How I manage children with Diamond-Blackfan anaemia

Perspectives of current understanding and therapeutics of Diamond-Blackfan anemia

ABSTACT

Diamond-Blackfan anemia (DBA) is a rare congenital bone marrow failure disorder characterized by erythroid hypoplasia. It primarily affects infants and is often caused by heterozygous allelic variations in ribosomal protein (RP) genes. Recent studies also indicated that non-RP genes like GATA1, TSR2, are associated with DBA. P53 activation, translational dysfunction, inflammation, imbalanced globin/heme synthesis, and autophagy dysregulation were shown to contribute to disrupted erythropoiesis and impaired red blood cell production. The main therapeutic option for DBA patients is corticosteroids. However, half of these patients become non-responsive to corticosteroid therapy over prolonged treatment and have to be given blood transfusions. Hematopoietic stem cell transplantation is currently the sole curative option, however, the treatment is limited by the availability of suitable donors and the potential for serious immunological complications. Recent advances in gene therapy using lentiviral vectors have shown promise in treating RPS19-deficient DBA by promoting normal hematopoiesis. With deepening insights into the molecular framework of DBA, emerging therapies like gene therapy hold promise for providing curative solutions and advancing comprehension of the underlying disease mechanisms.

Posttransplant complications in patients with marrow failure syndromes: are we improving long-term outcomes?

Inherited bone marrow failure syndromes (IBMFS) encompass a group of rare genetic disorders characterized by bone marrow failure, non-hematologic multisystemic comorbidities, disease defining congenital anomalies, and a susceptibility to myelodysplastic syndrome, acute myeloid leukemia, and in some instances solid tumors. The most common IBMFS include Fanconi anemia, Shwachman-Diamond syndrome, Diamond-Blackfan anemia, and telomere biology disorders/ dyskeratosis congenita. Allogeneic hematopoietic stem cell transplant (HCT) is a well-established curative treatment to correct the hematological manifestations but does not halt or reverse the nonhematological complications and may hasten them. With advances in HCT and in our ability to care for patients with IBMFS, an increasing number of survivors are making it imperative to not only diagnose but also treat late effects from the pre-, peri-, and post-HCT course and complications relating to the natural history of the syndrome. As the field of HCT evolves to allow for the incorporation of alternate graft sources, for expansion of donor options to include unrelated and mismatched donors, and for use of reduced-intensity conditioning or reduced toxicity myeloablative regimens, we have yet to determine if these advances modify the disease-specific course. While long-term outcomes of these patients are often included under one umbrella, this article seeks to address disease-specific post-HCT outcomes within IBMFS.

Pediatric Bone Marrow Failure: A Broad Landscape in Need of Personalized Management

Irreversible severe bone marrow failure (BMF) is a life-threatening condition in pediatric patients. Most important causes are inherited bone marrow failure syndromes (IBMFSs) and (pre)malignant diseases, such as myelodysplastic syndrome (MDS) and (idiopathic) aplastic anemia (AA). Timely treatment is essential to prevent infections and bleeding complications and increase overall survival (OS). Allogeneic hematopoietic stem cell transplantation (HSCT) provides a cure for most types of BMF but cannot restore non-hematological defects. When using a matched sibling donor (MSD) or a matched unrelated donor (MUD), the OS after HSCT ranges between 60 and 90%. Due to the introduction of post-transplantation cyclophosphamide (PT-Cy) to prevent graft versus host disease (GVHD), alternative donor HSCT can reach similar survival rates. Although HSCT can restore ineffective hematopoiesis, it is not always used as a first-line therapy due to the severe risks associated with HSCT. Therefore, depending on the underlying cause, other treatment options might be preferred. Finally, for IBMFSs with an identified genetic etiology, gene therapy might provide a novel treatment strategy as it could bypass certain limitations of HSCT. However, gene therapy for most IBMFSs is still in its infancy. This review summarizes current clinical practices for pediatric BMF, including HSCT as well as other disease-specific treatment options.

Diamond-Blackfan anemia in adults: In pursuit of a common approach for a rare disease

Diamond-Blackfan anemia (DBA) is a rare bone marrow failure syndrome, usually caused by loss-of function variants in genes encoding ribosomal proteins. The hallmarks of DBA are anemia, congenital anomalies and cancer predisposition. Although DBA usually presents in childhood, the prevalence in later life is increasing due to an expanding repertoire of implicated genes, improvements in genetic diagnosis and increasing life expectancy. Adult patients uniquely suffer the manifestations of end-organ damage caused by the disease and its treatment, and transition to adulthood poses specific issues in disease management. To standardize and optimize care for this rare disease, in this review we provide updated guidance on the diagnosis and management of DBA, with a specific focus on older adolescents and adults. Recommendations are based upon published literature and our pooled clinical experience from three centres in the United Kingdom (U·K.). Uniquely we have also solicited and incorporated the views of affected families, represented by the independent patient organization, DBA U.K.

