Longitudinal analysis of heart and liver iron in thalassemia major patients according to chelation treatment.

Iron chelators and nuclear magnetic resonance imaging (MRI) techniques for assessing iron loading in liver and heart have greatly improved survival of thalassemic patients suffering iron overload-associated cardiomyopathy. However, the correlation between liver iron concentration and myocardial siderosis is ambiguous. Using an objective metric of time delay, scientists have demonstrated a lag in the loading and unloading of cardiac iron with respect to that of the liver. In the present study, we further tested this hypothesis with different chelation treatments. We analyzed the effect of three chelating treatment approaches on liver and cardiac iron content in 24 highly compliant patients who underwent 3 or more MRIs under each chelation treatment. Of the 84 MRIs considered, 32 were performed on deferoxamine (DFO - 8 patients), 24 on deferiprone (DFP - 7 patients), and 28 on combined therapy (DFO+DFP - 9 patients). In patients treated with DFO, changes in cardiac iron significantly lagged changes in liver iron but the opposite pattern was observed in patients treated with DFP (p=0.005), while combined therapy showed a pattern in-between DFO and DFP. We conclude that the temporality of changes of cardiac and liver iron is chelator-dependent, so that chelation therapy can be tailored to balance iron elimination from the liver and the heart.

Relationship between neonatal screening results by HPLC and the number of α-thalassaemia gene mutations; consequences for the cut-off value.

OBJECTIVES: To evaluate the relationship between FAST peak percentage by adapted Bio-Rad Vnbs analysis using the valley-to-valley integration and genotypes with the aim to improve differentiation between severe α-thalassaemia forms (HbH disease) and the milder disease types. METHOD: DNA analysis for α-thalassaemia was performed on 91 dried blood spot samples presenting normal and elevated FAST peak levels, selected during three years of Dutch national newborn screening. RESULTS: Significant differences were found between samples with and without α-thalassaemia mutations, regardless of the genetic profiles. No significant difference was demonstrated between HPLC in -α/αα and -α/-α, between -α/-α and - -/αα and between - -/αα and - -/-α genotypes. CONCLUSION: This study confirms that the percentage HbBart's, as depicted by the FAST peak, is only a relative indication for the number of α genes affected in α-thalassaemia. Based on the data obtained using the modified Bio-Rad Vnbs software, we adopted a cut-off value of 22.5% to discriminate between possible severe α-thalassaemia or HbH disease and other α-thalassaemia phenotypes. Retrospectively, if this cut-off value was utilized during this initial three-year period of neonatal screening, the positive predictive value would have been 0.030 instead of 0.014.

Red cell pyruvate kinase deficiency in Southern Sardinia.

Pyruvate kinase (PK) deficiency is the most frequent red cell enzymatic defect responsible for hereditary non-spherocytic hemolytic anemia. The clinical picture is quite variable and the reasons of this variability have been only partially clarified. We report the clinical description and the extended molecular analysis in 3 PK deficient patients with clinical phenotype of variable severity. We studied the clinical and hematological aspects of 3 patients and analyzed the following genes: pyruvate kinase-R, glucose-6-phosphate-dehydrogenase, α-globin, uridindiphosphoglucuronil transferase and HFE. One patient (A) with a severe clinical picture resulted homozygote for exon 8 nt994A substitution, the other 2 (brothers) were compound heterozygotes for exon 8 nt994A and exon 11 nt1456T mutation. One of the two brothers with a more severe phenotype coinherited also had G6PD deficiency, while both had microcytosis due to the homozygosity for the non-deletional form of α-thalassemia ATG→ACG substitution at the initiation codon of the alpha2 globin gene. Our results suggest that extended molecular analysis is useful for studying how several interacting gene mutations contribute to the clinical variability of pyruvate kinase deficiency.

Deferiprone chelation therapy for thalassemia major.

