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Query: UMLS:C0039730 (thalassemia)
 10,305 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The indications and management of blood transfusion in the haemoglobinopathies have been reviewed. The sickle cell diseases that require transfusion support are sickle cell anaemia, sickle haemoglobin-C and -D diseases and sickle beta-thalassaemia. Homozygous beta-thalassaemia (Cooley's anaemia) is the major problem among the thalassaemias. The pathophysiology of the sickle cell disorders is largely based on the secondary effects of increased blood viscosity, whereas in the thalassaemias the defect is ineffective haematopoiesis. In the former the major problems occur as manifestations of vaso-occlusive crises with disseminated bone and abdominal pain, priapism, stroke and leg ulcers. Bone infarction and aseptic necrosis occur but the widespread bone changes, underdevelopment and haemochromatosis that complicate the thalassaemia are not prominent. Transfusion therapy in the sickle cell diseases is mainly episodic and is guided by the frequency of crises and the severity of vaso-occlusive complications. Partial exchange transfusion and the maintenance of haemoglobin A concentrations at 40 to 50 per cent is frequently indicated. In the thalassaemias, maintenance of haemoglobin levels is essential for normal growth and development. The problem of haemochromatosis is very serious. With hypertransfusion regimens the haemoglobin and haemotocrit are maintained above 12-13 g/dl and 35 per cent. The resulting benefit appears to be reduced blood volume, less iron turnover, and less intestinal iron absorption. The splenomegaly in these disorders is frequently associated with hypersplenism requiring well-timed splenectomy. Chronic and intensive chelation is necessary to prevent the ravages of iron overload. The availability of automated equipment for in vivo and ex vivo blood cell separation has brought new possibilities for improving the management of these haemoglobinopathies. It is feasible, but not as yet practical, to offer transfusions of neocytes (red cells with a mean age of 30 days) which have a 50 per cent longer survival than routine red cell preparations (mean age of 60 days). Neocytes can be prepared ex vivo from fresh routine blood donations using blood cell separator devices. The result is reduced transfusion requirements. A more recent suggestion for using the new technology is to remove the patient's oldest and most abnormal corpuscles on the basis of buoyant density and replacing them with neocytes . Thus the short-lived abnormal red cells would be removed before they could unload their iron. With automation it is possible to perform these procedures on an outpatient basis.
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PMID:Transfusion support for haemoglobinopathies. 637 80

The characteristic clinical heterogeneity of sickle cell anemia (HbSS) may be, in part, a result of its interactions with alpha-thalassemia. Although alpha-thalassemia clearly affects some hematologic features of HbSS, its role in modulating the vasoocclusive severity of disease is not clear. To further explore this relationship, we examined the incidence of painful episodes, acute chest syndrome, aseptic bone necrosis, and leg ulcers in 3 patient groups with sickle cell disease: (1) 2,147 patients over age 2 yr, stratified according to mean corpuscular volume (MCV); (2) 183 patients selected on the basis of microcytosis and elevated HbA2, on whom globin biosynthesis studies were done; and (3) 125 patients who had alpha-globin genotype assigned by restriction endonuclease gene mapping. When patients were stratified by MCV, there was a reciprocal relationship between HbA2 levels and MCV, reflecting the presence of patients with beta o and alpha-thalassemia in the low MCV groups. The erythrocyte indices and HbA2 levels in patients classified as HbSS-alpha-thalassemia, by either globin synthesis studies or gene mapping, were very similar to those previously reported by others. Neither microcytosis, beta o, or alpha-thalassemia appeared to provide any clear protection from the vasoocclusive complication evaluated, and the prevalence of aseptic necrosis was increased in patients with microcytosis over age 20 yr and in groups with alpha-thalassemia. The effects of a reduced MCV and mean corpuscular hemoglobin concentration (MCHC), of possible benefit by themselves, when accompanied by a reduction in hemolysis and rise in hemoglobin concentration, as in HbSS-alpha-thalassemia, may cause sufficient rise in blood viscosity in critical vascular beds to impair blood flow and negate any amelioration of vasoocclusive complications in HbSS.
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PMID:Effects of thalassemia and microcytosis on the hematologic and vasoocclusive severity of sickle cell anemia. 672 53

