Serum ferritin and transferrin saturation levels in β0 and β + thalassemia patients

There have been few studies on the mutations that cause heterozygous beta-thalassemia and how they affect the iron profile. One hundred and thirty-eight individuals were analyzed, 90 thalasemic β0 and 48 thalasemic β+, identified by classical and molecular methods. Mutations in the hemochromatosis (HFE) gene, detected using PCR-RFLP, were found in 30.4% of these beta-thalassemic patients; heterozygosity for H63D (20.3%) was the most frequent. Ferritin levels and transferrin saturation were similar in beta-thalassemics with and without mutations in the HFE gene. Ferritin concentrations were significantly higher in men and in individuals over 40 years of age. Transferrin saturation also was significantly higher in men, but only in those without HFE gene mutations. There was no significant difference in the iron profile among the β0 and β+ thalassemics, with and without HFE gene mutations. The frequency of ferritin values above 200 ng/mL in women and 300 ng/mL in men was also similar in β0 and β+ thalassemics (P > 0.72). Our conclusion is that ferritin levels are variable in the beta-thalassemia, trait regardless of the type of beta-globin mutation. Furthermore, HFE gene polymorphisms do not change the iron profile in these individuals. ©FUNPEC-RP www.funpecrp.com.br.

Influence of δβ-thalassemia or regulatory elements in individuals with increased fetal Hb levels in the São Paulo northwest population

Fetal hemoglobin (Hb F), formed by two alpha globin chains (α) and two gamma chains (γ) (α2 γ2), has reduced expression in adults, ranging from 0 to 1% of total hemoglobin. Increased levels of Hb F are due to mutations in the β-globin family, which cause hereditary persistence of fetal hemoglobin (HPFH) and delta-beta thalassemia (δβ-thalassemia).The control of the production takes place by the regulatory region and regions outside the β-globin family, among them 2q16, 6q23, 8q, and Xp22.2.The aims of this study were to determine the presence and frequency of two mutations for δβ-thalassemia, the XmnI polymorphism and β-globin haplotypes in healthy individuals with increased Hb F in the State of São Paulo. We analyzed 60 samples of peripheral blood of healthy adults, without complaints of anemia. The samples were separated into two groups according to Hb F level: group I - 34 samples with Hb F ranging from 2 to 15% and group II - 26 samples with Hb F over 15%. In relation to the polymorphisms examined, we found three heterozygous individuals (5%) for Spanish δβ-thalassemia, belonging to group I, whose Hb F levels were within the normal range.The Sicilian δβ-thalassemia mutation was not found, indicating the need to study other polymorphisms related to the increase of Hb F in adult life.The frequency of XmnI polymorphism was 33.3% and the mean Hb F levels were 15.48 ± 11.69%.The frequency observed in our study for this polymorphic site is higher than that found in the literature for healthy subjects.This polymorphism was more prevalent in individuals with Hb F levels below 15%. For four samples positive for this polymorphism, the Hb F levels were explained by the presence of HPFH and Spanish δβ-thalassemia mutations, so that the presence of the XmnI polymorphic site was not a determinant in the overexpression of γ-globin genes. Regarding β-globin haplotypes, 18 alleles and 27 distinct genotypic patterns were found.The pattern Atp1/Atp2 was the mostfrequent genotype (13.72%).Of the 18 alleles, 13 showed atypical patterns.The results show that the haplotype V was the most frequent (27.45%), followed by atypical Atp2 (13.72%) and Atp1 (11.76%), and that there was a higher correlation with the presence of HPFH and XmnI polymorphism.The high frequency of haplotype V in our samples and high frequency of atypical haplotypes may reflect a high rate of miscegenation in this population, suggesting an ethnic characteristic for the Brazilian population, requiring the evaluation of population genetic markers to corroborate this hypothesis. © FUNPEC-RP.

Evaluation of HPFH and δβ-thalassemia mutations in a Brazilian group with high Hb F levels.

