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PubMed1990

High incidence of cholelithiasis in older patients with homozygous beta-thalassemia.

The records of 48 patients with homozygous beta-thalassemia were reviewed for evidence of cholelithiasis by abdominal ultrasonography or plain abdominal X-ray. The presence of cholelithiasis was reported in 25 patients (52%). The incidence increased with age to 83% in patients over 31 years of age. Gallstones were more frequent among patients with beta-thalassemia intermedia and with less blood transfusion requirements. Eleven patients with cholelithiasis (44%) became symptomatic. Eight received operations on an elective or semielective basis. Another patient had incidental cholecystectomy during splenectomy. The preoperative evaluation included abdominal ultrasonography, nucleotide biliary scan and evaluation of the cardiopulmonary status. Due to the longer survival of patients with homozygous beta-thalassemia, the problem of cholelithiasis is becoming more frequent.

Adolescent↗
PubMed1985

Alpha globin gene triplication in severe heterozygous beta thalassemia.

In an Algerian family, three sibs with an unusually severe heterozygous beta-thalassemia and two sibs with a typical heterozygous beta-thalassemia were found. Both conditions were transmitted vertically. Globin chain synthesis and DNA restriction enzyme analysis showed that the unusual severity of heterozygous beta-thalassemia observed in this family is related to an overproduction of alpha-globin chains originating from an alpha-globin gene triplication.

Adolescent↗
PubMed1984

Natural killer cell activity and T subpopulations in thalassemia major.

Natural killer (NK) cell activity against K562 cell targets and the distribution of T cell subpopulations were investigated in the peripheral blood of 25 patients affected by beta thalassemia major, 18 clinically healthy heterozygotes, and 25 age-matched normal subjects. It was found that thalassemia major patients display augmented levels of NK activity [specific lysis 41.9 +/- (se) 4.5%], while thalassemic carriers behave as normal controls [specific lysis 34.6 +/- (se) 3.5%]. The increase of NK function was neither related to the splenectomy nor to the siderosis, but rather to the age and the amount of blood units that the patients had received. An imbalance of circulating T subsets with the helper/suppressor cell ratio significantly diminished (p less than 0.001) was also detected in homozygotes but not in carriers. The finding that NK function is enhanced in homozygous beta thalassemia might be of clinical interest in assessing the risk of development of malignancies in these patients.

Adolescent↗
PubMed1980

beta 0-Thalassemia complicated by autoimmune hemolytic anemia. Globin synthesis during immunosuppressive therapy.

The unusual occurrence of both beta o-thalassemia and autoimmune hemolytic anemia (AIHA) in a 28-month-old child is reported to illustrate special diagnostic and therapeutic studies. The diagnosis of beta o-thalassemia was established by clinical, family and globin synthesis studies. The diagnosis of AIHA was confirmed by the shortened survival of transfused autologous and homologous red blood cells and by positive direct antiglobulin tests. During treatment of the AIHA were corticosteroids and various immunosuppressive drugs, globin synthesis studies were performed to evaluate the coincidental effects on gamma/alpha-globin chain synthetic ratios. A 50% increase in the gamma/alpha synthetic ratio during cyclophosphamide treatment suggests that further studies of the possible benefits of cytotoxic drug therapy in beta-thalassemia may be indicated.

Anemia, Hemolytic, Autoimmune↗
PubMed1980

Hemoglobin Hasharon [alpha 247 (CD5)Asp leads to His beta 2] linked to alpha-Thalassemia in northern Italian carriers. Hematological and biosynthetic studies.

This report is concerned with the evaluation of hematological parameters and of both relative (%) and absolute (mean pg/cell) quantities of the abnormal Hemoglobin (Hb) Hasharon in 53 heterozygous carriers and 7 double heterozygotes for Hb Hasharon and beta-thalassemia from 43 apparently unrelated families living in the province of Rovigo (northern Italy). Biosynthetic studies are also reported. The data strongly suggest the presence of an alpha-thalassemia-2 determinant closely linked to the alpha Hasharon-chain locus. Selective advantage of heterozygotes carrying such alpha-haplotype would explain the relatively high frequency of Hb Hasharon (0.23%) in northeastern Italy, a past-endemic malaria region. The interaction between Hb Hasharon and beta-thalassemia results in preferential decrease of the abnormal Hb level.

