Current Review of Iron Overload and Related Complications in Hematopoietic Stem Cell Transplantation

Targeting ferroptosis for leukemia therapy: exploring novel strategies from its mechanisms and role in leukemia based on nanotechnology

The latest findings in iron metabolism and the newly uncovered process of ferroptosis have paved the way for new potential strategies in anti-leukemia treatments. In the current project, we reviewed and summarized the current role of nanomedicine in the treatment and diagnosis of leukemia through a comparison made between traditional approaches applied in the treatment and diagnosis of leukemia via the existing investigations about the ferroptosis molecular mechanisms involved in various anti-tumor treatments. The application of nanotechnology and other novel technologies may provide a new direction in ferroptosis-driven leukemia therapies. The article explores the potential of targeting ferroptosis, a new form of regulated cell death, as a new therapeutic strategy for leukemia. It discusses the mechanisms of ferroptosis and its role in leukemia and how nanotechnology can enhance the delivery and efficacy of ferroptosis-inducing agents. The article not only highlights the promise of ferroptosis-targeted therapies and nanotechnology in revolutionizing leukemia treatment, but also calls for further research to overcome challenges and fully realize the clinical potential of this innovative approach. Finally, it discusses the challenges and opportunities in clinical applications of ferroptosis.

Magnetic resonance imaging assessment of the changes of cardiac and hepatic iron load in thalassemia patients before and after hematopoietic stem cell transplantation

To investigate the value of T2* technique on 3.0 T magnetic resonance imaging (MRI) in evaluating the changes of cardiac and hepatic iron load before and after hematopoietic stem cell transplantation (HSCT) in patients with thalassemia (TM), the 141 TM patients were divided into 6 group for subgroup analysis: 6, 12, 18, 24 and > 24 months group, according to the postoperative interval. The T2* values of heart and liver (H-T2*, L-T2*) were quantified in TM patients before and after HSCT using 3.0 T MRI T2* technology, and the corresponding serum ferritin (SF) was collected at the same time, and the changes of the three before and after HSCT were compared. The overall H-T2* (P = 0.001) and L-T2* (P = 0.041) of patients after HSCT were higher than those before HSCT (mean relative changes = 19.63%, 7.19%). The H-T2* (P < 0.001) and L-T2* (P < 0.001) > 24 months after HSCT were significantly higher than those before HSCT (mean relative changes = 69.19%, 93.73%). The SF of 6 months (P < 0.001), 12 months (P = 0.008), 18 months (P = 0.002) and > 24 months (P = 0.001) were significantly higher than those before HSCT (mean relative changes = 57.93%, 73.84%, 128.51%, 85.47%). There was no significant improvement in cardiac and liver iron content in TM patients within 24 months after HSCT, while the reduction of cardiac and liver iron content in patients is obvious when > 24 months after HSCT.

Impact of Iron overload and Iron Chelation with deferasirox on outcomes of patients with severe aplastic anemia after allogeneic hematopoietic stem cell transplantation

BACKGROUND

Patients suffering from severe aplastic anemia (SAA) need frequent blood transfusions during allogeneic hematopoietic stem cell transplantation (allo-HSCT). However, these transfusions can result in an excess of iron in the body tissues, which can negatively impact the success of the transplant.

OBJECTIVES

This study aimed to examine the impact of pre-transplant iron overload (IO) on the outcomes of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in patients with severe aplastic anemia (SAA). It also investigated whether iron chelation (IC) therapy was necessary to enhance transplantation outcomes in SAA patients by providing guidelines for determining when excess iron should be chelated.

STUDY DESIGN

The study consisted of two parts: Cohort 1, which was retrospective and conducted from April 2012 to December 2018, divided SAA patients receiving their first allo-HSCT into two groups based on their pre-transplant serum ferritin (SF) levels: the iron overload (IO) group (SF >1000 ng/ml, n=17) and the non-IO group (SF ≤ 1000 ng/ml, n=48). Cohort 2 was a prospective clinical trial conducted from January 2019 to July 2020. It involved SAA patients diagnosed with IO who were treated with iron chelation (IC) therapy using deferasirox (DFX) at a dose of 10-30 mg/kg. Patients were separated into two groups based on their pre-transplant SF levels: the IC success (IC^success) group (SF ≤ 1000 ng/ml, n=18) and the IC failure (IC^failure) group (SF >1000 ng/ml, n=28) groups. All participants were evaluated for the correlation between pre-transplant SF levels and transplantation outcomes. A P-value of less than 0.05 was considered statistically significant.

RESULTS

There was no significant difference in the speed of engraftment for the three lineages or in the incidence of 100-day grade II-IV acute graft-versus-host disease (aGVHD), grade III-IV aGVHD, or 3-year chronic GVHD between the two groups in both cohorts. However, in cohort 1, it was noteworthy that 1-year OS (83.3% vs. 41.2%, p < 0.001) and 3-year OS (83.3% vs. 35.3%, p < 0.001) were significantly worse in the IO group. Furthermore, 180-day TRM (14.6% vs. 47.1%, p = 0.005) and 1-year TRM (16.7% vs. 52.9%, p = 0.002) were significantly higher in the IO group. The IO group was significantly associated with inferior 3-year OS in both univariate and multivariate analyses. In cohort 2, it was found that 1-year OS (42.9% vs. 88.9%, p = 0.003) and 3-year OS (42.9% vs. 83.3%, p = 0.007) were significantly better in the IC^success group, while 180-day TRM (11.1% vs. 39.3%, p = 0.040) and 1-year TRM (11.1% vs. 57.1%, p = 0.003) were significantly lower in the IC^success group. These differences were confirmed in both univariate and multivariate analyses.