Fetal hemoglobin (Hb F) is characteristic of the fetal development period. However, in some genetic conditions, such as hereditary persistence of fetal hemoglobin (HPFH) and delta-beta thalassemia (δβ-thalassemia), Hb F continues to be produced in adulthood. We evaluated the frequency of two mutations of HPFH, HPFH-1 and HPFH-2 African, and two mutations in δβ-thalassemia, Sicilian and Spanish, in a Brazilian population. Peripheral blood samples were collected from adults from hospitals and blood centers in southeast and northeast Brazil. These individuals were healthy and without complaints of anemia, but had increased Hb F. Samples were submitted to electrophoretic and chromatographic analyses to quantify Hb F values and, subsequently, to molecular analyses to verify the mutations. In the molecular analysis, 16 of the 60 samples showed a heterozygous profile for the HPFH mutations, two for HPFH-1 and 14 for HPFH-2. In the same sample set, three were heterozygous for Spanish δβ-thalassemia and none were heterozygous for Sicilian δβ- thalassemia. The Hb F values in the HPFH-2 heterozygotes differed from those previously reported for this mutation. In this group, the HPFH mutations were more frequent than the δβ-thalassemia mutations. The finding of these mutations in this Brazilian population reflects the mixing process that occurred during its formation.

Oxidative stress and antioxidant status in beta-thalassemia heterozygotes

Background: Several studies have evaluated the oxidant and antioxidant status of thalassemia patients but most focused mainly on the severe and intermediate states of the disease. Moreover, the oxidative status has not been evaluated for the different beta-thalassemia mutations. Objective: To evaluate lipid peroxidation and Trolox equivalent antioxidant capacity in relation to serum iron and ferritin in beta thalassemia resulting from two different mutations (CD39 and IVS-I-110) compared to individuals without beta-thalassemia. Methods: One hundred and thirty subjects were studied, including 49 who were heterozygous for beta-thalassemia and 81 controls. Blood samples were subjected to screening tests for hemoglobin. Allele-specific polymerase chain reaction was used to confirm mutations for beta-thalassemia, an analysis of thiobarbituric acid reactive species was used to determine lipid peroxidation, and Trolox equivalent antioxidant capacity evaluations were performed. The heterozygous beta-thalassemia group was also evaluated for serum iron and ferritin status. Results: Thiobarbituric acid reactive species (486.24 ± 119.64 ng/mL) and Trolox equivalent antioxidant capacity values (2.23 ± 0.11 mM/L) were higher in beta-thalassemia heterozygotes compared to controls (260.86 ± 92.40 ng/mL and 2.12 ± 0.10 mM/L, respectively; p-value < 0.01). Increased thiobarbituric acid reactive species values were observed in subjects with the CD39 mutation compared with those with the IVS-I-110 mutation (529.94 ± 115.60 ng/mL and 453.39 ± 121.10 ng/mL, respectively; p-value = 0.04). However, average Trolox equivalent antioxidant capacity values were similar for both mutations (2.20 ± 0.08 mM/L and 2.23 ± 0.12 mM/L, respectively; p-value = 0.39). There was no influence of serum iron and ferritin levels on thiobarbituric acid reactive species and Trolox equivalent antioxidant capacity values. Conclusion: This study shows an increase of oxidative stress and antioxidant capacity in beta-thalassemia heterozygotes, mainly in carriers of the CD39 mutation.

