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PubMed1985

Efficient clearance of non-transferrin-bound iron by rat liver. Implications for hepatic iron loading in iron overload states.

In hemochromatosis and other disorders associated with iron overload, a significant fraction of the total iron in plasma circulates in the form of low molecular weight complexes not bound to transferrin. Efficient and unregulated clearance of this form of iron by the liver may account for the hepatic iron loading and toxicity that characterize these diseases. We tested this possibility by examining the hepatic removal process for representative iron complexes in the single-pass perfused rat liver. Hepatic uptake of both ferrous and ferric 55Fe from ultrafiltered human serum was found to be highly efficient and effectively irreversible (single-pass extraction of 1 microM iron, 58-75%). Similar high efficiencies were seen for iron complexed to specific physiologic and nonphysiologic coordinators, including histidine, citrate, fructose, oxalate and glutamate, and tricine. Because of lower plasma flow rates, single-pass extraction of these iron complexes in vivo should be even greater. Autoradiography confirmed that most iron had been removed by parenchymal cells. Hepatic removal from Krebs-tricine buffer was saturable with similar kinetic parameters for ferrous and ferric iron (apparent Km, 14-22 microM; V max, 24-38 nmol min-1 g liver-1). These findings suggest that high levels of non-transferrin-bound iron in plasma may be an important cause of hepatic iron loading in iron overload states.

Anaerobiosis↗

PubMed1984

Iron metabolism and "sports anemia". I. A study of several iron parameters in elite runners with differences in iron status.

Several reports have suggested that iron deficiency might explain "sports anemia" especially in long distance runners. The present study was made to further study the iron metabolism in runners as the proposed cause of "sports anemia" is abstruse considering the good iron nutrition in these athletes. Based on a screening of 43 elite male runners, using bone marrow hemosiderin, serum ferritin and transferrin saturation, two groups of subjects were selected for a very extensive study on iron metabolism. In group 1 (n = 5) iron depletion was suggested in at least one of the screening studies. In group 2 (n = 7) at least one test strongly indicated good iron repletion. This experimental design was chosen to obtain two groups with similar body composition and exercise load but different iron metabolism. The studies comprised determinations of red cell and plasma volumes, plasma iron turnover and red cell incorporation of radioiron, red cell indices, plasma iron and transferrin, red cell protoporphyrin, serum ferritin, serum haptoglobin, urinary iron losses, iron absorption, bone marrow hemosiderin, dietary intake of energy and nutrients and a Desferal test. Pooling the results together it was obvious that none of the subjects were truly iron-deficient. A few occasional findings suggesting low iron stores cannot be satisfactorily explained and indicate that further studies are needed.

Adult↗

PubMed2004

Transcription of the yeast iron regulon does not respond directly to iron but rather to iron-sulfur cluster biosynthesis.

Saccharomyces cerevisiae responds to iron deprivation by increased transcription of the iron regulon, including the high affinity cell-surface transport system encoded by FET3 and FTR1. Here we demonstrate that transcription of these genes does not respond directly to cytosolic iron but rather to the mitochondrial utilization of iron for the synthesis of iron-sulfur (Fe-S) clusters. We took advantage of a mutant form of an iron-dependent enzyme in the sterol pathway (Erg25-2p) to assess cytosolic iron levels. We showed that disruption of mitochondrial Fe-S biosynthesis, which results in excessive mitochondrial iron accumulation, leads to transcription of the iron transport system independent of the cytosolic iron level. There is an inverse correlation between the activity of the mitochondrial Fe-S-containing enzyme aconitase and the induction of FET3. Regulation of transcription by Fe-S biosynthesis represents a mechanism by which cellular iron acquisition is integrated with mitochondrial iron metabolism.

Aconitate Hydratase↗

PubMed1998

Reduction of soluble iron and reductive dissolution of ferric iron-containing minerals by moderately thermophilic iron-oxidizing bacteria

Five moderately thermophilic iron-oxidizing bacteria, including representative strains of the three classified species (Sulfobacillus thermosulfidooxidans, Sulfobacillus acidophilus, and Acidimicrobium ferrooxidans), were shown to be capable of reducing ferric iron to ferrous iron when they were grown under oxygen limitation conditions. Iron reduction was most readily observed when the isolates were grown as mixotrophs or heterotrophs with glycerol as an electron donor; in addition, some strains were able to couple the oxidation of tetrathionate to the reduction of ferric iron. Cycling of iron between the ferrous and ferric states was observed during batch culture growth in unshaken flasks incubated under aerobic conditions, although the patterns of oxidoreduction of iron varied in different species of iron-oxidizing moderate thermophiles and in strains of a single species (S. acidophilus). All three bacterial species were able to grow anaerobically with ferric iron as a sole electron acceptor; the growth yields correlated with the amount of ferric iron reduced when the isolates were grown in the absence of oxygen. One of the moderate thermophiles (identified as a strain of S. acidophilus) was able to bring about the reductive dissolution of three ferric iron-containing minerals (ferric hydroxide, jarosite, and goethite) when it was grown under restricted aeration conditions with glycerol as a carbon and energy source. The significance of iron reduction by moderately thermophilic iron oxidizers in both environmental and applied contexts is discussed.