Unusual Association of Diamond-Blackfan Anemia and Severe Sinus Bradycardia in a Six-Month-Old White Infant: A Case Report and Literature Review

Diamond-Blackfan anemia is a rare (6-7 million live births), inherited condition manifesting as severe anemia due to the impaired bone marrow production of red blood cells. We present the unusual case of a six month old infant with a de novo mutation of the RPS19 gene causing Diamond-Blackfan anemia who additionally suffers from severe sinus bradycardia. The infant was diagnosed with this condition at the age of four months; at the age of 6 months, she presents with severe anemia causing hypoxia which, in turn, caused severe dyspnea and polypnea, which had mixed causes (hypoxic and infectious) as the child was febrile. After correction of the overlapping diarrhea, metabolic acidosis, and severe anemia (hemoglobin < 3 g/dL), she developed severe persistent sinus bradycardia immediately after mild sedation (before central venous catheter insertion), not attributable to any of the more frequent causes, with a heart rate as low as 49 beats/min on 24 h Holter monitoring, less than the first percentile for age, but with a regular QT interval and no arrhythmia. The echocardiogram was unremarkable, showing a small interatrial communication (patent foramen ovale with left-to-right shunting), mild left ventricular hypertrophy, normal systolic and diastolic function, and mild tricuspid regurgitation. After red cell transfusion and appropriate antibiotic and supportive treatment, the child's general condition improved dramatically but the sinus bradycardia persisted. We consider this a case of well-tolerated sinus bradycardia and foresee a good cardiologic prognosis, while the hematologic prognosis remains determined by future corticoid response, treatment-related complications and risk of leukemia.

Craniofacial Characteristics and Orthodontic Treatment of Diamond Blackfan Syndrome: Two Case Reports

Diamond Blackfan anemia (DBA) is a chronic congenital form of erythrocytic hypoplasia in which erythroid precursor cell levels are low. DBA reflects ribosomal dysfunction and is accompanied by hematopoietic cell apoptosis, anemia, and various somatic symptoms. We report the characteristic symptoms of the craniofacial region and the orthodontic treatments of two DBA cases. Case 1 was a 12-year-old female. The typical physical and facial characteristics of DBA were lacking. On initial examination, she exhibited a skeletal Class II jaw and end to end molar relationships and a large overjet. An edgewise appliance was placed after extraction of the first maxillary premolars. After 3 years and 11 months, an appropriate overjet and overbite, rigid intercuspation, and an acceptable profile were evident without any clinical adverse effects. Case 2 was a 13-year-old female. She exhibited a skeletal Class I jaw relationship, a spaced dental arch, the maxillofacial dysplasia characteristic of Binder syndrome, hypoplasia of the right mandibular condyle, and labial protrusions of the maxillary and mandibular incisors. We placed an edgewise appliance and after 1 year and 7 months, the occlusion was optimal in the absence of any adverse effects. Our two DBA cases exhibited a broad spectrum of physical and dentofacial symptoms. Patients with DBA are often prescribed combined steroid/bisphosphonate therapies. Both agents are likely to affect alveolar bone remodeling after tooth extraction and orthodontic tooth movement. Careful consideration of medication with reference to various dentofacial characteristics is necessary.

[Pure red cell aplasia: Diagnosis, classification and treatment]

Pure red cell aplasia (PRCA) is a rare anemia characterised by profound reticulocytopenia caused by a marked reduction in bone marrow erythroblasts, without abnormalities in other blood lineages. Blackfan-Diamond anemia is an inherited ribosomopathy responsible for a hereditary form of PRCA. Acquired PRCA are separated in primary and secondary forms, including Parvovirus B19 infection, thymoma, lymphoproliferative disorders, autoimmune diseases (lupus) and drug-induced PRCA. The pathophysiology of PRCA is not fully understood and involves both humoral and T lymphocyte autoreactive cells. In Parvovirus B19-related PRCA, treatment is based on polyvalent immunoglobulins. Thymectomy for thymoma is mandatory but results in prolonged remission in a limited number of cases. The therapeutic strategy is based on expert opinion: corticosteroids in monotherapy provide few sustained responses. The choice of an additional immunosuppressant drug is guided by the presence of an underlying disease. In most cases, cyclosporine A is the first choice providing the best response rate but requires a concentration monitoring (150 to 250 ng/mL). The second choice is cyclophosphamide in large granular lymphocyte leukaemia. Sirolimus (mTOR inhibitor) seems to be a promising option especially in refractory cases. Transfusion independence is the main objective. If the patient receives numerous red blood cell transfusions (> 20 packs), iron overload assessment is crucial to initiate an iron chelation. A retrospective and prospective national cohort (EPIC-F) has been set up and is now available to include each case of PRCA to improve the knowledge of this disease and to optimize the therapeutic strategy.