Oxidative stress and antioxidant status in beta-thalassemia heterozygotes

Background:Several studies have evaluated the oxidant and antioxidant status of thalassemia patients but most focused mainly on the severe and intermediate states of the disease. Moreover, the oxidative status has not been evaluated for the different beta-thalassemia mutations.Objective:To evaluate lipid peroxidation and Trolox equivalent antioxidant capacity in relation to serum iron and ferritin in beta thalassemia resulting from two different mutations (CD39 and IVS-I-110) compared to individuals without beta-thalassemia.Methods:One hundred and thirty subjects were studied, including 49 who were heterozygous for beta-thalassemia and 81 controls. Blood samples were subjected to screening tests for hemoglobin. Allele-specific polymerase chain reaction was used to confirm mutations for beta-thalassemia, an analysis of thiobarbituric acid reactive species was used to determine lipid peroxidation, and Trolox equivalent antioxidant capacity evaluations were performed. The heterozygous beta-thalassemia group was also evaluated for serum iron and ferritin status.Results:Thiobarbituric acid reactive species (486.24 ± 119.64 ng/mL) and Trolox equivalent antioxidant capacity values (2.23 ± 0.11 mM/L) were higher in beta-thalassemia heterozygotes compared to controls (260.86 ± 92.40 ng/mL and 2.12 ± 0.10 mM/L, respectively; p-value < 0.01). Increased thiobarbituric acid reactive species values were observed in subjects with the CD39 mutation compared with those with the IVS-I-110 mutation (529.94 ± 115.60 ng/mL and 453.39 ± 121.10 ng/mL, respectively; p-value = 0.04). However, average Trolox equivalent antioxidant capacity values were similar for both mutations (2.20 ± 0.08 mM/L and 2.23 ± 0.12 mM/L, respectively; p-value = 0.39). There was no influence of serum iron and ferritin levels on thiobarbituric acid reactive species and Trolox equivalent antioxidant capacity values.Conclusion:This study shows an increase of oxidative stress and antioxidant capacity in beta-thalassemia heterozygotes, mainly in carriers of the CD39 mutation.

Molecular and phylogenetic analyses of human Parvovirus B19 isolated from Brazilian patients with sickle cell disease and beta-thalassemia major and healthy blood donors

Human Parvovirus B19 (B19V) is a recognized cause of life-threatening conditions among patients with hemoglobinopathies. This study investigates B19V infection in patients with sickle cell disease and beta-thalassemia using different experimental approaches. A total of 183 individuals (144 with sickle cell disease and 39 with beta-thalassemia major) and 100 healthy blood donors were examined for B19V using anti-B19V IgG enzyme immunoassay, quantitative PCR, DNA sequencing, and phylogenetic analysis. Viremia was documented in 18.6% of patients and 1% of donors, and was generally characterized by low viral load (VL); however, acute infections were also observed. Anti-B19V IgG was detected in 65.9% of patients with sickle cell disease and in 60% of donors, whereas the patients with thalassemia exhibited relatively low seroreactivity. The seroprevalence varied among the different age groups. In patients, it progressively increased with age, whereas in donors it reached a plateau. Based on partial NS1 fragments, all isolates detected were classified as subgenotype 1A with a tendency to elicit genetically complex infections. Interestingly, quasispecies occurred in the plasma of not only patients but also donors with even higher heterogeneity. The partial NS1 sequence examined did not exhibit positive selection. Quantitation of B19V with a conservative probe is a technically and practically useful approach. The extensive spread of B19V subgenotype 1A in patients and donors and its recent introduction into the countryside of the Sao Paulo State, Brazil were demonstrated; however, it is difficult to establish a relationship between viral sequences and the clinical outcomes of the infection. J. Med. Virol. 84:16521665, 2012. (c) 2012 Wiley Periodicals, Inc.

A randomized controlled 1-year study of daily deferiprone plus twice weekly desferrioxamine compared with daily deferiprone monotherapy in patients with thalassemia major

