Evaluation of spine and hip bone density by DXA and QCT in thalassemic patients.
Explore the source record for details and available documents.
Absorptiometry, Photon↗
Biomedical subjects
M D Cappellini
Publications and source records attributed to M D Cappellini.
The effect of dietary magnesium supplementation on the cellular abnormalities of erythrocytes in patients with beta thalassemia intermedia.
BACKGROUND AND OBJECTIVE: Reduced serum or erythrocyte Mg have been reported in human beta thalassemia. These deficiencies may play a role in the cellular abnormalities characteristic of this disorder. We have therefore studied the effect of dietary Mg supplementation in patients with beta thalassemia intermedia in order to establish whether it improves the abnormalities of thalassemic erythrocytes. DESIGN AND METHODS: Plasma and erythrocyte Mg were determined in 11 patients with b thalassemia intermedia, not requiring chronic transfusion therapy, and in 17 normal controls. Inclusion criteria included normal renal and liver function and performance status of 70% or greater. Seven patients were enrolled for the Mg supplementation study, after the appropriate informed consent was obtained. They were given a starting dose of 0.6 mEq/kg/day of magnesium pidolate, divided into two oral daily doses, for four weeks. In a 70-kg subject, a daily Mg dose of 42 mEq corresponds to 504 mg of Mg, with the daily Mg intake of normal subjects being 418 +/- 120 mg for males and 343 +/- 94 mg for females. After 28 days of treatment, five of the patients continued the protocol with a daily dosage increased to 1.2 mEq magnesium pidolate/kg/day, divided into two oral administrations, for an additional four weeks. RESULTS: In patients with untransfused beta thalassemia intermedia we found reduced erythrocyte Mg (in mmol/kg Hb, 6.12 +/- 1.5, n = 11 vs. 8.69 +/- 0.89, n = 17, respectively, p < 0.0001) and normal serum Mg. In the seven patients given oral Mg supplements, at Mg dosages of 0.6 mEq/kg/day we observed significant increases in erythrocyte Mg, and significant improvement in some of the characteristic abnormalities of beta that erythrocytes (increased Na-K pump, KCl cotransport, cell dehydration, increased osmotic resistance). These changes were maintained in the 5 patients who were treated with 1.2 mEq of Mg/kg/day. Follow-up studies showed a return to baseline conditions. There were no signs of Mg toxicity, with the only side effect being diarrhea, which was generally mild, but led to discontinuation for one patient after the first four weeks. INTERPRETATION AND CONCLUSIONS: These data indicate that dietary Mg supplementation improves some of the characteristic cellular function abnormalities of b thalassemia intermedia. The possible therapeutic value of this strategy should be further tested in these patients.
Biological Transport, Active↗
Hemoglobin SC disease and proliferative retinopathy.
Explore the source record for details and available documents.
Adult↗
Prevalence and clinical significance of hepatitis G virus infection in adult beta-thalassaemia major patients.
The risk of polytransfused patients for hepatitis C virus (HCV) infection is likely to extend to another recently identified member of the Flaviviridae, hepatitis G virus (HGV). We investigated the prevalence of HGV in 40 adult Italian patients with transfusion-dependent thalassaemia and evaluated the clinical significance of HGV infection. HGV-RNA was detected in 9/40 patients (22.5%). HGV infection was significantly associated with HCV viraemia (P = 0.0012), with all patients positive for HGV being also viraemic for HCV. Overall, the clinical picture of patients with HCV/HGV co-infection was not different from that of patients with isolated HCV. However, patients co-infected with both viruses had lower values of alanine-transferase (P = 0.035) and a lower titre of HCV viraemia (P = 0.042) in the absence of other evident factors which could influence the clinical expression of HCV infection. In conclusion, HGV is highly prevalent among Italian polytransfused patients. No evidence of a clinically significant pathogenic role for HGV in liver disease could be found in these patients. In a subset of cases a possible interference of HGV with HCV infection was observed.