Iron overload is one of the major causes of morbidity in patients with thalassemia major. Deferiprone (DFP), an orally active iron chelator, emerged from an extensive search for new drugs to treat iron overload. Comparative studies have shown that at comparable doses the efficacy of DFP in removing body iron is similar to that of desferoxamine (DFO). In retrospective and prospective studies, DFP monotherapy was significantly more effective than DFO in the treatment of myocardial siderosis in thalassemia major. DFP can be used in combination with DFO in the management of severe iron overload. This chelation regimen is tolerable and attractive for patients unable to comply with standard DFO infusions or with inadequate response to DFP monotherapy. DFP has a well-known long-term safety profile. Agranulocytosis is the most serious side effect associated with its use, occurring in about 1% of the patients. More common but less serious side effects are gastrointestinal symptoms, arthralgia, zinc deficiency, and fluctuating transaminase levels.

The role of haemoglobin A(2) testing in the diagnosis of thalassaemias and related haemoglobinopathies.

The increase in haemoglobin (Hb)A(2) level is the most significant parameter in the identification of beta thalassaemia carriers. However, in some cases the level of HbA(2) is not typically elevated and some difficulties may arise in making the diagnosis. For these reasons the quantification of HbA(2) has to be performed with great accuracy and the results must be interpreted together with other haematological and biochemical evidence. The present document includes comments on the need for accuracy and standardisation, and on the interpretation of the HbA(2) value, reviewing the most crucial aspects related to this test. A practical flow-chart is presented to summarise the significance of HbA(2) estimation in different thalassaemia syndromes and related haemoglobinopathies.

Thalassaemia and glucose-6-phosphate dehydrogenase screening in 13- to 14-year-old students of the Sardinian population: preliminary findings.

OBJECTIVES: In this paper we describe the outline and results of a 7-year screening programme for thalassaemias and glucose-6-phosphate dehydrogenase (G6PD) deficiency in 13- to 14-year-old students from the Sardinian population. METHOD: This programme had several steps: formal education on thalassaemia, request of informed consent by parents, blood testing and genetic counselling. RESULTS: Out of 63,285 subjects tested, 6,521 (10.3%) were heterozygotes for beta-thalassaemia, 16,175 (25.6%) for alpha-thalassaemia and 101 were carriers of a haemoglobin variant. One thousand four hundred and twenty (16.4%) males were hemizygotes for G6PD deficiency and 1,893 (20.6%) females were heterozygotes. CONCLUSION: The uptake of the programme was remarkably high and homogeneous across the island, indicating and confirming a great interest of the Sardinian population in any initiative directed at the prevention of homozygous beta-thalassaemia.

A randomized, placebo-controlled, double-blind trial of the effect of combined therapy with deferoxamine and deferiprone on myocardial iron in thalassemia major using cardiovascular magnetic resonance.

BACKGROUND: Cardiac complications secondary to iron overload are the leading cause of death in beta-thalassemia major. Approximately two thirds of patients maintained on the parenteral iron chelator deferoxamine have myocardial iron loading. The oral iron chelator deferiprone has been demonstrated to remove myocardial iron, and it has been proposed that in combination with deferoxamine it may have additional effect. METHODS AND RESULTS: Myocardial iron loading was assessed with the use of myocardial T2* cardiovascular magnetic resonance in 167 patients with thalassemia major receiving standard maintenance chelation monotherapy with subcutaneous deferoxamine. Of these patients, 65 with mild to moderate myocardial iron loading (T2* 8 to 20 ms) entered the trial with continuation of subcutaneous deferoxamine and were randomized to receive additional oral placebo (deferoxamine group) or oral deferiprone 75 mg/kg per day (combined group). The primary end point was the change in myocardial T2* over 12 months. Secondary end points of endothelial function (flow-mediated dilatation of the brachial artery) and cardiac function were also measured with cardiovascular magnetic resonance. There were significant improvements in the combined treatment group compared with the deferoxamine group in myocardial T2* (ratio of change in geometric means 1.50 versus 1.24; P=0.02), absolute left ventricular ejection fraction (2.6% versus 0.6%; P=0.05), and absolute endothelial function (8.8% versus 3.3%; P=0.02). There was also a significantly greater improvement in serum ferritin in the combined group (-976 versus -233 microg/L; P<0.001). CONCLUSIONS: In comparison to the standard chelation monotherapy of deferoxamine, combination treatment with additional deferiprone reduced myocardial iron and improved the ejection fraction and endothelial function in thalassemia major patients with mild to moderate cardiac iron loading.

