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Biomedical subjects

R Galanello

Publications and source records attributed to R Galanello.

At least 19 recordsLinked to original sources

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.

Adolescent↗

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.

Cardiomyopathies↗

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).

Adult↗

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.

Adolescent↗

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.

Animals↗

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.

Adolescent↗

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.

Agranulocytosis↗

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.

Amino Acid Substitution↗

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.

Amino Acid Substitution↗

[Histological picture of liver disease in thalassemia 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.

Adolescent↗

Hyperbilirubinemia, glucose-6-phosphate-dehydrogenase deficiency and Gilbert's syndrome.

The pathogenesis of neonatal hyperbilirubinemia has not yet been completely defined in normal and glucose-6-phosphate-dehydrogenase (G6PD)-deficient newborns. The recent identification of a variant promoter in the gene encoding for the bilirubin uridine-diphosphoglucuronosyl-transferase (UGT-1 A) associated with Gilbert's syndrome, allowed us to explore whether the presence of this variant promoter is a risk factor for the development of neonatal hyperbilirubinemia in normal newborns and in association with G6PD deficiency. We found that the variant (TA)7/(TA)7 promoter shows no statistically significant difference in normal or G6PD-deficient newborns developing severe hyperbilirubinemia and in control subjects from the same population. This finding indicates that the variant promoter of UGT-1 A does not contribute to the development of hyperbilirubinemia in the newborn.

Adult↗

Soluble transferrin receptor as a potential determinant of iron loading in congenital anaemias due to ineffective erythropoiesis.

Congenital anaemias due to ineffective erythropoiesis may be associated with excessive iron absorption and progressive iron loading. We investigated whether the soluble transferrin receptor (TfR) level was related to the degree of iron overload in 20 patients with thalassaemia intermedia, six patients with congenital dyserythropoietic anaemia type II (CDA II) and four patients with X-linked congenital sideroblastic anaemia (XLSA). All but two patients had increased serum ferritin levels (median 601 microgram/l, range 105-2855 microgram/l). Multiple regression analysis showed that 62% (P < 0.0001) of the variation in serum ferritin was explained by age and by changes in soluble TfR.

Adolescent↗

Co-inherited Gilbert's syndrome: a factor determining hyperbilirubinemia in homozygous beta-thalassemia.

BACKGROUND AND OBJECTIVE: Patients with thalassemia major and intermedia show a marked variability of serum indirect bilirubin levels. In this paper we tested the hypothesis related to the variability of the glucuronidation bilirubin rate which depends on the configuration of the A(TA)nTAA motif of the UGT1*1 glucuronosyltransferase gene promoter. DESIGN AND METHODS: We studied the configuration of the A(TA)nTAA motif in 26 patients with thalassemia major and 34 with thalassemia intermedia. RESULTS: In patients with thalassemia major and in those with thalassemia intermedia significantly higher bilirubin levels were found in patients with the (TA)7/(TA)7 genotype, than in those with the (TA)7/(TA)6 or (TA)6/(TA)6 genotype. INTERPRETATION AND CONCLUSIONS: These results indicate that the (TA)7/(TA)7 genotype, the configuration found in patients with Gilbert's syndrome, is capable of modifying the clinical phenotype of homozygous beta-thalassemia. This is an example of the role played by co-inherited modifying gene(s) on the extent of clinical heterogeneity of monogenic disorders.

Gilbert Disease↗

Posttranslational deamidation of proteins: the case of hemoglobin J Sardegna [alpha50(CD8)His-->Asn-->Asp].

Hemoglobin J Sardegna [alpha50(CD8)His-->Asn -->Asp] is a human Hb variant in which a posttranslational deamidation process takes place, transforming an Asn to an Asp residue. This variant, particularly widespread in northern Sardinia, has for the first time been characterized at the DNA level (codon 50 C-->A) on the selectively amplified alpha2-globin gene. We determined the protein and DNA sequences and performed cellulose acetate electrophoresis, isoelectric focusing, globin chain separation, stability tests with isopropanol and heat precipitation, and oxygen affinity analyses on whole blood to fully characterize the variant. A comprehensive review of the deamidation processes involving Asn and Gln residues in mutant proteins is reported, together with a discussion of the molecular mechanisms of such deamidations. Finally, examples of other proteins of clinical importance in which Asn or Gln residues have been implicated by DNA analysis alone are presented. These findings point out the importance of the complete characterization of variant proteins by use of both DNA and protein analyses.

Asparagine↗

A multi-center safety trial of the oral iron chelator deferiprone.

Deferiprone, also known as L1, is an orally active iron chelator that has been studied extensively in clinical trials. The sporadic occurrence of agranulocytosis in association with deferiprone and the highly variable frequency of other possible side effects such as arthralgia have created uncertainty about the true incidence of deferiprone-related complications. A multi-center, 1-year trial was initiated to determine the safety profile of deferiprone. Using the Apotex formulation of deferiprone, 187 patients with thalassemia who were unable or unwilling to use deferoxamine were enrolled in four centers; 162 patients completed one year of therapy. Agranulocytosis (ANC < 500/mm3) occurred in one patient after 15 weeks of treatment, was not accompanied by infection and resolved following treatment with G-CSF. Nine other subjects developed less severe neutropenia (ANC 500-1500/mm3) with the lowest absolute neutrophil count reaching 500-1250/mm3. The neutropenia in these patients developed after 1-50 weeks of therapy, frequently accompanied febrile illnesses, and occurred predominantly in non-splenectomized patients. Reasons other than neutropenia for discontinuing use of deferiprone included nausea (4), voluntary withdrawal (3), high ALT (2), platelet count < 100,000/mm3 (2), low but unconfirmed ANC (1), protocol violation (1) fatigue (1), and depression (1). Mean ALT levels rose within three months of therapy and stabilized thereafter. Arthralgia and nausea and/or vomiting occurred in 6% and 24% of subjects, respectively. In this multi-center trial with weekly monitoring of blood counts, the incidence of agranulocytosis was 0.58 per 100 patient-years, and the frequency of agranulocytosis after one year was 0.5%. These findings support the safety of this formulation of deferiprone, using the careful monitoring system employed in this trial.

Administration, Oral↗

Relationship between genotype and phenotype. Thalassemia intermedia.

Thalassemia intermedia encompasses a number of clinical conditions ranging in severity from beta-thalassemia carrier state to transfusion-dependent thalassemia major. The molecular bases of thalassemia intermedia, only partially defined, are very heterogeneous, but in general any factor able to reduce the globin-chain imbalance results in a milder form of thalassemia. These factors are the presence of a silent or mild beta-thalassemia allele, associated with a high residual beta-globin production, and the coinheritance of alpha-thalassemia or of genetic determinants that increase the gamma-chain production. Less frequent mechanisms are double heterozygosity for beta-thalassemia and triplicated alpha genes, and the presence of a hyperunstable hemoglobin variant. However, for a consistent number of beta zero-thalassemia homozygotes with a thalassemia intermedia phenotype the modifying factor has not been defined yet. In contrast, there are simple beta-thalassemia carriers who, for unknown reasons, have an unusually severe clinical phenotype.

Blood Transfusion↗