Upfront Alternative Donor Transplant versus Immunosuppressive Therapy in Patients with Severe Aplastic Anemia Who Lack a Fully HLA-Matched Related Donor: Systematic Review and Meta-Analysis of Retrospective Studies, on Behalf of the Severe Aplastic Anemia Working Party of the European Group for Blood and Marrow Transplantation.

Idiopathic aplastic anemia is a rare and life-threatening disorder, and hematopoietic stem cell transplantation (HSCT) from a matched sibling donor (MSD) is the standard treatment strategy for young patients. Alternative donor transplantation (ADT) from a matched unrelated donor or an HLA haploidentical donor is not commonly used in the frontline setting. This systematic review/meta-analysis was conducted to compare ADT as an upfront, rather than delayed, treatment strategy in the absence of an MSD to immunosuppressive therapy (IST) in severe aplastic anemia (SAA). We searched PubMed/MEDLINE and Embase (1998 to 2019) for studies that compared the outcomes of ADT with IST as upfront therapy in patients with SAA. We included studies with 5 patients or more in each arm. Studies that included patients with inherited forms of bone marrow failure syndromes were excluded. The primary outcome was the 5-year overall survival (OS) rate. Five studies met the inclusion criteria and were included in this meta-analysis. The pooled 5-year odds ratio (OR) for OS was statistically significant at 0.44 (95% confidence interval [CI], 0.23 to 0.85) in favor of upfront ADT. In addition, survival was compared between upfront ADT versus salvage ADT in 6 studies. The pooled 5-year OR for OS was statistically significant at 0.31 (95% CI, 0.15 to 0.64) in favor of upfront ADT. Although this analysis has some limitations, including the retrospective nature of the included studies, the lack of ethnic diversity, the predominantly pediatric population, and the relatively suboptimal IST regimen used in some of the studies, it indicates that upfront ADT is a potential alternative treatment option in young and pediatric SAA patients who lack an HLA identical sibling donor, particularly when optimal IST is not available. © 2021 American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc.

Evaluation of energy metabolism and calcium homeostasis in cells affected by Shwachman-Diamond syndrome.

Isomorphic mutation of the SBDS gene causes Shwachman-Diamond syndrome (SDS). SDS is a rare genetic bone marrow failure and cancer predisposition syndrome. SDS cells have ribosome biogenesis and their protein synthesis altered, which are two high-energy consuming cellular processes. The reported changes in reactive oxygen species production, endoplasmic reticulum stress response and reduced mitochondrial functionality suggest an energy production defect in SDS cells. In our work, we have demonstrated that SDS cells display a Complex IV activity impairment, which causes an oxidative phosphorylation metabolism defect, with a consequent decrease in ATP production. These data were confirmed by an increased glycolytic rate, which compensated for the energetic stress. Moreover, the signalling pathways involved in glycolysis activation also appeared more activated; i.e. we reported AMP-activated protein kinase hyper-phosphorylation. Notably, we also observed an increase in a mammalian target of rapamycin phosphorylation and high intracellular calcium concentration levels ([Ca(2+)]i), which probably represent new biochemical equilibrium modulation in SDS cells. Finally, the SDS cell response to leucine (Leu) was investigated, suggesting its possible use as a therapeutic adjuvant to be tested in clinical trials.

Unrelated alternative donor transplantation for severe acquired aplastic anemia: a study from the French Society of Bone Marrow Transplantation and Cell Therapies and the EBMT Severe Aplastic Anemia Working Party.

Unrelated allogeneic transplantation for severe aplastic anemia is a treatment option after immunosuppressive treatment failure in the absence of a matched sibling donor. Age, delay between disease diagnosis and transplantation, and HLA matching are the key factors in transplantation decisions, but their combined impact on patient outcomes remains unclear. Using the French Society of Bone Marrow Transplantation and Cell Therapies registry, we analyzed all consecutive patients (n=139) who underwent a first allogeneic transplantation for idiopathic severe aplastic anemia from an unrelated donor between 2000 and 2012. In an adjusted multivariate model, age over 30 years (Hazard Ratio=2.39; P=0.011), time from diagnosis to transplantation over 12 months (Hazard Ratio=2.18; P=0.027) and the use of a 9/10 mismatched unrelated donor (Hazard Ratio=2.14; P=0.036) were independent risk factors that significantly worsened overall survival. Accordingly, we built a predictive score using these three parameters, considering patients at low (zero or one risk factors, n=94) or high (two or three risk factors, n=45) risk. High-risk patients had significantly shorter survival (Hazard Ratio=3.04; P<0.001). The score was then confirmed on an independent cohort from the European Group for Blood and Marrow Transplantation database of 296 patients, with shorter survival in patients with at least 2 risk factors (Hazard Ratio=2.13; P=0.005) In conclusion, a simple score using age, transplantation timing and HLA matching would appear useful to help physicians in the daily care of patients with severe aplastic anemia.

