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

This paper is written in the context of our changing perception of the immunological system as a system with possible biological roles exceeding the prevailing view of a system concerned principally with the defense against external pathogens. The view discussed here relates the immunological system inextricably to the metabolism of iron, the circulation of the blood and the resolution of the evolutionary paradox created by oxygen and iron. Indirect evidence for this inextricable relationship between the two systems can be derived from the discrepancy between the theoretical quasi-impossibility of the existence of an iron deficiency state in the adult and the reality of the WHO numbers of people in the world with iron deficiency anemia. With the mounting evidence that TNF, IL-1, and T lymphocyte cytokines affect hemopoiesis and iron metabolism it is possible that the reported discrepancy is a reflection of that inextricable interdependence between the two systems in the face of infection. Further direct evidence for a relationship between T cell subset numbers and iron metabolism is presented from the results of a study of T cell populations in patients with hereditary hemochromatosis. The recent finding of a correlation between low CD8+ lymphocyte numbers, liver damage associated with HCV positivity and severity of iron overload in beta-thalassemia major patients (unpublished data of RW Grady, P. Giardina, M. Hilgartner) concludes this review.
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PMID:T lymphocytes and iron overload: novel correlations of possible significance to the biology of the immunological system. 134 13

The aim of this cross-sectional study was to estimate the prevalence of iron deficiency and overload in the adult population in Iceland, a developed Scandinavian country. The study population consisted of 4240 individuals aged 25-74 years randomly selected from the national roster. Basic hematological, S-iron, S-total iron binding capacity (TIBC), and S-ferritin measurements were obtained on 2588 individuals (61.0%). The results indicated unusually large iron stores in the adult Icelandic population and significantly larger iron stores in the rural compared to the urban population. Iron deficiency was rare except in urban premenopausal women, where 1 in 4 showed evidence of iron deficiency and 3.2% had iron deficiency anemia. Seven patients with hereditary hemochromatosis were identified from a subgroup of 1887 subjects, resulting in a prevalence of 0.37%. Two of the hereditary hemochromatosis patients had been gastrectomized. Measures to improve the iron balance in urban premenopausal women cannot therefore include increased iron fortification of food but must be more directed towards the target group.
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PMID:Prevalence of iron deficiency and iron overload in the adult Icelandic population. 175 60

Fluorescently labeled antibodies were used to identify transferrin receptors and mucosal transferrin in human gastrointestinal biopsy sections. Transferrin receptors were evident in the villous epithelium and the crypt areas of duodenum, ileum, and colon, predominantly in the basal-lateral area. In 7 subjects with low iron stores, the intensity of duodenal villous staining for receptor, on a scale of 0-4, was 2.1 +/- 0.3 (mean +/- SD). This value was significantly higher than the value in 13 subjects with normal iron stores (1.1 +/- 0.4). In 5 patients with hereditary hemochromatosis, duodenal transferrin receptor staining was not significantly different from that in the subjects with normal iron stores. Transferrin staining was found in the apical cytoplasm of epithelial cells in the duodenum, ileum, and colon, but observer assessment was not sufficiently reproducible to make a quantitative analysis. Our results suggest that iron deficiency is accompanied by an increase in transferrin receptors in duodenal absorptive cells, and the genetic lesion in hemochromatosis does not involve an increase in transferrin receptors in the intestinal mucosa compared with subjects with normal iron stores.
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PMID:Transferrin receptors in the human gastrointestinal tract. Relationship to body iron stores. 301 5

We made direct noninvasive magnetic measurements of hepatic iron stores with a specially designed superconducting quantum-interference-device (SQUID) susceptometer in 20 normal subjects and in 110 patients with liver disease, iron deficiency, hereditary hemochromatosis, or transfusional iron overload. Magnetic in vivo measurements of liver non-heme iron were closely correlated with chemical in vitro measurements in liver-biopsy specimens (r = 0.98, P less than 10(-5) up to 115 mumol per gram of liver tissue (wet weight) or more. Magnetically determined storage-iron concentrations were below 6.0 mumol per gram in iron-deficient patients and normal men and premenopausal women, but they were raised (9.7 to 31.4 mumol) in 12 of 67 patients with liver disease and were greatly increased (22.9 to 117.7 mumol) in patients with untreated hereditary hemochromatosis or transfusional iron overload. Magnetic measurements of iron stores provide a new quantitative technique for early detection of hereditary hemochromatosis and for rapid evaluation of treatment regimens for transfusional iron overload.
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PMID:Magnetic-susceptibility measurement of human iron stores. 714 66