Transfusion burden in early childhood plays an important role in iron overload in Diamond-Blackfan anaemia

In Diamond-Blackfan anaemia (DBA), iron overload (IO) is common in transfusion-dependent patients, yet has also been reported in non-transfusion-dependent patients. We explored the incidence of IO in transfusion-dependent and non-transfusion-dependent DBA patients. We observed hepatic IO in 65% of patients analysed with MRI, including three patients that were only treated with transfusions in the past. Whereas overall ferritin levels and liver iron content correlated, ferritin levels did not reflect total body iron adequately. Our data suggest that transfusion burden in the past plays an important role in IO in DBA, and should be taken into account during follow up.

Use of blood and its components in the treatment of anaemia in children

Blood transfusion is a well-established treatment for anaemia. Herein, blood and its components are transfused to replenish circulating blood volume, maintain the oxygen capacity of the blood and normalise the function of the coagulation system. Anaemia treatment by blood transfusions is a great challenge, especially with reference to paediatric patients. Blood is irreplaceable in a life-threatening situation, but it has its own side effects, just like all applied pharmacological products. Hence, it is extremely important to carefully select donors and utilise blood components according to the patient’s individual needs. Children represent a group that requires specific criteria to be met, mainly because of the fact that their physiological and haematological systems differ from those of adults. The most common types of anaemia seen in children are deficiency anaemias such as iron-deficiency anaemia, while less common are vitamin B12 deficiency anaemia or folate deficiency anaemia. Secondary anaemia is also relatively frequent in chronic diseases, among others, immunological or infectious, as well as renal, liver, endocrine and neoplastic diseases. Anaemia due to blood loss is also included in this group. Furthermore, some anaemias, such as aplastic anaemia (due to impaired erythrocyte production) and haemolytic anaemia (due to excessive destruction of red blood cells) may be congenital or acquired. Before deciding to implement blood therapy, the patient’s clinical condition or the different haematological, biochemical and immunological parameters at different stages of life should be considered. Since each transfusion may result in a variety of post-transfusion reactions, immunisation or transmission of infectious diseases, the decision to transfuse blood or blood components should be taken only when the patient cannot be treated effectively by any other means and the expected benefits of the transfusion outweigh the risks associated with possible complications. Considering the recipients’ low blood volume, low metabolic efficiency, higher haematocrit levels than in adults and immature immune system, products for these patients should be prepared in a special way. These components must ensure minimal risk of metabolic and haemostatic disorders. The collection of these products, as well as their preparation, storage and transfusion, should be carried out in accordance with current legislation.

Diamond-Blackfan anaemia caused by a de novo initiation codon mutation resulting in a shorter isoform of GATA1

Diamond-Blackfan Anaemia (DBA) is an inherited marrow failure disorder characterised by selective erythroid aplasia. Herein, we reported a case of DBA caused by a novel GATA1 gene mutation. The proband manifested normocytic normochromic anaemia, while the parents were asymptomatic. Next-generation sequencing identified a novel de novo mutation at GATA1 initiation codon (GATA1:c.3G>A) in the proband. The mutation led to a shortened GATA1 protein (GATA1s), which caused a reduction in full-length functional GATA1 protein (GATA1fl). This is the first report of GATA1-related DBA patient in the East Asian population, which expanded the mutational spectrum of DBA furthering understanding of its pathogenesis.

Anemia in the pediatric patient

The World Health Organization estimates that approximately a quarter of the world's population suffers from anemia, including almost half of preschool-age children. Globally, iron deficiency anemia is the most common cause of anemia. Other important causes of anemia in children are hemoglobinopathies, infection, and other chronic diseases. Anemia is associated with increased morbidity, including neurologic complications, increased risk of low birth weight, infection, and heart failure, as well as increased mortality. When approaching a child with anemia, detailed historical information, particularly diet, environmental exposures, and family history, often yield important clues to the diagnosis. Dysmorphic features on physical examination may indicate syndromic causes of anemia. Diagnostic testing involves a stepwise approach utilizing various laboratory techniques. The increasing availability of genetic testing is providing new mechanistic insights into inherited anemias and allowing diagnosis in many previously undiagnosed cases. Population-based approaches are being taken to address nutritional anemias. Novel pharmacologic agents and advances in gene therapy-based therapeutics have the potential to ameliorate anemia-associated disease and provide treatment strategies even in the most difficult and complex cases.

