A specific serum lipid signature characterizes patients with glycogen storage disease type Ia.

Glycogen storage disease type Ia (GSDIa) is a rare, inherited glucose-6-phosphatase-α (G6Pase-α) deficiency-induced carbohydrate metabolism disorder. Although hyperlipidemia is a hallmark of GSDI, the extent of lipid metabolism disruption remains incompletely understood. Lipidomic analysis was performed to characterize the serum lipidome in patients with GSDIa, by including age- and sex-matched healthy controls and age-matched hypercholesterolemic controls. Metabolic control and dietary information biochemical markers were obtained from patients with GSDIa. Patients with GSDIa showed higher total serum lysophosphatidylcholine (Fold Change, (FC) 2.2, P < 0.0001), acyl-acyl-phosphatidylcholine (FC 2.1, P < 0.0001), and ceramide (FC 2.4, P < 0.0001) levels and bile acid (FC 0.7, P < 0.001), acylcarnitines (FC 0.7, P < 0.001), and cholesterol esters (FC 1.0, P < 0.001) than those of healthy controls, and higher di- (FC 1.1, P < 0.0001; FC 0.9, P < 0.01) and triacylglycerol (FC 6.3, P < 0.0001; FC 3.9, P < 0.01) levels than those of healthy controls and hypercholesterolemic subjects. Both total cholesterol and triglyceride values correlated with Cer (d16:1/22:0), Cer (d18:1/20:0), Cer (d18:1/20:0(OH)), Cer (d18:1/22:0), Cer (d18:1/23:0), Cer (d18:1/24:1), Cer (d18:2/22:0), Cer (d18:2/24:1). Total cholesterol also correlated with Cer (d18:1/24:0), Cer (d18:2/20:0), HexCer (d16:1/22:0), HexCer (d18:1/18:0), and Hex2Cer (d18:1/20:0). Triglyceridelevels correlated with Cer (d18:0/24:1). Alanine aminotransferase values correlated with Cer (d18:0/22:0), insulin with Cer (d18:1/22:1) and Cer (d18:1/24:1), and HDL with hexosylceramide (HexCer) (d18:2/23:0). These results expand on the currently known involvement of lipid metabolism in GSDIa. Circulating Cer may allow for refined dietary assessment compared with traditional biomarkers. Because specific lipid species are relatively easy to assess, they represent potential novel biomarkers of GSDIa.

Lipidomic alterations in human saliva from cystic fibrosis patients.

Cystic fibrosis is a hereditary metabolic disorder characterized by impaired traffic of chloride ions and water through membranes of the respiratory and gastrointestinal, that causes inadequate hydration of airway surfaces, dehydrated mucous secretions and a high-sodium chloride sweat. Although the classical presentation of the condition is well known, a better characterization of metabolic alterations related is need. In particular, the metabolic composition alterations of biological fluids may be influence by the disease state and could be captured as putative signature to set targeted therapeutic strategies. A targeted comprehensive mass spectrometry-based platform was employed to dissect the lipid content of saliva samples form CF patients, in order to investigate alterations in the lipid metabolic homeostasis related to the pathology, chronic obstructive pulmonary disease, Pseudomonas Aeruginosa infection, pancreatic insufficiency, liver disfunction and diabetes-related complications.

Metabolomic fingerprinting of renal disease progression in Bardet-Biedl syndrome reveals mitochondrial dysfunction in kidney tubular cells.

Chronic kidney disease (CKD) is a major clinical sign of patients with Bardet-Biedl syndrome (BBS), especially in those carrying BBS10 mutations. Twenty-nine patients with BBS and 30 controls underwent a serum-targeted metabolomic analysis. In vitro studies were conducted in two kidney-derived epithelial cell lines, where Bbs10 was stably deleted (IMCD3-Bbs10-/-cells) and over-expressed. The CKD status affected plasmatic metabolite fingerprinting in both patients with BBS and controls. Specific phosphatidylcholine and acylcarnitines discriminated eGFR decline only in patients with BBS. IMCD3-Bbs10-/ cells displayed intracellular lipidaccumulation, reduced mitochondrial potential membrane and citrate synthase staining. Mass-Spectrometry-based analysis revealed that human BBS10 interacted with six mitochondrial proteins, in vitro. In conclusion, renal dysfunction correlated with abnormal phosphatidylcholine and acylcarnitines plasma levels in patients with BBS; in vitro, Bbs10 depletion caused mitochondrial defects while human BBS10 interacted with several mitochondria-related proteins, suggesting an unexplored role of this protein.

