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PubMed1977

Urinary amino acid excretion by patients with beta-thalassemia.

Twenty-four hour urinary amino acid excretion has been studied in patients with beta-thalassemia (four adult major, two adult intermedia, and three children major). beta-Aminoisobutyric acid was found to be increased (14-fold on the average) in patients with beta-thalassemia without evidence for increase in the excretion of most other amino acids. No correlation of beta-aminoisobutyric acid excretion with the hematological status of the patient was found. Elevated taurine excretion (2-fold) was also noted in the adult patients with beta-thalassemia. Greatly increased excretion of beta-aminoisobutyric acid appears to correlate with a poor prognosis and may reflect generalized tissue catabolism rather than being a specific indicator of ineffective erythropoiesis.

Adolescent↗
PubMed1980

Globin synthesis studies in a person heterozygous for alpha-thalassemia-2, Hb S and Hb G Philadelphia.

A 21-year-old American black female with mild anemia was found to be triply heterozygous for alpha-thalassemia-2, hemoglobin S and hemoglobin G Philadelphia. Hemoglobin A comprised 39% of her total hemoglobin. The alpha-thalassemia gene was expressed by an alpha/non-alpha synthesis of ratio of 0.79 +/- 0.09 and was equally unbalanced in the peripheral blood and the bone marrow. Globin synthesis studies indicated that the percentage of Hb G and Hb S in the peripheral blood is about 32% and 31% respectively. These values are due to the coexistent alpha-thalassemia-2 gene with the following most likely genotype: --alpha G/alpha alpha, beta A/beta S (or --alpha/alpha G alpha, beta A beta S).

Adult↗
PubMed1988

Spinal cord compression due to extramedullary hematopoiesis in thalassemia: long-term follow-up after radiotherapy.

Spinal cord compression as a consequence of mass lesions due to extramedullary hematopoiesis is a well-described but rare syndrome occurring in thalassemia and some other hematologic conditions. After low-dose radiotherapy alone, a rapid and durable response occurred in a patient with thalassemia. No side effects were encountered and the patient has been stable neurologically for over 7 years since treatment. The results of the current case, and those previously reported in which radiotherapy alone was given, suggest that low-dose radiotherapy should be considered as a primary treatment modality for the management of this syndrome, at least in patients with thalassemia.

Adult↗
PubMed1976

Delta-beta-thalassemia is due to a gene deletion.

DNA has been prepared from peripheral blood or cultured skin fibroblasts obtained from three Sicilian and one Greed deltabeta-thalassemia homozygotes. Globin-gene analysis was carried out using a cDNAbeta probe, and the results indicate that deltabeta-thalassemia has arisen from a deletion of the beta-globin genes. A similar result was obtained using DNA prepared from cultured skin fibroblasts from an individual homozygous for the Negro form of hereditary persistence of fetal hemoglobin (HPFH). In both cases, the deletion has spared the Ggamma and Agamma loci directing the gamma chains of hemoglobin F, but it has not been possible to demonstrate any difference between the size of the deletion involved in the production of delta-beta-thalassemia and that which gave rise to HPFH. These experiments provide further direct evidence that deletions of critical areas of the gamma-delta-beta gene cluster result in persistent gamma chain synthesis in adult life.

Chromosome Aberrations↗
PubMed1984

The silent carrier allele: beta thalassemia without a mutation in the beta-globin gene or its immediate flanking regions.

A molecular genetic analysis has been performed using as subjects an Albanian family in which the father is a silent carrier, the mother has high Hb A2-beta thalassemia trait, and both children have beta thalassemia. Nucleotide sequence analysis of the daughter's paternal beta-globin gene and its flanking regions failed to reveal any base changes of known functional significance. When introduced into HeLa cells the gene was expressed at normal levels with proper processing of RNA. Haplotype analysis revealed that the affected son and daughter inherited different epsilon gamma delta beta-globin gene clusters from the father. The silent carrier allele is not due to a mutation within the beta-globin structural gene or its flanking regions and as such represents a novel form of beta+ thalassemia.