Genetic Disorders with Predisposition to Paediatric Haematopoietic Malignancies—A Review

The view of paediatric cancer as a genetic disease arises as genetic research develops. Germline mutations in cancer predisposition genes have been identified in about 10% of children. Paediatric cancers are characterized by heterogeneity in the types of genetic alterations that drive tumourigenesis. Interactions between germline and somatic mutations are a key determinant of cancer development. In 40% of patients, the family history does not predict the presence of inherited cancer predisposition syndromes and many cases go undetected. Paediatricians should be aware of specific symptoms, which highlight the need of evaluation for cancer syndromes. The quickest possible identification of such syndromes is of key importance, due to the possibility of early detection of neoplasms, followed by presymptomatic genetic testing of relatives, implementation of appropriate clinical procedures (e.g., avoiding radiotherapy), prophylactic surgical resection of organs at risk, or searching for donors of hematopoietic stem cells. Targetable driver mutations and corresponding signalling pathways provide a novel precision medicine strategy.Therefore, there is a need for multi-disciplinary cooperation between a paediatrician, an oncologist, a geneticist, and a psychologist during the surveillance of families with an increased cancer risk. This review aimed to emphasize the role of cancer-predisposition gene diagnostics in the genetic surveillance and medical care in paediatric oncology.

Recent advances in hematopoietic cell transplantation for inherited bone marrow failure syndromes

Inherited bone marrow failure syndromes (IBMFSs) are a group of rare genetic disorders characterized by bone marrow failure with unique phenotypes and predisposition to cancer. Classical IBMFSs primarily include Fanconi anemia with impaired DNA damage repair, dyskeratosis congenita with telomere maintenance dysfunction, and Diamond-Blackfan anemia with aberrant ribosomal protein biosynthesis. Recently, comprehensive genetic analyses have been implemented for the definitive diagnosis of classic IBMFSs, and advances in molecular genetics have led to the identification of novel disorders such as AMeD and MIRAGE syndromes. Allogeneic hematopoietic cell transplantation (HCT), a promising option to overcome impaired hematopoiesis in patients with IBMFSs, does not correct nonhematological defects and may enhance the risk of secondary malignancies. Disease-specific management is necessary because IBMFSs differ in underlying defects and are associated with varying degrees of risk for clonal evolution and early or late complications after HCT. In addition, long-term follow-up is essential to detect complications related to the IBMFS or HCT. This review provides a summary of current clinical practices along with the latest data on HCT in IBMFSs.

Role of Nuclear Receptors in Controlling Erythropoiesis

Nuclear receptors (NRs), are a wide family of ligand-regulated transcription factors sharing a common modular structure composed by an N-terminal domain and a ligand-binding domain connected by a short hinge linker to a DNA-binding domain. NRs are involved in many physiological processes, including metabolism, reproduction and development. Most of them respond to small lipophilic ligands, such as steroids, retinoids, and phospholipids, which act as conformational switches. Some NRs are still "orphan" and the search for their ligands is still ongoing. Upon DNA binding, NRs can act both as transcriptional activators or repressors of their target genes. Theoretically, the possibility to modulate NRs activity with small molecules makes them ideal therapeutic targets, although the complexity of their signaling makes drug design challenging. In this review, we discuss the role of NRs in erythropoiesis, in both homeostatic and stress conditions. This knowledge is important in view of modulating red blood cells production in disease conditions, such as anemias, and for the expansion of erythroid cells in culture for research purposes and for reaching the long-term goal of cultured blood for transfusion.

Effect of Glucocorticosteroids in Diamond-Blackfan Anaemia: Maybe Not as Elusive as It Seems

Diamond-Blackfan anaemia (DBA) is a red blood cell aplasia that in the majority of cases is associated with ribosomal protein (RP) aberrations. However, the mechanism by which this disorder leads to such a specific phenotype remains unclear. Even more elusive is the reason why non-specific agents such as glucocorticosteroids (GCs), also known as glucocorticoids, are an effective therapy for DBA. In this review, we (1) explore why GCs are successful in DBA treatment, (2) discuss the effect of GCs on erythropoiesis, and (3) summarise the GC impact on crucial pathways deregulated in DBA. Furthermore, we show that GCs do not regulate DBA erythropoiesis via a single mechanism but more likely via several interdependent pathways.

Individualized Dosage Optimization for Myeloablative Conditioning before Unrelated Cord Blood Transplantation in a Diamond–Blackfan Anemia Patient with Germline RPL11 Mutation: A Case Study

Unrelated cord blood transplantation (CBT) for Diamond–Blackfan anemia (DBA), a systemic ribosomopathy affecting the disposition of conditioning agents, has resulted in outcomes inferior to those by transplantations from matched donors. We report the experience of the pharmacokinetics-guided myeloablative unrelated CBT in a DBA patient with a germline RPL11 mutation. The conditioning consisted of individualized dosing of fludarabine (based on weight and renal function with a target area under the curve (AUC) of 17.5 mg·h/L) and busulfan (based on therapeutic drug monitoring with a target AUC of 90 mg·h/L), as well as dosing and timing of thymoglobulin (based on body weight and pre-dose lymphocyte count to target pre-CBT AUC of 30.7 AU·day/mL and post-CBT AUC of 4.3 AU·day/mL, respectively). The pharmacokinetic measures resulted in a 27.5% reduction in busulfan and a 35% increase in fludarabine, as well as an over three-fold increase in thymoglobulin dosage with the start time changed to day-9 instead of day-2 compared to regular regimens. The transplantation resulted in rapid, complete, and sustained hematopoietic engraftment. The patient is now healthy over 3 years after CBT. A pharmacokinetics-guided individualized dosing strategy for conditioning might be a feasible option to improve the outcomes of DBA patients receiving unrelated myeloablative CBT.