Blood Protein Electrophoresis↗
PubMed1979

Hematological and hemoglobin synthesis studies in a family with deltabeta-thalassemia trait.

A Basque Spanish family with heterozygous deltabeta-thalassemia is described. Patients with this anomaly usually present hematological findings observed in classical beta-thalassemia, but clinical conditions and unbalanced chain synthesis are less severe. Our propositus, however, presented clinical and biosynthetic data similar to those described in thalassemia intermedia. A family study was also performed.

Adolescent↗
PubMed1979

Biosynthetic studies and gamma-chain composition in the Greek type of hereditary persistence of fetal hemoglobin and in its association with beta-thalassemia.

Hematological data, biosynthetic studies and gamma-chain structure of three heterozygotes for HPFH Greek type and of two heterozygotes for both HPFH and beta-thalassemia are reported. In the HPFH heterozygotes, hematological data were normal and globin chain synthesis balanced, while subjects carrying both HPFH and beta-thalassemia presented a thalassemic picture and the same degree of alpha/non-alpha-chain imbalance as the beta-thalassemia carrier belonging to the same family. The gamma-chain composition studies showed only the presence of Agamma-chains in HPFH; in the association HPFH/beta-thalassemia also some Ggamma and Tgamma were found. The mechanisms determining the high production of Hb F in the association HPFH/beta-thalassemia are discussed.

Adolescent↗
PubMed1977

Quantitation of Hb a2 with DE-52 microchromatography in whole blood as screening test for beta-thalassemia heterozygotes.

HB A2 was assayed by means of DE-52 microchromatography in hemolysates from 285 normal subjects and 223 beta-thalassemia heterozygotes. No overlap was found between both groups. Comparable results were observed analyzing whole blood samples collected in capillary tubes from 550 normal subjects and 295 beta-thalassemia heterozygotes. Our results demonstrate that this technique is useful in a screening program for beta-thalassemia trait.

Adult↗
PubMed2002

Arterial stiffness and endothelial function in patients with beta-thalassemia major.

BACKGROUND: Increased iron store has been linked to risk of cardiovascular disease. Structural alterations of arteries in beta-thalassemia major patients and in vitro functional disturbance of vascular endothelial cells by thalassemic serum have been described. We sought to determine whether arterial stiffness and endothelial function are altered in vivo. METHODS AND RESULTS: Thirty thalassemia patients (16 male) aged 22.2+/-7.4 years were recruited. Left ventricular (LV) mass and function were assessed echocardiographically. Carotid and brachioradial artery stiffness was assessed by stiffness index and pulse-wave velocity (PWV), respectively. Brachial artery endothelial function was assessed by vascular response to reactive hyperemia (flow-mediated dilation [FMD]) and sublingual glyceryl trinitrate. These indexes were compared with those of 30 age- and sex-matched controls. None of the patients had LV systolic or diastolic dysfunction. When compared with controls, patients had greater absolute (113.8+/-38.0 versus 109.0+/- 32.6 g, P=0.04) and indexed (82.4+/-17.5 versus 66.7+/-12.7 g/m(2), P<0.001) LV mass, carotid artery stiffness index (8.1+/-3.5 versus 5.5+/-1.6, P<0.001), and brachioradial PWV (8.9+/-2.4 versus 7.9+/-1.7 m/s, P= 0.03). Their FMD was impaired (3.5+/-3.3% versus 8.8+/-3.9%, P<0.001), whereas glyceryl trinitrate- mediated dilation was preserved (17.9+/-7.6% versus 16.3+/-6.1%, P=0.40). Both stiffness index and PWV correlated inversely with magnitude of FMD (r=-0.40, P=0.03; r=-0.41, P=0.03) and positively with indexed LV mass (r=0.50, P=0.005; r=0.40, P=0.027). Nonetheless, no significant correlation existed between ferritin level and carotid stiffness, PWV, or FMD. CONCLUSIONS: Increased arterial stiffness, endothelial dysfunction, and LV hypertrophy occur in patients with beta-thalassemia major, which may result in reduction of mechanical efficiency of the heart.