Iron status was assessed by measurement of serum (S-) ferritin and hemoglobin (Hb) in 548 randomly selected healthy Danes (264 men, 284 women) with a median age of 25 years (range 16-31). S-ferritin values in men displayed a gradual increase with age, and at all ages, men had higher values than women. Iron deficiency (i.e., S-ferritin < 16 micrograms/l) was observed in 0.8%; none had iron deficiency anemia (i.e., S-ferritin < 16 micrograms/l and Hb < 129 g/l). Daily iron supplementation was used by 15.5%. The frequency of iron deficiency was 0% in supplement users vs 0.9% in nonusers. The frequency of preclinical hereditary hemochromatosis was 0.38%. There was a slight insignificant increase in S-ferritin values of women with age. Iron deficiency was observed in 14.7% of 16- to 19-year-olds, in 9.2% of 20- to 24-year-olds, and in 8.6% of 25- to 31-year-old women (p < 0.01), and iron deficiency anemia (i.e., S-ferritin < 16 micrograms/l and Hb < 121 g/l) in 14.7%, 3.4%, and 3.7%, respectively (p < 0.01). Daily iron supplementation was used by 21.5%. The frequency of iron deficiency in users was 4.9% vs. 10.8% in nonusers, and the frequency of iron deficiency anemia 1.6% in users vs. 5.8% in nonusers. The results indicate a satisfactory iron status in young men. There is a high frequency of iron deficiency in young women, suggesting that preventive measures should be considered in this risk group.
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PMID:Iron status in young Danish men and women: a population survey comprising 548 individuals. 774 66

Female Wistar rats with slight iron deficiency anemia were kept on a diet containing 0.5% trimethylhexanoyl (TMH)-ferrocene for up to 79 weeks. In the state of iron deficiency, the heart was free of light-microscopically detectable iron. After 7 weeks of the TMH-ferrocene diet, the first iron-positive granules appeared in perivascular macrophages. Further oral administration caused a progression of iron deposition in these cells, visible in the form of a granular staining but also as a diffuse iron staining of the cytoplasm. Accordingly, at the electron-microscopical level, the iron was stored partly as free ferritin molecules in the cytosol, and partly in lysosomes in the form of ferritin and/or hemosiderin. After 11 weeks, further iron-positive cells with relatively small dark-blue granules were found in the vicinity of capillaries, which could be identified as fibrocytes by means of electron microscopy. In addition, slight iron deposition occurred in the endothelial cells of the cardiac capillaries, likewise mainly in the form of small, uniform siderosomes. The myocytes showed no product of Perls' Prussian blue reaction during the whole period of investigation. From the 11th week onwards, discrete ferritin molecules were detected electron microscopically within lysosomes of these cells. Their amount increased slowly with progression of the TMH-ferrocene feeding period. Free ferritin molecules could be observed in the cytosol of fibrocytes, endothelial cells and myocytes in only very slight concentrations, whilst they were more plentiful in macrophages. In hereditary hemochromatosis and posttransfusional siderosis, the iron is found predominantly in myocytes and appears to cause cell damage, whilst this is not the case in experimental iron overload in rats.
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PMID:Pattern of iron storage in the rat heart following iron overloading with trimethylhexanoyl-ferrocene. 797 87

Iron deficiency severe enough to cause anemia is associated with significant morbidity while uncontrolled iron absorption which occurs in disorders such as hereditary hemochromatosis causes multiorgan failure and early death. Preliminary data from the Third National Health and Nutrition Examination Survey demonstrate that the prevalence of iron deficiency anemia in the United States is now very low. This implies that the current iron consumption is adequate for most individuals. An important unresolved question relates to the necessity for further reducing the prevalence of iron deficiency without anemia. More information is required to determine whether this lesser degree of iron deficiency is harmful. Recent survey data indicate that concomitantly with the reduced prevalence of iron deficiency there has been a rise in serum ferritin concentrations in American men and postmenopausal women. These findings have led to concern about the effectiveness of the physiological mechanisms for limiting storage accumulation in normal individuals and carriers of the hemochromatosis gene when dietary iron content is high. Furthermore, recent epidemiological observations suggest that a modest increase in iron stores (in a range previously considered safe) is a possible risk factor for ischemic heart disease and cancer; however, a causal relationship remains to be proven. Nonetheless, because there is no known benefit of high iron storage status, it seems prudent to avoid further increases in and possibly to reduce the dietary iron intake of men and postmenopausal women. Mean intake in these groups exceeds the current RDA by a significant margin. Therefore, the sources of dietary iron as well as other factors contributing to high serum ferritin values have to be defined. Also, efforts should be made to increase the awareness of professionals and the public about the possible risks of excessive dietary iron. The complexity of the Western diet and an incomplete understanding of all of the factors affecting serum ferritin concentrations make it very difficult to specify a safe upper range for daily iron intake at the present time.
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PMID:Deliberations and evaluations of the approaches, endpoints and paradigms for iron dietary recommendations. 881 5