CONCLUSIONS

The study involving two cohorts showed that pre-HSCT iron overload has a negative impact on transplantation outcomes in SAA patients. Chelating excess iron with a serum ferritin level below 1000 ng/ml was found to be necessary and could potentially improve the outcomes.

Molecular Mechanisms of Ferroptosis and Updates of Ferroptosis Studies in Cancers and Leukemia

Ferroptosis is a mode of cell death regulated by iron-dependent lipid peroxidation. Growing evidence suggests ferroptosis induction as a novel anti-cancer modality that could potentially overcome therapy resistance in cancers. The molecular mechanisms involved in the regulation of ferroptosis are complex and highly dependent on context. Therefore, a comprehensive understanding of its execution and protection machinery in each tumor type is necessary for the implementation of this unique cell death mode to target individual cancers. Since most of the current evidence for ferroptosis regulation mechanisms is based on solid cancer studies, the knowledge of ferroptosis with regard to leukemia is largely lacking. In this review, we summarize the current understanding of ferroptosis-regulating mechanisms with respect to the metabolism of phospholipids and iron as well as major anti-oxidative pathways that protect cells from ferroptosis. We also highlight the diverse impact of p53, a master regulator of cell death and cellular metabolic processes, on the regulation of ferroptosis. Lastly, we discuss recent ferroptosis studies in leukemia and provide a future perspective for the development of promising anti-leukemia therapies implementing ferroptosis induction.

Impact of iron overload in hematopoietic stem cell transplantation

Iron overload (IOL) is a common condition in patients with hematological malignancies(HMs) undergoing hematopoietic stem cell transplantation (HSCT). Pathophysiologically, IOL results in iron-induced toxicity in HSCT by producing reactive oxygen species (ROS), which leads to detrimental effects on hematopoiesis, clonal evolution, and immunosuppression. IOL, therefore, may have a negative impact on the clinical outcomes of HSCT. For patients at a higher risk of developing IOL before HSCT, it is necessary to monitor red blood cell transfusion units, serum ferritin (SF) levels and MRI image of organs, and initiate iron removal therapy as soon as possible. Iron chelating therapy (ICT) might be safe and efficient in the post-HSCT period. We provide an overview of results from experimental and clinical evidence on the current understanding of IOL in patients with HMs undergoing HSCT, involving the underlying pathophysiological and clinical impact of IOL, as well as the significance of iron reduction therapy.

Bioluminescence Imaging and ICP-MS Associated with SPION as a Tool for Hematopoietic Stem and Progenitor Cells Homing and Engraftment Evaluation

Bone marrow transplantation is a treatment for a variety of hematological and non-hematological diseases. For the transplant success, it is mandatory to have a thriving engraftment of transplanted cells, which directly depends on their homing. The present study proposes an alternative method to evaluate the homing and engraftment of hematopoietic stem cells using bioluminescence imaging and inductively coupled plasma mass spectrometry (ICP-MS) associated with superparamagnetic iron oxide nanoparticles. We have identified an enriched population of hematopoietic stem cells in the bone marrow following the administration of Fluorouracil (5-FU). Lately, the cell labeling with nanoparticles displayed the greatest internalization status when treated with 30 µg Fe/mL. The quantification by ICP-MS evaluate the stem cells homing by identifying 3.95 ± 0.37 µg Fe/mL in the control and 6.61 ± 0.84 µg Fe/mL in the bone marrow of transplanted animals. In addition, 2.14 ± 0.66 mg Fe/g in the spleen of the control group and 2.17 ± 0.59 mg Fe/g in the spleen of the experimental group was also measured. Moreover, the bioluminescence imaging provided the follow up on the hematopoietic stem cells behavior by monitoring their distribution by the bioluminescence signal. Lastly, the blood count enabled the monitoring of animal hematopoietic reconstitution and ensured the transplantation effectiveness.

Impact of iron overload on poor graft function after allo-HSCT in a patient with transfusion-dependent low-risk MDS: A case report and literature review

RATIONALE

Poor graft function (PGF) occurs in 5% to 27% of allogeneic hematopoietic stem cell transplantation (allo-HSCT) and is associated with high life-threatening complications. The etiology of PGF is complex and multifactorial, and iron overload (IOL) is considered as a predictive factor.

PATIENT CONCERN

A 45-years-old woman who was diagnosed as low-risk myelodysplastic syndrome in 2012 has been transfusion dependent and developed severe IOL.

DIAGNOSES

Due to transfusion dependency and also ineffective erythropoiesis, this patient was diagnosed as IOL and developed PGF after allo-HSCT.

INTERVENTIONS

Deferasirox (20mg/kg/d) was administered regularly after allo-HSCT for 2 years.

OUTCOMES

Hematopoiesis was gradually recovered during iron chelation therapy treatment after allo-HSCT and PGF was reverted.

LESSONS

IOL, as a prognostic factor for PGF, is a common problem in Transfusion dependent myelodysplastic syndrome patients undergoing HSCT. IOL issues should be considered at the time of diagnosis and throughout the treatment course for patients who are potential candidates for HSCT.

