The Diverse Genomic Landscape of Diamond-Blackfan Anemia: Two Novel Variants and a Mini-Review.

Diamond-Blackfan anemia (DBA) is a ribosomopathy characterized by bone marrow erythroid hypoplasia, which typically presents with severe anemia within the first months of life. DBA is typically attributed to a heterozygous mutation in a ribosomal protein (RP) gene along with a defect in the ribosomal RNA (rRNA) maturation or levels. Besides classic DBA, DBA-like disease has been described with variations in 16 genes (primarily in GATA1, followed by ADA2 alias CECR1, HEATR3, and TSR2). To date, more than a thousand variants have been reported in RP genes. Splice variants represent 6% of identifiable genetic defects in DBA, while their prevalence is 14.3% when focusing on pathogenic and likely pathogenic (P/LP) variants, thus highlighting the impact of such alterations in RP translation and, subsequently, in ribosome levels. We hereby present two cases with novel pathogenic splice variants in RPS17 and RPS26. Associations of DBA-related variants with specific phenotypic features and malignancies and the molecular consequences of pathogenic variations for each DBA-related gene are discussed. The determinants of the spontaneous remission, cancer development, variable expression of the same variants between families, and selectivity of RP defects towards the erythroid lineage remain to be elucidated.

Hemorrhage of Upper Digestive and Respiratory Tracts in a Child with Glanzmann Thrombasthenia.

Glanzmann thrombasthenia (GT) is an autosomal recessive platelet disorder that could cause mild to severe bleeding episodes. The incidence is approximately 1 per 1,000,000 births. Patients with GT frequently have mucocutaneous bleeding with absent platelet aggregation in response to all physiologic stimuli, but a normal platelet count and morphology. Specifically, the glycoprotein IIb/IIIa (GP IIb/IIIa) complex is either inadequate or dysfunctional. This case reports a 3.5-year-old boy with Glanzmann thrombasthenia who had two episodes with uncontrolled hemorrhage from upper digestive and respiratory tracts, the first with the bleeding point found in the left tonsil and the second in the adenoids.

Unraveling the Immune Microenvironment in Classic Hodgkin Lymphoma: Prognostic and Therapeutic Implications.

Classic Hodgkin lymphoma (cHL) is a lymphoid neoplasm composed of rare neoplastic Hodgkin and Reed-Sternberg (HRS) cells surrounded by a reactive tumor microenvironment (TME) with suppressive properties against anti-tumor immunity. TME is mainly composed of T cells (CD4 helper, CD8 cytotoxic and regulatory) and tumor-associated macrophages (TAMs), but the impact of these cells on the natural course of the disease is not absolutely understood. TME contributes to the immune evasion of neoplastic HRS cells through the production of various cytokines and/or the aberrant expression of immune checkpoint molecules in ways that have not been fully understood yet. Herein, we present a comprehensive review of findings regarding the cellular components and the molecular features of the immune TME in cHL, its correlation with treatment response and prognosis, as well as the potential targeting of the TME with novel therapies. Among all cells, macrophages appear to be a most appealing target for immunomodulatory therapies, based on their functional plasticity and antitumor potency.

Identification and Functional Analysis of Known and New Mutations in the Transcription Factor KLF1 Linked with ß-Thalassemia-like Phenotypes.

The erythroid transcriptional factor Krüppel-like factor 1 (KLF1) is a master regulator of erythropoiesis. Mutations that cause KLF1 haploinsufficiency have been linked to increased fetal hemoglobin (HbF) and hemoglobin A2 (HbA2) levels with ameliorative effects on the severity of ß-thalassemia. With the aim of determining if KLF1 gene variations might play a role in the modulation of ß-thalassemia, in this study we screened 17 subjects showing a ß-thalassemia-like phenotype with a slight or marked increase in HbA2 and HbF levels. Overall, seven KLF1 gene variants were identified, of which two were novel. Functional studies were performed in K562 cells to clarify the pathogenic significance of these mutations. Our study confirmed the ameliorative effect on the thalassemia phenotype for some of these variants but also raised the notion that certain mutations may have deteriorating effects by increasing KLF1 expression levels or enhancing its transcriptional activity. Our results indicate that functional studies are required to evaluate the possible effects of KLF1 mutations, particularly in the case of the co-existence of two or more mutations that could differently contribute to KLF1 expression or transcriptional activity and consequently to the thalassemia phenotype.