A series of 12 patients with beta-thalassemia who developed juvenile leg ulcers is described. The trophic skin changes and leg ulcers occurred after the age of 15 years. Usually the ulcer occurred after trauma over the predisposed medial aspect of the leg. In four out of seven females, the trophic changes deteriorated during or following pregnancy. The development of trophic changes and subsequent leg ulcers is not related to the severity of the anemia or to the patients' transfusion requirements, but may be related to high fetal hemoglobin concentration. The ulcers are slow to heal and tend to recur. Multiple skin-grafting operations are required in order to achieve satisfactory coverage of the ulcers. Since tissue hypoxia may be the underlying pathophysiology, the use of topical hyperbaric oxygen chamber may be beneficial in the treatment of thalassemic leg ulcers.
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PMID:Juvenile leg ulceration in beta-thalassemia major and intermedia. 703 14

Case reports are presented on 4 outpatients with hereditary disorders of metabolism. 1. In a 46-year-old male of Sicilian origin with haemolytic anaemia and leg ulcers, the blood contained numerous target cells, the sickling test was positive, and more than 80% of the haemoglobin was found to be HbS. Investigation of the family revealed double heterozygosity for HbS and beta-thalassaemia. 2. In a family with hereditary nonspherocytic haemolytic anaemic, the biochemical characterization of an abnormal pyruvate kinase is reported: the kinetic data were found to be normal, the electrophoretic migration rate of the abnormal enzyme was increased, and its thermostability was marked decreased. 3. Malignant hyperthermia was observed in an 18-year-old male. The limited value of all methods for identifying affected family members is discussed. 4. In 2 sisters who suffered life-threatening attacks of acute myoglobinuria, differential diagnosis comprised hereditary deficiency of phosphofructokinase, muscle phosphorylase and carnitine palmityl transferase. The activity of the former two enzymes was found to be normal. The circumstances of the myolytic crisis in the two patients provide strong evidence for the presence of a muscle carnitine palmityl transferase deficiency.
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PMID:[Clinical demonstrations of hereditary disorders of metabolism]. 745 56

An increased level of plasma thrombomodulin (TM) in alpha- and beta-thalassaemia was demonstrated using an enzyme-linked immunosorbent assay (ELISA). Nonsplenectomized patients with beta-thalassaemia/haemoglobin E (BE) had higher levels of TM than splenectomized cases (BE-S). Patients with leg ulcers (BE-LU) were found to have the highest increase in TM level. Appearance of larger platelets in all types of thalassaemic blood was observed indicating an increase in the number of younger platelets. These data indicate that injury of vascular endothelial cells is present in thalassaemic patients.
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PMID:Alterations in vascular endothelial cell-related plasma proteins in thalassaemic patients and their correlation with clinical symptoms. 856 Apr 11

To compare the features of sickle-cell anemia in Brazil with those in other locales, we studied the effects of the beta-globin-like gene cluster haplotype and alpha-thalassemia upon the clinical and hematological features in 85 patients. The distribution of haplotypes differed from that in the United States and Jamaica. The Central African Republic (CAR) haplotype predominated; 34% of patients were CAR haplotype homozygotes, 45% CAR/Benin homozygotes, and 11% Benin homozygotes. No Senegal haplotype chromosomes were observed. Alpha-thalassemia was present in 17.5% of patients. HbF levels were higher in Benin homozygotes, compared with the other two groups (P < 0.05). Nearly half the patients with a CAR haplotype had leg ulcers, compared to 12.5% of the Benin homozygote group; stroke did not occur in alpha-thalassemia carriers, but neither result was statistically significant. As in other studies, our results indicate that the CAR haplotype may be associated with more severe disease.
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PMID:Effect of alpha-thalassemia and beta-globin gene cluster haplotypes on the hematological and clinical features of sickle-cell anemia in Brazil. 889 30

Thirteen patients with sickle cell anemia (SS) were found to have two alpha gene deletions with a presumptive genotype of beta(S)/beta(S); -alpha/-alpha. Hematological data showed that this group of patients had elevated Hb A2 level. In order to determine whether the elevation of Hb A2 is typical of SS with a two alpha gene deletion or is due to undiagnosed S-beta(O)-thalassemia with a two alpha gene deletion we looked for the presence or absence of beta(O)-thalassemia by molecular techniques. The latter included reverse dot-blot hybridization to rule out a beta-thalassemia mutation, digestion with CvnI endonuclease followed by Southern blotting and hybridization with a beta genomic probe, and, in selected patients, determination of the synthetic alpha/beta ratio. One of the 13 patients had S-beta(O)-thalassemia with a G-->A mutation at IVS-II-1 indicating that her genotype was beta(S)/beta(O) thalassemia; -alpha/-alpha. The remaining 12 patients were homozygous for the sickle gene, had relatively elevated Hb levels, increased Hb A2 values, and Hb F levels similar to those in patients with SS and four or three alpha genes. At the clinical level, the 12 patients with SS and a two alpha gene deletion had increased prevalence of avascular necrosis, retinopathy, and splenomegaly, but decreased prevalence of leg ulcers and cerebrovascular accidents. Together, the data indicate that SS with a two alpha gene deletion (beta(S)/beta(S); -alpha/-alpha) is a unique subset of patients with SS characterised by distinct hematological and clinical features.
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PMID:Is Hb A2 elevated in adults with sickle-alpha-thalassemia (beta(S)/beta(S); -alpha/-alpha)? 932 76