From Unit to Dose: A Machine Learning Approach for Precise Prediction of Hemoglobin and Iron Content in Individual Packed Red Blood Cell Units

Transfusion of packed red blood cells (pRBCs) saves lives, but iron overload limits survival of chronically transfused patients. Quality control methods, which involve entering pRBC units and removing them from the blood supply, reveal that hemoglobin (38.5-79.9 g) and heme iron (133.42-276.89 mg) vary substantially between pRBCs. Yet, neither hemoglobin nor iron content can be quantified for individual clinically used pRBCs leading to rules of thumb for pRBC transfusions. Keeping their integrity, the authors seek to predict hemoglobin/iron content of any given pRBC unit applying eight machine learning models on 6,058 pRBCs. Based on thirteen features routinely collected during blood donation, production and quality control testing, the model with best trade-off between performance and complexity in hemoglobin/iron content prediction is identified. Validation of this model in an independent cohort of 2637 pRBCs confirms an adjusted R2 > 0.9 corresponding to a mean absolute prediction error of ≤1.43 g hemoglobin/4.96 mg iron (associated standard deviation: ≤1.13 g hemoglobin/3.92 mg iron). Such unprecedented precise prediction enables reliable pRBC dosing per pharmaceutically active agent, and monitoring iron uptake in patients and individual iron loss in donors. The model is implemented in a free open source web application to facilitate clinical application.

How We Manage Myelofibrosis Candidates for Allogeneic Stem Cell Transplantation

Moving from indication to transplantation is a critical process in myelofibrosis. Most of guidelines specifically focus on either myelofibrosis disease or transplant procedure, and, currently, no distinct indication for the management of MF candidates to transplant is available. Nevertheless, this period of time is crucial for the transplant outcome because engraftment, non-relapse mortality, and relapse incidence are greatly dependent upon the pre-transplant management. Based on these premises, in this review, we will go through the path of identification of the MF patients suitable for a transplant, by using disease-specific prognostic scores, and the evaluation of eligibility for a transplant, based on performance, comorbidity, and other combined tools. Then, we will focus on the process of donor and conditioning regimens’ choice. The pre-transplant management of splenomegaly and constitutional symptoms, cytopenias, iron overload and transplant timing will be comprehensively discussed. The principal aim of this review is, therefore, to give a practical guidance for managing MF patients who are potential candidates for allo-HCT.

Efficacy and Safety of Iron Chelation Therapy After Allogeneic Hematopoietic Stem Cell Transplantation in Pediatric Thalassemia Patients: A Retrospective Observational Study

BACKGROUND

Studies on the increased body iron load in patients with thalassemia major have thoroughly demonstrated the problems caused by iron overload. In patients who undergo hematopoietic stem cell transplantation (HSCT) as curative therapy, iron overload continues long after transplantation. There are few pediatric studies on chelation therapy in the posttransplant period. In this study, we present the outcomes of our patients who received posttransplant oral chelation therapy.

PATIENTS AND METHODS

This retrospective observational study evaluated the outcomes of pediatric patients with thalassemia major who used oral chelation therapy after allogeneic HSCT at the Akdeniz University Pediatric Bone Marrow Unit between January 2008 and October 2019.

RESULTS

Deferasirox therapy was initiated in 58 pediatric patients who underwent HSCT for thalassemia. Pretreatment mean serum ferritin was 2166±1038 ng/mL. Treatment was initiated at a mean of 12±6.7 months after transplantation and continued for a mean of 15.7±11.5 months. At treatment discontinuation, the mean serum ferritin was 693±405 ng/mL and the mean reduction was -1472.75±1121.09 ng/mL (P<0.001 vs. posttreatment). Serum ferritin was below 500 ng/mL in 52% of the patients at treatment discontinuation. Manageable side effects such as nausea, vomiting, liver enzyme elevation, and proteinuria were observed in 17% of the patients, while one patient developed ototoxicity.

CONCLUSIONS

Deferasirox therapy effectively reduces iron overload in the posttransplant period. Studies evaluating the effects of early treatment on the graft may help to establish guidelines for posttransplant chelation therapy. Clear guidelines are needed regarding when to initiate and discontinue treatment.

Early Post-Transplantation Serum Ferritin Level Predicts Survival in Recipients of Haploidentical Stem Cell Transplantation Using Post-Transplantation Cyclophosphamide as Graft-versus-Host Disease Prophylaxis

The negative impact of high serum ferritin level (SFL) before and after allogeneic hematopoietic cell transplantation (allo-HSCT) on outcomes is well recognized. However, it is poorly documented in adults undergoing haploidentical HSCT (haplo-HSCT) with post-transplantation cyclophosphamide (PTCY) for hematologic malignancies. The main objective was to assess the impact of pretransplantation and post-transplantation SFL on overall survival (OS), disease-free survival (DFS), and nonrelapse mortality (NRM) in patients undergoing haplo-HSCT with PTCY. The secondary objective was to identify factors associated with outcomes after transplantation by comparing SFL with other parameters related to the status of patients or donors. This multicentric retrospective study included 223 consecutive patients who underwent haplo-HSCT with PTCY in 4 French centers (Nantes, Angers, Besançon, and Brest) between October 2013 and January 2020. The impact of SFL on OS, DFS, and NRM at different time points was assessed based on receiver operating characteristic curves. With a median follow-up of 37.6 months (interquartile range, 23.5 to 51.0 months), 3-year OS, DFS, and NRM were 48.1 ± 4%, 46.3 ± 4%, and 30.0 ± 3%, respectively. Pretransplantation SFL had no impact on outcomes irrespective of the cutoff tested. Considering patients alive at 3 months post-transplantation, an SFL ≥3500 µg/L at 3 months was statistically significantly associated with worse 3-year OS (32.7 ± 8.7% versus 53.4 ± 7.2%; P = .01) and DFS (30.1 ± 8.2% versus 53.1 ± 7.1%; P = .008), with a trend toward higher NRM (33.2 ± 8.6% versus 17.6 ± 5.4%; P = .10). Similarly, high SFL (≥2700 µg/L) at 6 months post-transplantation was associated with worse 3-year OS (56.1 ± 9.1% versus 79.2 ± 6.0%; P = .02) and DFS (53.6 ± 8.7% versus 74.9 ± 6.2%; P = .01), with a trend toward higher NRM (21.4 ± 7.4% versus 8.2 ± 4.0%; P = .10). In multivariate analysis, high 3-month and 6-month FL remained associated with lower OS and DFS, with a trend toward higher NRM. Pretransplantation SFL appears to have no impact on outcomes in haplo-HSCT with PTCY, in contrast to what is documented in the matched allo-HSCT setting. In contrast, in the haplo-HSCT setting, high SFL early post-transplantation is associated with lower survival and a trend toward higher NRM.

