Osteoporosis in thalassaemia

Osteoporosis is a prominent cause of morbidity in patients with thalassaemia major (TM) with a complex pathophysiology. Patients with TM and osteoporosis have elevated markers of bone resorption. This increased osteoclast activity seems to be at least partially due to an imbalance in the receptor–activator of nuclear factor-kappa B ligand (RANKL)/osteoprotegerin (OPG) system, which is of great importance for the regulation of osteoclast differentiation and function. Denosumab is a fully human monoclonal antibody that binds to RANKL and thereby inhibits the activation of osteoclasts by RANKL. By blocking RANKL, denosumab inhibits osteoclast formation, function and survival, thereby decreasing bone resorption and increasing bone mass in postmenopausal women and patients with thalassaemia-induced osteoporosis

The effect of prolonged administration of hydroxyurea on morbidity and mortality in adult patients with sickle cell syndromes: results of a 17-year, single-center trial

The aim of this prospective study was to evaluate the long-term efficacy and safety of hydroxyurea (HU) in patients with sickle cell disease (SCD). Thirty-four patients with sickle cell anemia (hemoglobin S [HbS]/HbS), 131 with HbS/␤ 0 -thal, and 165 with HbS/␤ ؉ -thal participated in this trial. HU was administered to 131 patients, whereas 199 patients were conventionally treated. The median follow-up period was 8 years for HU patients and 5 years for non-HU patients. HU produced a dramatic reduction in the frequency of severe painful crises, transfusion requirements, hospital admissions, and incidence of acute chest syndrome. The probability of 10-year survival was 86% and 65% for HU and non-HU patients, respectively (P ‫؍‬ .001), although HU patients had more severe forms of SCD. The 10-year probability of survival for HbS/ HbS, HbS/␤ 0 -thal, and HbS/IVSI-110 patients was 100%, 87%, and 82%, respectively, for HU patients and 10%, 54%, and 66%, for non-HU patients. The multivariate analysis showed that fetal hemoglobin values at baseline and percentage change of lactate dehydrogenase between baseline and 6 months were independently predicted for survival in the HU group. These results highlight the beneficial effect of HU, which seems to modify the natural history of SCD and raise the issue of expanding its use in all SCD patients. (Blood

Sickle cell disease complications

Sickle cell disease (SCD) is an inherited, lifelong condition. The sickle mutation consists a single nucleotide change (GAT->GTT) in the sixth codon of exon 1 of the β-globin gene coding for the β-globin polypeptide of hemoglobin (Hb) (a2β2). This change results in replacement of the wild type glutamic acid residue by a valine residue in β-globin chain and the formation of the sickle Hb (HbS) in homozygotes for this mutation. Heterozygotes live a normal life. In SCD patients, sickle erythrocytes are rigid with decreased deformability and reduced life span resulting in hemolysis, vaso-occlusive disease, vasculopathy and subsequent inflammation and end organ damage. Sickle cell disease affects millions of people worldwide. Today, with proper health care, many SCD patients have a good quality of life (QoL) and are in fairly good health most of the time. These people can live up to their forties or fifties, or longer. Despite the ‘common’ underlying genetic basis and a similar pathophysiology, patients with SCD present a highly variable clinical phenotype due to Single Nucleotide Polymorphisms (SNPs) variability throughout the genome. Patients with SCD are at high risk for developing multisystem acute and chronic complications associated with significant morbidity and mortality

Bone disease in haemoglobin disorders

Bone disease represents a prominent cause of morbidity in patients with thalassaemia and other haemoglobin disorders. The delay in sexual maturation, the presence of diabetes and hypothyroidism, the parathyroid gland dysfunction, the haemolytic anaemia, the progressive marrow expansion, the iron toxicity on osteoblasts, the iron chelators, and the deficiency of growth hormone or insulin growth factors have been identified as major causes of osteoporosis in thalassaemia. Adequate hormonal replacement, effective iron chelation, improvement of hemoglobin levels, calcium and vitamin D administration, physical activity, and smoking cessation are the main to-date measures for the management of the disease. During the last decade, novel pathogenetic data suggest that the reduced osteoblastic activity, which is believed to be the basic mechanism of bone loss in thalassemia, is accompanied by a comparable or even greater increase in bone resorption. Therefore, potent inhibitors of osteoclast activation, such as the aminobisphosphonates, arise as key drugs for the management of osteoporosis in thalassaemia patients and other haemoglobin disorders