The non-healing leg ulcer is examined by discussing three disease processes: peripheral vascular occlusive disease (PVOD), chronic venous insufficiency (CVI), and vasculitis. For PVOD, management decisions are based on risk factors and disease history. Comprehensive management includes the discontinuation of smoking, exercise conditioning and regulation of diabetes, hyperlipidemia, hypertension, and the appropriate application of anticoagulant/antiplatelet drugs. Methods of surgical management include bypass with autogenous or synthetic material in addition to reconstructive surgery with patch angioplasty or extra-anatomic bypass, amputation, percutaneous transluminal angioplasty/stents, thrombolytic infusion, atherectomy, intraluminal ultrasound, and angioscopy. The optimal healing environment for all ulcers prevents contamination, pain, and fluid loss. In CVI, higher venous pressure in the veins of the lower limb during exercise results in ambulatory venous hypertension and ulceration. Various theories are associated with the disease and ulceration process; the classic treatment of elevation, ambulation, and compression for venous disease remains unchallenged. Diagnosis is based on history, physical examination, invasive venography, and/or non-invasive studies. Two groups of vasculitic disorders that share varying degrees of vascular inflammation and necrosis are arteritis (lupus, erythematosus, periarteritis nodosa, dermatomyositis) and blood dyscrasias (sickle cell disease, thalassemia). Leg ulcers associated with vasculitis are due to inadequate tissue oxygenation at the local level, are typically chronic, slow to heal, and commonly recur.
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PMID:The non-healing leg ulcer: peripheral vascular disease, chronic venous insufficiency, and ischemic vasculitis. 939 80

Since the obtained results from the pilot study indicated that dilazep which was a membrane stabilizer would be benefit to treatment and prevention of anemia and chronic leg ulcer in beta-thalassemia/hemoglobin E (beta-thal/HbE) patients, the authors had continued the study in a second phase, ie a double blind placebo control trial. Twenty-seven beta-thal/HbE patients were recruited in the study. Eight patients who suffered from chronic leg ulcer were given dilazep. The rest of patients were given dilazep or placebo according to a randomized table. Hence, 16 patients received dilazep and 11 received placebo. When we compared the number of unit of blood transfusion, hemoglobin level, 2-3 DPG and P50 value between the dilazep and placebo groups using unpaired t-test, we found that there were no statistical differences in any of the parameters. However, when we compared the data within the group using paired t-test, there was statistical decrease in blood requirement after treatment in the dilazep group (p < 0.05). Concerning with the treatment of chronic leg ulcer, 3 in 8 patients were completely healed within 3 months, 4 in 8 patients were improved and 1 in 8 patients was not improved. There were complaints of skin itching and mild epigastric pain in placebo group but the liver function tests, kidney function tests and cardiac enzyme did not significantly change during the medication.
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PMID:A double-blind placebo control trial of dilazep in beta-thalassemia/hemoglobin E patients. 964 Jun 22

In many of the parts of the world where thalassaemia is common, the blood supply is inadequate or unsafe, and desferrioxamine is too expensive for routine use. We classify some patients as having 'severe thalassaemia intermedia', i.e. those with moderately severe thalassaemia who can survive without regular transfusions, but who are at risk of many complications which are reviewed here. These include bone deformity and fractures, extramedullary haemopoietic tumours, leg ulcers, autoimmune haemolysis and, especially after splenectomy, thromboembolism and infection. An increase in the quality and safety of the blood supply, and a cheaper and/or oral iron chelator, would enable more of these patients to be treated as thalassaemia major and have improved survival and quality of life.
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PMID:Severe thalassaemia intermedia: clinical problems in the absence of hypertransfusion. 974 86


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