Adolescent↗
The expression of uridine diphosphate glucuronosyltransferase gene is a major determinant of bilirubin level in heterozygous beta-thalassaemia and in glucose-6-phosphate dehydrogenase deficiency.
We evaluated the effect of Gilbert's syndrome, the most common defect of bilirubin conjugation, on the bilirubin levels of subjects with inherited haematological disorders which cause increased bilirubin production. 57 patients heterozygous for beta-thalassaemia, 21 with G6PD deficiency and 44 controls were examined by typing the TATA-box in the promoter of the gene uridine diphosphate glucuronosyltransferase 1A. Nearly 80% of patients with increased bilirubin levels were heterozygous or homozygous for the UGT1A TA(7) variant associated with Gilbert's syndrome. These findings indicate that Gilbert's syndrome accounts for a large proportion of the variability of bilirubin levels in beta-thalassaemia and G6PD deficiency.
Gene Expression↗
Multiple G6PD mutations are associated with a clinical and biochemical phenotype similar to that of G6PD Mediterranean.
Glucose-6-phosphate dehydrogenase (G6PD) deficiency, one of the most common red cell abnormalities, is characterized by a wide clinical, biochemical, and molecular heterogeneity. In this study we have determined the molecular basis of G6PD deficiency in a sample of 70 male subjects, originating from different parts of Italy, who all shared a clinical and biochemical phenotype identical or very similar to that of G6PD Mediterranean, the most common variant in Italy. In 59 cases (84%) we found the mutation 563 C --> T, previously known to be underlying the G6PD Mediterranean and the two polymorphic variants G6PD Cagliari and G6PD Sassari. From the remaining 11 we amplified the entire coding region of G6PD in 8 different fragments and subjected them to nonradioactive single-strand conformation analysis. Direct sequencing was then performed on abnormal fragments. By this approach we found six cases (8.5%) with 1360 G --> A mutation (G6PD Union) and two cases (2.8%) with 1376 G --> C (G6PD Cosenza). In the remaining three samples we found two other mutations: 1342 A --> G (two cases, 2.8%) and 1052 G --> T (one case, 1.4%). These two molecular defects have never been described before and were designated by us as G6PD S. Antioco and G6PD Partenope, respectively. Haplotype analysis suggested that all the non-Mediterranean mutations occurred independently on a normal G6PD allele. This study shows that the G6PD Union mutation has a high polymorphic frequency in the Italian population and that the genetic heterogeneity of G6PD Mediterranean-like variants is higher at the molecular level than expected from biochemical characterization.
Base Sequence↗
Genetic hemochromatosis in Italian patients with porphyria cutanea tarda: possible explanation for iron overload.
BACKGROUND/AIMS: Mild to moderate iron overload is found in most patients with porphyria cutanea tarda. This study aimed to evaluate whether iron overload in patients with porphyria cutanea tarda is related to the presence of a coexistent genetic hemochromatosis gene. METHODS: A cohort study of 94 Italian patients with porphyria cutanea tarda (90 men and 4 women) and 20 relatives of five patients with iron overload were studied. Diagnosis of iron overload was assessed by transferrin saturation, serum ferritin and iron removed by phlebotomy to reach depletion. HLA typing by microlymphocytotoxicity test and duodenal ferritin analysis by immunohistochemistry were performed in a smaller number of patients. The chi square test was used to compare means and prevalences. RESULTS: Iron overload was present in 62% of the patients. HLA-A3 prevalence was significantly higher (p < 0.01) in subjects with iron overload than in those without. A lack of duodenal ferritin was observed in 14/18 patients with and in 6/12 without iron overload. Family studies showed the presence of iron overload but not of porphyria cutanea tarda in HLA identical or semi-identical relatives of the patients. CONCLUSIONS: Italian patients with porphyria cutanea tarda and iron overload appear to have one or even two genes for genetic hemochromatosis.
