Stratification of βSβ+ Compound Heterozygotes Based on L-Glutamine Administration and RDW: Focusing on Disease Severity

Sickle cell disease (SCD) is heterogeneous in terms of manifestation severity, even more so when in compound heterozygosity with beta-thalassemia. The aim of the present study was to stratify βSβ+ patient blood samples in a severity-dependent manner. Blood from thirty-two patients with HbS/β-thalassemia compound heterozygosity was examined for several parameters (e.g., hemostasis, inflammation, redox equilibrium) against healthy controls. Additionally, SCD patients were a posteriori (a) categorized based on the L-glutamine dose and (b) clustered into high-/low-RDW subgroups. The patient cohort was characterized by anemia, inflammation, and elevated coagulation. Higher-dose administration of L-glutamine was associated with decreased markers of inflammation and oxidation (e.g., intracellular reactive oxygen species) and an altered coagulation profile. The higher-RDW group was characterized by increased hemolysis, elevated markers of inflammation and stress erythropoiesis, and oxidative phenomena (e.g., membrane-bound hemoglobin). Moreover, the levels of hemostasis parameters (e.g., D-Dimers) were greater compared to the lower-RDW subgroup. The administration of higher doses of L-glutamine along with hydroxyurea seems to attenuate several features in SCD patients, probably by enhancing antioxidant power. Moreover, anisocytosis may alter erythrocytes' coagulation processes and hemolytic propensity. This results in the disruption of the redox and pro-/anti-inflammatory equilibria, creating a positive feedback loop by inducing stress erythropoiesis and, thus, the occurrence of a mixed erythrocyte population.

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.

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.

Right ventricular mechanics among beta-thalassemia major patients

Introduction

Right ventricular function among β-thalassemia (β-TM) patients is affected by both pulmonary circulation pressure and primary iron deposition on right ventricular myocardium.

Purpose

In our study we aimed to detect the presence of impaired right ventricular function and right ventricle to pulmonary circulation (RV-PC) coupling by applying novel echocardiographic techniques among these patients.

Methods

47 β-TM patients (mean age 39.02±8.76 years, 48.9% male sex) and 24, age and sex matched, healthy controls were examined by transthoracic echocardiography. Conventional echocardiographic parameters were estimated (LVEF, E/e' ratio, left atrial volume index (LAVI), right ventricular systolic pressure (RVSP), S' wave of tricuspid annulus), alongside with deformation indices (left atrial strain at reservoir phase (LASr), right ventricular free wall (RVfw) and 4 chamber (RV4c) strain), as well as RV-PC coupling expressed as S'/RVSP, RVfw/RVSP and RV4c/RVSP. T2* was calculated by cardiac magnetic resonance imaging in β-TM patient group.

Results

E/e' ratio, LVEF, LAVI, RVSP, LASr, RVfw, RV4c, S'/RVSP, RVfw/RVSP and RV4c/RVSP differed significantly between patients and controls (Table 1). T2* did not correlate with either right ventricular deformation indices or RV-PC coupling indices. A correlation was found regarding LASr with both S'/RVSP (r=0.383, p=0.008) and RV4c/RVSP (r=−0.388, p=0.007) but not with RVfw/PVSP (Table 2).

Conclusions

Right ventricular deformation indices were found to be impaired in β-TM patients compared to controls, but they do not seem to be associated with myocardial iron load (T2* index). RV-PC coupling was also found to be impaired among patients and a correlation was found between RV-PC indices and left atrial strain. The latter suggests that the presence of atrial cardiomyopathy in β-TM patients could be associated with the impaired RV-PC coupling.

Funding Acknowledgement

Type of funding sources: None.

Iron Chelators, Such as Deferasirox, When Combined With Hydroxyurea, Provide an Additional Benefit of Iron Chelation in Patients Receiving Chronic Transfusion Therapy

Red blood cell (RBC) transfusions have been established as one of the primary therapies in treating sickle cell anemia. However, they are not free of side effects, with overloading the body with iron being one of the most important. Iron chelation therapy greatly reduces the iron load of the body. In addition, hydroxyurea (HU), an oral chemotherapeutic drug also has a significant role in the treatment of the disease with beneficial effects on many of the clinical problems that arise, mainly in reducing painful crises. The aim of this study was to investigate the effect of synergistic transfusion therapy and HU on the response to deferasirox (DFX) chelation therapy. Eighteen patients with sickle cell disease were divided into two groups based on their treatment, either with simple transfusions and DFX or with a combination of transfusion therapy, DFX and HU, and were evaluated with magnetic resonance imaging (MRI) for liver iron concentration (LIC) and biochemistry. All patients completed the study. The results of the study showed improvement in serum ferritin (FER) levels and LIC after 12 months of therapy in both groups, especially in the group receiving the combination therapy with HU. In addition, there was a noteworthy improvement in serum glutamic-oxaloacetic transaminase (SGOT), serum glutamic pyruvic transaminase (SGPT) and lactate dehydrogenase (LDH) levels with serum creatinine (Cr) levels remaining stable during the study in both groups. Hydroxyurea, when combined with iron chelators such as DFX, provides an additional benefit of iron chelation in patients receiving chronic transfusion therapy.