Clinical and molecular analysis of haemoglobin H disease in Sardinia: haematological, obstetric and cardiac aspects in patients with different genotypes.

In this study, 251 Sardinian patients (187 adults and 64 children) with haemoglobin (Hb) H disease were evaluated. Two-hundred and sixteen patients (86%) had the deletional type (- -/-alpha) and 36 (14%) patients had the non-deletional type (- -/alpha(ND)alpha). A clear genotype-phenotype correlation was found, with the non-deletional type more severe than the deletional type. Diagnosis of Hb H disease was incidental in about 60% of cases. Aplastic crises due to B19 parvovirus infection were found in five patients (2.1%), while 23 patients (9.6%) experienced one or more haemolytic crises. Nineteen patients with Hb H received sporadic red blood cell transfusions and three patients were repeatedly transfused. Forty-seven of 61 married women (77%) had 82 pregnancies. In children, mean serum ferritin was 87 +/-92 mug/l and in adults, was 192 +/- 180 mug/l in females and 363 +/- 303 mug/l in males. For the 98 male patients, a significant correlation was found between ferritin values and age (r2 = 0.33, P < 0.0001). In the Sardinian population, Hb H disease needs regular monitoring for early detection and treatment of possible complications, such as worsening of anaemia that may require red cell transfusion, cholelithiasis and iron overload.

Myocardial iron loading in patients with thalassemia major on deferoxamine chelation.

BACKGROUND: Heart failure secondary to myocardial iron loading remains the leading cause of death in thalassemia major (TM). We used cardiovascular magnetic resonance (CMR) to assess the prevalence of myocardial iron overload and ventricular dysfunction in a large cohort of TM patients maintained on conventional chelation treatment with deferoxamine. METHODS: A mobile CMR scanner was transported from London, UK, to Sardinia, Italy where 167 TM patients were assessed for myocardial iron loading, B-natriuretic peptide (BNP), and ferritin. In patients with myocardial iron loading CMR assessments of ventricular function were also made. RESULTS: Myocardial iron loading (T2* < 20 ms) was present in 108 (65%) patients, which was severe (T2* < 8 ms) in 22 (13%). Impaired (< 56%) left ventricular (LV) ejection fraction (EF) was present in 5%, 20% and 62% of patients with mild, moderate or severe iron loading. Increasing myocardial iron was related to impaired LVEF (Rs = 0.57, p < 0.001), weakly related to serum ferritin (Rs = -0.34, p < 0.001), and not related to liver iron (Rs = 0.11, p = 0.26). BNP was weakly related to myocardial iron (Rs = -0.35, p < 0.001) and was abnormal in only 5 patients. CONCLUSIONS: Myocardial siderosis was found in two-thirds of thalassemia major patients on maintenance deferoxamine treatment. This was combined with a high prevalence of impaired LV function, the severity of which tracked the severity of iron deposition. BNP was not useful to assess myocardial siderosis.

Osteoporosis in beta-thalassemia: Clinical and genetic aspects.

Osteoporosis and osteopenia are frequent complications of thalassemia major (TM) and intermedia (TI). Osteoporosis was found in 23/25 patients with TI and in 115/239 patients with TM. In TM, no association was found with specific polymorphisms in candidate genes (vitamin D receptor, estrogen receptor, calcitonin receptor, and collagen type 1 alpha 1). Osteoporosis in female patients with TM was strongly associated with primary amenorrhea (P < .0001), while in male patients with TM, hypogonadism was not significantly related to bone mineral density (BMD) (P = .0001). Low BMD was also associated with cardiomiopathy (P = .01), diabetes mellitus (P = .0001), chronic hepatitis (P = .0029), and increased ALT (P = .01).