Adult↗
Lack of association between porphyria cutanea tarda and alpha 1-antitrypsin deficiency.
OBJECTIVE: To determine whether alpha 1-antitrypsin deficiency is involved in the pathogenesis of chronic liver disease in patients with porphyria cutanea tarda and in their recently described high prevalence of hepatitis C virus infection. DESIGN: Consecutive patients diagnosed as having porphyria cutanea tarda and chronic liver disease. SETTING: A northern Italian hospital. METHODS: alpha 1-antitrypsin phenotypes were characterized by isoelectric focusing and the results confirmed by DNA analysis in 63 Italian patients with porphyria cutanea tarda. RESULTS: alpha 1-antitrypsin phenotypes different from the normal one were found in 13% of the patients. This prevalence did not differ from that in control subjects (9%). Clinical characteristics of patients with porphyria cutanea tarda with normal or altered alpha 1-antitrypsin phenotype, including age of presentation of the disease, prevalence of hepatitis C virus infection, liver histology, prevalence of iron overload and hepatocellular carcinoma occurrence, did not differ significantly. CONCLUSION: alpha 1-antitrypsin does not seem to play a role in the pathogenesis of chronic liver disease and hepatitis C virus infection in patients with porphyria cutanea tarda. Patients in whom the two defects coexist do not have a more severe disease.
Adult↗
Role of hemichrome binding to erythrocyte membrane in the generation of band-3 alterations in beta-thalassemia intermedia erythrocytes.
Nine splenectomized, hematologically well-compensated beta-thalassemia intermedia patients randomly chosen from a pool of 60 similar patients were studied. Membrane proteins solubilized with nondenaturing detergent C12E8 were gel filtered on Sepharose CL-6B (Pharmacia Fine Chemicals, Uppsala, Sweden). Fractions containing higher than 4,000-kD molecular-weight aggregates were isolated and analyzed. Four patients had remarkably increased amounts of membrane-bound hemichromes and Igs. In those patients, band 3 underwent oxidative modifications such as aggregation and a decrease in sulfhydryl groups. The other five patients had low amounts of membrane-bound hemichromes and less modifications of band 3. The same band-3 modifications could be reproduced by challenging normal membranes with artificially generated hemichromes or with hemolysates prepared from thalassemic erythrocytes of the high-hemichrome group. Addition of reduced glutathione to the challenged membranes did not hinder hemichrome binding, but prevented oxidative modifications of band 3 and Ig binding to high-molecular-weight band-3 aggregates. Hemichrome binding to band 3, hemichrome-mediated oxidation of band-3 cytoplasmic domains, generation of high-molecular-weight band-3 aggregates, and enhanced opsonization by anti-band-3 antibodies is a possible sequence of events leading to phagocytic removal of erythrocytes in thalassemia.
Adolescent↗
Genetic interactions in thalassemia intermedia: analysis of beta-mutations, alpha-genotype, gamma-promoters, and beta-LCR hypersensitive sites 2 and 4 in Italian patients.
In order to verify the genetic factors influencing the clinical expression of beta-thalassemia we have studied 292 Italian patients, 165 with thalassemia intermedia and 127 with thalassemia major. The beta-globin gene mutations were defined in all cases. The number of alpha-globin genes and the integrity of specific control regions of the beta-globin cluster--gamma promoters and beta-Locus Control Region (beta-LCR)--were studied in selected cases. Homozygosity for mild mutations (group I) accounts for 24% of the intermedia patients and it is not represented among major patients. Forty-four percent of intermedia patients had combinations of mild/severe (group II) mutations and 32% had homozygosity or double heterozygosity for severe mutations (group III). Seventy-six percent of patients with thalassemia major were classified in group III and 24% in group II. Deletion type-alpha3.7 thalassemia, assessed in a part of the cases, was found in 5% of thalassemia major and 19.5% of intermedia patients in groups II and III. Structural analysis of gamma promoters and beta-LCR HS2 and HS4 regions, carried out in order to look for alterations associated with Hb F increase, did not reveal new mutations. Only rare polymorphic changes were observed at the HS2 and HS4 level. The -158G gamma C T change was found with an increased incidence in intermedia patients in groups II and III. A subset of 10 beta-thalassemia heterozygotes with mild intermedia phenotype resulted from coinheritance of a triplicated alpha-locus. We have been unable to find a molecular basis for the benign clinical course in approximately 20% of patients with thalassemia intermedia. Other genetic or acquired factors must be hypothesized which ameliorate the clinical condition.