Alleles↗
PubMed1987

Results of programmes for antenatal detection of thalassemia in reducing the incidence of the disorder.

The characteristics and the effectiveness of programmes designed to prevent beta-thalassemia major present in high frequency in several areas of the world such as Cyprus, Greece and Sardinia are reviewed. All these programmes are based on heterozygote detection, counselling and foetal diagnosis. The target population for screening have been couples at marriage, conception or early pregnancy. Awareness of the problem and involvement of the population was achieved via mass-media or personal approaches through lectures or discussions. Parent's Association were consulted and have been actively involved. Information leaflets have been made available to prospective couples at several critical areas. Education on thalassemias was introduced into the school curriculum. Counselling was based on a private interview at which the several options available were discussed with the individual carrier or the couple. Prenatal diagnosis was chosen by the large majority of couples counselled. All these programmes resulted in a decline of thalassemia major births by 50-97%. The reasons for residual cases were mostly lack of information and, less frequently, misdiagnoses or refusal of fetal diagnoses.

Female↗
PubMed1990

Nucleotide sequence of the Belgian G gamma+(A gamma delta beta)0-thalassemia deletion breakpoint suggests a common mechanism for a number of such recombination events.

Various types of thalassemia or hereditary persistence of fetal hemoglobin (HPFH) are caused by deletions at the human beta-globin gene cluster. Many of these molecular lesions show a clear clustering as far as size and location of their breakpoints are concerned. This might indicate common recombination mechanisms responsible for the generation of these deletions. The Belgian G gamma+(A gamma delta beta)zero-thalassemia results from a large deletion spanning the beta-globin gene cluster 3' of the A gamma gene. The extent of this deletion, analyzed by field-inversion gel electrophoresis, is approximately 50 kb and is very similar to that of the Indian HPFH (G gamma A gamma HPFH III) previously characterized by P. S. Henthorn et al. (1986). Proc. Natl. Acad. Sci. USA 83: 5194-5198. Isolation of the deletion junction of the Belgian G gamma+(A gamma delta beta)zero-thalassemia by means of inverse polymerase chain reaction confirmed a very close relationship between these two independent deletions. The 3' breakpoint of the Belgian deletion is located at the midpoint of a 160-bp palindrome, only four nucleotides 5' from the correspondent endpoint of the Indian HPFH.

Base Sequence↗
PubMed2006

Ocular findings among thalassemia patients.

PURPOSE: The study aims at studying the ophthalmologic status in a group of thalassemia patients. DESIGN: A cross-sectional study. METHODS: Eighty-four thalassemia patients were randomly selected and underwent an ophthalmologic examination. RESULTS: Visual acuity (VA) was affected in 13 patients and retinal pigment epithelial changes were detected in 21 patients. Decrease in VA was found to be significantly associated with type of thalassemia (P < .05) and having splenectomy (P = .05). Retinal pigment epithelium changes, conversely, were significantly associated with type of iron chelation. CONCLUSIONS: The occurrence of ophthalmologic problems in Lebanese thalassemic patients is common. These patients, especially those with severe anemia, should be screened for such complications. However, the results were not conclusive on whether these complications are attributable to the anemia, the iron overload, or a side effect of the iron chelating agents.

Adolescent↗
PubMed2006

Seroprevalence of hepatitis B and hepatitis C in patients with thalassemia and sickle cell anemia in a long-term follow-up.