Adult↗
PubMed1990

Restrictive diastolic abnormalities identified by Doppler echocardiography in patients with thalassemia major.

The consequences of transfusional iron overload on left ventricular diastolic filling have never been investigated systematically in patients with thalassemia major. In the present study, the pattern of left ventricular filling was assessed by Doppler echocardiography in 32 patients with thalassemia major (age, 17 +/- 5 years) who had not experienced symptoms of heart failure and had normal left ventricular systolic function. Data were compared with those obtained in 32 age-matched and sex-matched normal subjects. An abnormal Doppler pattern of left ventricular filling with increased flow velocity at mitral valve opening followed by an abrupt and premature decrease of flow velocity in early diastole was identified in the patients with thalassemia. Peak flow velocity in early diastole was increased in patients compared with controls (90 +/- 10 vs. 81 +/- 15 cm/sec; p less than 0.01), and rate of deceleration of flow velocity after the early diastolic peak and the ratio between the early and late (atrial) peaks of flow velocity were also increased (1,050 +/- 325 vs. 762 +/- 193 cm/sec2 and 2.7 +/- 0.7 vs. 2.2 +/- 0.5, respectively; p less than 0.001), whereas flow velocity deceleration time was reduced (97 +/- 22 vs. 119 +/- 19 msec; p less than 0.001). This Doppler pattern of diastolic filling is usually described as "restrictive" and reflects a decrease in left ventricular chamber compliance. A restrictive pattern of left ventricular filling was also identified in the subgroup of 16 study patients who had undergone optimal iron chelation therapy with deferoxamine.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1969

Influence of hemoglobin precipitation on erythrocyte metabolism in alpha and beta thalassemia.

Certain aspects of the metabolism of centrifuged young and old erythrocytes in hemoglobin H disease have been examined and compared with similar studies of beta thalassemia and normal cells. Glycolysis, hexose monophosphate shunt activity (HMPS), potassium flux, and glutathione (GSH) content were measured. The distributions of hemoglobins H and F, as well as the activities of erythrocyte glucose-6-phosphate dehydrogenase (G6PD) and glutamic oxalacetic transaminase (GOT), were utilized for estimations of the relative ages of the cell samples. The young erythrocytes in hemoglobin H disease differed in several respects from older hemoglobin H cells. They contained more soluble hemoglobin H and GSH and, after splenectomy, fewer inclusions. HMPS activity was subnormal in hemoglobin H young cells and rose to normal activity in old cells. Potassium flux tended to increase in old cells when inclusions were present.Beta thalassemia young cells contained less hemoglobin F and, after splenectomy, more inclusions than old cells. In addition, they had markedly increased glycolysis and HMPS activity. GSH was randomly distributed. Potassium flux was increased in younger cells and particularly increased when inclusions appeared in younger cells after splenectomy. The results are interpreted to indicate that inclusion formation is associated with increased erythrocyte cation permeability in the thalassemia syndromes. This is not related to the level of intracellular GSH. The decreased HMPS activity in young hemoglobin H cells may be due to the presence of the extra thiols of soluble hemoglobin H which can act as a reducing agent. The substitution of hemoglobin H for glutathione in this capacity would then spare the NADPH-requiring glutathione reductase system. As a consequence, HMPS activity would decline. However, in older cells the oxidized hemoglobin H precipitates; these must rely upon GSH and glutathione reductase activity for thiol reduction capacity. Accordingly, HMPS activity increases to normal in the old cell population.

Carbon Isotopes↗
PubMed1971

An unusual hemoglobin anomaly and its relation to alpha-thalassemia and hemoglobin-H disease.