Adolescent↗
Molecular characterisation of the glucose-6-phosphate dehydrogenase (G6PD) Ferrara II variant.
During the last ten years, molecular biological techniques such as cloning and sequencing and, more recently, polymerase chain reaction (PCR) amplification have led to the identification of the molecular defects responsible for more than fifty glucose-6-phosphate dehydrogenase (G6PD) variants. In this paper, we report the identification of the molecular abnormality underlying the G6PD Ferrara II variant, present in the Po delta area of Northern Italy. Biochemical characterisation shows an enzymatic activity of about 15% of normal (WHO class III), slow electrophoretic mobility, low Km for G6P, high percentage substrate analogue utilisation and a biphasic pH optimum curve. After PCR amplification, non-radioisotopic single-strand conformation polymorphism analysis carried out for the entire coding region has revealed a mobility shift in exon 8. Nucleotide sequencing has demonstrated a missense 844 G > C mutation, causing an Asp > His amino-acid replacement, known as being responsible for G6PD Seattle, G6PD Modena and G6PD Lodi.
Adult↗
Transfusion-transmitted human parvovirus B19 infection in a thalassemic patient.
BACKGROUND: Human parvovirus (HPV) B19 infection has been shown to be transmissible by clotting factor concentrates, most often resulting in asymptomatic seroconversion. So far, no case of B19 transmission due to single-donor transfusion has been documented. CASE REPORT: A case of transfusion-transmitted HPV B19 infection in a 22-year-old female thalassemia major patient is described. She presented with an aplastic crisis; this was followed 1 week later by transitory heart failure and acute tricuspid incompetence. The echocardiogram revealed a grade III tricuspid regurgitation and a floating vegetation on the atrial face of the tricuspid lateral leaflet. The tricuspid regurgitation and vegetation spontaneously disappeared within 15 days. Blood cultures for bacteria were repeatedly negative. IgM anti-HPV B19 seroconversion was documented in the acute phase. B19 DNA was detected by polymerase chain reaction and remained detectable up to 4 months after diagnosis. High-titer IgM anti-HPV and B19 DNA were also found in serum samples collected at the time of donation from one of the donors of the blood transfused before the onset of clinical symptoms. CONCLUSION: This case documents the transmission of HPV B19 by the transfusion of 1 red cell unit and the occurrence of possible transient cardiac involvement in this infectious complication.
Adult↗
Carbohydrate-deficient transferrin in alcohol and nonalcohol abusers with liver disease.
Carbohydrate-deficient transferrin (CDT) has been demonstrated to be a marker of prolonged heavy alcohol consumption. We compared this marker with gamma-glutamyltranspeptidase (GGT) and mean corpuscular volume (MCV) in alcohol and nonalcohol abusers with liver disease. Our results confirm that the sensitivity of CDT in alcoholics is high, although lower than that of GGT and MCV; however, the specificity of CDT was higher than that of the other two markers. This finding supports the notion that CDT is only partially influenced by the presence of liver damage, whereas increases of GGT and MCV are greatly affected by several factors, including liver damage and drugs. Moreover, we observed that the sensitivity and the specificity of CDT were greater than those of GGT and MCV in younger drinkers.