BACKGROUND: Transfusion-dependent patients are more prone to acquiring various transfusion-transmitted infections such as hepatitis B (HBV), hepatitis C (HCV) and human immunodeficiency virus (HIV). The aim of the study was to investigate the prevalence of these infections in patients with thalassemia and with sickle cell anemia (SCA) receiving multiple blood transfusions. METHODS: The subjects of the present study were 399 multi-transfused patients with beta-thalassemia major or intermedia and SCA who have been registered at the two regional hemoglobinopathy centers in Turkey since 1996. Hepatitis B surface antigen (HBsAg), hepatitis C virus antibodies (anti-HCV) and human immunodeficiency virus antibodies (anti-HIV) tests were assayed by a second-generation enzyme-linked immunosorbent assay method. RESULTS: Of the 399 patients, 3 were HBsAg positive (0.75%), 18 were anti-HCV positive (4.5%), and none was anti-HIV positive. All patients with HBsAg and 14 (77.7 %) patients with HCV received initial blood transfusions before second-generation tests were performed. Patients who were anti-HCV positive had a significantly higher mean number of blood transfusions and peak serum alanine transaminase level than anti-HCV-negative patients. CONCLUSIONS: These results showed that after introduction of more sensitive screening tests and stringent donor selection procedures, incidence of HCV infection was significantly reduced, but there was still a serious risk for HCV infection, and there was a minor risk for HBV infection in patients with thalassemia and SCA.

Adolescent↗
PubMed2005

Rapid and complete donor chimerism after unrelated mismatched cord blood transplantation in 5 children with beta-thalassemia major.

Hematopoietic stem cell transplantation is currently the only curative therapy for beta-thalassemia major. However, <30% of patients have unaffected HLA-identical siblings to serve as donors. We investigated the feasibility of using umbilical cord blood transplants from unrelated HLA mismatched donors and a myeloablative preparative regimen that did not involve total body irradiation. Between October 2003 and November 2004, 5 children with beta-thalassemia major received busulfan, cyclophosphamide, and antithymocyte globulin before cord blood transplantation (median dose, 8.8 x 10(7) cells per kilogram of body weight) from unrelated donors (1 or 2 of 6 HLA antigens were mismatched) and were then evaluated for engraftment, adverse effects, and treatment outcome. The median times to neutrophil engraftment, red blood cell transfusion independence, and platelet engraftment were 12, 34, and 46 days after transplantation, respectively. All patients showed grade II or III acute graft-versus-host disease; none developed extensive chronic graft-versus-host disease until the date of last contact. All patients were alive at a median follow-up of 303 days after transplantation, with complete donor chimerism and transfusion independence. These results are encouraging and clearly show the feasibility of unrelated mismatched umbilical cord blood transplantation in the treatment of children with beta-thalassemia major.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2006

Use of strain and tissue velocity imaging for early detection of regional myocardial dysfunction in patients with beta thalassemia.

BACKGROUND AND AIM OF STUDY: Iron overload contributes to cardiac dysfunction in patients with beta thalassemia (Th). Tissue velocity and strain imaging (TVI and SI) might prove useful in early detection of regional myocardial dysfunction in these patients. The aim of this study is to clarify the value of TVI and SI in early detection of regional myocardial dysfunction in thalassemia patients. METHODS AND RESULTS: This study included two age-matched groups; G1: 27 Th patients and G2: 14 normal subjects. Conventional echo-Doppler measures of LV and RV dimensions and function were obtained. TVI measures included systolic and diastolic myocardial velocities (Sm, Em, Am and Em/Am) of the basal segments of septal wall, lateral LV and RV free walls. Systolic strain values were measured in the same basal segments and included S-septal, S-LV and S-RV. Strain and TVI data were compared in the two groups. Sm and strain values were compared in the different walls (LV, RV and septum) in each group separately. S-LV was lower in G1 than G2 (20.9 +/- 6.8 vs 27.2 +/- 4.3, p < 0.001), while S-septal was higher in G1 than G2 (31.1 +/- 8.3 vs 25.1 +/- 3.8, p < 0.01). TVI measures of diastolic performance of the septal and RV walls were different in G1 compared to G2. Septal-Em was lower, septal-Am was higher and septal-Em/Am was lower in G1 compared to G2. RV-Am was higher and RV-Em/Am was lower in G1 compared to G2. Other SI and TVI measures were not significantly different in G1 from G2. Sm and strain values were lower in the lateral LV wall compared to septal wall in G1 but not in G2, while the corresponding values of the RV wall were higher than those of the septal and LV walls in both groups (G1 and G2). CONCLUSION: Thalassemia patients have regional systolic dysfunction in the lateral LV wall and regional diastolic dysfunction in the septal and RV wall. TVI and the newer modality SI are promising tools for quantitative assessment of regional myocardial function. SI seems more capable of early detection of regional myocardial dysfunction.