Serum PCSK9 levels in infants with deviant birth weight: a biomarker of the lipoprotein metabolism.

OBJECTIVE: Proprotein Convertase Subtilisin/Kexin-Type 9 (PCSK9), a modulator of low-density lipoprotein (LDL) cholesterol metabolism, has been reported to be a promising biomarker for evaluating lipoprotein metabolism; however, evidence in infants is limited. In the current study, we sought to investigate potential differences in serum PCSK9 levels between infants with deviant birth weight and controls. METHODS: We enrolled 82 infants, classified into 33 small (SGA), 32 appropriate (AGA), and 17 large for gestation (LGA) infants. Serum PCSK9 was measured on routine blood analysis within the first postnatal 48 h. RESULTS: PCSK9 was significantly higher in SGA as compared to AGA and LGA infants [322 (236-431) as compared to 263 (217-302) and 218 (194-291) ng/ml respectively, p = .011]. In comparison to term AGA infants, PCSK9 was significantly elevated in preterm AGA and SGA infants. We also found a significantly higher level of PCSK9 in term female SGA infants as compared to term male SGA infants [325 (293-377) as compared to 174 (163-216) ng/ml, p = .011]. PCSK9 was significantly correlated with gestational age (R = -0.404, p < .001), birth weight (R = -0.419, p < .001), total cholesterol (R = 0.248, p = .028) and LDL cholesterol (R = 0.370, p = .001). SGA status (OR 2.56, p = .004, 95% CI 1.83-4.28) and prematurity (OR 3.10, p = .001, 95% CI 1.39-4.82) were strongly related to serum PCSK9 levels. CONCLUSION: PCSK9 levels were significantly associated with total and LDL cholesterol. Moreover, PCSK9 levels were higher in preterm and SGA infants, suggesting that PCSK9 might be a promising biomarker for evaluating infants with increased later cardiovascular risk.HighlightsWhat's already known? Proprotein Convertase Subtilisin/Kexin-Type 9 (PCSK9) is a promising biomarker for evaluating lipoprotein metabolism; however, evidence in infants is limited. Infants that were born with a deviant birth weight have a unique lipoprotein metabolism profile.What this study adds? Serum PCSK9 levels were significantly associated with total and LDL cholesterol. PCSK9 levels were higher in preterm and small for gestation infants, suggesting that PCSK9 might be a promising biomarker for evaluating infants with increased later cardiovascular risk.

Are the current feeding volumes adequate for the growth of very preterm neonates?

Postnatal growth failure, a common problem in very preterm neonates associated with adverse neurodevelopmental outcome, has recently been shown not to be inevitable. There is a wide discussion regarding feeding practices of very preterm neonates, specifically regarding feeding volumes and nutrients supply to avoid postnatal growth failure. Current guidelines recommend an energy intake of 115­140 kcal /kg per d with a considerably higher upper limit of 160 kcal/kg per d. The feeding volume corresponding to this energy supply is not higher than 200 ml/kg in most cases. From the other side, randomised and observational studies used higher feeding volumes, and these were associated with better weight gain and growth, while no complications were noted. Taking into account the above, nutritional practices should be individualised in each very and extremely preterm infant trying to reduce postnatal growth failure, pointing out that available data are inconclusive regarding the effect of high-volume feeds on growth. Large clinical trials are necessary to conclude in the best feeding practices of very preterm neonates.

Gaucher Disease Type 2 Manifested as Hemophagocytic Lymphohistiocytosis in a Neonate in the COVID-19 Era.

BACKGROUND: A term neonate presented with persistent severe thrombocytopenia, elevated liver enzymes, conjugated hyperbilirubinemia, hepatosplenomegaly, and mild hypotonia. OBSERVATIONS: A thorough workup for infections, congenital thrombocytopenias, and neonatal malignancies was negative. Because of increased anti-SARS-CoV-2 IgG antibodies after maternal COVID-19, multisystem inflammatory syndrome of neonates was considered and intravenous immunoglobulin was administered. The clinical condition of the neonate deteriorated and due to laboratory evidence of hyperinflammation, hemophagocytic lymphohistiocytosis was suspected, and treatment with etoposide and dexamethasone was initiated with temporary stabilization. Gaucher disease type 2 was eventually diagnosed. CONCLUSION: Gaucher disease can rarely present in neonates as hemophagocytic lymphohistiocytosis.