Recent advances in graphite carbon nitride-based nanocomposites: structure, antibacterial properties and synergies

Bacterial infections and transmission threaten human health and well-being. Graphite carbon nitride (g-C₃N₄), a promising photocatalytic antibacterial nanomaterial, has attracted increasing attention to combat bacterial transmission, due to the outstanding stability, high efficiency and environmental sustainability of this material. However, the antibacterial efficiency of g-C₃N₄ is affected by several factors, including its specific surface area, rapid electron/hole recombination processes and optical absorption properties. To improve the efficiency of the antibacterial properties of g-C₃N₄ and extend its range of applications, various nanocomposites have been prepared and evaluated. In this review, the advances in amplifying the photocatalytic antibacterial efficiency of g-C₃N₄-based nanocomposites is discussed, including different topologies, noble metal decoration, non-noble metal doping and heterojunction construction. The enhancement mechanisms and synergistic effects in g-C₃N₄-based nanocomposites are highlighted. The remaining challenges and future perspectives of antibacterial g-C₃N₄-based nanocomposites are also discussed.

Iron Toxicity and Chelation Therapy in Hematopoietic Stem Cell Transplant

Many patients with hematologic malignancies receive RBC transfusion support, which often causes systemic and tissue iron toxicity. Because of their compromised bone marrow function, hematopoietic stem cell transplant (HSCT) recipients are especially vulnerable to excess iron levels. Iron toxicity may compromise transplant engraftment and eventually promote relapse by mediating oxidative and genotoxic stress in hematopoietic stem cells (HSCs) and further impairing the already dysfunctional bone marrow microenvironment in HSCT recipients. Iron toxicity is thought to be primarily mediated by its ability to induce reactive oxygen species and trigger inflammation. Elevated iron levels in the bone marrow can decrease the number of HSCs and progenitor cells, as well as their clonogenic potential, alter mesenchymal stem cell differentiation, and inhibit the expression of chemokines and adhesion molecules involved in hematopoiesis. In vivo, in vitro, and clinical studies support the concept that iron chelation therapy may limit iron toxicity in the bone marrow and promote hematologic improvement and engraftment in HSCT recipients. This review will provide an overview of the current knowledge of the detrimental impact of iron toxicity in the setting of HSCT in patients with hematologic malignancies and the use of iron restriction approaches to improve transplant outcome.

Invasive fungal disease and the immunocompromised host including allogeneic hematopoietic cell transplant recipients: Improved understanding and new strategic approach with sargramostim

In hosts with damaged or impaired immune systems such as those undergoing hematopoietic cell transplant (HCT) or intensive chemotherapy, breakthrough fungal infections can be fatal. Risk factors for breakthrough infections include severe neutropenia, use of corticosteroids, extended use of broad-spectrum antibiotics, and intensive care unit admission. An individual's cumulative state of immunosuppression directly contributes to the likelihood of experiencing increased infection risk. Incidence of invasive fungal infection (IFI) after HCT may be up to 5-8%. Early intervention may improve IFI outcomes, although many infections are resistant to standard therapies (voriconazole, caspofungin, micafungin, amphotericin B, posaconazole or itraconazole, as single agents or in combination). We review herein several contributing factors that may contribute to the net state of immunosuppression in recipients of HCT. We also review a new approach for IFI utilizing adjunctive therapy with sargramostim, a yeast-derived recombinant human granulocyte-macrophage colony-stimulating factor (rhu GM-CSF).

Early transplantation-related mortality after allogeneic hematopoietic cell transplantation in patients with acute leukemia

Background

Transplantation-related mortality (TRM) is a major obstacle in allogeneic hematopoietic cell transplantation (allo-HCT). Approximately 60–80% of TRM occurs early, within 100 days of transplantation.

Methods

This was a nationwide population cohort study involving 5395 patients with acute leukemia who underwent allo-HCT between 2003 and 2015. Patient data were collected from the Korean National Health Insurance Service database. We investigated the cumulative incidence rates (CIRs) of early TRM at 50 and 100 days.

Results

The CIRs of early TRM at 50 and 100 days were 2.9 and 8.3%, respectively. There was no decrease in the CIRs of early TRM over time. The early mortality was significantly higher in patients with more than 9 months between the diagnosis and transplantation (CIRs of TRM at 50, 100 days; 6.0, 13.2%), previous transplantations (CIRs of TRM at 50, 100 days; 9.4, 17.2%), and cord blood transplantation (CIRs of TRM at 50, 100 days; 6.1, 8.3%). The early TRM was significantly lower in patients who received iron chelation before transplantation (CIRs of TRM at 50, 100 days; 0.3, 1.8%).

Conclusions

In conclusion, the overall CIR of early TRM was less than 10%. The predictable factors for early TRM included age, time from diagnosis to transplantation, the number of prior transplantations, the graft source, and previous iron chelation therapy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-07897-3.