Chromosomal aberration frequencies in patients with thalassaemia major undergoing therapy with deferiprone and deferoxamine in a comparative crossover study.

Measurements of chromosomal aberrations were made in 10 thalassaemia major patients treated long-term with deferiprone (at least 5 years) and compared with an equal number of patients matched for age, sex and iron overload, treated long-term with deferoxamine. Two blood samples were collected from each patient, 7 and 20 days after a transfusion episode, and the frequency of chromosomal aberrations (gaps, breaks and exchanges) in the patients' circulating lymphocytes analysed in both samples using standard cytogenetic staining techniques. The frequency of reciprocal translocations was also analysed using fluorescence in situ hybridization. Relatively low frequencies of cells with stable and unstable aberrations were seen at both sampling times in all patients, with no statistically significant differences between sexes. Chromosomal aberrations were less frequent in patients treated long-term with deferiprone than in patients treated with deferoxamine, although the difference did not reach statistical significance. After the second blood sample had been collected, all patients had their iron chelation therapy switched to the other chelator. Patients treated long-term with deferiprone had their therapy switched to deferoxamine and patients treated long-term with deferoxamine had their therapy switched to deferiprone. After the switch, two further blood samples were collected 7 and 20 days after transfusion for each of the next two transfusion cycles in all patients. Analysis of the post-switch samples also revealed a slightly higher frequency of chromosomal aberrations during therapy with deferoxamine than with deferiprone at all time points. A small, but statistically significant, increase in cells with aberrations was observed at the first post-switch assessment in the group of patients whose therapy was switched from deferiprone to deferoxamine, whereas the switch from deferoxamine to deferiprone was associated with a decrease in the frequency of chromosomal aberrations. The results of the study demonstrate that, in a clinical setting, deferiprone has no greater clastogenic activity than that of deferoxamine.

Iron chelation: new therapies.

Iron chelators are used in clinical practice to protect patients from the complications of iron overload and iron toxicity because there is no physiologic way for excess iron to be actively excreted. Deferoxamine, the only iron-chelating agent available for clinical use in the United States, is administered as a prolonged (8 to 24 hours) infusion, leading to poor compliance in many patients. Although many compounds have been screened in tissue cultures and animals as iron chelators, few have reached the stage of phase I and II clinical trials. The search for new chelating agents, which includes the "slow-release" depot formulation of deferoxamine and the "long-acting" hydroxyethyl starch-deferoxamine, has been disappointing because clinical trials have not demonstrated the intended efficacy. A more promising compound, ICL 670A--an orally active representative of a new class of iron chelators designed by computer modeling-is a potent and selective iron chelator. Its ability to mobilize tissue iron and promote its excretion has been shown in several animal models. In phase I dose-finding trials, ICL 670A was well tolerated and had a good safety profile. This compound is currently undergoing further clinical evaluation.

Cholelithiasis and Gilbert's syndrome in homozygous beta-thalassaemia.

Cholelithiasis has been reported with a variable incidence in homozygous beta-thalassaemia, the reasons for which have only partially been defined. Disease-associated factors or specific modifier genes may be implicated. We assessed the prevalence of cholelithiasis and the effect of co-inherited Gilbert's syndrome genotype on its development in 261 thalassaemia major (TM) and 35 thalassaemia intermedia (TI) patients. Cholelithiasis was found in 20.3% of TM and in 57.1% of TI patients. Its incidence was higher (P < 0.05) in patients homozygous for the (TA7) motif in the promoter of the UGT1-A1 gene, the genotype associated with Gilbert's syndrome, which seems to be a risk factor for the development of gallstones in TM and TI patients.

[Histological picture of liver disease in thalassemia intermedia]. / Quadro istologico dell'epatopatia nella Talassemia intermedia.