BACKGROUND AND OBJECTIVES: The aim of this prospective, randomized, 1-year study was to compare the efficacy and safety of oral deferiprone (DFP) with those of combinations of parenteral desferrioxamine (DFO) with oral DFP. DESIGN AND METHODS: A total of 24 patients with thalassemia major were randomized to receive one of the following two treatments; DFP given at a daily dose of 75 mg/kg in combination with DFO (40-50 mg/kg twice weekly) (n=12) or as single agent (n=12). In addition, 12 patients treated with 40-50 mg/kg DFO 5 days weekly were included as a reference group without randomization. Changes in liver iron concentration (LIC) and serum ferritin (SF) were assessed; total iron excretion (TIE), urinary iron excretion (UIE) and iron balance were calculated. Cardiac function and toxicity were also examined. DESIGN AND METHODS: SF and LIC were significantly reduced after 1 year of combination therapy (p=0.01 and 0.07, respectively). A decrease of LIC was observed in all but one patient (87.5%) following the combination therapy but in only 42% of patients treated with DFP monotherapy. In the DFO reference group, a statistically significant decrease in LIC (p=0.01) associated with a substantial decrease in SF (p=0.08) was observed after 1 year. The combination regimen resulted in greater TIE compared to DFP monotherapy (p=0.08) and was the regimen associated with the highest iron balance compared to DFP monotherapy (p=0.04) or standard DFO treatment (p=0.006). INTERPRETATIONS AND CONCLUSIONS: The addition of subcutaneous DFO twice weekly to oral DFP 75 mg/kg is a highly efficacious and safe chelation therapy providing superior chelation activity to that of DFP and likely has an efficacy profile comparable to that of standard DFO.

α+-Thalassemia protects children against disease caused by other infections as well as malaria

In the South West Pacific region, the striking geographical correlation between the frequency of α+-thalassemia and the endemicity of Plasmodium falciparum suggests that this hemoglobinopathy provides a selective advantage against malaria. In Vanuatu, paradoxically, α+-thalassemia increases the incidence of contracting mild malaria in the first 2 years of life, but severe disease was too uncommon to assess adequately. Therefore, we undertook a prospective case-control study of children with severe malaria on the north coast of Papua New Guinea, where malaria transmission is intense and α+-thalassemia affects more than 90% of the population. Compared with normal children, the risk of having severe malaria was 0.40 (95% confidence interval 0.22–0.74) in α+-thalassemia homozygotes and 0.66 (0.37–1.20) in heterozygotes. Unexpectedly, the risk of hospital admission with infections other than malaria also was reduced to a similar degree in homozygous (0.36; 95% confidence interval 0.22–0.60) and heterozygous (0.63; 0.38–1.07) children. This clinical study demonstrates that a malaria resistance gene protects against disease caused by infections other than malaria. The mechanism of the remarkable protective effect of α+-thalassemia against severe childhood disease remains unclear but must encompass the clear interaction between this hemoglobinopathy and both malarial and nonmalarial infections.

A normal β-globin allele as a modifier gene ameliorating the severity of α-thalassemia in mice

Thalassemia is a heritable human anemia caused by a variety of mutations that affect expression of the α- or the β-chain of hemoglobin. The expressivity of the phenotype is likely to be influenced by unlinked modifying genes. Indeed, by using a mouse model of α-thalassemia, we find that its phenotype is strongly influenced by the genetic background in which the α-thalassemia mutation resides [129sv/ev/129sv/ev (severe) or 129sv/ev/C57BL/6 (mild)]. Linkage mapping indicates that the modifying gene is very tightly linked to the β-globin locus (Lod score = 13.3). Furthermore, the severity of the phenotype correlates with the size of β-chain-containing inclusion bodies that accumulate in red blood cells and likely accelerate their destruction. The β-major globin chains encoded by the two strains differ by three amino acids, one of which is a glycine-to-cysteine substitution at position 13. The Cys-13 should be available for interchain disulfide bridging and consequent aggregation between excess β-chains. This normal polymorphic variation between murine β-globin chains could account for the modifying action of the unlinked β-globin locus. Here, the variation in severity of the phenotype would not depend on a change in the ratio between α- and β-chains but on the chemical nature of the normal β-chain, which is in excess. This work also indicates that modifying genes can be normal variants that—absent an apparent physiologic rationale—may be difficult to identify on the basis of structure alone.

A mouse model for beta 0-thalassemia.