Journal Article↗

PubMed1994

Liver iron quantification: studies in aqueous iron solutions, iron overloaded rats, and patients with hereditary hemochromatosis.

For the noninvasive liver iron quantification by MRI in human iron overload diseases, fundamental proton relaxation mechanisms were studied in aqueous solutions with ferritin and other iron compounds, in experimentally iron overloaded rats, and in patients with iron overload diseases. MR-relaxation rates as a function of iron concentrations in the range of 0-7.5 mg Fe/g aqueous iron solutions, 0-5.4 mg Fe/g rat liver in vivo, and 0.16-4.9 mg Fe/g human liver in vivo were determined from multi- and sets of single-spin echo sequences (1.5 T imager). As predicted by theory, transverse relaxation rates (1/T2) in aqueous iron solutions, in liver tissue of rats, and in human liver tissue increased linearly with the iron concentration. A preliminary calibration for the liver iron quantification by MRI was performed from in vivo measurements of liver 1/T2-relaxation rates and liver iron quantification by atomic absorption spectroscopy in biopsies from 13 patients. With the single spin-echo method, precise in vivo liver iron quantification in humans also above 2.0 mg Fe/g liver tissue (T2 < 15 ms) should be accomplished on any imager with shortest spin-echo time available, at least TE < 20 ms.

Adult↗

PubMed2004

Iron fortification and iron supplementation are cost-effective interventions to reduce iron deficiency in four subregions of the world.

Iron deficiency is the most common and widespread nutritional disorder in the world, affecting millions of people in both nonindustrialized and industrialized countries. We estimated the costs, effects, and cost-effectiveness of iron supplementation and iron fortification interventions in 4 regions of the world. The effects on population health were arrived at by using a population model designed to estimate the lifelong impact of iron supplementation or iron fortification on individuals benefiting from such interventions. The population model took into consideration effectiveness, patient adherence, and geographic coverage. Costs were based on primary data collection and on a review of the literature. At 95% geographic coverage, iron supplementation has a larger impact on population health than iron fortification. Iron supplementation would avert <12,500 disability adjusted life years (DALY) annually in the European subregion, with very low rates of adult and child mortality, to almost 2.5 million DALYs in the African and Southeast Asian subregions, with high rates of adult and child mortality. On the other hand, fortification is less costly than supplementation and appears to be more cost effective than iron supplementation, regardless of the geographic coverage of fortification. We conclude that iron fortification is economically more attractive than iron supplementation. However, spending the extra resources to implement iron supplementation is still a cost-effective option. The results should be interpreted with caution, because evidence of intervention effectiveness predominantly relates to small-scale efficacy trials, which may not reflect the actual effect under expected conditions.

Anemia, Iron-Deficiency↗

PubMed2005

Effect of postpartum iron supplementation on red cell and iron parameters in non-anaemic iron-deficient women: a randomised placebo-controlled study.

OBJECTIVE: To investigate the effect of oral iron on postpartum red cell and iron parameters in non-anaemic women with iron deficiency. DESIGN: Randomised study of supplementation with oral iron sulphate 80 mg daily or placebo for 12 weeks starting 24-48 hours after delivery, with visits antepartum and 1, 4, 6 and 12 weeks postpartum. SETTING: Swiss university hospital obstetric unit. PARTICIPANTS: Fifty-two women with antenatal iron deficiency (serum ferritin <15 microg/L) and no antenatal or postnatal anaemia (haemoglobin >11 g/dL up to 48 hours before delivery, and >10 g/dL postpartum), divided into two groups comparable in antenatal iron status. METHODS: Supplementation was started 24-48 hours after delivery (visit 1:V1). Additional tablets were issued one week after V1 (V2), four weeks after V1 (V3) and six weeks after V1 (V4). The last visit took place 12 weeks after visit 1 and 6 weeks after visit 4 (V5). Patients were required to return blisters and boxes whether they were used and unused at each visit and compliance was assessed by counting the tablets. Blood samples for haematology and iron status testing were taken before delivery and at each visit. MAIN OUTCOME MEASURES: Iron status (serum ferritin, hypochromic red cells, iron, transferrin saturation, soluble transferrin receptor concentration); erythropoiesis (standard parameters, including reticulocyte indices); and inflammatory response (serum neopterin, C-reactive protein, white cell count) in five-datapoint profiles. RESULTS: Increased ferritin (P= 0.0004) and transferrin saturation (P= 0.03), decreased soluble transferrin receptors (P= 0.02); increased haemoglobin (P= 0.02) and decreased hypochromic red cells (P= 0.04) compared with placebo at 12 weeks, with no differences in other red cell or reticulocyte parameters. There was a positive correlation between C-reactive protein and postpartum ferritin. No correlation was observed in the puerperium between C-reactive protein and hypochromic red cells or soluble transferrin receptors. CONCLUSIONS: Haemoglobin levels and iron stores in women with term gestational iron deficiency benefit significantly from iron supplementation compared with placebo, even in an industrialised population.

