Clinical significance of mutational variants in beta and alpha genes in patients with hemoglobinopathies from two large Greek centers: a complex interplay between genotype and phenotype

Hemoglobinopathies affect patients in the wider Mediterranean area consisting of 4 distinct subgroups: beta thalassemia major (TM), beta thalassemia intermedia (TI), sickle cell disease (SCD) and hemoglobin H disease (alpha thalassemia). The clinical spectrum varies from mild to severe. Complex interactions between genes and environmental factors form the clinical manifestations. There is an unmet need to clarify these multifactorial mechanisms. This is the first Greek study describing mutational alleles (HBB and HBA1/HBA2 gene variants) in 217 patients with hemoglobinopathies of two large centers in Greece (Larissa and Athens) and associating particular genotypes or gene variants with clinical manifestations (transfusion frequency, complications). Thus, the complex interplay between corresponding genotypes and phenotypes was investigated. Our results are in accordance with previous national studies with limited variations, due to regional prevalence of specific gene variants, as expected. It is also a description of the prevalence of hemoglobinopathies in the Greek population. The type and prevalence of beta and alpha globin gene variants differ significantly among countries. We also confirm the well-known observation of many studies that in our beta thalassemic or SCD patients, co-inheritance of variants in the alpha globin genes, leading to absence or reduction of alpha globin synthesis were associated with milder clinical course, whereas the inheritance of additional alpha genes (triplication) led to a more severe clinical phenotype. In cases in whom the genotype and phenotype did not correlate, factors like the function or modification of possible regulatory genes or additional nutritional-environmental effects should be investigated. KEY MESSAGES: • This is the first Greek study, fully molecularly defining the beta and alpha mutational alleles in 217 patients with hemoglobinopathies of two large centers in Greece and correlating particular genotypes or gene variants with clinical manifestations (transfusion frequency, complications). • In the beta thalassemic or SCD patients of our cohort, co-inheritance of variants in the alpha globin genes, leading to absence or reduction of alpha globin synthesis were associated with milder clinical course (confirmation of a well-known previous observation). • The inheritance of additional alpha genes (triplication) led to a more severe clinical phenotype (confirmation of a well known previous observation). • The function or modification of possible regulatory genes should be investigated in cases in whom the genotype and phenotype did not correlate.

Concurrent presentation of nodal myeloid sarcoma and bone marrow chronic lymphocytic leukemia/small lymphocytic lymphoma: a unique association

Myeloid sarcoma (MS), previously known as granulocytic sarcoma, is a rare, localized, tumor mass composed of myeloid precursor cells, with or without maturation, and occurring at an anatomical site other than the bone marrow (BM). Chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL), in contrast, is a B-cell hematological malignancy. We describe the first reported case of concurrent presentation of nodal MS and of BM CLL/SLL in the same patient. Fatal leukemic central nervous system infiltration was the final outcome. We provide possible explanations and investigate the pathophysiology of this unique, previously unreported co-morbidity.

Massive bone marrow necrosis revealing an HIV-related primary bone marrow lymphoma: a diagnostic challenge

Bone marrow necrosis (BMN) is a condition that can be difficult to diagnose, requiring a hematologist experienced in bone marrow morphology. This diagnostic challenge should alert the clinician of a severe disease or a possible underlying malignancy, either hematological or a solid tumor. We describe the concomitant presence of a primary bone marrow lymphoma (diffuse large B-cell lymphoma-DLBCL), along with an extensive BMN in an HIV patient for the first time in a living individual. HIV infection, BMN and DLBCL presented a multifactorial crossword of molecular events underlying the complex pathophysiology. The exact precipitating pathophysiological events resulting in BMN remain obscure and provide their clear impact for future research. The present report is instructive and also contains a critical review of the literature related to the case presented.

Balloon pulmonary angioplasty is a promising option in thalassemic patients with inoperable chronic thromboembolic pulmonary hypertension

Pulmonary hypertension (PH), a serious disorder with a high morbidity and mortality rate, is known to occur in a number of unrelated systemic diseases. β-Thalassaemia, among other haematological disorders, develop PH which is not an infrequent finding and worsens the prognosis. Haemolysis, iron overload and hypercoagulable state are among the main pathogenetic mechanisms. Haemoglobinopathies and congenital haemolytic anaemia constitute a unique patients population more predisposed to developing chronic thromboembolic pulmonary hypertension (CTEPH). Although pulmonary endarterectomy is accepted as the best treatment for CTEPH, surgery in these patients poses significant practical challenges given the distinct nature of the disease. As drug therapy is not expected to offer relief from the mechanical obstructions of pulmonary arteries and the use of specific pulmonary arterial hypertension drugs is not established in thalassaemia patients, the novel technique of balloon pulmonary angioplasty (BPA) may emerge as a new therapeutic option for patients with inoperable CTEPH and thalassaemia. We are reporting the case of a thalassaemic patient with a history of splenectomy suffering from progressive severe pulmonary hypertension related to chronic thromboembolic disease, who was successfully treated by BPA with substantial improvement.