Unusual Manifestations of Kawasaki Disease in the COVID Era: A Case Series and Review of the Literature.

Kawasaki disease (KD) is an acute medium-vessel vasculitis, mainly affecting infants older than six months and children under five years. It predisposes to the development of coronary artery aneurysms and constitutes the leading cause of acquired heart disease in children. Its diagnosis is based on clinical criteria, namely, fever lasting for ≥ five days together with at least four of the five principal clinical features of the disease. Occasionally, children with KD present with fever, but they fulfill only some of the five principal criteria, and this is described as incomplete KD. Furthermore, "atypical" KD is a term that is usually used for cases that appear with rather unusual clinical manifestations, which complicate clinical judgment and may delay diagnosis and treatment. In this case series, we present four cases of KD with rather unusual clinical features: a five-year-old boy with lobar pneumonia, a six-year-old girl with orange-brown chromonychia appearing on the 10th day of the disease, a 2.5-month-old infant with prolonged fever and urinary tract infection, and an 18-month-old infant with refractory KD and high suspicion of multisystem inflammatory syndrome in children (MIS-C). A literature review on the unusual manifestations of atypical KD was performed to identify clinical findings that must alert the clinician to consider this clinical entity.

Luspatercept: A New Tool for the Treatment of Anemia Related to ß-Thalassemia, Myelodysplastic Syndromes and Primary Myelofibrosis.

Anemia is a common feature of both benign and malignant hematologic diseases. Beta-thalassemia (ß-thalassemia) syndromes are a group of hereditary disorders characterized by ineffective erythropoiesis, due to a genetic deficiency in the synthesis of the beta chains of hemoglobin, often accompanied by severe anemia and the need for red blood cell (RBC) transfusions. Myelodysplastic syndromes (MDS) are characterized by cytopenia(s) and ineffective hematopoiesis, despite a hypercellular bone marrow. Primary myelofibrosis (PMF) is a clonal myeloproliferative neoplasm characterized by reactive fibrosis of the bone marrow, accompanied by extramedullary hematopoiesis. Luspatercept, previously known as ACE-536, is a fusion protein that combines a modified activin receptor IIB (ActRIIB), a member of the transforming growth factor-ß (TGF-ß) superfamily, with the Fc domain of human immunoglobulin G (IgG1). It has shown efficacy in the treatment of anemia due to beta ß-thalassemia, MDS and PMF and recently gained approval by the Federal Drug Agency (FDA) and the European Medicines Agency (EMA) for transfusion-dependent (TD) patients with ß-thalassemia and very low to intermediate-risk patients with MDS with ringed sideroblasts who have failed to respond to, or are ineligible for, an erythropoiesis-stimulating agent. In this review, we describe the key pathways involved in normal hematopoiesis and the possible mechanism of action of luspatercept, present its development and data from the most recent clinical trials in ß-thalassemia, MDS and PMF, and discuss its potential use in the treatment of these hematological disorders.

The role of epigenetics in childhood autoimmune diseases with hematological manifestations.

Autoimmune diseases with hematological manifestations are often characterized by chronicity and relapses despite treatment, and the underlying pathogenetic mechanisms remain unknown. Epigenetic alterations play a vital role in the deregulation of immune tolerance and the development of autoimmune diseases. In recent years, study of epigenetic mechanisms in both adult and childhood autoimmune disorders has been seeking to explain the pathophysiology of these heterogeneous diseases and to elucidate the interaction between genetic and environmental factors. Various mechanisms, including DNA methylation, histone modifications (chromatin remodeling), and noncoding RNAs (ncRNAs), have been studied extensively in the context of autoimmune diseases. This paper summarizes the epigenetic patterns in some of the most common childhood autoimmune disorders with hematological manifestations, based on epigenetic studies in children with primary immune thrombocytopenia (ITP), systemic lupus erythematosus (SLE), and juvenile idiopathic arthritis (JIA). Research findings indicate that methylation changes in genes expressed on T cells, modifications at a variety of histone sites, and alterations in the expression of several ncRNAs are involved in the pathogenesis of these diseases. These mechanisms not only determine the development of these diseases but also affect the severity of the clinical presentation and biochemical markers. Further studies will provide new tools for the prevention and diagnosis of childhood autoimmune disorders, and possible novel treatment options.