Administration, Oral↗

PubMed1979

Iron and the liver: subcellular distribution of iron and decreased microsomal cytochrome P-450 in livers of iron-loaded rats.

To understand better the intracellular iron distribution and metabolic consequences of chronic hepatic iron overload, rats were given large doses of iron dextran or ferric citrate intraperitoneally. They accumulated large quantities of iron within Kupffer cells and hepatocytes. The relative subcellular iron distributions were similar in controls and iron-loaded rats, despite a ten- to 20-fold difference in hepatic iron concentration. Electron microscopy of whole liver and subcellular particulate fractions suggested that iron was present in highest concentration in lysosomes, which were rendered more labile by its presence. Nevertheless, quantitative iron determinations on all subcellular fractions, obtained by two preparative methods, showed that most of the iron was present in the "soluble" fraction. The amount of iron in the "microsomal" fraction varied, depending on the techniques used for preparation of this fraction. Cytochrome P-450 and total heme concentrations were decreased 40% to 50% in microsomes isolated from iron-loaded livers.

Animals↗

PubMed1987

Bioavailability of bi- and trivalent oral iron preparations. Investigations of iron absorption by postabsorption serum iron concentrations curves.

Since 1977 the bioavailability of 14 bi- and trivalent oral iron preparations has been investigated in five separate orientated clinical studies by using postabsorption serum iron concentration curves. The range of relative bioavailability was 46 to 100% in the first group of preparations, 31 to 47% in the second group and 6 to 29% in the third group. The first group contained mainly bivalent quick release preparations, the second group slow or sustained release preparations and the third mainly trivalent iron preparations. The postabsorption serum iron concentration curves which show a good congruence with exact 59Fe whole body retention tests again confirmed the nearly 50-year-old rule that bivalent iron is up to 16 times better absorbed than trivalent iron. There is no doubt that the oral iron preparations of good bioavailability are able to cure an iron deficiency more rapidly than iron preparations with a low bioavailability. This therefore has a clear influence on the overall expense of iron therapy. Only those preparations from the first group can be recommended for oral iron therapy. The preparations in the second group are less suitable and those in the third group should be excluded from iron therapy in all countries.

Administration, Oral↗

PubMed2003

Comparison of response between food supplemented with powdered iron and iron in syrup form for iron deficiency anemia.

OBJECTIVE: To evaluate and compare the response between food supplemented with iron in powdered and iron in syrup forms for the treatment of iron deficiency anemia in children aged 1-5 years. DESIGN: Quasi-experimental study. PLACE AND DURATION OF STUDY: This study was conducted at Combined Military Hospital, Multan, from January 2000 to December 2000. PATIENTS AND METHODS: Consecutive 200 cases of iron deficiency anemia, aged 1-5 years, were included in the study. Diagnosis was based on history, physical examination, complete blood counts (CBC) and serum ferritin levels. The patients were randomized to receive either iron in syrup form (Group A) or equivalent doses of iron powder sprinkled over food (Group B). The patients were followed up with hemoglobin estimation (Hb) and reticulocyte response at 2 weeks, 4 weeks and 6 weeks. CBC and serum ferritin were repeated at 6 weeks. RESULTS: Over half (51%) of the patients were between 1-2 years of age. One hundred thirty-two were males and 68 females. Most of the patients belonged to poor socioeconomic class. The iron in powder form was better tolerated than iron syrup as this group witnessed fewer episodes of gastrointestinal disturbances. The rise in mean Hb level after 6 weeks of treatment in group A and B was 1.6 g/dl and 1.9 g/dl respectively. Hemoglobin rise in group B was more than group A but this was statistically non-significant (p > 0.05). There was small but significant (p < 0.05) rise in serum ferritin in both the groups. There was no significant difference between the two groups for response to the two forms of iron administration. CONCLUSION: The powdered form of iron is a cost-effective and better tolerated method of iron administration in children and can be considered as an alternate option for the treatment of iron deficiency anemia in children.