The landscape of pediatric Diamond-Blackfan anemia in Switzerland: genotype and phenotype characteristics

Diamond-Blackfan anemia (DBA) is caused mainly by genetic mutations in large (RPL) or small ribosomal subunit genes (RPS) and presents with macrocytic anemia and congenital malformations. Clinical differences between genotypes are insufficiently understood. The aim of this study was to assess clinical features, treatment strategies, and genotypes in the Swiss pediatric DBA population. We retrospectively reviewed medical charts of pediatric patients with DBA in Switzerland and stratified patients by RPL versus RPS mutations. We report 17 DBA patients in Switzerland who were all genetically investigated. In our cohort, patients showed a wide spectrum of clinical presentations and treatment needs. We found a high proportion of physical malformations (77%) including lower limb (17%) and anorectal (12%) malformations. The two patients with anorectal malformations presented both with antepositioning of the anus needing surgery within the first 15 months of life. One of these patients had sphincteric dysfunction, the other coccygeal agenesis. We found that included patients with an RPL mutation more frequently tended to have physical malformations and a milder anemia compared to patients with an RPS mutation (median hemoglobin at diagnosis 76 g/l versus 22 g/l).Conclusion: We illustrate the wide clinical and genetic spectrum of DBA in Switzerland. Our findings highlight the need to take this diagnosis into consideration in patients with severe anemia but also in patients with mild anemia where malformations are present. Lower limb and anorectal malformation extend the spectrum of DBA-associated malformations. What is Known? • There is a large variation in the phenotype of Diamond-Blackfan Anemia (DBA) and diversity of genetic mutations. • Malformation of the upper limbs, head and face, heart, and genitourinary system is frequently identified. What is New? • Patients with lower limb and anorectal malformations were repetitively found in our cohort enlarging the clinical spectrum of malformations. • We show two patients of the same family with a DBA-like condition where the same RPL17 variant was identified.

Dysregulation of ribosome-related genes in ankylosing spondylitis: a systems biology approach and experimental method

Background

Ankylosing spondylitis (AS) is an autoimmune rheumatic disease. Few candidate gene associations have been reported for AS and the current understanding of its pathogenesis remains still poor. Thus, the exact mechanism of AS is needed to urgently be disclosed. The purpose of this study was to identify candidate genes involving in AS disease.

Methods and results

GSE25101 publicly available microarray and GSE117769 RNA-seq datasets of AS patients were obtained for bioinformatics analyses. Gene set enrichment analysis showed that in the microarray dataset, the ribosome pathway was significantly up-regulated in AS compared with controls. Furthermore, some ribosomal components demonstrated overexpression in patients in the RNA-seq dataset. To confirm the findings, 20 AS patients and 20 matching controls were selected from the Rheumatology Research Center clinic, Shariati Hospital. PBMCs were separated from whole blood and RNA contents were extracted. Following the results of datasets analysis, the expression level of rRNA5.8S pseudogene, rRNA18S pseudogene, RPL23, RPL7, and RPL17 genes were measured through real-time PCR. Our findings showed dysregulation of rRNA5.8S and rRNA18S pseudogenes, and also the RPL17 gene in patients.

Conclusion

Considering that genes involved in ribosome biogenesis contributed to some AS-associated biological processes as well as diseases that have comorbidities with AS, our results might advance our understanding of the pathological mechanisms of ankylosing spondylitis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-021-04662-2.

Hematopoietic stem cell transplantation for classical inherited bone marrow failure syndromes: an update

INTRODUCTION

Inherited bone marrow failure syndromes (IBMFS) feature complex molecular pathophysiology resulting in ineffective hematopoiesis and increased risk of progression to myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). Allogenic hematopoietic stem cell transplantation (HSCT) is the only well-established cure for the hematological manifestations of these diseases.

AREAS COVERED

In recent years, analysis of large series from international databases (mainly from the European Bone Marrow Transplantation [EBMT] database) has improved knowledge about HSCT in IBMFS. This review, following a thorough Medline search of the pertinent published studies, reports the most recent data on HSCT in IBMFS.

EXPERT OPINION

Despite the common features, IBMFS are very different in their manifestations and in the occurrence and management of HSCT complications. Thus, a 'disease-specific' HSCT using an optimized conditioning regimen based on the characteristics of the disease is essential for achieving long-term survival. The phenotypical heterogeneity associated with extramedullary abnormalities has to be carefully evaluated before HSCT because transplantation may only correct impaired hematopoiesis. HSCT may be associated with the risk of treatment-related mortality and with significant early and late morbidity. For these reasons, the benefits should be carefully weighed against the risks.

