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Query: UMLS:C0019045 (hemoglobinopathies)
 2,704 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Prophylactic transfusions of normal donor red cells were administered during 37 pregnancies to women with sickle cell anemia, sickle cell-hemoglobin C disease, or sickle cell-beta thalassemia disease. Once the diagnosis was confirmed, the transfusions were administered intermittently throughout the rest of the pregnancy in such amounts and at such frequencies that no more than 60% of the circulating red cells contained hemoglobin S and the hematocrit was above 25. The maternal mortality rate was zero and maternal morbidity as the consequence of the sickle cell hemoglobinopathy was minimal. The perinatal mortality rate was appreciably reduced when compared to that previously observed without prophylactic transfusions but perinatal morbidity was still excessive. Evidence that the intrauterine environment was compromised, in spite of the transfusions consisted of an increased frequency of growth-retarded fetuses, of meconium staining of amnionic fluid, and of ominous decelerations of fetal heart rate. Morbidity from the transfusions was troublesome. Nonetheless, it is concluded tentatively that both the mother with a sickle cell hemoglobinopathy and her fetus are likely to benefit from prophylactic transfusions of normal donor red cells administered during one pregnancy according to the protocol employed in this study.
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PMID:Prophylactic transfusions of normal red blood cells during pregnancies complicated by sickle cell hemoglobinopathies. 50 38

Techniques are currently available at a few specialized centers for the antenatal detection of hemoglobinopathies such as beta thalassemia and sickle cell anemia. The risks are not yet clearly defined, but it seems reasonable to suggest that about 90 per cent of families may obtain useful information about the genotype of their fetus. Obtaining fetal blood as well as analyzing the sample requires considerable experience and skill. These factors continue to limit the availability of this procedure.
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PMID:Prenatal diagnosis of hemoglobinopathies. 69 83

The structure, properties, genetics, and clinical and biochemical expression of hemoglobins Lepore (deltabeta) and anti-Lepore (betadelta) are described. In addition to the three Lepore variants (Lepore Hollandia, Lepore Baltimore and Lepore Washington) at least four anti-Lepore variants (Miyada, P Nilotic (P Congo), Coventry and Lincoln Park) are known at the present time. All known hemoglobins Lepore and anti-Lepore are products of non-homologous crossing-over between the delta and the beta genes. Although the Hb Lepore condition is expressed phenotypically and clinically as beta thalassemia, the presence of about 10% of Hb Lepore distinguishes the condition hematologically from beta thalassemia. Data on the hematological and biochemical expression of this hemoglobinopathy are presented. In contrast to the anemia in the Lepore condition, there is no phenotypic evidence of thalassemia in persons with hemoglobin anti-Lepore, because no beta chain deficiency accompanies the latter condition. Although no adequate explanation has been advanced concerning the factors which maintain a low synthesis of the Lepore and anti-Lepore chains, it has been suggested that multiple rare codons may introduce rate-limiting steps or that the deltabeta and betadelta mRNAs may be unstable. Data on the geographical distribution and structural identification of Hb Lepore are presented.
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PMID:Hemoglobins Lepore and anti-Lepore. 70 Oct 81

The strategic advantages of neonatal diagnosis of sickle hemoglobinopathies depend on an accurate cord blood screening procedure. One hundred thirty-eight black children in whom a range of normal and abnormal hemoglobin genotypes was identified by agar gel and cellulose acetate hemoglobin electrophoresis at birth were retested by cellulose acetate three to five years later. The original cord blood diagnoses were verified in all 138, including all 26 with major sickle syndromes (SS, S-beta thalassemia, and SC). Cord blood hemoglobin electrophoresis using these techniques permits accurate neonatal diagnosis of major and minor sickle hemoglobinopathies.
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PMID:Accuracy of cord blood screening for sickle hemoglobinopathies. Three- to five-year follow-up. 75 62

The past decade has witnessed profound increases in knowledge of the structure, function, and developmental regulation of the human globin genes. This information has deepened our understanding of the molecular and cellular mechanisms underlying inherited disorders affecting hemoglobin, and it has provided a new perspective for attaining meaningful increases in fetal hemoglobin synthesis in the management of sickle cell anemia and beta thalassemia. Efforts to provide therapy for these disorders are based on three factors: an understanding of their pathophysiology; the potential for fetal hemoglobin to alter its manifestation; and the concept that developmental changes in globin gene expression might be reversed by manipulating cellular and molecular regulatory mechanisms. In this review we discuss these topics and examine critically recent efforts to apply various pharmacological agents to in vitro, animal, and human models with the goal of increasing HbF synthesis. Several agents have demonstrated activity in patients with hemoglobin disorders. One such agent, hydroxyurea, has been shown to be potentially efficacious in phase II clinical trials in patients with sickle cell anemia and awaits testing in a placebo-controlled phase III study.
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PMID:Therapeutic approaches to hemoglobin switching in treatment of hemoglobinopathies. 137