Total Annual Economic Burden of Patients with Sickle Cell Disease in Steady State in Greece

Sickle cell disease includes a group of congenital hemolytic anemias, all characterized by the predominance of Hb S (HBB: c.20A>T). The population movement due to economic migration or escape from conflict zones will further affect the health systems of countries by either increasing the number of patients or forcing countries to create care units for sickle cell disease patients. This will probably also increase the incidence of the disease in areas where their incidence and prevalence were previously low. In the present study, an attempt has been made to estimate the total annual cost of the treatment of sickle cell disease in Greece. This was the first attempt to calculate the total annual cost of treating sickle cell disease patients in a steady state. The annual cost of sickle cell disease was estimated to be €21,152,340.00 (US$25,219,300.41), without calculating the cost of hospitalization for severe complications. Since 2013, in Greece, a pharmaceutical expenditure limit (decreasing with the years) has been budgeted at €1,945,000,000.00 (US$2,318,965,150.00), annually. It is therefore calculated that approximately 1.0% of the budget allocated to pharmaceutical spending is used to treat patients with sickle cell disease.

COVID- 19 in patients affected by red blood cell disorders, results from the European registry ERN-EuroBloodNet

BACKGROUND

Despite several publications covering patients from multiple centers, no international registry covered all patients with red blood cell diseases (RBCD) affected by COVID- 19. The ERN-EuroBloodNet's registry provided real-time registration of SARS-CoV- 2 patients with RBCD, promoting timely disease-specific knowledge sharing during the pandemic's early stages.

PROCEDURES

The study evaluated patient distribution, the infection across different RBCDs, and severity risk factors across similar healthcare systems, using data collected from the ERN-EuroBloodNet's REDCap platform.

RESULTS

From April 2020 to April 2023, 681 infections were recorded among 663 patients, of which 373 had transfusion-dependent thalassemia or non-transfusion-dependent thalassemia (TDT/NTDT), and 269 had sickle cell disease (SCD). SCD patients had a higher incidence of COVID- 19 than those with TDT/NTDT (10.5 vs. 4.8 COVID/100 patients). Notably, 92% of the cases were mild, with neither age nor the specific RBCD affecting severity. The number of comorbidities, notably obesity and hypertension, that patients had prior to infection was associated with more severe COVID- 19. During the infection, the presence of vaso-occlusive crises, acute chest syndrome, kidney failure, and ground-glass opacities on chest tomography scans were associated with a more severe clinical picture. The vaccination rate (32%) mirrored that of the general population and showed a protective effect against severe COVID- 19. The observed mortality rate was 0.7%, aligning with Europe's general population.

CONCLUSION

SARS-CoV- 2 infection in SCD and TDT/NTDT patients is mild and without higher mortality than the general population. The ERN-Eurobloodnet's registry collaborative structure exemplifies the power of international cooperation in tackling rare diseases, especially during health emergencies.

Comparative analysis of mortality patterns and treatment strategies in thalassaemia and sickle cell disease patients: A 12-year study

This study examined mortality rates among 2475 patients with thalassaemia and sickle cell disease (SCD) per year over 12 years in Greece, recording 335 deaths (27.92/year), with an overall mortality rate of 1.13% per year. The primary aim was to identify causes of death, comorbidities, treatment efficacy and iron overload prevalence. Of the deaths, 239 were attributed to thalassaemia and 96 to SCD. For thalassaemia patients, cardiac failure, hepatocellular carcinoma and sepsis were the leading causes of death, with no neoplasms observed in β+/β+ genotypes. In SCD, sepsis, liver failure and stroke were the predominant causes, with sepsis-related deaths higher in frequently transfused patients. The median age of death was significantly lower in thalassaemia (50 years) compared to SCD (58.49 years, p < 0.001). Differences in comorbidities and treatment effectiveness highlight the need for improved management strategies. Addressing iron overload, optimizing chelation therapy and expanding hydroxyurea use in SCD patients could enhance survival and quality of life. Strengthening treatment protocols and monitoring may reduce mortality, emphasizing the importance of targeted interventions in haemoglobinopathies.

Predisposing factors for advanced liver fibrosis in patients with sickle cell disease

Sickle cell disease (SCD) is one of the most common monogenic disorders worldwide and liver complications are common in this group of patients. Our study aims to highlight the prevalence of chronic liver complications and the main predisposing factors for advanced liver fibrosis in SCD patients. For this purpose, 219 patients from eight Thalassemia and Sickle Cell Units across Greece enrolled in our study and history of liver related disease complications was recorded, as well as a full laboratory and imaging analysis concerning their liver function. 13.6% of the patients had advanced liver fibrosis. The presence of liver fibrosis was significantly correlated with advanced age, male gender, cholelithiasis and higher LDH, γ-GT, INR, direct and indirect bilirubin levels. These patients had exhibited significantly more episodes of liver crises and acute intrahepatic cholestasis. No correlation was observed with right heart failure or previous viral hepatitis. Patients with advanced liver fibrosis were receiving a more intensive transfusion therapy for a longer period of time and had higher Liver Iron Concentration levels. Our study shows that liver complications and cirrhosis is a significant cause of morbidity in patients with SCD and it is primarily associated with intravascular hemolysis and vaso-occlusive phenomena and secondarily with iron overload.

