate and rescue potential hematopoietic toxicity still need to explore.

Case Presentation: We used donor-derived CART123 as part of conditioning regimen for haploidentical HSCT (haplo-HSCT) in a patient with FUS-ERG+ AML who relapsed after allogeneic transplantation within 3 months, resists to multi-agent chemotherapy and donor lymphocyte infusion (DLI) and remained non-remission, aiming to reduce these chemotherapy-resistant blasts and rescue potential hematopoietic toxicity. The blasts in BM were reduced within 2 weeks and coincided with CAR copies expansion after CART123 infusion. The patient achieved full donor chimerism, CR with incomplete blood count recovery, and myeloid implantation.

Conclusion: Our results hints that CART123 reduces the chemotherapy-resistant AML blasts for FUS-ERG+ AML without affecting the full donor chimerism and myeloid implantation.

[Risk-factor analysis of poor graft function after allogeneic hematopoietic stem cell transplantation for severe aplastic anemia]

Objective: To investigate the risk factors of poor graft function (PGF) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) for severe aplastic anemia (SAA) . Methods: Clinical data from 111 SAA patients who received allo-HSCT were analyzed retrospectively. Factors including age, gender, interval to transplantation, the level of serum ferritin before transplantation were analyzed by Cox multivariate regression analysis. Results: Among the 111 patients who underwent allo-HSCT, 16 developed PGF (14.4%) . Multivariate analysis showed donor type (HR=2.656, 95%CI 1.204-5.858, P= 0.016) and the level of serum ferritin before tansplantation (HR=3.170, 95%CI 1.400-7.180, P=0.006) were significant risk factors for PGF. Conclusion: Unrelated donor transplantation and the high level of serum ferritin before transplantation are risk factors for PGF.

Cotransplantation of bone marrow-derived mesenchymal stem cells in haploidentical hematopoietic stem cell transplantation in patients with severe aplastic anemia: an interim summary for a multicenter phase II trial results

This corrects the article DOI: 10.1038/bmt.2016.347.