Osteoporosis in thalassaemia

Osteoporosis is a prominent cause of morbidity in patients with thalassaemia major (TM) with a complex pathophysiology. Patients with TM and osteoporosis have elevated markers of bone resorption. This increased osteoclast activity seems to be at least partially due to an imbalance in the receptor-activator of nuclear factor-kappa B ligand (RANKL)/osteoprotegerin (OPG) system, which is of great importance for the regulation of osteoclast differentiation and function. Denosumab is a fully human monoclonal antibody that binds to RANKL and thereby inhibits the activation of osteoclasts by RANKL. By blocking RANKL, denosumab inhibits osteoclast formation, function and survival, thereby decreasing bone resorption and increasing bone mass in postmenopausal women and patients with thalassaemia-induced osteoporosis

Sickle-cell disease and the heart: review of the current literature

Sickle cell disease (SCD) is an inherited chronic haemolytic anaemia whose clinical manifestations arise from the tendency of the haemoglobin to polymerize and deform red blood cells into the characteristic sickle shape due to a single nucleotide change in the beta-globin. Vascular occlusion of small and large vessels can lead to chronic damage of multiple organs including brain, lung, bone, kidney, liver, spleen, and retina. However, the extent to which SCD impacts myocardial function is not very clear. Cardiovascular manifestations include both right and left ventricular systolic and diastolic dysfunction, elevated cardiac output, cardiomegaly and myocardial ischaemia. Progressive heart damage from iron overload occurs in patients requiring routine transfusion therapy. Pulmonary hypertension resulting from intravascular haemolysis has also been recognized as a major complication that independently correlates with survival. This review summarizes all available data for the heart complications in SCD to update the physicians for their appearance, diagnostic procedures and possible management

Development of a High-Resolution Melting Approach for Scanning Beta Globin Gene Point Mutations in the Greek and Other Mediterranean Populations.

Beta-thalassaemia is one of the most common autosomal recessive disorders worldwide. The disease's high incidence, which is observed in the broader Mediterranean area has led to the establishment of molecular diagnostics' assays to prevent affected births. Therefore, the development of a reliable, cost-effective and rapid scanning method for β globin gene point mutations, easily adapted to a routine laboratory, is absolutely essential. Here, we describe, for the first time, the development of a High-Resolution Melting Analysis (HRMA) approach, suitable for scanning the particularly heterogeneous beta globin gene mutations present in the Greek population, and thus adaptable to the Mediterranean and other areas where these mutations have been identified. Within this context, β globin gene regions containing mutations frequently identified in the Greek population were divided in ten overlapping amplicons. Our reactions' setup allowed for the simultaneous amplification of multiple primer sets and partial multiplexing, thereby resulting in significant reduction of the experimental time. DNA samples from β-thalassaemia patients/carriers with defined genotypes were tested. Distinct genotypes displayed distinguishable melting curves, enabling accurate detection of mutations. The described HRMA can be adapted to a high-throughput level. It represents a rapid, simple, cost-effective, reliable, highly feasible and sensitive method for β-thalassaemia gene scanning

Novel Therapeutic Advances in β-Thalassemia

The main characteristic of the pathophysiology of β-thalassemia is reduced β-globin chain production. The inevitable imbalance in the α/β-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 β-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 β-globin gene have entered the clinical trial setting. Agents such as TGF-β ligand traps and pyruvate kinase activators, which reduce the ineffective erythropoiesis, have been tested in clinical trials with favorable results. One TGF-β ligand trap, luspatercept, has been approved for use in adults with transfusion-dependent β-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 β-thalassemia