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

This study examines the effect of different levels of fetal hemoglobin (Hb F) and the presence or absence of genes for alpha-thalassemia on the red cell indices and degree of anemia among 102 patients with homozygous sickle cell disease (S/S) between the ages of 15 and 62 years. Patients were divided into those with an average Hb F of less than 10 gm/L ("low" Hb F group) and those with greater than 10 gm/L ("high" Hb F group). alpha-Thalassemia was assessed by restriction enzyme analysis of DNA by the Southern blotting technique. Homozygosity for the beta(s) gene was confirmed by restriction enzyme analysis of DNA using the enzyme Mst II. There were 51 patients with four alpha-globin genes, 28 of whom had "high" and 23 "low" Hb F levels. Fifty-one patients had alpha-thalassemia, 38 of whom were heterozygous and 13 homozygous for the 3.7 kb alpha-thalassemia deletion. Nine had "high" and 31 had "low" Hb F. Irrespective of alpha-globin genotype, patients in the high Hb F group had a higher mean Hb, Hct, MCV, and MCH than those in the low HB F group. In patients without alpha-thalassemia Hb F was positively correlated with MCV and MCH (p less than 0.001), patients with high Hb F levels having macrocytosis confirmed by microhematocrit studies. Patients with alpha-thalassemia had a lower MCHC than patients with four alpha-globin genes and this was not significantly affected by the level of Hb F. The combination of alpha-thalassemia and high levels of Hb F appears to result in a distinctive S/S phenotype that is similar to the type of S/S disease described in Southern India.
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PMID:The effect of Hb F and alpha-thalassemia on the red cell indices in sickle cell anemia. 242 Jan 72

Sickle cell disease (SCD) occurs at a high prevalence in different parts of Saudi Arabia. Several reports indicate that the disease follows a mild clinical course in the Saudi population of the eastern province of Saudi Arabia, while little is known about the disease in other parts of the country. This study was conducted on 53 children from the Saudi Arabian south-western province with sickle cell disease and 53 age- and sex-matched normal controls (haemoglobin AA phenotype). A statistically significant difference was encountered in the haematological parameters investigated in the two groups. The SCD patients were divided into subgroups with high and low Hb F levels, alpha- and beta-thalassaemia and glucose-6-phosphate dehydrogenase (G-6-PD) deficiency. The haematological parameters were then compared in the different sub-groups. No significant difference could be demonstrated in the haematological parameters in patients with a high or low Hb F level. In patients without thalassaemia, the red cell count, total haemoglobin and haematocrit were significantly lower, while MCV, MCH and MCHC were higher. G-6 PD deficiency existed in association with thalassaemias, and apart from a reduction in MCV and MCH, no other statistically significant difference could be demonstrated. Clinical examination revealed a severe disease with several cases suffering from the hand and foot syndrome.
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PMID:On the nature of sickle cell disease in the south-western province of Saudi Arabia. 243 51

The alpha globin genotype of a total of 282 Indians from Orissa state has been analyzed. The overall alpha thalassemia gene frequency is 0.29, most frequently caused by the -alpha 3.7 and -alpha 4.2 deletions. In one family a novel -alpha 3.5 deletion removing the alpha 1 globin gene with some of its flanking sequences has been found, suggesting further sequence homology of the alpha globin gene cluster 3' to the alpha 1 globin gene. Patients with sickle cell disease and alpha thalassemia had higher hemoglobin (Hb) levels, RBC counts, and Hb A2 levels, and lower reticulocyte counts, MCV, MCH, and Hb F levels than those with a normal alpha genotype. The frequency of splenomegaly was not influenced by the alpha globin genotype. A higher prevalence of alpha thalassemia was found in patients greater than or equal to 10 years of age than in the younger group, suggesting a possible advantageous effect of alpha thalassemia on the survival of patients with sickle cell disease.
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PMID:The molecular basis of alpha thalassemia in India. Its interaction with the sickle cell gene. 282 16

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

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

The amount of trapped plasma in the microhematocrit red blood cell column of samples from 25 normal individuals and 102 patients was investigated. The mean value for the normal individuals was 1.53%, and the mean values for the samples from the patient groups ranged from 1.41% to 1.82%. These groups included patients with sickle cell disease, iron deficiency, and hereditary spherocytosis. There was an inverse correlation between trapped plasma and the MCH in the samples from patients with iron-deficiency (MCH less than or equal to 25.0 pg). These findings have relevance to the determination of the PCV and derived red blood cell indices.
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PMID:Trapped plasma in the microhematocrit. 713 20

Seventy children homozygous for Hb S (SS) and their 111 heterozygous (AS) parents were evaluated through their erythrocytic indices, hemoglobin composition, and occasionally through in vitro Hb chain synthesis values. Three groups of SS patients and of AS parents were identified based on differences in degree of microcytosis (MCV) and (degree of hypochromia (MCH) values. The level of Hb S in the Hb S heterozygotes showed a trimodal distribution. Five SS patients had an alpha-thalassemia homozygosity (alpha(0) alpha/alpha(0) alpha; beta(s)/beta(s) which was characterized by a distinct microcytosis and hypochromia (MCV), less than or equal to 70 fl; MCH, less than or equal to 22 pp). Nine SS patients had an alpha-thalassemia heterozygosity (alpha(0)/alpha/alpha alpha; beta(s)/beta(s)) with an MCV value of 71 to 78 fl, and an MCH value of 21.3 to 26.5 pg. Four AS parents had an alpha-thalassemia-2 homozygosity with values of MCV less than or equal to 71 fl and MCH less than or equal to 23.5. The level of Hb S was less than 31%. Thirty-nine AS parents had an alpha-thalassemia-2 heterozygosity characterized by an MCV value of 72 to 79 fl, an MCH value of 23.6 to 26.5, and a level of Hb S ranging between 31.0 and 36.8%. The Hb A2 level in SS patients was significantly correlated with the RBC counts and the MCV and MCH (r = 0.38, -0.52, and -0.47, respectively). Significant correlations in AS parents were also noted between the MCV, MCH, RBC, and Hb S percentages (r = 0.62, 0.68, and -0.49, respectively). Although the data are limited, the simultaneous occurrence of an alpha-thal-2 homozygosity seems to decrease the level of Hb F in sickle cell anemia. The presence of an alpha-thal-2 heterozygosity or homozygosity together with an SS or AS condition resulted in identifiable hematologic phenotypes.
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PMID:alpha-thalassemia-2 and the variability of hematological values in children with sickle cell anemia. 726 82