Effectiveness of phytotherapeutics in the prevention and treatment of 5-fluorouracil-induced oral mucositis in animal models: A systematic review

OBJECTIVES

This systematic review evaluated the effect of phytotherapeutics in the treatment and prevention of 5-fluorouracil (5-FU)-induced oral mucositis (OM) in animal models.

DESIGN

A search was performed in PubMed/Medline, CENTRAL (The Cochrane Library), EMBASE, and Web of Science, including studies published up to January 2020. Only articles investigating the chemoinduction of OM by 5-FU in animal models were included. Eligibility was evaluated and data were extracted from the eligible studies following the predefined PICO questions. The Cochrane Collaboration Risk of Bias Assessment tool was used to evaluate the quality of the included studies.

RESULT

A total of 503 articles were retrieved and 13 were included. The hamster was the animal model used in all included studies. The treatment method ranged from the topical application of ointment (n = 3), gel (n = 5) and extract (n = 3) to the oral ingestion of the phytotherapeutics (n = 3). Chamomilla recutita L. (n = 3) and Pistacia atlantica (n = 3) were the most used therapeutic agents. Although all studies were classified as high risk of bias, all of them reported promising results regarding the use of phytotherapeutics in the management of OM, including lower clinical and histopathological scores as well as healing, anti-inflammatory, antimicrobial, and antioxidant activities.

CONCLUSION

Despite the high risk of bias of the studies, phytotherapy is a promising alternative for the treatment of 5-FU-induced OM, showing interesting results in terms of tissue healing and anti-inflammatory, antimicrobial and antioxidant activity.

Retrospective Evaluation of Relationship Between Iron Overload and Transplantation Complications in Pediatric Patient Who Underwent Allogeneic Stem Cell Transplantation Due to Acute Leukemia and Myelodysplastic Syndrome

BACKGROUND

Hematopoietic stem cell transplantation (HSCT) is a curative therapy option for hematologic malignancies. Iron overload is common in this patient group and can impact short-term and long-term nonrelapse mortality.

STUDY DESIGN

Retrospective observational cohort study.

AIMS

To evaluate the effect of iron load on early and late HSCT outcomes in patients with acute leukemia and myelodysplasia to assess the necessity of reducing iron load.

PATIENTS AND METHODS

Sixty patients who underwent HSCT in pediatric stem cell transplantation unit between 2000 and 2012 were evaluated retrospectively. The patients were divided into those with pretransplantation serum ferritin levels above and below the median value of 1299 ng/mL.

RESULTS

Forty-two (70%) of the patients were male, mean ages of the low and high ferritin groups were 85.43±9.42 and 118.56±10.04 months, respectively. Acute graft-versus-host disease (GVHD) within the first 100 days and acute liver GVHD were significantly more common in the high ferritin group (P<0.011 for both). Ferritin level was not associated with rates of engraftment syndrome, veno-occlusive disease, early/late infection, relapse, or overall and disease-free survival.

CONCLUSIONS

In our study, significant result especially in terms of acute liver GVHD, was important to emphasize the need to be more careful in terms of acute liver GVHD risk in early liver pathologies in patients with high levels of ferritin after transplantation. In future large studies may be helpful to explain the relationship between acute liver GVHD and high ferritin levels.

Imaging in Hepatic Veno-Occlusive Disease/Sinusoidal Obstruction Syndrome

Veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS) is a potentially life-threatening complication of hematopoietic cell transplantation. Early diagnosis and, subsequently, earlier intervention have been shown to be beneficial to clinical outcomes. Diagnostic criteria from the European Society for Blood and Marrow Transplantation include recommendations on the use of imaging for diagnosis. This review discusses evidence on the use of imaging in the management of VOD/SOS and how imaging biomarkers can contribute to earlier diagnosis/treatment.

Successful allogeneic bone marrow transplantation using immunosuppressive conditioning regimen for a patient with red blood cell transfusiondependent pyruvate kinase deficiency anemia

Pyruvate kinase deficiency (PKD) is the rare glycolytic enzyme defect causing hemolytic anemia. Treatments are mainly red cell transfusion and/or splenectomy, leading to iron overload. Allogeneic bone marrow transplantation (BMT) is alternatively curative treatment for severe PKD. The intensity of conditioning is often controversial because of higher risk of graft failure and organ damage. Here, we present a transfusion-dependent PKD patient undergoing BMT from an HLA-identical sibling using intensively immunosuppressive conditioning regimen. This report suggests that BMT using immunosuppressive conditioning regimen may be a feasible and effective treatment for patients with severe PKD with iron overload. We suggest the timing of the transplantation at an earlier age in severe PKD predicted from gene mutation is preferred before cumulative damage of transfusion.

Diagnosis and Treatment of VOD/SOS After Allogeneic Hematopoietic Stem Cell Transplantation

Hepatic veno-occlusive disease (VOD) or sinusoidal obstruction syndrome (SOS) is a rare complication characterized by hepatomegaly, right-upper quadrant pain, jaundice, and ascites, occurring after high-dose chemotherapy, hematopoietic stem cell transplantation (HSCT) and, less commonly, other conditions. We review pathogenesis, clinical appearance and diagnostic criteria, risk factors, prophylaxis, and treatment of the VOD occurring post-HSCT. The injury of the sinusoidal endothelial cells with loss of wall integrity and sinusoidal obstruction is the basis of development of postsinusoidal portal hypertension responsible for clinical syndrome. Risk factors associated with the onset of VOD and diagnostic tools have been recently updated both in the pediatric and adult settings and here are reported. Treatment includes supportive care, intensive management, and specific drug therapy with defibrotide. Because of its severity, particularly in VOD with associated multiorgan disease, prophylaxis approaches are under investigation. During the last years, decreased mortality associated to VOD/SOS has been reported being it attributable to a better intensive and multidisciplinary approach.