Multi-Omics Studies Unveil Extraciliary Functions of BBS10 and Show Metabolic Aberrations Underlying Renal Disease in Bardet-Biedl Syndrome.

Bardet-Biedl syndrome (BBS) is a rare autosomal recessive ciliopathy resulting in multiple organ dysfunctions, including chronic kidney disease (CKD). Despite the recent progress in the 'ciliopathy' field, there is still little information on the mechanisms underlying renal disease. To elucidate these pathomechanisms, we conducted a translational study, including (i) the characterization of the urine metabolomic pattern of BBS patients and controls in a pilot and confirmation study and (ii) the proteomic analysis of the BBS10 interactome, one of the major mutated BBS genes in patients, in a renal-epithelial-derived cell culture model. The urine metabolomic fingerprinting of BBS patients differed from controls in both pilot and confirmation studies, demonstrating an increased urinary excretion of several monocarboxylates, including lactic acid (LA), at both early and late CKD stages. Increased urine LA was detected in the absence of both increased plasmatic LA levels and generalized proximal tubular dysfunction, suggesting a possible renal-specific defective handling. The inner medulla renal epithelial (IMCD3) cell line, where Bbs10 was stably invalidated, displayed an increased proliferative rate, increased ATP production, and an up-regulation of aerobic glycolysis. A mass spectrometry-based analysis detected several putative BBS10 interactors in vitro, indicating a potential role of BBS10 in several biological processes, including renal metabolism, RNA processing, and cell proliferation. The present study suggests that the urine metabolomic pattern of BBS patients may reflect intra-renal metabolic aberrations. The analysis of BBS10 interactors unveils possible novel functions, including cell metabolism.

COVIDomics: The Proteomic and Metabolomic Signatures of COVID-19.

Omics-based technologies have been largely adopted during this unprecedented global COVID-19 pandemic, allowing the scientific community to perform research on a large scale to understand the pathobiology of the SARS-CoV-2 infection and its replication into human cells. The application of omics techniques has been addressed to every level of application, from the detection of mutations, methods of diagnosis or monitoring, drug target discovery, and vaccine generation, to the basic definition of the pathophysiological processes and the biochemical mechanisms behind the infection and spread of SARS-CoV-2. Thus, the term COVIDomics wants to include those efforts provided by omics-scale investigations with application to the current COVID-19 research. This review summarizes the diverse pieces of knowledge acquired with the application of COVIDomics techniques, with the main focus on proteomics and metabolomics studies, in order to capture a common signature in terms of proteins, metabolites, and pathways dysregulated in COVID-19 disease. Exploring the multiomics perspective and the concurrent data integration may provide new suitable therapeutic solutions to combat the COVID-19 pandemic.

The Serum Metabolome of Moderate and Severe COVID-19 Patients Reflects Possible Liver Alterations Involving Carbon and Nitrogen Metabolism.

COVID-19 is a global threat that has spread since the end of 2019, causing severe clinical sequelae and deaths, in the context of a world pandemic. The infection of the highly pathogenetic and infectious SARS-CoV-2 coronavirus has been proven to exert systemic effects impacting the metabolism. Yet, the metabolic pathways involved in the pathophysiology and progression of COVID-19 are still unclear. Here, we present the results of a mass spectrometry-based targeted metabolomic analysis on a cohort of 52 hospitalized COVID-19 patients, classified according to disease severity as mild, moderate, and severe. Our analysis defines a clear signature of COVID-19 that includes increased serum levels of lactic acid in all the forms of the disease. Pathway analysis revealed dysregulation of energy production and amino acid metabolism. Globally, the variations found in the serum metabolome of COVID-19 patients may reflect a more complex systemic perturbation induced by SARS-CoV-2, possibly affecting carbon and nitrogen liver metabolism.

Dysregulation of lipid metabolism and pathological inflammation in patients with COVID-19.