The diagnosis and treatment of aplastic anemia: a review.

Aplastic anemia is a rare disorder characterized by suppression of bone marrow function resulting in progressive pancytopenia. A trigger-related abnormal T cell response facilitated by some genetic predisposition has been postulated as the pathogenetic mechanism leading to the overproduction of bone marrow-inhibiting cytokines. Immuno-mediated pathogenesis is confirmed by the response to immunosuppressive treatment (IST) (cyclosporin A+ATG), which represents the first-choice therapy for patients <40 years when a matched sibling donor (MSD) is not available for transplant. MSD hematopoietic stem cell transplantation (HSCT) is associated with cure in ~90 % of patients. IST up-front provides an overall survival (OS) rate of above 90 %, but a response rate of about 60 %. Front-line matched unrelated donor (MUD) appears to be a viable option in children with similar OS and event-free survival to that in MSD HSCT. MUD HSCT post-IST failure proved to be a very good rescue strategy. Haploidentical donors/cord blood transplants or alternative immunosuppressive therapies, such as alemtuzumab, may represent valid tools for resistant/relapsing cases. New promising strategies, such as eltrombopag, are now under investigation. Patients should be offered an accurate diagnostic work-up in order to rule out other underlying disorders, primarily constitutional marrow failures, which may require different approaches.

Modelling Fanconi anemia pathogenesis and therapeutics using integration-free patient-derived iPSCs.

Fanconi anaemia (FA) is a recessive disorder characterized by genomic instability, congenital abnormalities, cancer predisposition and bone marrow (BM) failure. However, the pathogenesis of FA is not fully understood partly due to the limitations of current disease models. Here, we derive integration free-induced pluripotent stem cells (iPSCs) from an FA patient without genetic complementation and report in situ gene correction in FA-iPSCs as well as the generation of isogenic FANCA-deficient human embryonic stem cell (ESC) lines. FA cellular phenotypes are recapitulated in iPSCs/ESCs and their adult stem/progenitor cell derivatives. By using isogenic pathogenic mutation-free controls as well as cellular and genomic tools, our model serves to facilitate the discovery of novel disease features. We validate our model as a drug-screening platform by identifying several compounds that improve hematopoietic differentiation of FA-iPSCs. These compounds are also able to rescue the hematopoietic phenotype of FA patient BM cells.

Diagnostic potential of hepcidin testing in pediatrics.

OBJECTIVES: Hepcidin, a peptide hormone released by hepatocytes into circulation is the main regulator of dietary iron absorption and cellular iron release. Although commercial tests are available, assay harmonization for hepcidin has not been yet reached, making reference intervals and consequent clinical decisions still elusive for each assay and specific population. The aim of this study is to set up hepcidin measurement in pediatric age and to investigate its potential usefulness in the diagnosis and management of iron disorders in children. METHODS: Serum hepcidin was measured by using an automated commercial immunoassay. Reference values were obtained from 86 healthy children. Hepcidin was then evaluated in 52 children with diseases where this hormone was expected to be differently regulated. RESULTS: Hepcidin values were 43.6 ng/mL median; 32-52.7 1-3 q: in males and 36.4 ng/mL median; 28.5-45.7 1-3 q: in females (P = 0.039). Hepcidin was significantly higher in postpubertal normal females than in normal males. Hepcidin resulted up-regulated in anemia of chronic disease of children affected by systemic Juvenile Idiopathic Arthritis and decreased after treatment with anakinra, an anti-interleukin-1 receptor antagonist. In iron deficiency anemia patients on oral iron supplementation and in ß-thalassemia subjects, hepcidin levels were similar to those found in healthy subjects. CONCLUSIONS: This study sets up reference values for pediatric population and shows that in normal controls serum hepcidin react differently to puberty in females vs. males. In addition, it suggests that serum hepcidin may discriminate microcytic inflammatory anemia of Juvenile Idiopathic Arthritis from iron deficiency anemia. Overall these findings may represent a helpful tool for future studies tailored to understand the role of hepcidin in management of iron disorders in children.

Severe lactic acidosis due to thiamine deficiency in a patient with B-cell leukemia/lymphoma on total parenteral nutrition during high-dose methotrexate therapy.

An 11-month-old girl with B-cell leukemia/lymphoma developed profound lethargy due to severe lactic acidosis during chemotherapy and total parenteral nutrition (TPN). Initial treatment with NaHCO3 was ineffective. Treatment with a vitamin cocktail (OH-cobalamin, pyridoxine, thiamine, riboflavine, biotin, carnitine) at pharmacologic doses rapidly improved the child's clinical and laboratory status. Lactic acidosis was caused by an impairment of pyruvate dehydrogenase complex, which was due to lack of its necessary cofactor thiamine in the TPN. This case report indicates that lactic acidosis may be a front-line diagnosis in patients on TPN with lethargy and outlines the need for monitoring thiamine supply in TPN.