Immunosuppressant-Induced Oxidative Stress and Iron: A Paradigm Shift from Systemic to Intrahepatic Abnormalities

Immunosuppressants are used clinically to lower rejection rates in transplant patients. Unfortunately, the adverse side effects of these immunosuppressants can be severe, which is one of the rationales that life expectancy of individuals after transplant still significantly falls short of that of the general population. The current experimental setup was designed to analyze the tacrolimus-induced hepatic iron overload in Wistar rats. Four experimental groups were orally given 1 ml of aqueous suspension of tacrolimus (12 mg/kg) through oral gavage, and rats were sacrificed after 6, 12, 24, and 48 h of tacrolimus dose. Hepatic hepcidin expression was found to be significantly augmented along with the upregulation of Tf and TfR1, Ferritin-L, Ferritin-H, TNF-α, and HO-1 gene expression at 6 and 12 h, and downregulation of Fpn-1, Hjv, and Heph at 6 h was detected. Significant downregulation of IL-6, IFN-α, IFN-β, and IFN-γ at all study time points was also observed. Serum iron level was decreased while serum hepcidin level was found to be significantly increased. Iron staining showed blue-stained hemosiderin granules within the hepatocytes, sinusoidal spaces, and portal areas at 12 and 24 h time points and remarkable fall of iron contents in the splenic red pulp. These results suggest that the use of tacrolimus leads to the onset of an intrahepatic acute-phase response-like reaction and causes iron overload in hepatic cells by altering the expression of key proteins involved in iron metabolism.

Brazilian Nutritional Consensus in Hematopoietic Stem Cell Transplantation: Graft- versus -host disease

The Brazilian Consensus on Nutrition in Hematopoietic Stem Cell Transplantation: Graft- versus -host disease was approved by Sociedade Brasileira de Transplante de Medula Óssea , with the participation of 26 Brazilian hematopoietic stem cell transplantation centers. It describes the main nutritional protocols in cases of Graft- versus -host disease, the main complication of hematopoietic stem cell transplantation.

The impact of iron chelation therapy on patients with lower/intermediate IPSS MDS and the prognostic role of elevated serum ferritin in patients with MDS and AML: A meta-analysis

Serum ferritin (SF) has been identified as a potential prognostic factor for patients undergoing stem cell transplantation, but the prognostic value of SF in acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS) patients and the impact of iron chelation therapy (ICT) on MDS patients are controversial. The present meta-analysis aimed to better elucidate these relationships.Three electronic databases were searched systematically to identify reports on the prognostic role of SF in MDS and AML patients, and those investigating the impact of ICT on prognosis of MDS patients. The hazard ratios (HRs) and its 95% confidence interval (95%CI) were extracted from the identified studies using Cox proportional hazard regression model for overall survival (OS) and progression of MDS to AML.Twenty reports including 1066 AML patients and 4054 MDS patients were included in present study. The overall pooled HRs for OS of AML and MDS patients with elevated SF prior to transplantation was 1.73 (1.40-2.14), subgroup analyses stratified by the cut-off value of SF ≥1400/1000 ng/mL showed that the pooled HRs were 1.45 (0.98-2.15) and 1.65 (1.30-2.10), respectively. The pooled HRs for ICT in MDS patients was 0.30 (0.23-0.40). For ICT, the pooled HRs for the progression of MDS to AML was 0.84 (0.61-1.61).SF has a negative impact on the OS of AML and MDS patients when it is higher than 1000 ng/mL. ICT can improve the OS of MDS patients with iron overload but it is not associated with the progression of MDS to AML.

Iron overload threatens the growth of osteoblast cells via inhibiting the PI3K/AKT/FOXO3a/DUSP14 signaling pathway

Iron overload is a common stress in the development of cells. Growing evidence has indicated that iron overload is associated with osteoporosis. Therefore, enhancing the understanding of iron overload would benefit the development of novel approaches to the treatment of osteoporosis. The purpose of the present study was to analyze the effect of iron overload on osteoblast cells, via the MC3T3-E1 cell line, and to explore its possible underlying molecular mechanisms. Ferric ammonium citrate (FAC) was utilized to simulate iron overload conditions in vitro. FAC-induced iron overload strongly suppressed proliferation of osteoblast cells and induced apoptosis. Moreover, iron overload strongly suppressed the expression of dual-specificity phosphatase 14 (DUSP14). Additionally, overexpression of DUSP14 protected osteoblast cells from the deleterious effects of iron overload, and this protective effect was mediated by FOXO3a. Additionally, matrine rescued the function of DUSP14 in osteoblast cells. Most importantly, our analysis demonstrated the essential role of the PI3K/AKT/FOXO3a/DUSP14 signaling pathway in the defense against iron overload in osteoblast cells. Overall, our results not only elucidate deleterious effects of iron overload, but also unveil its possible signaling pathway in osteoblast cells.

