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Query: UMLS:C0002895 (sickle cell disease)
 11,747 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

There are at least 240 million heterozygotes for the haemoglobinopathies throughout the world, and at least 200 000 lethally affected homozygotes are born annually, about half with thalassaemia and half with sickle cell anaemia. These diseases are already making important demands on health resources in developing countries, and with further progress in primary health care, they will become a major public health problem. This has already happened in the Mediterranean areas where thalassaemias are predominant, and is now beginning in parts of south-east Asia. Important new developments in the treatment and community control of the haemoglobinopathies now make it advisable for all countries where they are endemic, regardless of their present state of development, to evaluate the present and potential problems presented by these diseases.Although effective management of thalassaemia major, involving intensive treatment with blood and iron-chelating agents, is too expensive for most developing countries, community control by prospective heterozygote detection, education, and fetal diagnosis has now been successfully applied in some European and Mediterranean areas. Within three years of starting these programmes, the birth rate of infants with thalassaemia major had fallen by 50-80%. The relatively low cost of setting up and running the control programmes has already been greatly outweighed by the financial and social benefits of the reduced thalassaemia birth rate. Detailed guidelines are provided for community control programmes that could be incorporated into the health care service of many developing countries.In sickle cell disease, which varies in severity with both genetic and environmental factors, the commonest problem is death in early childhood from overwhelming infections. A major effort should be put into heterozygote screening and neonatal diagnosis to permit earlier identification and protection of affected individuals. This will also provide a good basis for a prevention programme if more acceptable methodology, such as first trimester fetal diagnosis, becomes available. Heterozygote detection and counselling, and education in management of homozygotes should be integrated into the primary care system of countries with a high incidence of sickle cell disease.
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PMID:Community control of hereditary anaemias: memorandum from a WHO meeting. 660 44

In a patient with sickle cell anemia, iron deficiency was accompanied by hypochromic, microcytic RBCs, absence of bone marrow iron, and a low serum ferritin level. The mean corpuscular hemoglobin concentration (MCHC) was decreased (27.6 g/dL) and was associated with an extreme scarcity of sickled erythrocytes in blood smears. Iron therapy resulted in reticulocytosis and an increase in sickled erythrocytes. In vitro studies demonstrated a decrease in sickling of erythrocytes as a function of oxygen saturation of the blood when the patient was iron deficient. The whole blood oxygen dissociation curve showed a substantial decrease in oxygen pressure necessary to produce 50% saturation of hemoglobin at pH 7.4 and 37 degrees C (P50), indicating an increased oxygen affinity. These data suggest that a reduction of the MCHC induced by iron deficiency may ameliorate sickling.
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PMID:Iron deficiency and sickle cell anemia. 667 16

Stroke is a relatively frequent and severe complication of sickle cell disease. We performed cerebral arteriograms in 30 patients with sickle cell disease to evaluate the cause of acute neurologic deficits and to assess the effects of transfusion therapy given for a year or more after the acute episode. Twenty-three patients with motor and speech deficits had multiple abnormalities of major cerebral arteries. The internal carotid and anterior and middle cerebral arteries showed stenosis and/or occlusion at their common junction. Irregular luminal surfaces suggested that endothelial damage and intimal hyperplasia were the basis of stroke. Prolonged transfusion therapy nearly stopped progression of stenosis and markedly decreased the irregularity of the luminal surfaces; in 4 untransfused patients, the degree of stenosis doubled and the luminal abnormalities persisted. Prior to transfusion, 90% of patients had recurrence of stroke. With transfusion therapy, only 10% of patients had recurrence despite persistent arterial abnormalities. Clinical recurrences per patient-month decreased 75-fold. The patients tolerated prolonged transfusion therapy well, despite progressive iron accumulation. Seven patients with smooth abnormalities of a single artery, nonocclusive changes, or with normal arteriograms did not receive transfusions. Only one of this group had recurrence of symptoms.
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PMID:Effect of transfusion therapy on arteriographic abnormalities and on recurrence of stroke in sickle cell disease. 668 47

The relationships among hemoglobin concentration (Hb), red cell 2,3-diphosphoglycerate (2,3-DPG), and p50 were studied in 20 chronically hypertransfused patients with thalassemia major. In the nontransfused control group, which included normal individuals as well as patients with sickle cell disease or iron deficiency anemia, the Hb correlated inversely with both 2,3-DPG concentration and p50, as is well established. In contrast, however, prior to transfusion, at the nadir of Hb, patients with thalassemia major had inappropriately low 2,3-DPG concentrations and p50s. These findings occurred in all patients, regardless of whether they had received packed, leukocyte-poor, or frozen-thawed red cells. The hypothesis that the time of blood storage was a factor was excluded by repeatedly transfusing one patient with packed red cells administered within 4 hr of collection in CPDA-1. A second hypothesis, that red cell function might be impaired by the iron-overloaded thalassemic environment, was excluded by studying a newly diagnosed, newly transfused patient with aplastic anemia. In both cases, the same inability to appropriately increase 2,3-DPG and p50 as the Hb fell during the intertransfusion interval was noticed. These data suggest that red cells of chronically transfused patients are unable to adapt to the decline in Hb that occurs during the intertransfusion interval.
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PMID:Inappropriately low red cell 2,3-diphosphoglycerate and p50 in transfused beta-thalassemia. 670 41