Sickle hemoglobinopathies include sickle cell disease, sickle-C disease, and sickle-beta thalassemia. Patients with these disorders commonly suffer a multitude of destructive events to vital organs, especially to the central nervous system, the spleen, the kidney, the lung, and the heart as a result of microvascular plugging by the sickled erythrocytes. Thoughtful preparation for anesthesia and operation, especially when directed by experienced individuals, can greatly reduce the hazard of inducing the sickle crises that formerly plagued individuals with sickle hemoglobinopathies who faced major operations under general anesthesia. The patient must be free of any acute illness, especially one involving the respiratory system. Adequate hydration preoperatively combined with avoiding perioperative hypoxia, hypothermia, and acidosis, the triggers for sickling, will go far toward avoiding sickle-induced complications. Modern transfusion therapy, consisting of multiple small transfusions of Hb A erythrocytes administered over several weeks prior to the operation, not only corrects the chronic anemia but suppresses erythropoiesis of cells containing Hb S in the patient's bone marrow and leaves him or her with a majority of cells containing Hb A. This provides a safety net in case a sickle-inducing insult occurs despite the best efforts to avoid one. Individuals with sickle hemoglobinopathies may require any of the operations common to all children, for example, herniorrhaphy, appendectomy, tonsillectomy, and circumcision, but a significant number will develop calcium bilirubinate cholelithiasis and possibly cholecystitis as a result of the continual increased load of bile salts resulting from the shortened lifespan of the cells containing Hb S. Also, although most individuals with Hb S will gradually suffer splenic infarction by late childhood, a significant number of infants will experience acute splenic sequestration crisis, a life-threatening entity, the recurrence of which is prevented by splenectomy. Several publications have demonstrated that such surgical procedures can be performed in large numbers of patients with sickle hemoglobinopathies without deaths and with minimal morbidity.
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PMID:Surgical management of children with hemoglobinopathies. 144 Jan 54

Between 1970-1990, the Laboratory tested 38,391 specimens for hemoglobinopathies, of which 7,935 were positive. The major abnormalities detected were beta thalassemia trait (4,688), alpha thalassemia trait (1,248) and sickle cell trait (847). Clinically significant hemoglobinopathies detected were Hemoglobin H disease (100), sickle cell disease (67) and sickle cell Hemoglobin C disease (79). Hemoglobinopathies are therefore common in the Hamilton area as a reflection of the cultural diversity of area citizens. Of the 49 patients with thalassemia without documented iron deficiency, 8 (16%) received iron therapy for a variable period of time and 3 were investigated for gastrointestinal blood loss. Hemoglobin abnormalities cause or have the potential to cause clinical disease and they can, if not detected, result in unnecessary iron therapy or gastrointestinal investigation.
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PMID:The clinical significance of hemoglobinopathies in the Hamilton region: a twenty-year review. 145 12

beta-Thalassemia, a hemoglobinopathy that results in the precipitation of denatured alpha-globin chains on the membrane, is characterized by erythrocytes with significantly reduced lifespans. We have demonstrated previously that hemoglobin denaturation on the membrane can promote clustering of integral membrane proteins, and that this clustering in turn leads to autologous antibody binding, complement fixation, and rapid removal of the cell by macrophages. To evaluate whether this pathway also occurs in beta-thalassemic cells, we have isolated and characterized the immune complexes from the membranes of these cells. We observe that autologous IgG-containing complexes obtained by either immunoprecipitation or simple centrifugation of nondenaturing detergent extracts of beta-thalassemic cell membranes contain globin, band 3, IgG, and complement as major components. Absorption spectra of these complexes demonstrate that the globin is, indeed, mainly in the form of hemichromes. Immunoblotting studies further show that much of the band 3 protein in the aggregates is covalently cross-linked to a dimeric or tetrameric form, consistent with the preference of the autologous IgG for clustered band 3. Although the insoluble aggregates constitute only approximately 1.6% of the total membrane protein, they still contain 27% of the total IgG and 35% of the total complement C3 on the thalassemic cell surface. Because cell surface IgG and complement component C3 are thought to trigger removal of erythrocytes from circulation, the hemichrome-induced clustering of band 3 may contribute to the beta-thalassemic cell's shortened lifespan.
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PMID:Isolation, characterization, and immunoprecipitation studies of immune complexes from membranes of beta-thalassemic erythrocytes. 158 45

A program for the detection of thalassemias and other hemoglobinopathies in high-risk populations is described. This program, based on two screening tests, was applied to the Hellenic Army recruits and was found to work well. Red cell one-point osmotic fragility was used for the detection of thalassemic samples and hemoglobin electrophoresis for screening of other hemoglobinopathies. Samples with decreased red cell osmotic fragility and/or abnormal electrophoretic pattern were submitted for further detailed investigation. Following this program, 64,814 recruits, representing 0.651% of the total Greek population and 9.917% of the 20-year-old Greek male population, were tested. beta-Thalassemia was found with an average incidence of 5.476% and alpha-Thalassemia with an incidence of 0.201%. Hemoglobinopathy Lepore was detected in 51 samples (0.079%) and hemoglobinopathy-S in 352 samples (0.543%).
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PMID:Diagnostic strategy for thalassemias and other hemoglobinopathies: a program applied to the Hellenic Army recruits. 162 Mar 78

Delta beta Thalassemia and hereditary persistence of fetal hemoglobin (HPFH) constitute a heterogeneous group of disorders characterized by absent or reduced synthesis of adult hemoglobin (Hb A) and increased synthesis of fetal hemoglobin (Hb F). Coinheritance of these disorders with other beta chain hemoglobinopathies, such as beta thalassemia and the sickle cell (beta s) gene, can result in attenuation of the clinical severity of these hemoglobinopathies owing to the increased Hb F levels. The molecular basis of these disorders is quite heterogeneous and consists of both deletion and nondeletion types of mutations. The characterization of these molecular defects has provided new insights on the structure and function of important regulatory elements that are involved in the normal control of expression of the beta- and gamma-globin genes and in hemoglobin switching.
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PMID:Delta beta thalassemia and hereditary persistence of fetal hemoglobin. 171 9


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