Safety of Ferric Carboxymaltose in Children: Report of a Case Series from Greece and Review of the Literature.

BACKGROUND: Parenteral iron is generally considered safe in adults, and severe adverse events are extremely rare. Ferric carboxymaltose (FCM), a third-generation parenteral iron product, is not licensed for pediatric use. OBJECTIVE: The aim of this study was to present our data on the safety of FCM in children with iron deficiency (ID) and/or iron deficiency anemia (IDA) and to investigate through a systematic literature review articles reporting on the safety of FCM use in children with ID/IDA. PATIENTS AND METHODS: Safety data regarding children treated with FCM for ID/IDA from four pediatric departments in Greece over a 26-month period are presented. Additionally, a literature search was performed in PubMed, Scopus, and Google Scholar on December 4, 2021 for articles reporting on the use of FCM in children with ID/IDA. Review articles, guidelines, case reports/case series, and reports on the use of FCM for conditions other than ID/IDA were excluded. Identified articles were screened for all reported adverse events (AE) that were graded according to the Common Terminology Criteria for Adverse Events, version 5.0. RESULTS: In our cohort, 37 children with ID/IDA received 41 FCM infusions. All infusions were tolerated well. In addition, 11 articles reporting 1231 infusions of FCM in 866 children were identified in the literature. Among them, 52 (6%) children developed AE that were graded as mild or moderate (grades I-III). CONCLUSIONS: Our patient cohort and this literature review provide further evidence for the good safety profile of FCM in children, although well-designed prospective clinical trials with appropriate safety endpoints are still required.

Novel Therapeutic Advances in ß-Thalassemia.

The main characteristic of the pathophysiology of ß-thalassemia is reduced ß-globin chain production. The inevitable imbalance in the α/ß-globin ratio and α-globin accumulation lead to oxidative stress in the erythroid lineage, apoptosis, and ineffective erythropoiesis. The result is compensatory hematopoietic expansion and impaired hepcidin production that causes increased intestinal iron absorption and progressive iron overload. Chronic hemolysis and red blood cell transfusions also contribute to iron tissue deposition. A better understanding of the underlying mechanisms led to the detection of new curative or "disease-modifying" therapeutic options. Substantial evolvement has been made in allogeneic hematopoietic stem cell transplantation with current clinical trials investigating new condition regimens as well as different donors and stem cell source options. Gene therapy has also moved forward, and phase 2 clinical trials with the use of ß-globin insertion techniques have recently been successfully completed leading to approval for use in transfusion-dependent patients. Genetic and epigenetic manipulation of the γ- or ß-globin gene have entered the clinical trial setting. Agents such as TGF-ß ligand traps and pyruvate kinase activators, which reduce the ineffective erythropoiesis, have been tested in clinical trials with favorable results. One TGF-ß ligand trap, luspatercept, has been approved for use in adults with transfusion-dependent ß-thalassemia. The induction of HbF with the phosphodiesterase 9 inhibitor IMR-687, which increase cyclic guanosine monophosphate, is currently being tested. Another therapeutic approach is to target the dysregulation of iron homeostasis, using, for example, hepcidin agonists (inhibitors of TMPRSS6 and minihepcidins) or ferroportin inhibitors (VIT-2763). This review provides an update on the novel therapeutic options that are presently in development at the clinical level in ß-thalassemia.

A refugee child with multiple patterned ecchymoses: a diagnostic dilemma between nonaccidental injury and primary hemostatic defect.

A 4-year-old girl from Syria presented to the hospital with multiple bruises on her body. Bruises were observed in protected areas in a shape of fingerprints and objects, while no other bruises occurred during hospitalization. The parents also reported a history of bleeding diathesis from infancy. Both the initial laboratory evaluation and the secondary tests done for possible thrombocytopenia and coagulation factors deficiencies were normal. Thus, the nonaccidental injury protocol of the Hospital was activated, and the possibility of abuse was not quite evident. Investigation for platelet disorders followed. Platelet aggregation test and flow cytometry were indicative of Glanzmann's thrombasthenia. It is of great importance in these cases, that the doctor eliminates any possibility of physical abuse and examines the patient for common and rare primary hemostatic defects, although both can co-exist.

A Novel εγδß-Thalassemia Deletion Associated with Severe Anemia at Birth and a ß-Thalassemia Intermedia Phenotype Later in Life in Three Generations of a Greek Family.