In recent months, Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread throughout the world. COVID-19 patients show mild, moderate or severe symptoms with the latter ones requiring access to specialized intensive care. SARS-CoV-2 infections, pathogenesis and progression have not been clearly elucidated yet, thus forcing the development of many complementary approaches to identify candidate cellular pathways involved in disease progression. Host lipids play a critical role in the virus life, being the double-membrane vesicles a key factor in coronavirus replication. Moreover, lipid biogenesis pathways affect receptor-mediated virus entry at the endosomal cell surface and modulate virus propagation. In this study, targeted lipidomic analysis coupled with proinflammatory cytokines and alarmins measurement were carried out in serum of COVID-19 patients characterized by different severity degree. Serum IL-26, a cytokine involved in IL-17 pathway, TSLP and adiponectin were measured and correlated to lipid COVID-19 patient profiles. These results could be important for the classification of the COVID-19 disease and the identification of therapeutic targets.

Dataset of a comparative proteomics experiment in a methylmalonyl-CoA mutase knockout HEK 293 cell model.

Methylmalonic acidemia is a rare inborn error of metabolism with severe clinical complications and poor outcome. The present data article is related to a proteomic investigation conducted on a HEK 293 cell line which has been genetically modified using CRISPR-CAS9 system to knockout the methylmalonyl-CoA mutase enzyme (MUT-KO). Thus, the generated cell model for methylmalonic acidemia was used for a proteomic comparison with respect to HEK 293 wild type cells performing a label-free quantification (LFQ) experiment. A comparison between FASP and S-Trap digestion methods was performed on protein extracts before to proceed with the proteomic analysis of the samples. Four biological replicates were employed for LC-MS/MS analysis and each was run in technical triplicates. MaxQuant and Perseus platforms were used to perform the LFQ of the proteomes and carry out statistical analysis, respectively. Globally, 4341 proteins were identified, and 243 as differentially regulated, of which 150 down-regulated and 93 up-regulated in the MUT-KO condition. MS proteomics data have been deposited to the ProteomeXchange Consortium with the dataset identifier PXD017977. The information provided in this dataset shed new light on the cellular mechanisms altered in this rare metabolic disorder, highlighting quantitative unbalances in proteins acting in cell structure and architecture organization and response to the stress. This article can be used as a new source of protein actors to be validated and a starting point for the identification of clinically relevant therapeutic targets.

Proteomics Reveals that Methylmalonyl-CoA Mutase Modulates Cell Architecture and Increases Susceptibility to Stress.

Methylmalonic acidemia (MMA) is a rare inborn error of metabolism caused by deficiency of the methylmalonyl-CoA mutase (MUT) enzyme. Downstream MUT deficiency, methylmalonic acid accumulates together with toxic metabolites from propionyl-CoA and other compounds upstream of the block in the enzyme pathway. The presentation is with life-threatening acidosis, respiratory distress, brain disturbance, hyperammonemia, and ketosis. Survivors develop poorly understood multi-organ damage, notably to the brain and kidneys. The HEK 293 cell line was engineered by CRISPR/Cas9 technology to knock out the MUT gene (MUT-KO). Shotgun label-free quantitative proteomics and bioinformatics analyses revealed potential damaging biological processes in MUT-deficient cells. MUT-KO induced alteration of cellular architecture and morphology, and ROS overproduction. We found the alteration of proteins involved in cytoskeleton and cell adhesion organization, cell trafficking, mitochondrial, and oxidative processes, as validated by the regulation of VIM, EXT2, SDC2, FN1, GLUL, and CHD1. Additionally, a cell model of MUT-rescuing was developed in order to control the specificity of MUT-KO effects. Globally, the proteomic landscape of MUT-KO suggests the cell model to have an increased susceptibility to propionate- and H2O2-induced stress through an impairment of the mitochondrial functionality and unbalances in the oxidation-reduction processes.

Targeted Metabolomic Analysis of a Mucopolysaccharidosis IIIB Mouse Model Reveals an Imbalance of Branched-Chain Amino Acid and Fatty Acid Metabolism.