Adolescent↗
PubMed2005

Allele-specific transcription of fetal genes in primary erythroid cell cultures from Lepore and deltabeta degrees thalassemia patients.

OBJECTIVE: Autonomous gene silencing and gene competition by globin promoters for locus control region (LCR) function have been proposed as mechanisms in developmental regulation of beta-like genes. deltabeta degrees thalassemias are syndromes presenting an increased production of fetal hemoglobin in adult life; the majority of them are due to various deletions in beta-globin gene cluster. We studied samples from double heterozygotes for beta-thalassemia and for Lepore or Sicilian deltabeta degrees deletions, both lacking beta-promoter sequence. Our goal was to address the question of whether the allele carrying the deltabeta degrees deletion is responsible for high level of fetal hemoglobin (HbF) production. PATIENTS AND METHODS: We analyzed the globin gene transcription in human erythroid cell cultures from peripheral blood stem cells, using primary transcript in situ hybridization. We performed primary erythroid cultures from patients with the following genotypes: Lepore/beta degrees 39, Sicilian deltabeta degrees /beta degrees 39, and, as controls, two thalassemia patients with nondeletional mutations (IVS1,6/IVS1,6; IVS1,6/beta degrees 39), and one normal individual. RESULTS: The cells where it is possible to unambiguously assign gamma genes transcription in cis with the deletion (gamma:beta) are strongly represented with respect to the nine other combinations of gamma and beta hybridization signals. These cells are at least nine times more represented than those expressing the gamma allele in trans to the deletion. CONCLUSION: The allele-specific transcription of fetal genes in cis with the deletion is favored in both deletional genotypes. The absence of the adult promoter may influence LCR recruitment by fetal promoter, supporting the hypothesis that competition mechanism and gene silencing can coexist in regulating human globin gene transcription.

Alleles↗
PubMed2006

A qualitative study on the experiences of mothers caring for their children with thalassemia in Athens, Greece.

This qualitative study investigated the caregiving experiences of mothers of children with thalassemia. Using a semistructured questionnaire, the researchers interviewed a convenient sample of 19 mothers who have children with thalassemia. A considerable failure to provide information regarding carrier testing prior to marriage or genetic screening for thalassemia during early pregnancy at the time of the participants' pregnancies was noted. Emotional distress, fear of death, and difficulties in dealing with feelings were some of the mothers' concerns. Although they reported that support was provided, approximately half of the subjects wished that support be offered on a more regular basis. Furthermore, most of the mothers stressed that, owing to the tremendous shortage of nursing staff, support services provided by nurses are difficult to obtain.

Adaptation, Psychological↗
PubMed2006

Natural and vaccine-induced immunity against Haemophilus influenzae type b in patients with beta-thalassemia.

Natural and vaccine-induced immunity and immunological memory to Haemophilus influenzae type b (Hib) were evaluated in adolescents and adults with beta-thalassemia. At baseline 10/23 (43%) unvaccinated patients had naturally acquired anticapsular antibodies >0.15 microg/ml, the threshold of protection, compared to 9/10 (90%) aged-matched controls. Hib-conjugate vaccine (PRP-T) induced protective immune responses in all subjects and there were no differences in geometric mean concentrations at 1 month (GMC) between patients and controls (69.04 versus 40.5, respectively). Vaccine-induced immunological memory was assessed in 12 subjects with beta-thalassemia who had been vaccinated against Hib in the past. All subjects had retained PRP>1 microg/ml at baseline; PRP-T revaccination induced anamnestic responses which were similar, in terms of post vaccination antibody concentration (P=0.54) and avidity (P=0.08), with primary responses given by previously unvaccinated patients. A single dose of PRP-T induces adequate and long-lasting immunity and should be given in all unvaccinated adolescents and adults with beta-thalassemia.