Hemodialysis patients treated with recombinant human erythropoietin (rhEPO) need adequate iron supplementation to avoid rhEPO hyporesponsiveness due to iron deficiency. Low serum ferritin reflects absolute iron deficiency, whereas normal or high ferritin values in combination with low transferrin saturation (< 20%) indicate functional iron deficiency. In this study, healthy subjects (group I) were compared with intravenous (i.v.) rhEPO-treated and i.v. iron-saccharate-treated regular hemodialysis patients that were subdivided into three groups as follows: patients with serum ferritin > 100 and < 350 micrograms/L (group II), patients with ferritin < 60 micrograms/L (group III), and patients with ferritin > 650 micrograms/L but transferrin saturation < 20% (group IV). Polymorphonuclear leukocyte (PMNL) parameters (phagocytosis, intracellular killing of bacteria, oxidative metabolism, glucose uptake, intracellular calcium) for each group were compared with those of multitransfused, iron-overloaded primary hematologic patients (group V) and those of patients suffering from hereditary hemochromatosis (group VI). Compared with PMNL obtained from healthy subjects (group I), group II hemodialysis patients showed mild inhibition of phagocytosis but significant inhibition of intracellular killing of bacteria. Oxidative burst of PMNL from group II patients was also significantly reduced after stimulation in vitro. These dysfunctions were not affected by absolute iron deficiency (comparable data in group III patients). However, impairment of PMNL was markedly aggravated in group IV patients. Intracellular calcium concentration under basal conditions and after stimulation was not different. These data suggest that iron is responsible for the PMNL dysfunctions observed in group IV patients. The PMNL defect of group IV patients was comparable to group V and group VI patients with normal renal function, suggesting again a direct inhibitory effect of iron. It is concluded that hemodialysis patients with high ferritin but low serum iron and low transferrin saturation ("functional iron deficiency") display a significant impairment of fundamental PMNL functions during i.v. iron and rhEPO therapy. This may result in increased risk of infectious complications. Therefore, overtreatment of hemodialysis patients with i.v. iron should be avoided.
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PMID:Neutrophil impairment associated with iron therapy in hemodialysis patients with functional iron deficiency. 955 68

HFE is a non-typical MHC class 1-type protein that is mutated in hereditary hemochromatosis. The purpose of this study was to identify possible splice variants of HFE mRNA and investigate the regulation of these isoforms in duodenum and liver of patients with normal and altered iron stores. RT-PCR was performed using HFE specific primers and duodenal RNA obtained from patients with hemochromatosis, iron deficiency, secondary iron overload and normal controls. The reaction products were visualized by Southern blot and identified by DNA sequence analysis. Additional studies were performed on RNA isolated from liver and a range of human tissues. A truncated (soluble) form of HFE protein was identified that lacks the transmembrane domain and occurs as a result of alternative splicing. Soluble HFE was found predominantly in the duodenum, spleen, breast, skin and testicle. In hereditary hemochromatosis full length HFE was the predominant isoform present in the duodenum similar to iron deficiency. Alternate splicing produces soluble HFE that may have a unique function to regulate cellular iron transport.
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PMID:Alternate splicing produces a soluble form of the hereditary hemochromatosis protein HFE. 1034 14

Reference values for two ferritin assays (Tina-quanta Ferritin, Enzymun, both Roche Diagnostics, Mannheim, Germany) were established (136 males and 139 females). To rule out inflammation as well as iron deficiency in the reference population, subjects with the C-reactive protein concentration < 5 mg/l, and zinc protoporphyrin < 40 micromol/mol heme and the soluble transferrin receptor < 3 mg/l were selected. Taking into account latent iron deficiency as well as hereditary hemochromatosis the 5-95 percentile range was as follows: male, 27-365 microg/l; female, 13-148 microg/l for Tina-quanta and 12-151 microg/l for Enzymun. The Tina-quanta Ferritin assay showed a very good correlation (r > or = 0.990) to Enzymun ferritin, Ferritin Abbott (Abbott Diagnostics, Delkenheim, Germany), N Latex Ferritin (Dade Behring, Marburg, Germany) and the Ferritin Chiron (Chiron Diagnostics, Fernwald, Germany). However, the slopes of the standard principal component method analysis were calculated to be between 1.03 (Enzymun) and 1.41 (N Latex Ferritin). For four assays the median recovery of the 3rd International Recombinant Ferritin Standard (NIBSC 94/572) measured by serial dilution was 89-109%. The N Latex Ferritin assay recovered half of the target values. Because of the good correlation with other assays, a matrix effect is likely. The question arises whether the manufacturers' agreement on the recombinant ferritin standard would harmonize ferritin measurement.
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PMID:Reference values for a homogeneous Ferritin assay and traceability to the 3rd International Recombinant Standard for Ferritin (NIBSC code 94/572). 1053 31


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