Efthymia Vlachaki

Anemia is one of the most common health conditions worldwide, affecting people of different ages and backgrounds

In vivo hematopoietic stem/progenitor cell (HSPC) gene therapy remains limited by low gene-editing efficiency and a lack of clinically applicable selection strategies to enrich therapeutically corrected progeny. We used in vivo base and prime editing to introduce a nonpathogenic EPOR variant into HSPCs, conferring erythropoietin hypersensitivity and promoting preferential expansion of gene-corrected erythroid cells. EPOR editing was combined with three therapeutic approaches for the correction of hemoglobinopathies: γ-globin gene addition, γ-globin reactivation, or correction of the sickle cell disease mutation. Tropism-modified helper-dependent adenoviral vectors (HDAd6/3+) targeting HSPCs were used to simultaneously deliver the EPOR-editing machinery and the corresponding therapeutic components. In vitro studies in an erythroid progenitor cell line and primary CD34+ cells demonstrated that the EPORW439* variant conferred a strong proliferative advantage to therapeutically modified erythroid progenitors. Mice humanized with CD34+ cells from a β⁰/β⁰-thalassemia patient were subjected to EPORW439*-mediated EPO hypersensitivity alongside a therapeutic γ-globin transgene which resulted in >70% HbF-positive erythroid cells and substantial reversion of the disease-associated phenotype, including reduced oxidative stress, near-complete elimination of splenic iron deposition, and reduced splenomegaly. Importantly, these effects were achieved after simple intravenous administration of the vectors following HSPC mobilization and cytokine prophylaxis, without subsequent pharmacologic selection. Together, these findings establish a strategy to amplify the therapeutic benefit of otherwise limited in vivo HSPC gene editing for hemoglobinopathies.

Background: Haemoglobinopathies are the most common monogenic disorders both in Greece and worldwide. The most effective strategies against them are carrier detection and prenatal testing following genetic risk assessment consultation for couples on the likelihood of their offspring being affected. Case Presentation: A novel alpha globin chain variant, named Hb Thessaloniki, was detected in Northern Greece. The underlying point variation HBA1:c.260T>C (ref. seq. NM_000558.5) was detected in the HBA1 gene, in heterozygosity, during a routinely performed population screening for haemoglobinopathies. The amino-acid residue Leu86 was replaced by a structure disrupting Pro residue, resulting in a hyperunstable product as shown by the isopropanol test and predicted by the Dynamut2 and Alphafold3 algorithms. The haematological phenotype, due to which genetic analysis was performed, presented with mild microcytosis and hypochromia and was also indicative of the presence of an unstable haemoglobin produced in small quantities (variant encoded by HBA1). Since the proband’s partner presented with a normal haematological phenotype, there is no risk of the couple giving birth to an affected offspring. Expanded analysis of the proband’s relatives identified biallelic variants (α^Parmaα/αα^{Τhessaloniki}) in the proband’s mother, who presented with no apparent clinical findings, expect for slightly reduced haematological indices. Conclusions: The novel Hb Thessaloniki identified, although theoretically hyperunstable, seems to have minor effects on erythrocyte function, as indicated by haematological findings on the proband and his close relatives. Future identification of co-inheritance with HBA pathogenic point variations or deletions may provide further information regarding genetic counselling. In parallel, the usage of structure–function relation-calculating algorithms may enhance our prediction capability for novel variants.

In the long-term follow up study (de-LIGHT), the magnitude of transfusion burden was significantly and incrementally associated with morbidity development in transfusion-dependent patients achieving target hemoglobin thresholds.

Background: Sickle cell disease (SCD) is among the most prevalent inherited hemoglobinopathies and is strongly associated with numerous coagulation abnormalities, hence constituting a severe hypercoagulable state. Methods: We conducted a single-center retrospective observational study of patients with SCD who were monitored at Hippokration Hospital of Thessaloniki between 1999 and 2024. Demographic characteristics, hemoglobin (Hb) genotype, medical history, anticoagulant and antiplatelet therapy, dosage of anticoagulant treatment, recurrence of the first episode of venous thromboembolism (VTE) and relevant laboratory values were examined as possible risk factors. Results: Among 46 patients, 12 (26.1%) developed thrombosis with the majority (75%) carrying the HbS/β-thal genotype. The prevalence of VTE in this study was 17.4%. Variables significantly associated with an increased risk of thrombosis included age at the time of thrombosis, patient age, use of anticoagulant treatment, anticoagulant dosage, antiplatelet therapy and type of transfusion (p < 0.05). On multivariate analysis, anticoagulant treatment and its dosage retained statistical significance (p < 0.05). Conclusions: These findings reinforce the strong association between SCD and thrombotic events. Despite the availability of a broad therapeutic armamentarium and increasing knowledge of the underlying disease mechanisms, the prevention and management of thrombosis in these patients remains a challenge.