Recommendations on hematopoietic stem cell transplantation for patients with Diamond-Blackfan anemia. On behalf of the Pediatric Diseases and Severe Aplastic Anemia Working Parties of the EBMT

Diamond Blackfan anemia (DBA) is a rare congenital syndrome presenting primarily as pure red cell aplasia with constitutional abnormalities and cancer predisposition. Established treatment options are corticosteroids, regular erythrocyte transfusions with iron chelation therapy, and hematopoietic stem cell transplantation (HSCT). To date, HSCT is the only definitive curative treatment for the hematological phenotype of DBA, but there is little experience with its use. Given the rarity of the disease and its unique features, an expert panel agreed to draw up a set of recommendations on the use of HSCT in DBA to guide clinical decision-making and practice. The recommendations address indications, pretransplant patient evaluation, donor selection, stem cell sources, conditioning regimens, prophylaxis of rejection and graft versus host disease, and post-transplant follow-up.

Dried blood spot metabolomics reveals a metabolic fingerprint with diagnostic potential for Diamond Blackfan Anaemia

The diagnostic evaluation of Diamond Blackfan Anaemia (DBA), an inherited bone marrow failure syndrome characterised by erythroid hypoplasia, is challenging because of a broad phenotypic variability and the lack of functional screening tests. In this study, we explored the potential of untargeted metabolomics to diagnose DBA. In dried blood spot samples from 18 DBA patients and 40 healthy controls, a total of 1752 unique metabolite features were identified. This metabolic fingerprint was incorporated into a machine‐learning algorithm, and a binary classification model was constructed using a training set. The model showed high performance characteristics (average accuracy 91·9%), and correct prediction of class was observed for all controls (n = 12) and all but one patient (n = 4/5) from the validation or ‘test’ set (accuracy 94%). Importantly, in patients with congenital dyserythropoietic anaemia (CDA) – an erythroid disorder with overlapping features – we observed a distinct metabolic profile, indicating the disease specificity of the DBA fingerprint and underlining its diagnostic potential. Furthermore, when exploring phenotypic heterogeneity, DBA treatment subgroups yielded discrete differences in metabolic profiles, which could hold future potential in understanding therapy responses. Our data demonstrate that untargeted metabolomics in dried blood spots is a promising new diagnostic tool for DBA.

Favorable outcomes of hematopoietic stem cell transplantation in children and adolescents with Diamond-Blackfan anemia

Diamond-Blackfan anemia (DBA) is a congenital pure red cell aplasia associated with congenital abnormalities and cancer predisposition. Allogeneic hematopoietic stem cell transplantation (HSCT) can correct the hematological phenotype and is indicated in transfusion-dependent patients. In 70 children reported to the German DBA and French HSCT registries, HSCT was performed from 1985 to 2017. Median age at HSCT was 5.5 years (range, 0.9-17.3 years). Two-thirds of patients (64%) were transplanted from a matched sibling donor (MSD), and most procedures were performed after the year 1999 (73%). Primary engraftment was achieved in all patients. One patient developed secondary graft failure. Cumulative incidence of acute graft-versus-host disease (GVHD) was 24% for °II-IV (95% confidence interval [CI], 16% to 37%) and 7% for °III-IV (95% CI, 3% to 17%); cumulative incidence of chronic GVHD was 11% (95% CI, 5% to 22%). The probability of chronic GVHD-free survival (cGFS) was 87% (95% CI, 79% to 95%) and significantly improved over time (<2000: 68% [95% CI, 47% to 89%] vs ≥2000: 94% [95% CI, 87% to 100%], P < .01). cGFS was comparable following HSCT from a MSD and an unrelated donor (UD). Of note, no severe chronic GVHD or deaths were reported following MSD-HSCT after 1999. The difference of cGFS in children transplanted <10 years of age compared with older patients did not reach statistical significance (<10 years: 90% [95% CI, 81% to 99%] vs 10-18 years 78% [95% CI, 58% to 98%]). In summary, these data indicate that HSCT is efficient and safe in young DBA patients and should be considered if a MSD or matched UD is available. HSCT for transfusion dependency only must be critically discussed in older patients.

Diamond-Blackfan Anemia: 2 Cases With a Twist

BACKGROUND

Diamond-Blackfan anemia is a rare inherited bone marrow failure disease. Typical findings include hypoplastic macrocytic anemia, congenital anomalies, and a predisposition to cancer. The molecular basis of the disease is heterozygous mutations of ribosomal proteins without a strict correlation between genotype and phenotype.

OBSERVATION

We present 2 cases of Diamond-Blackfan anemia diagnosed during infancy with interesting clinical, molecular, and family characteristics.

CONCLUSIONS

A thorough evaluation of all family members is imperative to identify possible 'silent carriers' who are those with no physical stigmata and minor or absent hematologic manifestations. New mutations could add in the map of the disease.