A Chinese family with hemoglobin H in the propositus has been reinvestigated. Although the original propositus is now deceased, a sister has the same hematological manifestations. Her hemoglobin, like that of the deceased sister, contains hemoglobins A, H, and Bart's. In addition, however, two minor components have been detected. These minor components appear to have abnormal alpha-chains and are also present in the maternal grandmother, the mother, a maternal aunt, and three other siblings but only in about one-tenth the amount. One of the minor components may be the same as Hb-Thai (25). The father has the characteristics of classical alpha-thalassemia. These results are discussed in relation to current concepts of alpha-thalassemia as they relate to "silent" and "classical" alpha-thalassemia and to possible multiple alpha-chain loci.

Adolescent↗
PubMed1972

Potassium permeability in -thalassemia minor red blood cells.

The intracellular content of K(+) in thalassemia minor red blood cells is markedly reduced after incubation in autologous serum for 24 hr at 37 degrees C. There is no compensatory increase in intracellular Na(+) concentration of the cell thus reduced. This change is due to an acquired increase in selective permeability of the membrane to K(+). This phenomenon follows the depletion of energy sources in the thalassemia minor cells but does not follow comparable depletion in normal cells. The loss of osmotically active intracellular contents probably accounts for the increased resistance of incubated thalassemia minor red blood cells to osmotic lysis.

Adenosine Triphosphate↗
PubMed1975

Globin synthesis in fractionated Normoblasts of beta-thalassemia heterozygotes.

Globin chain synthesis was examined in erythroid cells of increasing maturity, fractionated from the whole bone marrow of beta-thalassemia heterozygotes by a density gradient centrifugation procedure. In experiments using total cell "globin," a gradient of alpha/beta chain ratios was observed, increasing with erythroid cell maturation from unity in the basophilic cells up to 2.0 in reticulocytes. Gel filtration of the lysates from these marrow fractions revealed the presence of free alpha chains even in the most immature cells, the amount of which increased with erythroid cell age; the total alpha/beta ratio derived from gel filtration experiments showed a gradient similar to that observed in the total globin experiments. However, the alpha/beta ratio of the hemoglobin fraction obtained by gel filtration remained constant throughout maturation at an average of 0.65. This latter finding is incompatible with balanced synthesis at any stage of red cell development and excludes the possibility that total beta chain production is higher in the early cells than in the later cells or that alpha chain production in the early cells is reduced to the level of beta chain synthesis. Furthermore, in a Hb S/beta-thalassemia marrow examined, the beta A/beta S ratio remained constant throughout maturation while the alpha/non-alpha ratio showed an increase like that observed in the simple beta-thalassemia heterozygotes. This argues strongly against increased synthesis from either the thalassemic or nonthalassemic beta chain gene being responsible for the balanced synthesis in the immature cells. These findings lead us to suggest that, in beta-thalassemia heterozygotes, a large alpha chain pool is present throughout erythroid cell maturation and that the observed increase in alpha/beta ratios is a function of the ability of those cells to degrade the excess alpha chains.

Adult↗
PubMed1980

Two different molecular organizations account for the single alpha-globin gene of the alpha-thalassemia-2 genotype.

The alpha-thalassemia-2 (alpha-thal-2) genotype or mild alpha-thalassemia gene consists of a single structural alpha-globin gene on the chromosome that normally bears two alpha-globin genes. We used blot hybridization to investigate variation in the molecular organization of this genotype and to determine the distributions of these variations in the world population. Two different patterns of gene organization responsible for the alpha-thal-2 genotype were found: the first was the result of a 4.2-kilobase pair deletion involving the normal 5' alpha-globin gene (leftward deletion alpha-thal-2 genotype), and the second probably the result of a crossover deletion of a DNA fragment bridging the two normal alpha-globin genes (rightward deletion alpha-thal-2- genotype). The rightward deletion was found in all 9 Black subjects, all 8 Mediterranean subjects, and 4 of 13 Chinese subjects. The leftward deletion was found in four and the nondeletion alpha-thalassemia lesion was found in five of the nine remaining Chinese subjects. It is likely that these deletions are related to specific DNA sequences that determine DNA recombinational events.