Iron status was investigated in 60 adults with sickle cell anemia as determined by stainable iron in bone marrow aspirates, serum ferritin, serum iron, and the total iron-binding capacity. Seventeen patients (28%) were found to have absent bone marrow iron. There was an excellent inverse correlation between serum ferritin and the serum transferrin (p less than 0.001), and a significant positive correlation between serum ferritin and transferrin saturation (p less than 0.005), bone marrow iron (p less than (p less than 0.001), and history of prior blood transfusion (p = 0.005). Results of complete radiologic examination of the gastrointestinal tract and proctoscopy were negative in the 17 patients in the iron-deficient group. The high incidence of iron deficiency may be related to excessive urinary losses of iron. Our data indicate that serum ferritin values of less than 30 ng/ml are diagnostic of iron deficiency in patients with sickle cell anemia, with a high degree of specificity (98.7%). However the sensitivity of the test at a serum ferritin level of 30 ng/ml is only 32%. The diagnostic evaluation and the management of sickle cell anemia in iron-deficient patients needs to be better defined.
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PMID:Iron stores in adults with sickle cell anemia. 671 57

The iron status of 31 patients with sickle cell anaemia (Hb SS) and balanced globin chain synthesis was studied. Twelve patients (group I) had never been transfused; 14 had received up to 4 units of blood in the past (group II) and five had been hypertransfused for 6 months to 2 years (group III). The hypertransfused group had significantly higher MCV and MCH than the nontransfused one, and significantly lower total iron binding capacity and higher serum ferritin concentration than either groups I or II. The serum ferritin concentration was lower than normal in eight patients (five in group I and three in group II), and higher than normal in seven patients (four in group III and three in group II). The remaining 16 patients had normal serum ferritin concentrations. Our results indicate that iron overload is uncommon in adults with Hb SS who have not been transfused, and that a proportion of patients have lower than normal serum ferritin concentrations. Transfused patients, even 6 months after the last transfusion, show increased haemoglobin content of red cells, which may have an adverse effect on the frequency and severity of sickle crises.
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PMID:Effect of blood transfusion on iron status in sickle cell anaemia. 673 96

Samples of bone marrow from 33 Ghanaian children with homozygous sickle cell anaemia who presented with profound anaemia (haemoglobin less than 5 g/dl) were studied. The principal finding was depression of erythropoiesis (aplastic crisis) in 14 children and erythroid hyperplasia in 17. A splenic sequestration crisis was clinically diagnosed in the remaining two children. Stainable iron was absent in the marrow of 14 children and reduced in another five. Megaloblastic changes compatible with folate deficiency were present in 8 children. It is suggested that iron and folate deficiencies may complicate sickle cell anaemia in children living in geographical areas where nutritional deficiencies are prevalent.
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PMID:Bone marrow in sickle cell anaemia at time of anaemic crisis. 674 77

Serious defects in the living conditions of the vast majority of people in the tropics, rather than racial factors, are the underlying reasons why anaemia is common, why malaria is rampant and why the complications of sickle cell disease are so serious. Mass illiteracy, poor environmental hygiene and widespread poverty with all their implications explain why malaria eradication programmes have so far failed in tropical Africa and why basic health-care schemes have been difficult to establish. Pregnant women are very vulnerable to the effects of anaemia, malaria and sickle cell disease. However, appropriate use of folic acid and iron supplements as well as malarial chemosuppression succeeds in maintaining haemoglobin concentrations at reasonable levels during pregnancy. If, for whatever reason, the haemoglobin level falls to under 4.4 g/dl or the haematocrit value is 0.14 or less, anaemia becomes an obstetric emergency. Both maternal and fetal mortality rise sharply, maternal death being due to anaemic heart failure, fulminating bacterial infection and shock from even small loss at delivery or abortion. With the haemoglobin concentration as low as 4.4 g/dl, blood transfusion greatly improves maternal but not necessarily fetal prognosis. Additional cause of morbidity in sickle cell disease is painful crises, the control of which remains largely unsatisfactory. Now that sickle cell disease can be diagnosed early in intrauterine life the idea of aborting the affected fetuses as a means of controlling or reducing sickle cell disease is well within the means of developed countries, but it is a line of approach which developing countries cannot afford at present.
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PMID:Anaemia, malaria and sickle cell disease. 675 46

Thirty-seven patients with SCD were studied: 24 were diagnosed as homozygous Hb S on the basis of their haematological findings, and alpha:non-alpha globin chain ratios were found to be balanced in all. Thirteen patients were thought to have alpha or beta thalassaemia interaction with Hb S on the basis of low MCV and MCH, family history and/or presence of Hb A on electrophoresis. Six of them had abnormal alpha:non-alpha ratio (one had a ratio of 0.72 suggestive of alpha thalassaemia, and five had ratios between 1.4 and 1.9, compatible with beta thalassaemia interaction). The remaining seven patients with microcytosis had balanced globin chain synthesis and five were found to be iron deficient. Five additional patients (3 with Hb SS and 2 with Hb S/beta thalassaemia) had lower than normal serum ferritin concentration. The analysis of case histories disclosed that peptic ulceration, recurrent epistaxis and multiple pregnancies could account for iron loss in seven patients. These findings indicate that iron deficiency may be common in SCD and should be excluded as a cause of microcytosis. Microcytosis, in the absence of conclusive family studies and/or presence of Hb A on electrophoresis, is an unreliable indicator of alpha or beta thalassaemia interaction with Hb S.
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PMID:Iron deficiency in sickle cell anaemia. 688 17

Anemia is a problem in all countries of the English-speaking Caribbean where data are available. It affects mostly preschool age children and pregnant and lactating women. The most common cause is a deficiency of iron. This is probably due to an adequate intake with a low absorption. A deficiency of folate is also probably a responsible factor in the pathogenesis of some of the anemias. Anemias associated with parasitic infestations such as hookworm and whipworm and hemoglobinopathies such as sickle cell anemia are also noted.
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PMID:Nutritional anemia in the English-speaking Caribbean and Suriname. 706 93


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