We describe a novel deletion causing heterozygous εγδß-thalassemia (εγδß-thal) across three generations of a Greek family. The Greek deletion is about 72 kb in length, spanning from the hypersensitive site 4 (HS4) in the locus control region (LCR) to the 3' end of the ß-globin gene, thus encompassing the entire ß-globin gene cluster. The deletion caused severe but transient neonatal anemia and a non transfusion-dependent chronic hemolytic anemia state later in life, resembling mild ß-thalassemia intermedia (ß-TI) rather than ß-thalassemia (ß-thal) trait, as had been previously reported. Apart from the presentation of clinical and laboratory characteristics, the challenges involving clinical management are also discussed.

Risk Factors for Severity in Children with Coronavirus Disease 2019: A Comprehensive Literature Review.

The coronavirus disease 2019 (COVID-19) pandemic has affected hundreds of thousands of people. The authors performed a comprehensive literature review to identify the underlying mechanisms and risk factors for severe COVID-19 in children. Children have accounted for 1.7% to 2% of the diagnosed cases of COVID-19. They often have milder disease than adults, and child deaths have been rare. The documented risk factors for severe disease in children are young age and underlying comorbidities. It is unclear whether male gender and certain laboratory and imaging findings are also risk factors. Reports on other potential factors have not been published.

Cyanosis Due to Methemoglobinemia as the Presenting Sign of Glucose-6-Phosphate Dehydrogenase Deficiency in a Child: Diagnostic and Clinical Implications.

A previously healthy 3-year-old boy presented with pallor, jaundice, cyanosis, and a 24-hour history of vomiting and anorexia following fava bean ingestion. Clinical examination and laboratory findings were consistent with severe nonimmune hemolytic anemia with methemoglobinemia. Given the patient's history, a previously unrecognized glucose-6-phosphate dehydrogenase deficiency was suspected and diagnosed. The aim of this article is to delineate the possible coexistence of methemoglobinemia and glucose-6-phosphate dehydrogenase deficiency in children presented with acute hemolysis and discuss its management while reviewing the existing literature.

Severe aplastic anaemia in children: Impact of histopathology profile and treatment on very long-term outcomes.

AIM: To assess very long-term outcomes of children with severe aplastic anaemia (SAA) and impact of histopathology and of different treatments over time. METHODS: We conducted a retrospective study of 57 consecutive patients with SAA during 1973-2019. According to period, treatment consisted of androgens, immunosuppressive treatment (IST) and haematopoietic cell transplantation (HCT) in 14, 31 and 13 patients, respectively. Histopathology immune profiles were studied on bone marrow (BM). RESULTS: Response rate (RR) to androgens was 35%, with long-term survivorship in 4 of 5 responders. RR and 10-year overall survival (OS) after IST was 65% and 80%, respectively. RR was higher in girls (92% vs 43% in boys, P = .02). Mean baseline BM values of CD34 + and of B-lymphocytes in responders vs non-responders were 1.3% vs 0 (P = .08) and 14.1% vs 9.7% (P = .07), respectively. After IST, BM cellularity gradually increased and cytotoxic T-lymphocytes decreased (time variation P = .003 and 0.07, respectively). Outcome did not differ between patients with IST or frontline HCT. Ten-year OS improved over time, increasing from 35.3% to 77.1% and 77% during 1973-1985, 1986-2003 and 2004-2019, respectively. CONCLUSION: Histopathology may refine response prediction to IST. The course of SAA in children, a previously fatal disease, was altered in recent times.

Hematological manifestations of SARS-CoV-2 in children.

Infection from severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), though mainly a respiratory disease, can impair many systems, including causing hematological complications. Lymphopenia and hypercoagulability have been reported in adults with coronavirus disease 2019 (COVID-19) and are considered markers of poor prognosis. This review summarizes the hematological findings in children with SARS-CoV-2 infection. The majority of infected children had a normal leukocyte count, while the most common white blood cell abnormality was leukopenia. Lymphopenia, which may be a marker of severe disease, was rarer in children than in adults, possibly due to their immature immune system or due to the less severe manifestation of COVID-19 in this age group. Age may have an impact, and in neonates and infants the most common abnormality was lymphocytosis. Abnormalities of red blood cells and platelets were uncommon. Anemia and hypercoagulability were reported mainly in children presenting the novel multisystem inflammatory syndrome (MIS) associated with SARS-CoV-2.