Acute Chest Syndrome in Sickle Cell Disease: Clinical Presentation and Outcomes. The Experience of a Single Thalassemia and Sickle Cell Unit in a University Hospital

Acute chest syndrome (ACS) is a common cause of death for sickle cell disease patients. This syndrome is defined as: respiratory symptoms, new X-ray findings developed and/or fever; ACS requires prompt treatment to avoid clinical deterioration and death in adults with sickle cell disease. Sixteen episodes of acute chest syndrome were studied in 16 adults with sickle cell disease. The clinical and radiological findings, treatment, response and outcome of the episode were evaluated respectively. The patient's past history and comorbidities were taken into account in the outcome and days of hospitalization. Fourteen patients recovered with no sequelae; one patient who required mechanical ventilation also recovered; one patient died due to pulmonary emboli. The mean hospitalization days were 7.43.

Severity of heart failure and health-related quality of life in beta-thalassemia patients: a cross-sectional study

Cardiovascular complications account for a substantial increase in morbidity and mortality in beta-thalassemia patients. Many patients have structural heart disease, and some of them present with symptomatic heart failure (HF). Quality of life (QOL) of beta-thalassemia patients is lower than that of the general population. The aim of our study was to explore the relationship between HF stages and QOL in beta-thalassemia patients. Seventy-three consecutive adult beta-thalassemia patients took part in this cross-sectional study. Stages of HF, classified with increasing severity as A, B, and C, were determined based on ACC/AHA guidelines. QOL was assessed using the SF-36 questionnaire. Fifteen patients had stage C HF, twenty-eight had stage B HF, and the remaining were considered stage A patients, as beta thalassemia is a predisposing factor for HF. All QOL domains except for bodily pain were significantly lower in stage C patients than in stage A patients. Stage C patients had significantly lower QOL scores for physical functioning, role physical, and social functioning domains than stage B patients. Stage B patients' QOL differed from stage A patients only in the vitality domain. In the multiple regression analysis which took several demographic and clinical factors into account, stage of HF was the most important factor associated with QOL, and negatively and significantly related to five QOL domains, namely physical functioning, role physical, general health, social functioning, and vitality. In conclusion, QOL is negatively affected by the severity of heart failure in beta-thalassemia patients.

Disorders of the erythrocyte membrane

Hemolytic anemia due to abnormalities of the erythrocyte membrane comprises an important group of inherited disorders. These include hereditary spherocytosis, hereditary elliptocytosis, hereditary pyropoikilocytosis, and the hereditary stomatocytosis syndromes. The erythrocyte membrane skeleton composed of spectrin, actin, and several other proteins is essential for the maintenance of the erythrocyte shape, reversible deformability, and membrane structural integrity in addition to controlling the lateral mobility of integral membrane proteins. These disorders are characterized by clinical and laboratory heterogeneity and, as evidenced by recent molecular studies, by genetic heterogeneity. Defects in various proteins involved in linking the lipid bilayer to membrane skeleton result in loss in membrane cohesion leading to surface area loss and hereditary spherocytosis while defects in proteins involved in lateral interactions of the spectrin-based skeleton lead to decreased mechanical stability, membrane fragmentation and hereditary elliptocytosis. The disease severity is primarily dependent on the extent of membrane surface area loss. Treatment with splenectomy is curative in most patients.

Steroid-induced hypocalcaemia with tetany in a patient with hypoparathyroidism

Although glucocorticoids have a known negative effect on calcium balance, they do not normally cause clinically significant hypocalcaemia. A young woman with post-surgical hypoparathyroidism developed symptomatic hypocalcaemia on two occasions following treatment with intravenous hydrocortisone for allergic reactions. Oral calcium and vitamin D supplementation could not prevent the development of hypocalcaemia. She was treated successfully with intravenous calcium gluconate infusions and discontinuation of glucocorticoids. In patients with hypoparathyroidism, impaired parathyroid hormone response to steroid-induced negative calcium balance may result in severe symptomatic hypocalcaemia requiring hospitalisation.