Asian People↗
PubMed1984

Concurrent sickle cell anemia and alpha-thalassemia. Effect on pathological properties of sickle erythrocytes.

The concurrence of sickle cell anemia and alpha-thalassemia results in less severe hemolytic anemia apparently as a result of reduced intraerythrocytic concentration of hemoglobin S and its retarded polymerization. We have evaluated the effect of alpha-globin gene number on several interrelated properties of sickle erythrocytes (RBC) that are expected to correlate with the hemolytic and rheologic consequences of sickle cell disease. The irreversibly sickled cell number, proportion of very dense sickle RBC, and diminished deformability of sickle RBC each varied directly with alpha-globin gene number. Sickle RBC density was a direct function of the mean corpuscular hemoglobin concentration (MCHC). Even in nonsickle RBC, alpha-globin gene number varied directly with RBC density. Despite differences in alpha-globin gene number, sickle RBC of the same density had the same degree of deformability and dehydration. These data indicate that the fundamental effect of alpha-thalassemia is to inhibit the generation of sickle RBC having high density and MCHC, and that the other beneficial effects of sickle RBC are secondary to this process. The less consistent effect on overall clinical severity reported for subjects with this concurrence may reflect an undefined detrimental effect of alpha-thalassemia, possibly on the whole blood viscosity or on sickle RBC membrane-mediated adherence phenomena.

Anemia, Sickle Cell↗
PubMed1987

Different hematologic phenotypes are associated with the leftward (-alpha 4.2) and rightward (-alpha 3.7) alpha+-thalassemia deletions.

We have compared the phenotypes of the two common deletion forms of alpha+-thalassemia by analysis of umbilical cord blood samples from Melanesia. Homozygotes for the leftward, 4.2-kilobase, deletion (-alpha 4.2) had significantly higher levels of Hb Bart's at birth than homozygotes for the rightward, 3.7-kilobase, deletion (-alpha 3.7). Compound heterozygotes for each deletion had intermediate values. Although deletion forms of alpha 0 thalassemia were not found in this survey, nondeletion alpha-thalassemia was present at low frequency. Since the predominant rightward deletion in this population, -alpha 3.7III, entirely removes the alpha 1-gene and the 4.2-kilobase deletion deletes the alpha 2-gene, these data indicate that the alpha 2-globin gene has a higher output than the alpha 1-gene, on single alpha-gene chromosomes.

Chromosome Deletion↗
PubMed1989

Differing erythrocyte membrane skeletal protein defects in alpha and beta thalassemia.

Thalassemic red cells show irregular morphology and maldistribution of glycoproteins and sialic acids. These changes are compatible with damage to the red cell membrane skeleton. To test this possibility, we systematically studied the interconnections of skeletal proteins in patients with a form of alpha thalassemia (HbH disease), in patients with beta thalassemia intermedia, and in normal individuals. Alpha- and beta-thalassemic spectrin functions normally in spectrin self-association, binding to normal inside-out vesicles (IOVs), and binding to actin in the presence and absence of normal protein 4.1. Binding of normal spectrin to beta: thalassemic IOVs is normal but alpha-thalassemic IOVs are defective and bind only half the normal amount of spectrin (66 +/- 5 vs. 120 +/- 16 micrograms spectrin dimer/mg IOV protein, respectively). A different defect is detected in beta thalassemia, in which protein 4.1 shows markedly reduced ability (48 +/- 7% of normal) to enhance the binding of normal spectrin to actin and a decreased ability to bind normal spectrin in a binary interaction, compared with normal protein 4.1 (24 +/- 1 and 43 +/- 1 micrograms protein 4.1/mg spectrin, respectively). As no quantitative deficiency of beta-thalassemic protein 4.1 is detected, we assume an acquired lesion is present, which affects about half of the protein 4.1 molecules. These findings indicate that specific, localized, yet different defects exist in the skeletal proteins of alpha- and beta-thalassemic red cells. The different molecular lesions imply that the mechanism of hemolysis and probably the interaction of unpaired globin chains with the membrane differs in the two diseases.

Ankyrins↗