Nontoxic Carbon Quantum Dots/g-C3 N4 for Efficient Photocatalytic Inactivation of Staphylococcus aureus under Visible Light

The widespread use of antibiotics has caused the rapid emergence of antibiotic-resistant bacterial strains and antibiotic resistance genes in the past few decades. Photocatalytic inactivation, a promising approach for the killing of pathogens, efficiently avoids the problems induced by antimicrobial drugs. However, traditional photocatalysts usually have some disadvantages, such as high costs of raw materials, ultraviolet ray excitation, and potential leaching of toxic metals. Here, a metal-free heterojunction photocatalyst, denoted as CQDs/g-C₃ N₄ , is synthesized through incorporating carbon quantum dots (CQDs) on graphitic carbon nitride (g-C₃ N₄ ), which significantly enhances photocatalytic inactivation of Staphylococcus aureus (S. aureus) compared with pure g-C₃ N₄ in vitro. CQDs/g-C₃ N₄ causes a rapid increase of intracellular reactive oxygen species levels and destruction of cell membranes under visible light, eventually leading to death of bacteria. The efficacy of CQDs/g-C₃ N₄ is further examined by a mouse cutaneous infection model of S. aureus. CQDs/g-C₃ N₄ markedly reduces the bacterial loads and prompts lesion recovery in mice, as compared with g-C₃ N₄ -treated group. In vivo and in vitro toxicity analyses show that the side effects of CQDs/g-C₃ N₄ are negligible. Considering the efficient photocatalytic inactivation and nontoxicity of CQDs/g-C₃ N₄ , this visible-light-driven photocatalyst paves a brand new avenue for the treatment of S. aureus infection.

Iron Toxicity and Hemopoietic Cell Transplantation: Time to Change the Paradigm

The issue of iron overload in hemopoietic cell transplantation has been first discussed in the field of transplantation for thalassemia. Thalassemia major is characterized by ineffective erythropoiesis and hemolysis leading to severe anemia. Patients require regular blood transfusion therefore they develop iron overload causing organ damage and hematopoietic cell transplantation (HCT) is a consolidated reliably curative option.

In this category of patients an important issue for transplant outcome is the iron burden before transplant and in the long-life post-transplant. Nevertheless today the concept of the impact of iron overload / toxicity on the outcome of HCT has been extended to other diseases characterized by periods of variable duration of transfusion dependence.

Recent preclinical data has shown how increased production of reactive oxygen species (ROS) resulting under iron overload condition, could impair the stem cells clonality capacity, proliferation and maturation. Also, microenvironment cells could be affected through this mechanism. For this reason, iron overload is becoming an important issue also in the engraftment period post-transplant.

The aim of this review is to update consolidated knowledge about the role of iron overload/iron toxicity in the HCT setting in non-malignant and in malignant diseases introducing the concept of exposition of free toxic iron forms and related cellular damage in the different stage of transplant.

Improved survival outcomes and restoration of graft-vs-leukemia effect by deferasirox after allogeneic stem cell transplantation in acute myeloid leukemia

Deferasirox is an oral iron-chelating agent having possible antileukemia and immune modulatory effects. Few reports have evaluated deferasirox in the setting of allogeneic hematopoietic stem cell transplantation (allo-HSCT). We investigated the impact of deferasirox after allo-HSCT in acute myeloid leukemia (AML). Of 326 consecutive patients undergoing allo-HSCT in remission, analysis of 198 patients not receiving deferasirox revealed the negative prognostic effect of hyperferritinemia (≥1000 ng/mL) before and after allo-HSCT on survival mainly due to increase in relapse. Of 276 patients with hyperferritinemia at 1 month after allo-HSCT, 128 patients (46%) received deferasirox. Deferasirox induced a faster decline in serum ferritin level with a manageable safety profile, which significantly reduced relapse rather than nonrelapse mortality, resulting in better survival compared to patients not receiving deferasirox. Of note, the deferasirox group had a significantly higher incidence of chronic graft-vs-host disease, indicating improved graft-vs-leukemia (GVL) effects evidenced by the presence of suppressed regulatory T cells and sustained higher proportion of NK cells in peripheral blood. This study firstly demonstrates the improved survival and restoration of GVL effects of patients with AML by deferasirox, which also clarifies the detrimental effect of hyperferritinemia through after allo-HSCT.

Effect of pre-transplantation serum ferritin on outcomes in patients undergoing allogeneic hematopoietic stem cell transplantation: A meta-analysis

BACKGROUND

Pre-transplantation serum ferritin (SF) has been considered to be a potential prognostic biomarker in patients undergoing allogeneic hematopoietic stem cell transplantation (allogeneic HSCT), but this conclusion remains controversial. Thus, we performed a meta-analysis to investigate the prognostic significance of pre-transplantation SF in patients undergoing allogeneic HSCT.

METHODS

We systematically searched PubMed, Embase, and Web of Science up to September 2017, and finally identified a total of 25 eligible studies with 4545 patients.

RESULTS

The pooled results of our meta-analysis showed that high pre-transplantation SF was markedly related to worse overall survival (OS) [hazard ratio (HR) = 1.82; 95% confidence interval (95% CI): 1.47-2.26; P < .001], nonrelapse mortality (NRM) (HR = 2.28; 95% CI: 1.79-2.89; P < .001), and progression-free survival (PFS) (HR = 1.72; 95% CI: 1.27-2.33; P < .001). In addition, high pre-transplantation SF was closely associated with a lower incidence of chronic graft versus host disease (cGVHD) (OR = 0.74, 95% CI: 0.58-0.96; P < .05), and a higher incidence of blood stream infections (BSIs) (OR = 1.67, 95% CI: 0.93-3.01; P = .09). However, no significance relationship was found between elevated pre-transplantation SF and acute graft versus host disease (aGVHD) (OR = 1.08, 95% CI:.72-1.62; P = .70).

CONCLUSION

In patients undergoing allogeneic HSCT for hematological malignancies, elevated pre-transplantation SF was significantly associated with worse OS and PFS, higher incidence of NRM and BSI, and lower incidence of cGVHD, but it had no effect on aGVHD. Considering the limitations in our meta-analysis, more prospective and homogeneous clinical studies are needed to further confirm our findings.