Hydroxyurea (HU), an inhibitor of DNA synthesis, has been shown to increase fetal hemoglobin (HbF) levels in patients with sickle cell anemia and in some patients with beta-thalassemia. However, until now there have not been good in vitro model systems that simulate this effect for study of the molecular and cellular mechanism(s) involved in perturbing the normal ontogeny of the globin genes. We analyzed the cellular effects of HU using a two-phase liquid culture procedure (Fibach et al: Blood 73:100, 1989) in which human peripheral blood-derived progenitor cells undergo proliferation and differentiation. HU was found to have multiple effects on these cultured cells: (1) an increase in the proportion of HbF produced; (2) a decrease in cell number due to inhibition of cell proliferation; (3) an increase in hemoglobin content per cell (mean corpuscular hemoglobin [MCH]); and (4) an increase in cell size (mean corpuscular volume). The extent of these effects was related to the HU dose and time of addition. When added to cell cultures from normal individuals, 4 days following their exposure to erythropoietin (EPO), 100 mumol/L HU caused a 1.3- to 3.5-fold increase in the proportion of HbF, from 0.4% to 5.2% (mean 1.6) in untreated to 1.5% to 8.2% (mean 3.1) in HU-treated cultures and a 45% +/- 10% increase in MCH but only a 25% +/- 7% decrease in cell number on day 13. Cultures of cells derived from five patients with sickle cell anemia have shown a twofold to fivefold increase in the percentage of Hb F following addition of HU while four patients with beta-thalassemia showed a 1.3- to 6.2-fold increase. We believe that this primary cell culture procedure should prove useful in studying the cellular and molecular mechanisms of pharmacologic induction of HbF and might provide a valuable predictive assay system for evaluation of the response of individual patients with hemoglobinopathies to HU and similar agents.
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PMID:Hydroxyurea increases fetal hemoglobin in cultured erythroid cells derived from normal individuals and patients with sickle cell anemia or beta-thalassemia. 768 Sep 23

The red cell distribution width index (RDW) and other cell indices (HCT, MCV, MCH) were determined in 171 normal infants and children, 37 patients with sickle cell disease (SCD) and 44 patients with sickle cell trait (SCT). The red blood cell indices including RDW in normal children showed a significant difference between different age groups (P < 0.01), while in different sex groups, they did not differ significantly. SCD group showed a significant increase in RDW and a significant decrease in the hematocrit (HCT) value when compared either with the control or the SCT groups (P < 0.01). Patients with SCD showed a significant increase in their RDW and a significant decrease in their hematocrit values during haemolytic crises as compared with those during vaso-occlusive crises (P < 0.01). A positive linear correlation between RDW and the reticulocyte count in SCD and SCT patients. (r = .8842, P < 0.01) was also found. In this context it was concluded that RWD values do reflect the reticulocytes magnitude which would provide clinical and pathological information about SCD and its crises.
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PMID:Red cell profile in normal and sickle cell diseased children. 816 36

This study evaluated the efficacy of hydroxyurea treatment in the prevention of vaso-occlusive crises among children and teenagers with severe sickle cell anemia and sickle cell beta-thalassemia. Nineteen children and young adults with severe sickle cell disease were enrolled to the hydroxyurea treatment trial. The incidence of vaso-occlusive crises, acute chest syndrome, hemolytic crises, splenic sequestration episodes, blood transfusions, and hospital days in the 2 years before hydroxyurea (HU) treatment were compared with the same parameters in the first 2 years of treatment. The patients received a mean dose of 21.3 mg/kg/day daily and were treated during a mean period of 40.3 +/- 14 months (range 20 to 68 months). Significant increases were observed after 1 month in the Hgb, MCV, MCH, and MCHC levels and were more notable after 3 months. The increase in the Hgb F level became important after 3 months of HU therapy and was highly significant (p < .001) beyond 6 months. No differences were observed in the RDW, reticulocyte count, Hgb S, and Hgb A2. Severe neutropenia was observed in one case. A decrease in the frequency of vaso-occlusive crises, acute chest syndrome, hemolytic crises, blood transfusions, and days spent in the hospital was demonstrated during the HU treatment period compared to the same period before. The clinical and laboratory response to HU was dramatic in severely affected sickle cell anemia (SCA) patients. The response to HU in children and teenagers with severe sickle cell anemia is similar to the response in adults, and no severe adverse effects were observed.
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PMID:Effect of hydroxyurea in sickle cell anemia: a clinical trial in children and teenagers with severe sickle cell anemia and sickle cell beta-thalassemia. 1032 20


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