We have used a "plug and socket" targeting technique to generate a mouse model of beta 0-thalassemia in which both the b1 and b2 adult globin genes have been deleted. Mice homozygous for this deletion (Hbbth-3/Hbbth-3) die perinatally, similar to the most severe form of Cooley anemia in humans. Mice heterozygous for the deletion appear normal, but their hematologic indices show characteristics typical of severe thalassemia, including dramatically decreased hematocrit, hemoglobin, red blood cell counts, mean corpuscular volume, mean corpuscular hemoglobin, and mean corpuscular hemoglobin concentration, as well as dramatically increased reticulocyte counts, serum bilirubin concentrations, and red cell distribution widths. Tissue and organ damage typical of beta-thalassemia, such as bone deformities and splenic enlargement due to increased hematopoiesis, are also seen in the heterozygous animals, as is spontaneous iron overload in the spleen, liver, and kidneys. The mice homozygous for the b1 and b2 deletions should be of great value in developing therapies for the treatment of thalassemias in utero. The heterozygous animals will be useful for studying the pathophysiology of thalassemias and have the potential of generating a model of sickle cell anemia when mated with appropriate transgenic animals.

Mouse model of human beta zero thalassemia: targeted deletion of the mouse beta maj- and beta min-globin genes in embryonic stem cells.

beta zero-Thalassemia is an inherited disorder characterized by the absence of beta-globin polypeptides derived from the affected allele. The molecular basis for this deficiency is a mutation of the adult beta-globin structural gene or cis regulatory elements that control beta-globin gene expression. A mouse model of this disease would enable the testing of therapeutic regimens designed to correct the defect. Here we report a 16-kb deletion that includes both adult beta-like globin genes, beta maj and beta min, in mouse embryonic stem cells. Heterozygous animals derived from the targeted cells are severely anemic with dramatically reduced hemoglobin levels, abnormal red cell morphology, splenomegaly, and markedly increased reticulocyte counts. Homozygous animals die in utero; however, heterozygous mice are fertile and transmit the deleted allele to progeny. The anemic phenotype is completely rescued in progeny derived from mating beta zero-thalassemic animals with transgenic mice expressing high levels of human hemoglobin A. The beta zero-thalassemic mice can be used to test genetic therapies for beta zero-thalassemia and can be bred with transgenic mice expressing high levels of human hemoglobin HbS to produce an improved mouse model of sickle cell disease.

Psychological Aspects in Children and Adolescents With Major Thalassemia: A Case-Control Study

Background: Thalassemia is an inherited blood disease. It is a serious public health problem throughout the Mediterranean region, the Middle East and the Indian subcontinent, as well as in Southeast Asia. Objectives: Thalassemia is an inherited blood disease. It is a serious public health problem. In this study we assessed psychological aspects in Iranian children and adolescents with thalassemia major. Patients and Methods: In this case-control study sixty healthy subjects aged 7-18 years and Sixty Patients with confirmed diagnosis of major thalassemia were enrolled. After obtaining informed consent from parents of all participating thalassemia patients and healthycontrols, we assessed psychological aspects and quality of life by Pediatric Quality of LifeTM (PedsQL™), Strengths and Difficulties Questionnaires (SDQ), State and Trait Anxiety, Children's Depression Inventory (CDI). Results: The results of this study indicate that there are significant changes in depression, anxiety, QOL and behavioral screening between children with thalassemia major compared with healthy subjects by means of both parents and children reports. According to the results, children with thalassemia major have more psychological problems than healthy ones. Patients with thalassemia have a lower QOL than their peers (P = 0.001), the rate of depression is higher in this group (P = 0.015), Also behavioral problems in these children are more than healthy subjects (P = 0.009). Conclusions: We recommend appropriate treatment and counseling procedures in addition to specific treatment of thalassemia. According to the results we suggest to establish pediatric psychiatric clinics beside thalassemic clinics to cure psychological aspects of the disease.