Iron toxicity - Its effect on the bone marrow

Excess iron can be extremely toxic for the body and may cause organ damage in the absence of iron chelation therapy. Preclinical studies on the role of free iron on bone marrow function have shown that iron toxicity leads to the accumulation of reactive oxygen species, affects the expression of genes coding for proteins that regulate hematopoiesis, and disrupts hematopoiesis. These effects could be partially attenuated by iron-chelation treatment with deferasirox, suggesting iron toxicity may have a negative impact on the hematopoietic microenvironment. Iron toxicity is of concern in transfusion-dependent patients. Importantly, iron chelation with deferasirox can cause the loss of transfusion dependency and may induce hematological responses, although the mechanisms through which deferasirox exerts this action are currently unknown. This review will focus on the possible mechanisms of toxicity of free iron at the bone marrow level and in the bone marrow microenvironment.

Allogeneic stem-cell transplantation for myelofibrosis

PURPOSE OF REVIEW

Allogeneic hematopoietic stem-cell transplantation (HSCT) remains the only curative therapy for myelofibrosis. The number of HSCTs performed for this indication has been steadily increasing over the past years, even after the approval of the Janus kinase (JAK) inhibitor, ruxolitinib. This increase may be attributed to improved patient selection based on new prognostic molecular markers, more frequent use of matched unrelated donors, secondary to better (high-resolution) human leukocyte antigen typing and supportive care. Ruxolitinib approval raises new questions regarding the role of JAK inhibitors in the transplant setting.

RECENT FINDINGS

The current review summarizes recent updates on HSCT in myelofibrosis. Predictors for transplant outcomes, and specific considerations related to myelofibrosis patient selection for HSCT (e.g. molecular risk stratification) are reviewed. In addition, this review will consider management of myelofibrosis patients in the peritransplant period, including the role of ruxolitinib in the pretransplant period, pre and posttransplant splenomegaly, transplant protocols, posttransplant follow-up of minimal residual disease and interventions in the event of poor engraftment.

SUMMARY

HSCT remains a highly relevant treatment option for myelofibrosis in the era of JAK inhibitors. Recent advances may contribute to a refined definition of HSCT eligibility and identification of the optimal transplantation time, conditioning protocols and posttransplant management.

Serum ferritin is a different predictor from transfusion history for allogeneic transplantation outcome in patients with severe aplastic anemia

OBJECTIVES

Severe aplastic anemia (SAA) patients receive more red blood cell (RBC) transfusions as supportive management. We aim to clarify the associations between transfusion history or pre-transplantation serum ferritin (SF) and the overall survival of allogeneic hematopoietic stem cell transplantation (allo-HSCT) among SAA patients.

MATERIAL AND METHODS

We retrospectively investigated 96 SAA patients undergoing allo-HSCT, and grouped them according to pre-transplantation duration. Pre-transplantation SF, transfused units and other iron-related parameters were collected. Comparisons in transplantation outcomes and complications were made in groups with different SF levels and different transfusion histories.

RESULTS

Among the 96 SAA patients, 45 patients received transplantation within 2 months after diagnosis (short-term pre-transplantation period), and the rest of the patients had long-term pre-transplantation treatment. Among the patients with short-term pre-transplantation treatment, a higher risk of death was seen in the high-ferritin group (p < 0.05). Elevated SF also predicted a trend in incidence of higher bloodstream infection (p = 0.108). Significant correlations were observed between pre-transplantation SF and infection incidence, as well as transfusion history. However, for patients with longer pre-transplantation duration, transfusion history was associated with worse outcome (p = 0.026), in terms of higher incidence of acute graft versus host disease (p = 0.048). High SF was only significantly associated with prolonged RBC transfusion dependence post-transplantation (p = 0.044).

DISCUSSION AND CONCLUSIONS

Transfusion history was a stronger predictor of outcome than SF in patients undergoing transplantation more than 2 months after diagnosis.

Higher N stage and serum ferritin, but lower serum albumin levels are associated with distant metastasis and poor survival in patients with nasopharyngeal carcinoma following intensity-modulated radiotherapy

Purpose

To evaluate the potential risk factors for distant metastasis of nasopharyngeal carcinoma in Chinese patients following standard intensity-modulated radiotherapy and chemotherapy.

Methods

The potential risk factors for distant metastasis in 622 patients with newly-diagnosed primary nasopharyngeal carcinoma following standard radiotherapy and chemotherapy were evaluated retrospectively by stratification, univariate and multivariate analyses. The 5-year overall survival, distant metastasis-free survival, local recurrence-free survival and progression-free survival rates were determined.

Results

Univariate and multivariate analyses indicated that N2-3 stage, serum ferritin > 300 μg/L and serum albumin < 42 g/L were independent risk factors for distant metastasis of nasopharyngeal carcinoma (P < 0.001, P = 0.013, P = 0.002, respectively). A risk prediction model was developed as follows: 1) low-risk group: 0-1 risk factor; and 2) high-risk group: 2-3 risk factors. Compared with low-risk group, the high-risk group had significantly lower 5-year distant metastasis-free survival (76.4% vs. 89.6%, P < 0.001), overall survival (76% vs. 85.9%,P < 0.001), local recurrence-free survival (88% vs. 92.4%, P = 0.029) and progression-free survival rates (68.2% vs. 83.7%, P < 0.001). In the high-risk group, patients with three risk factors had the lowest distant metastasis-free survival rate (P = 0.036).

Conclusions

Combination of higher N stage, serum ferritin and lower serum albumin levels may be valuable for predicting distant metastasis of nasopharyngeal carcinoma patients following standard intensity-modulated radiotherapy and chemotherapy.