How I manage acquired pure red cell aplasia in adults

Pure red cell aplasia (PRCA) is a rare hematological disorder with multiple etiologies. The multifaceted nature of this disease is emphasized by the variety of concomitant clinical features. Classic idiopathic presentation aside, prompt recognition of pathogenetic clues is important because of their diagnostic and therapeutic implications. As a consequence, treatment of PRCA is diverse and strictly dependent on the presented clinical scenario. Here, we propose a series of clinical vignettes that showcase instructive representative situations derived from our routine clinical practice. Using these illustrative clinical cases, we review the diagnostic workup needed for a precise diagnosis and the currently available therapeutic options, discussing their applications in regard to the various PRCA-associated conditions and individual patients' characteristics. Finally, we propose a treatment algorithm that may offer guidance for personalized therapeutic recommendations.

The Interplay between Drivers of Erythropoiesis and Iron Homeostasis in Rare Hereditary Anemias: Tipping the Balance

Rare hereditary anemias (RHA) represent a group of disorders characterized by either impaired production of erythrocytes or decreased survival (i.e., hemolysis). In RHA, the regulation of iron metabolism and erythropoiesis is often disturbed, leading to iron overload or worsening of chronic anemia due to unavailability of iron for erythropoiesis. Whereas iron overload generally is a well-recognized complication in patients requiring regular blood transfusions, it is also a significant problem in a large proportion of patients with RHA that are not transfusion dependent. This indicates that RHA share disease-specific defects in erythroid development that are linked to intrinsic defects in iron metabolism. In this review, we discuss the key regulators involved in the interplay between iron and erythropoiesis and their importance in the spectrum of RHA.

Diamond-Blackfan Anemia: A Case Report and Review of the Literature

We report a case of a male neonate delivered urgently via cesarean at thirty-five 5/7 weeks gestation for non-reassuring fetal monitoring who was found to have severe anemia at birth that could not be explained by acute blood loss. He was born to a 24-year-old mother, whose pregnancy was complicated by abnormal ultrasound findings, including a radial ray defect and fetal growth restriction. Trio rapid whole-exome sequencing (rWES) confirmed Diamond-Blackfan anemia in both the neonate and mother. This case highlights the importance of fetal surveillance and the clinical utility of rWES in the neonatal intensive care setting.

Special pre- and posttransplant considerations in inherited bone marrow failure and hematopoietic malignancy predisposition syndromes

Advances in the diagnosis and treatment of inherited bone marrow failure syndromes (IBMFS) have provided insight into the complexity of these diseases. The diseases are heterogeneous and characterized by developmental abnormalities, progressive marrow failure, and predisposition to cancer. A correct diagnosis allows for appropriate treatment, genetic counseling, and cancer surveillance. The common IBMFSs are Fanconi anemia, dyskeratosis congenita, and Diamond-Blackfan anemia. Hematopoietic cell transplantation (HCT) offers curative treatment of the hematologic complications of IBMFS. Because of the systemic nature of these diseases, transplant strategies are modified to decrease immediate and late toxicities. HCT from HLA-matched related or unrelated donors offers excellent survival for young patients in aplasia. Challenges include the treatment of adults with marrow aplasia, presentation with myeloid malignancy regardless of age, and early detection or treatment of cancer. In this article, I will describe our approach and evaluation of patients transplanted with IBMFS and review most frequent complications before and after transplant.

Reduced-intensity conditioning is effective for hematopoietic stem cell transplantation in young pediatric patients with Diamond-Blackfan anemia

Allogeneic hematopoietic stem cell transplantation (HSCT) is the only curative therapy for the hematologic manifestations of Diamond-Blackfan anemia (DBA). However, data regarding the optimal conditioning regimen for DBA patients are limited. We retrospectively compared the outcomes of DBA patients who underwent HSCT using either myeloablative conditioning (MAC) or reduced-intensity conditioning (RIC) regimens. The patients belonged to a cohort treated at our hospitals between 2000 and 2018. HSCT was performed in 27 of 165 patients (16.4%). The median age at the time of HSCT was 3.6 years. Stem cell sources included bone marrow for 25 patients (HLA-matched sibling donors, n = 5; HLA-mismatched related donors, n = 2; HLA-matched/mismatched unrelated donors, n = 18) or cord blood for 2 patients. MAC or RIC regimens were used in 12 and 15 patients, respectively. Engraftment was successful in all 27 patients who underwent HSCT. Three patients who underwent HSCT using MAC regimens developed sinusoidal obstruction syndrome. The 3-year overall survival (OS) and failure-free survival rates (FFS) post-transplantations were 95.2% and 88.4%, respectively, with no significant differences between MAC and RIC regimens. Our data suggest that HSCTs using RIC regimens are effective and obtain engraftment with excellent OS and FFS for young DBA patients.

