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Query: UMLS:C0240066 (iron deficiency)
 7,156 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To test the hypothesis that tissue oxygen delivery would be affected by diminished oxygen stores in cyanotic congenital heart disease, serum ferritin, transferrin saturation, hemoglobin, red cell mean corpuscular volume (MCV), red cell 2,3-diphosphoglycerate (DPG), P50, blood gases, oxygen saturations and systemic oxygen transport were measured in 29 hypoxemic infants and children. For the group, aortic saturation was 81 +/- 9%, PaO2 was 50 +/- 12 mm Hg, hemoglobin 16.2 +/- 2.1 gm/dl and systemic oxygen transport 620 +/- 145 ml/min/m2. P50 was increased above normal values (28.8 +/- 2.3 vs 26.6 +/- 1.1 mm Hg, p less than 0.01), and DPG was 2.35 +/- 0.54 mumol/ml, at the upper limits of normal for this assay. Iron deficiency was present in 8. When patients with P50 greater than or equal to 30 mm Hg and P50 less than 30 mm Hg were compared, iron stores were diminished in the high P50 group: [serum ferritin (19 +/- 8 vs 53 +/- 48 ng/ml, p = 0.0006), transferrin saturation (11 +/- 6 vs 23 +/- 11%, p = 0.003) and MCV (79 +/- 8 vs 86 +/- 4 fl, p = 0.05)]. Hemoglobin, aortic oxygen saturation, PaO2 and systemic oxygen transport were similar in both groups. In children with iron sufficiency, 15 of 21 had MCV greater than 90th percentile for age and sex (p less than 0.001 versus expected distribution). Also, MCV greater than 90th percentile for age and sex had a positive predictive value of 0.88 for iron sufficiency. This study demonstrates that diminished iron stores in cyanotic congenital heart disease are associated with a more right-shifted oxyhemoglobin dissociation curve (increased P50).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effect of iron deficiency on tissue oxygen delivery in cyanotic congenital heart disease. 334 85

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

An increase in hemoglobin concentration characterizes the normal compensatory response to chronic tissue hypoxia. We observed no such increase in 42 chronically hypoxic patients with cystic fibrosis, in whom the mean concentration was 12.6 gm/dl; one third of the patients were anemic. Compared with patients with cyanotic heart disease, patients with cystic fibrosis did not have a compensatory increase in P50 or 2,3-diphosphoglycerate. Despite anemia, erythropoietin levels in patients with cystic fibrosis were not significantly different from normal control values. The growth of colony-forming units-erythroid in patients with cystic fibrosis was similar to that in control subjects, and there was no inhibition of growth with the addition of autologous serum. Erythropoietin sensitivity, determined by measuring the CFUe dose response curve, was normal in both patients and controls. Results of iron studies were consistent with iron deficiency in the majority of patients. Impaired absorption of iron was observed in six of 13 iron-deficient patients with cystic fibrosis. An inverse correlation between erythrocyte sedimentation rate and peak serum iron was obtained during the iron absorption study. Eight patients who underwent a therapeutic trial of iron demonstrated a 1.8 gm/dl rise in hemoglobin concentration. Two patients with previously documented iron malabsorption responded to parenteral iron therapy after failure to respond to oral supplementation. These studies demonstrate that patients with cystic fibrosis not only have an impaired erythroid response to hypoxia, but are frequently anemic. Their inadequate erythroid response to hypoxia results in part from disturbances in erythropoietin regulation and iron availability.
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PMID:Inadequate erythroid response to hypoxia in cystic fibrosis. 673 32

Hemoglobinopathies may be a significant clinical problem in certain racial groups. A patient presenting with obscure hemolytic anemia should, therefore, be investigated for hemoglobinopathies, particularly if he is of Mediterranean or southeast Asian descent. Longterm iron therapy should not be instituted on the basis of a hypochromic microcytic blood picture without documenting iron deficiency. When investigating polycythemia in young patients with normal white blood cell and platelet counts, hemoglobin oxygen affinity (P50) should be measured.
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PMID:The clinical significance of hemoglobinopathies. 2127 3