Mucopolysaccharidoses (MPSs) are inherited disorders of the glycosaminoglycan (GAG) metabolism. The defective digestion of GAGs within the intralysosomal compartment of affected patients leads to a broad spectrum of clinical manifestations ranging from cardiovascular disease to neurological impairment. The molecular mechanisms underlying the progression of the disease downstream of the genetic mutation of genes encoding for lysosomal enzymes still remain unclear. Here, we applied a targeted metabolomic approach to a mouse model of PS IIIB, using a platform dedicated to the diagnosis of inherited metabolic disorders, in order to identify amino acid and fatty acid metabolic pathway alterations or the manifestations of other metabolic phenotypes. Our analysis highlighted an increase in the levels of branched-chain amino acids (BCAAs: Val, Ile, and Leu), aromatic amino acids (Tyr and Phe), free carnitine, and acylcarnitines in the liver and heart tissues of MPS IIIB mice as compared to the wild type (WT). Moreover, Ala, Met, Glu, Gly, Arg, Orn, and Cit amino acids were also found upregulated in the liver of MPS IIIB mice. These findings show a specific impairment of the BCAA and fatty acid catabolism in the heart of MPS IIIB mice. In the liver of affected mice, the glucose-alanine cycle and urea cycle resulted in being altered alongside a deregulation of the BCAA metabolism. Thus, our data demonstrate that an accumulation of BCAAs occurs secondary to lysosomal GAG storage, in both the liver and the heart of MPS IIIB mice. Since BCAAs regulate the biogenesis of lysosomes and autophagy mechanisms through mTOR signaling, impacting on lipid metabolism, this condition might contribute to the progression of the MPS IIIB disease.

Chemotherapy and Cardiotoxicity in Hematologic Malignancies.

INTRODUCTION: Antineoplastic agents affect the cardiovascular system, and the incidence of cardiotoxicity is continuously growing in patients with hematologic malignancies and treated with antineoplastic therapy. METHODS: In this mini-review, we analyzed existing literature which evaluates the likelihood of cardiotoxicity related to the main agents employed in the treatment of hematologic malignancies. RESULTS: There is a significant need to optimize the early identification of patients who are at risk of cardiotoxicity. The conventional echocardiographic measurements used to detect cardiac alterations, such as LVEF, fractional shortening, diameters and volumes, allow only a late diagnosis of cardiac dysfunction, which might be already irreversible. The early identification of patients at risk for rapid progression towards irreversible cardiac failure has a primary purpose, the opportunity for them to benefit from early preventive and therapeutic measures. A useful imaging technique that points in this direction detecting subclinical LVD may be the speckle tracking echocardiography, that has demonstrated a previous detection of myocardial contractile dysfunction compared to the traditional left ventricular ejection fraction. In this view, the discovery of new biomarkers to identify patients at a high risk for the development of these complications is another priority. CONCLUSION: Cardiotoxicity induced by anticancer drugs is always the outcome of several concurrent factors. It is plausible that an asymptomatic dysfunction precedes clinical events. During this asymptomatic phase, an early treatment prepares the patient for cardiovascular "safety" conditions; on the other hand, a late or missing treatment paves the ground for the development of future cardiac events.

Recommended screening and preventive evaluation practices of adult candidates for hematopoietic stem cell transplantation.

INTRODUCTION: Hematopoietic stem cell transplantation (HSCT) is associated with a substantial risk of morbidity and mortality. Better selection of HSCT patients for intensive treatment, and consequently reduction of non-beneficial care, may improve the therapeutic outcome. AREAS COVERED: This manuscript provides a systematic review which examines t he current criteria for selection of HSCT patients. EXPERT OPINION: Identifying patients who may benefit from HSCT involves many factors, including overall health, prior therapies, age, disease, and stage. The decision regarding transplant eligibility should be made on a case by case basis, based on a risk-benefit assessment. The advent of the comorbidity index as a measure of health status at the time of HSCT has facilitated the incorporation of comorbidities into the pre-transplant assessment of patients. Many HSCT protocols are still age-dependent, with criteria limited to patients either younger or older than arbitrary age cut-offs.The prognostic role of age in the transplant setting has never been consistent. As physicians and researchers continue improving the HSCT process and outcomes, optimization of the delivery of a comprehensive treatment plan should become an important component of overall patient management.

The role of tandem stem cell transplantation for multiple myeloma patients.