Genetic Modifiers of Hemoglobin Expression from a Clinical Perspective in Hemoglobinopathy Patients with Beta Thalassemia and Sickle Cell Disease

Hemoglobinopathies, namely β-thalassemia and sickle cell disease (SCD), are hereditary diseases, characterized by molecular genetic aberrations in the beta chains of hemoglobin. These defects affect the normal production of hemoglobin with severe anemia due to less or no amount of beta globins in patients with β-thalassemia (quantitative disorder), while SCD is a serious disease in which a mutated form of hemoglobin distorts the red blood cells into a crescent shape at low oxygen levels (qualitative disorder). Despite the revolutionary progress in recent years with the approval of gene therapy and gene editing for specific patients, there is an unmet need for highlighting the mechanisms influencing hemoglobin production and for the development of novel drugs and targeted therapies. The identification of the transcription factors and other genetic modifiers of hemoglobin expression is of utmost importance for discovering novel therapeutic approaches for patients with hemoglobinopathies. The aim of this review is to describe these complex molecular mechanisms and pathways affecting hemoglobin expression and to highlight the relevant investigational approaches or pharmaceutical interventions focusing on restoring the hemoglobin normal function by linking the molecular background of the disease with the clinical perspective. All the associated drugs increasing the hemoglobin expression in patients with hemoglobinopathies, along with gene therapy and gene editing, are also discussed.

Concomitant Presence of Hb Agrinio and - -Med Deletion in a Greek Male Patient with Hemoglobinopathy H: More Severe Phenotype and Literature Review

Hemoglobin (Hb) Agrinio is a rare non-deletional a-globin mutation observed almost exclusively in Greek, Spanish or other Mediterranean families. The clinical manifestations of a carrier of a single Hb Agrinio mutation (single heterozygosity) depend on the concomitant presence or absence of other mutations or variants in the beta, alpha or other modifying genes. We present a Greek patient harboring a Hb Agrinio variant plus the - -Med alpha deletional allele, having an infrequent severe form of alpha thalassemia, in contrast to the typical alpha thalassemic patient and requiring regular red blood cell (RBC) transfusions and chelation treatment. We also provide a concise literature review regarding alpha thalassemic hemoglobin variants and their molecular and clinical combinations. A phase 2, double-blind, randomized, placebo-controlled, multicenter clinical trial to determine the efficacy and safety of luspatercept (BMS-986346/ACE-536) for the treatment of anemia in adults with alpha thalassemia with the participation of our center is currently recruiting patients (NCT05664737).

Splenectomy and complications: A complex different disease background, yet a common denominator exists

Splenectomy is a major element in the treatment of hemoglobinopathies, such as transfusion dependent thalassaemia (TDT), non-transfusion dependent thalassaemia (NTDT), sickle cell anaemia (SCA), other red cell disorders like spherocytosis or other haematological diseases of autoimmune origin. A recent, long-year study describes a large series of splenectomized patients in Italy. The authors of this systematic work found that the probability of a post-splenectomy complication depends on the underlying disease and not on the age of the patient at splenectomy. Thus, splenectomy should be performed, when clinically indicated, regardless of the patient's age. The following commentary provides a critical evaluation of the results of the published study, discussing also the novelty, quality and limitations of this important work, in the perspective of current knowledge. Commentary on: Casale et al. Underlying disease is the main risk factor in post-splenectomy complication risk: Data from a national database. Br J Haematol 2025 (Online ahead of print). doi: 10.1111/bjh.20114.

Myeloid Sarcoma: Novel Advances Regarding Molecular Pathogenesis, Presentation and Therapeutic Options

Myeloid sarcoma (MS), an extramedullary form of acute myeloid leukemia (AML) is a rare tumor mass of myeloid blasts. It can disseminate to any one or multiple anatomical sites, with (synchronous MS) or without (isolated MS) bone marrow (BM) involvement. The aim of this review is to describe the most recent advances in MS regarding diagnosis, molecular background, various clinical manifestations from several organs, and treatment approaches. Due to the lack of prospective, randomized clinical trials, therapeutic decisions are a challenge for the clinician. In the era of novel targeted AML treatments, a critical analysis of how to decide the best option for individual patients, also covering the possible central nervous system (CNS) prophylaxis is provided. For the majority of the patients, AML induction chemotherapy, followed by hematopoietic stem cell transplantation (HSCT) is generally recommended. This paper discusses the role of radiotherapy, the treatment of refractory and relapsed disease, along with the therapeutic approach of difficult-to-treat patients, due to specific problems related to different anatomical sites of MS.