Diamond-Blackfan anemia with mutation in RPS19: A case report and an overview of published pieces of literature

Introduction

Diamond-Blackfan anemia (DBA), one of a rare group of inherited bone marrow failure syndromes, is characterized by red cell failure, the presence of congenital anomalies, and cancer predisposition. It can be caused by mutations in the RPS19 gene (25% of the cases).

Methods

This case report describes a 10-month-old boy who presented with 2 months' history of gradually increasing weakness and pallor.

Results

The patient was diagnosed as a case of DBA based on peripheral blood finding, bone marrow aspiration with trephine biopsy reports, and genetic mutation analysis of the RPS19 gene. His father refused hematopoietic stem cell transplantation for financial constraints. Patient received prednisolone therapy with oral folic acid and iron supplements.

Conclusion

Hemoglobin raised from 6.7 to 9.8g/dL after 1 month of therapeutic intervention.

Hematopoietic cell transplantation for Diamond Blackfan anemia: A report from the Pediatric Group of the Brazilian Bone Marrow Transplantation Society

OBJECTIVES

The aim of this study was to analyze the outcomes of children with Diamond-Blackfan anemia (DBA) treated in Brazil with hematopoietic cell transplantation (HCT).

METHODS

We performed a retrospective analysis of 44 pediatrics patients transplanted between 1990 and 2018. The median age of patients was 5 years, and 57% were male. Twenty-five received their first HCT from an HLA-matched sibling donor (MSD), 12 from a HLA matched unrelated bone marrow donor (MUD 10/10, n = 12) and 7 other HLA mismatched donors (MMD).

RESULTS

After a median follow-up of 4 years, estimate 5-year overall survival (OS) for the entire cohort was 70%, 80% for MSD group, 73% for MUD, and 29% for MMD. Thirty-eight out of the 44 evaluable patients engrafted successfully. Primary and secondary graft failure was observed in five and three patients, respectively. Rates of grade II-IV and III-IV acute graft-versus-host disease (aGVHD) were 25% and 18%, respectively. Nine patients developed chronic GVHD (cGVHD).

CONCLUSION

Overall survival rates observed after HLA matched donors transplant for DBA were comparable to those reported from higher-income countries and international registries.

A Novel Deletion in the RPL5 Gene in a Lebanese Child With Diamond Blackfan Anemia Unresponsive to Steroid Treatment

Diamond-Blackfan Anemia (DBA) is a rare inherited form of pure red cell aplasia that usually manifests in infancy or early childhood, and is characterized by normochromic macrocytic anemia and bone marrow erythroblastopenia. The majority of DBA cases are associated with mutations in ribosomal protein genes. Here, we describe a Lebanese girl with RPL5-mutated DBA unresponsive to steroid treatment who died from complications following late hematopoietic stem cell transplantation performed at the age of 15 years.

Bochdalek hernia with Diamond-Blackfan anemia associated with RPS19 gene mutation: A case report

RATIONALE

Diamond-Blackfan anemia (DBA) is a rare inherited marrow disorder, characterized by erythrocyte aplasia and is associated with congenital anomalies and a susceptibility to cancer. Although congenital abnormalities have been observed in ∼50% of DBA patients, the occurrence of an associated congenital diaphragmatic hernia (CDH) has rarely been reported.

PATIENT CONCERNS

A 19-month-old male child was referred to our pediatric hematology-oncology outpatient clinic with anemic appearance. He presented to us with recurrent anemia, short stature, and developmental delay.

DIAGNOSIS

On bone marrow examination, only erythropoietic cells were markedly decreased in number, whereas other cell lines were unaffected. An abdominal computed tomography scan revealed a Bochdalek type of CDH. A genetic analysis revealed heterozygous mutation of RPS19; therefore, he was diagnosed as having DBA with CDH.

INTERVENTIONS

The patient received an initial packed red blood cell transfusion, followed by an administration of oral prednisone.

OUTCOMES

The patient is maintained on oral prednisone administered at a dose of 0.3 mg/kg every alternate day and has since a hemoglobin level of >9.0 g/dL without further RBC transfusions.

LESSONS

We learned that a Bochdalek type of CDH can manifest in a DBA patient with RPS19 gene mutation. Therefore, patients diagnosed with the latter disorder should also be screened for an early detection of potential CDHs.

Danazol: An Effective and Underutilised Treatment Option in Diamond-Blackfan Anaemia

Diamond-Blackfan anaemia (DBA) is a rare congenital red cell aplasia that presents in infancy. The exact molecular mechanism of ineffective erythropoiesis and red cell aplasia remains unclear, rendering targeted therapy elusive. The mainstay treatment of DBA is with regular blood transfusion and long-term corticosteroids, both of which have long-term side effects. We report a case of DBA successfully treated with danazol, a synthetic androgen, and suggest that danazol be considered as a viable option in patients who become refractory to steroids and are considered high risk or unfit for allogeneic stem cell transplantation.