INTRODUCTION: Autologous Stem Cell Transplantation (ASCT) represents the standard treatment in eligible "de-novo" multiple myeloma (MM) patients. AREAS COVERED: ASCT may be single or tandem, and a single ASCT can be followed by an allogeneic (Allo)-SCT. A systematic review has been conducted to examine the current evidence for the efficacy of using a tandem transplant strategy in MM. EXPERT OPINION: A tandem ASCT approach should be considered for all patients, although the benefit from the second ASCT in patients who are in complete remission or experience a very good partial response should be answered in a clinical trial. Recent results with the new induction regimens indicate that there is a role for tandem ASCT in the presence of adverse cytogenetic abnormalities. Planned AlloSCT after ASCT has not been found to be superior in the majority of studies and is not recommended outside of a clinical trial. However, single or tandem ASCT are both appropriate options and participation in prospective clinical trials should be encouraged to resolve the debate in the era of novel agents for MM.

Salvage treatment for relapsed/refractory Hodgkin lymphoma: role of allografting, brentuximab vedotin and newer agents.

INTRODUCTION: Second-line, salvage chemotherapy followed by high-dose chemotherapy and autologous stem cell transplantation (AUTO-SCT) is the standard of care for patients with relapsed/refractory (R/R) Hodgkin lymphoma (HL). Approximately 50% of patients relapse after AUTO-SCT and their prognosis is generally poor. Brentuximab Vedotin (BV) has demonstrated efficacy in this setting and allogeneic (ALLO)-SCT represents an option with curative potential in this subgroup of patients. AREAS COVERED: A systematic review has been conducted to explore the actual knowledge on ALLO-SCT, BV and newer agents in R/R HL. EXPERT OPINION: The introduction of BV in clinical practice has significantly improved the management of post-AUTO-SCT relapses and the drug can induce durable remissions in a subset of R/R HL. Allografting select patients has been used to improve clinical outcomes and recent case series have begun to explore BV as a potential 'bridge' to allo-SCT, even though the optimal timing of ALLO-SCT after BV response remains undetermined. However, reduced tumor burden at the time of ALLO-SCT is a key factor to decrease relapse risk. Based on the unique composition of the tumor, more recently new agents such as PD-1 inhibitors have been developed. The potential role of PD-1 inhibitors with ALLO-SCT remains to be explored.

Efficacy of biosimilar granulocyte colony-stimulating factor versus originator granulocyte colony-stimulating factor in peripheral blood stem cell mobilization in de novo multiple myeloma patients.

BACKGROUND AIMS: Filgrastim and lenograstim are the standard granulocyte colony-stimulating factor (G-CSF) agents for peripheral blood stem cell mobilization (PBSC) in patients who undergo autologous stem cell transplantation. METHODS: To assess whether biosimilars are effective, we conducted a single-center, prospective study that included 40 consecutive de novo multiple myeloma patients who received cyclophosphamide 4 g/m(2) per day plus biosimilar filgrastim G-CSF to mobilize PBSC. These patients were compared with a group of 37 patients matched for age, diagnosis, previous chemotherapy and mobilization who had been treated with originator G-CSF. The mean number of CD34+ cells/µL in the peripheral blood was 199.6 ± 207.4 in the biosimilar and 192.8 ± 154.7 in the originator group (P = 0.87). The median number of CD34+ cells/kg recipient collected was 11.5 ± 5.8 and 12.3 ± 5.3 in the biosimilar and originator groups, respectively (P = 0.51). The mobilization failure rate was 2.5% and 2.7% in the biosimilar filgrastim and originator filgrastim cohorts (P = NS), respectively. RESULTS: Twenty-nine patients in the biosimilar group and 28 patients in the originator group underwent autologous transplantation. There were no statistically significant differences between the biosimilar and originator G-CSF cohorts in terms of hematopoietic recovery parameters and transplant-related toxicities. CONCLUSIONS: The efficacy of biosimilar G-CSF appears to be equivalent to the reference G-CSF.

Allogeneic stem cell transplantation in multiple myeloma: immunotherapy and new drugs.

INTRODUCTION: Autologous (auto) stem cell transplantation (SCT) and the development of new drugs have improved the survival of multiple myeloma (MM) patients. By contrast, though potentially curative, the use of allogeneic (allo)-SCT is controversial. AREAS COVERED: A review has been conducted to examine the current evidence for the use of allo-SCT in MM. We have examined novel cell therapies that may be exploited to induce myeloma-specific immune responses including the new promising frontier of chimeric antigen receptor (CAR)-T and -natural killer (NK) cells. EXPERT OPINION: One of the major controversies facing researchers in exploring the allo approach is the remarkable recent treatment improvement observed with second- and third-generation proteasome inhibitors and immunomodulatory drugs, monoclonal antibodies and deacetylase inhibitors. Despite these great advances, the disease remains to be incurable and allo-SCT may still play a role in the cure of MM. We think that allo-SCT conserves a role in MM and its curative potential in high-risk patients should be explored in the setting of control clinical trials. Novel cell therapies such as CAR technologies may open new avenues of research toward a potential cure. Data from currently ongoing prospective studies will be helpful to clarify pending clinical questions.