Adult↗
Different origin of nt 1246 glucose-6-phosphate dehydrogenase mutation.
Explore the source record for details and available documents.
Codon↗
G6PD Ferrara I has the same two mutations as G6PD A(-) but a distinct biochemical phenotype.
The cloning and sequencing of the normal glucose-6-phosphate dehydrogenase (G6PD) gene has led to the study of the molecular defects that determine enzymatic variants. In this paper, we describe the mutations responsible for the Ferrara I variant in an Italian man with a family history of favism, from the Po delta. Nucleotide sequencing of this variant showed a G-->A mutation at nucleotide 202 in exon IV causing a Val-->Met amino acid exchange, and a second A-->G mutation at nucleotide 376 in exon V causing an Asn-->Asp amino acid substitution. Although on the basis of its biochemical properties this variant was classified as G6PD Ferrara I, it has the same two mutations as G6PD A(-), which is common in American and African blacks, and as the sporadic Italian G6PD Matera. The mutation at nucleotide 202 was confirmed by NlaIII digestion of a polymerase chain reaction amplified DNA fragment spanning 109 bp of exon IV. The 109-bp mutated amplified sequence is not distinguishable from the normal sequence in single strand conformation polymorphism analysis.
Cloning, Molecular↗
Glucose 6-phosphate dehydrogenase deficiency and red cell membrane defects: additive or synergistic interaction in producing chronic haemolytic anaemia.
We have investigated two unrelated patients with congenital haemolytic anaemia in both of whom we found a combination of hereditary spherocytosis (HS) and glucose-6-phosphate dehydrogenase (G6PD) deficiency. Segregation of the two defects was documented in both families, who had different molecular abnormalities for both HS and G6PD deficiency. In one family the propositus had a reduced level of spectrin and G6PD Seattle (282Asp-->His). In the other family the propositus had a band 3 abnormality and was heterozygous for G6PD Mediterranean (188Ser-->Phe). From a comparison of clinical and haematological findings in family members with either or both abnormalities we conclude that in one case the two defects exhibited a synergistic effect, resulting in a severe chronic haemolytic anaemia; whereas in the other the association was simply additive.
Anemia, Hemolytic, Congenital↗
Biochemical and molecular characterization of a new sporadic glucose-6-phosphate dehydrogenase variant described in Italy: G6PD Modena.
A new glucose-6-phosphate dehydrogenase variant detected in an Italian man from the Po delta is described and designated as G6PD Modena. Biochemical characterization of the variant enzyme revealed an activity 21% of normal, a slow electrophoretic mobility, increased Km value for NADP, decreased Km value for G6P and a complete absence of NADPH inhibition, which could account for the apparently nonhaemolytic feature of this variant. The cloning and sequencing of the G6PD Modena allele showed a G-->C transition at nucleotide 844 in exon VIII causing a Asp-->His amino acid substitution. On the basis of biochemical characterization, G6PD Modena is classified as a genuine variant but it has the same mutation as G6PD Seattle-like.
Adult↗
Molecular characterisation of an Italian G6PD variant responsible for chronic non-spherocytic haemolytic anaemia.
An Italian deficient G6PD variant associated with chronic non-spherocytic haemolytic anaemia (CNSHA) was biochemically characterised and studied at molecular level. Single-strand conformation polymorphism (SSCP) analysis led to the identification of an abnormal migration pattern of an amplified fragment encompassing exons 10 and 11 of the G6PD gene. Sequence analysis of both strands using an automated fluorescent DNA sequencer revealed a G-->A transition at nt. position 1246 in exon 10. A C-->T substitution at nt. 1311 in exon 11 was also found, which has already been described as a silent mutation common in Caucasians. The 1246 G-->A mutation has been described only in a Japanese subject with CNSHA (G6PD Tokyo) not associated with the 1311T polymorphism, suggesting that this mutation may have arisen independently in Europe and Asia.
Adult↗