Thalassemia Intermedia (TI) is a clinical definition in use for a spectrum of clinical conditions ranging in severity from the asymptomatic carrier status to the transfusion-dependent status. The histological lesions of the liver in patients affected by TI has not seen well characterized yet. The aim of this study was to define the histological picture of liver disease in TI. To this end we studied our pool of 22 Thalassemia Intermedia patients who underwent liver biopsy; none of them had blood transfusion. We took into consideration fibrosis according to Ishak's staging and iron overload according to Sciot's grading. Moreover, we determined the hepatic iron content by atomic absorption spectroscopy. Our results have shown that, in all patients studied, the histological picture was characterized by the increase in liver iron stores. By Perls's stain haemosiderin appeared to be stored mainly in hepatocytes in the majority of cases. Inspite of the large amounts of liver iron in these patients, fibrosis was absent or mild. We also noted the presence of iron-free-foci, in part of the patients. Our data show that the histological and histochemical picture of liver disease in Thalassemia Intermedia is very similar to that found in Thalassemia Major. The finding of iron-free-foci could induce to consider a follow up of these patients, even if asymptomatic.

Identification of three rare beta-thalassemia mutations in the Pakistani population.

Three rare beta-thalassemia mutations, not reported previously in Asian Indians or the Pakistani population, were identified by single strand conformation polymorphism analysis followed by direct sequencing. Two mutations, IVS-II-848 (C-->A) and initiation codon (ATG-->ACG), were found in the homozygous condition in patients belonging to Balochi and Sindhi ethnic groups of Pakistan, together with heterozygous and homozygous alpha(-3.7) deletions, respectively. A frameshift mutation at codon 44 (-C) was identified in a patient belonging to the Gujrati ethnic group together with IVS-I-1 (G-->T) and a normal complement of four a-globin genes. Haplotype analysis was performed to identify the chromosomal background associated with these mutations, and for tracing the origin and spread of these mutations.

Hb Sallanches [alpha104(G11)Cys-->Tyr]: a rare alpha2-globin chain variant found in the homozygous state in three members of a Pakistani family.

We have identified a rare alpha2-globin chain variant, Hb Sallanches [alpha104(G11) Cys-->Tyr], in a Pakistani family having three homozygous patients with transfusion-dependent Hb H disease. This variant, previously reported in a French patient and a West Indian homozygous patient with Hb H disease, is due to a mutation at codon 104 (TGC-->TAC). This is the third case of Hb Sallanches and the first case with three homozygous patients reported in Pakistan. Due to the different ethnic origins of the patients, it is very likely an independent mutation.

Safety profile of the oral iron chelator deferiprone: a multicentre study.

In previous trials, the orally active iron chelator deferiprone (L1) has been associated with sporadic agranulocytosis, milder forms of neutropenia and other side-effects. To determine the incidence of these events, we performed a multicentre prospective study of the chelator. Blood counts were performed weekly, and confirmed neutropenia mandated discontinuation of therapy. Among 187 patients with thalassaemia major, the incidence of agranulocytosis (neutrophils < 0.5 x 109/l) was 0.6/100 patient-years, and the incidence of milder forms of neutropenia (neutrophils 0.5-1.5 x 109/l) was 5.4/100 patient-years. All cases of neutropenia resolved after interruption of therapy. Neutropenia occurred predominantly in non-splenectomized patients. Nausea and/or vomiting occurred early in therapy, was usually transient and caused discontinuation of deferiprone in three patients. Mild to moderate joint pain and/or swelling did not require permanent cessation of deferiprone and occurred more commonly in patients with higher ferritin levels. Mean alanine transaminase (ALT) levels rose during therapy. Increased ALT levels were generally transient and occurred more commonly in patients with hepatitis C. Persistent changes in immunological studies were infrequent, although sporadic abnormalities occurred commonly. Mean zinc levels decreased during therapy. Ferritin levels did not change in the overall group but decreased in those patients with baseline levels > 2500 microgram/l. This study characterized the safety profile of deferiprone, and, under the specific conditions of monitoring, demonstrated that agranulocytosis is less common than previously predicted.