Mobilization of hematopoietic progenitor stem cells in allogeneic setting with lenograstim by subcutaneous injection, in daily or twice-daily dosing: a single-center prospective study with historical control.

BACKGROUND: Although the mobilization of hematopoietic progenitor stem cells from healthy donors (HDs) using granulocyte-colony-stimulating factor is widely used, the ideal method for the administration of the cytokine has not yet been determined. STUDY DESIGN AND METHODS: Seventy-five consecutive HDs received lenograstim (LENO) as mobilization agent. LENO was given subcutaneously at a dose of 10 µg/kg in a once-daily dose (ODD) every 24 hours. Results were compared with a historical control group of 181 HDs treated with 5 µg/kg LENO twice-daily dose (TDD) with a time interval of 12 hours. RESULTS: CD34+ cell concentrations evaluated on Day 4 and on Day 5 were 45 × 10(6) (range, 6 × 10(6) -217 × 10(6) )/L and 75 × 10(6) (range, 7 × 10(6) -279 × 10(6) )/L with ODD versus 36 × 10(6) (range, 3 × 10(6) -200 × 10(6) )/L and 55 × 10(6) (range, 3 × 10(6) -738 × 10(6) )/L with TDD (p = 0.067 and p = 0.001). The collected CD34+ cell counts in first apheresis procedure were 5.6 × 10(6) ± 2.9 × 10(6) and 5.7 × 10(6) ± 3 × 10(6) /kg donor and recipient body weight in the ODD versus 5.4 × 10(6) ± 3.8 × 10(6) and 5.3 × 10(6) ± 3.5 × 10(6) /kg in the TDD cohort, respectively (p = 0.08 and p = 0.02). Five HDs (6.7%) mobilized CD34+ cells of fewer than 2 × 10(6) /kg recipient body weight in the ODD group compared with seven HDs (3.9%) in the TDD group (p = 0.3). CONCLUSIONS: Once-daily administration of LENO is at least as effective as twice-daily administration for the mobilization of CD34+ cells in HDs.

Mobilization of hematopoietic stem cells with lenograstim in healthy donors: efficacy and safety analysis according to donor age.

We reviewed and analyzed safety and efficacy data after mobilization with granulocyte colony-stimulating factor (G-CSF) according to healthy donor's (HDs) age as follows: <50 years (HDs-1, n = 161), aged 50 to 59 years (HDs-2, n = 62), and ≥60 years or over (HDs-3, n = 23). Two hundred forty-six HDs were evaluated, and their characteristics were well balanced among age groups: most were male, siblings, and HLA matched. According to age group, the median numbers of CD34(+) cells in the peripheral blood for HDs-1, HDs-2, and HDs-3 were, respectively, 44.5, 34.5, and 26 (HDs-1 versus HDs-2, P = .002; HDs-1 versus HDs-3, P = .036; HDs-2 versus HDs-3, P = n.s.) at day 4 and 65.5, 58, and 46 (HDs-1 versus HDs-2, P = .039; HDs-1 versus HDs-3, P = .002; HDs-2 versus HDs-3, P = n.s.) at day 5. With a median apheresis session of 1, the number of CD34(+) cells/kg recipient body weight collected was not significantly different (6.4 in HDs-1, 6.0 in HDs-2, and 5.7 in HDs-3, P = n.s.). Short- and long-term safety did not differ among age groups. Bone pain was reported as the most frequent short-term adverse event (76.5%). After a median follow-up of 7.8 years, the observed rate of solid tumors, hematological malignancies, and cardiovascular and autoimmune events was similar to the expected incidence for these diseases in Western countries. These results show that G-CSF is effective in the mobilization of older HDs. Moreover, our data contribute to the growing body of evidence in support of the long-term safety of G-CSF for allogeneic donor stem cell mobilization also for elderly HDs.