Adolescent↗
PubMed2005

A humanized mouse model for a common beta0-thalassemia mutation.

Accurate animal models that recapitulate the phenotype and genotype of patients with beta-thalassemia would enable the development of a range of possible therapeutic approaches. Here we report the generation of a mouse model carrying the codons 41-42 (-TTCT) beta-thalassemia mutation in the intact human beta-globin locus. This mutation accounts for approximately 40% of beta-thalassemia mutations in southern China and Thailand. We demonstrate a low level of production of gamma-globins from the mutant locus in day 18 embryos, as well as production of mutant human beta-globin mRNA. However, in contrast to transgenic mice carrying the normal human beta-globin locus, 4-bp deletion mice fail to show any phenotypic complementation of the knockout mutation of both murine beta-globin genes. Our studies suggest that this is a valuable model for gene correction in hemopoietic stem cells and for studying the effects of HbF inducers in vivo in a "humanized" thalassemic environment.

Animals↗
PubMed1997

Pulmonary hypertension in patients with thalassemia major.

To evaluate the pulmonary artery pressure in patients with thalassemia major, Doppler echocardiography was performed in 33 patients with thalassemia major (aged 2 to 24 years) and 33 normal controls. Pulmonary artery pressure was estimated by (1) measuring the systolic transtricuspid gradient from tricuspid regurgitation and adding it to the right atrial pressure, estimated by the response of the inferior vena cava to deep inspiration, and (2) measuring the time to peak velocity of pulmonary flow. The results showed that of 33 patients, 28 had tricuspid regurgitation with a pulmonary systolic pressure ranging from 18 to 94 mm Hg (47 +/- 15 mm Hg). Pulmonary systolic pressure was > 30 mm Hg in all 22 patients > 10 years old and in four of six patients < 10 years old. Pressure correlated with left ventricular ejection fraction (r = -0.74), the ratio of mitral peak early diastolic flow velocity and peak velocity during the atrial contraction (r = 0.52), age (r = 0.56), and total blood transfusion units (r = 0.59). The pulmonary time to peak velocity was shortened compared with controls (p < 0.05). We concluded that pulmonary hypertension, as another cardiovascular complication of multiple factors of cause, seems to occur more frequently and at an early stage of the cardiac involvement in patients with thalassemia major.

Adolescent↗
PubMed2001

Heart failure in beta thalassemia: a 5-year follow-up study.

PURPOSE: To evaluate the survival of patients with beta thalassemia and heart failure who were treated with iron chelation therapy. SUBJECTS AND METHODS: Fifty-two consecutive patients with beta thalassemia and heart failure were followed in a prospective 5-year study. All patients underwent a full clinical examination with chest radiograph, electrocardiogram, and echocardiographic investigation performed at 6-month intervals or when a new symptom developed. RESULTS: Of the 52 patients (mean [+/- SD] age, 24 +/- 5 years), 25 (48%) survived 5 years after the onset of heart failure. Forty-three patients had left-sided heart failure, and 9 had right-sided heart failure. Those with left-sided heart failure were younger at presentation with heart failure (22 +/- 4 years vs. 31 +/- 6 years; P <0.001), had lower ejection fractions (36% +/- 9% vs. 64% +/- 10%; P <0.001), and had a lower mean serum ferritin level (3355 +/- 1241 ng/mL vs. 6,397 +/- 1,613 ng/mL; P <0.001). CONCLUSION: The 5-year survival rate in patients with beta thalassemia with heart failure was greater than previously reported. There are clinical characteristics that may make patients more likely to develop left- or right-sided heart failure.

Adult↗
PubMed1989

Direct demonstration of iron in a term placenta in a case of beta-thalassemia major.

Successful term pregnancy in homozygous beta-thalassemia is rare. A pregnant patient with thalassemia usually is found to have chronic anemia concurrent with tissue and circulatory iron overload. We have demonstrated and localized iron deposits in a term placenta of a patient with homozygous beta-thalassemia with the use of routine histochemical staining.

Adult↗