Summary: Evidence on the impact of anaemia and iron control on morbidity and mortality in β‐thalassaemia is limited to short‐term studies assessing spot measures. We conducted a retrospective longitudinal cohort study of 557 patients with β‐thalassaemia followed from diagnosis for a median of 38 years. There was a significant association between the lifetime proportion spent on transfusion and thalassaemia‐related mortality (adjusted hazard ratios (HR) 0.987 for each 1‐percent increase, p = 0.014). In both patients with non‐transfusion‐dependent β‐thalassaemia (NTDT) and transfusion‐dependent β‐thalassaemia (TDT) (lifetime proportion on transfusion ≤70% and >70%, respectively), there was a significant association between a lifetime anaemia and iron control index (LAICI) and mortality (NTDT: adjusted HR 0.916 for each 1‐point increase, p = 0.017; TDT: adjusted HR 0.672, p = 0.027). Survival was significantly lower in patients with suboptimal than optimal LAICI, defined based on international NTDT and TDT guidelines for anaemia and iron overload management (NTDT: adjusted HR 0.395, p = 0.046; TDT: adjusted HR 0.205, p = 0.020 for optimal vs. suboptimal LAICI). Patients with optimal LAICI had significantly lower odds of cardiac (NTDT, TDT), vascular (TDT), hepatic (NTDT), endocrine morbidity (NTDT, TDT) and osteoporosis (NTDT). Optimal anaemia and iron control throughout the entire disease course are essential to reduce morbidity and mortality in patients with β‐thalassaemia.

Sickle Cell Disease (SCD) is one of the most widespread inherited hemoglobinopathies that has been associated with numerous coagulation disorders, hence characterized as a severe hypercoagulable state. We conducted a single-center retrospective observational study of patients with SCD who were monitored at Hippokration Hospital of Thessaloniki between 1999 and 2024. In this study group, demographic data, hemoglobin (Hb) genotype, medical history, use of anticoagulant and antiplatelet treatment, dosage of anticoagulant treatment, recurrence of the first venous thromboembolism (VTE) and laboratory values were examined as possible provoking factors. Twelve patients (12/46-26,1%) developed thrombosis (75% with genotype HbS/β-thal). The prevalence of VTE in this group was 17,4%. Age of thrombosis, age of the patients, anticoagulant treatment, anticoagualants’ dosage, antiplatelet treatment and type of transfusion were significantly associated with increased risk of thrombosis (p<0.05). On multivariate analysis, the anticoagulant treatment and its dosage showed statistical significance (p<0.05).Sickle cell disease and thrombosis are strongly associated. Despite current arsenal of drugs and the broad knowledge related to each one, reducing thrombosis’ occurrence remains a challenge.

Background: Liver disease is common in patients with β‐thalassemia, but data on lifetime incidence and risk factors are limited.Methods: We conducted a retrospective cohort study of 557 patients with β‐thalassemia followed from diagnosis for a median of 38 years. Predictive, survival, and regression analyses were used to determine the association between liver disease and potential risk factors.Results: The crude incidence of liver disease was 26.4% (fibrosis/cirrhosis 24.2%, median age 34.4 years; hepatocellular carcinoma 2.3%, median age 45.4 years, 38.5% not preceded by cirrhosis). Among evaluated risk factors, only hepatitis C virus (HCV) infection (adjusted hazard ratio [HR]: 2.195, p < 0.001) and lifetime serum ferritin level (adjusted HR per 100‐ng/mL increase: 1.030, p < 0.001) were significantly associated with liver disease, with a lifetime serum ferritin level > 1500 ng/mL being the best predictor (p = 0.001). Liver disease‐free survival was significantly shorter in patients who had both versus either or neither risk factor (p < 0.001). Mostly severe and persistent but not mild–moderate or temporary/fluctuating elevation in liver enzymes was associated with liver disease development.Conclusion: Patients with β‐thalassemia have a considerably increased lifetime risk of liver disease that is primarily driven by HCV infection and/or uncontrolled iron overload, especially in the 4th–5th decades of life.