Administration, Oral↗

PubMed1989

Studies of iron:zinc interactions in adult rats and the effect of iron fortification of two commercial infant weaning products on iron and zinc status of weanling rats.

The effect of iron on zinc absorption in the rat, and vice versa, was investigated from single starch:sucrose test meals (containing 65Zn or 59Fe) by whole body counting. Zinc had no effect on iron absorption, but iron reduced zinc absorption when the total ionic species in the meal (iron plus zinc) reached 1.36 mg. Below this level, high iron:zinc molar ratios (10:1) had no effect on zinc absorption, presumably because the transport mechanism for zinc had not reached full capacity. Previous iron intake had no effect on zinc absorption. The relevance of these findings to infant foods was explored by feeding rats exclusively a vegetable or cereal weaning product, with or without additional iron, for 12 d and measuring zinc and iron status. The added iron raised body iron stores and caused a small reduction in zinc status in animals fed the oat, but not the vegetable, diet as measured by plasma and femur zinc concentrations. Since the threshold level of 1.36 mg ionic species would be exceeded when the animal ate 3-4 g of the iron-fortified weaning food at any one time, it appears that the iron:zinc interactive effect was absent in the vegetable and less potent in the oat formulation than in a carbohydrate test meal. Alternatively, it may be the case that the animals had responded over time to reduced zinc availability by increasing whole body zinc retention.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorption↗

PubMed2006

Weekly low-dose treatment with intravenous iron sucrose maintains iron status and decreases epoetin requirement in iron-replete haemodialysis patients.

BACKGROUND: Haemodialysis patients need sustained treatment with intravenous iron because iron deficiency limits the efficacy of recombinant human epoetin therapy in these patients. However, the optimal intravenous iron maintenance dose has not been established yet. METHODS: We performed a prospective multicentre clinical trial in iron-replete haemodialysis patients to evaluate the efficacy of weekly low-dose (50 mg) intravenous iron sucrose administration for 6 months to maintain the iron status, and to examine the effect on epoetin dosage needed to maintain stable haemoglobin values in these patients. Fifty patients were enrolled in this prospective, open-label, single arm, phase IV study. RESULTS: Forty-two patients (84%) completed the study. After 6 months of intravenous iron sucrose treatment, the mean ferritin value showed a tendency to increase slightly from 405 +/- 159 at baseline to 490 +/- 275 microg/l at the end of the study, but iron, transferrin levels and transferrin saturation did not change. The haemoglobin level remained stable (12 +/- 1.1 at baseline and 12.1 +/- 1.5 g/dl at the end of the study). The mean dose of darbepoetin alfa could be reduced from 0.75 to 0.46 microg/kg/week; epoetin alfa was decreased from 101 to 74 IU/kg/week; and the mean dose of epoetin beta could be reduced from 148 to 131 IU/kg/week at the end of treatment. CONCLUSIONS: A regular 50 mg weekly dosing schedule of iron sucrose maintains stable iron stores and haemoglobin levels in haemodialysed patients and allows considerable dose reductions for epoetins. Low-dose intravenous iron therapy may represent an optimal approach to treat the continuous loss of iron in dialysis patients.

Adolescent↗

PubMed2002

Comparative study--efficacy, safety and compliance of intravenous iron sucrose and intramuscular iron sorbitol in iron deficiency anemia of pregnancy.

OBJECTIVE: (1) To determine an alternative iron supplementation with better efficacy, compliance & safety in treatment of iron deficiency anemia during pregnancy, (2) to reduce blood transfusion during pregnancy, labor and puerperium. MATERIAL AND METHOD: A prospective comparative study. A total number of 60 pregnant women with the gestational age of 12-34 weeks were included in the study who were suffering from iron deficiency anemia. They were divided in 3 groups (A, B and C). Group A (n = 15) received intravenous iron sucrose according to recommended dose containing 500 mg of iron sucrose for storage, in group B (n = 20) iron sucrose was administered according to deficit calculated as per formula but 200 mg of iron was given for storage instead of 500 mg, to reduce cost. While group C received intra muscular iron Sorbitol in the dose used as practice. RESULTS: Mean hemoglobin in group A and B was 8.0 +/- 1.1 g/dl and 8.9 +/- 0.7 respectively, in group C, it was 8.8 +/- 0.9 g/dl. In group A & B initial hemoglobin was assessed 3 weeks post therapy which showed an average rise of 2.8 g/dl (group A) and 1.9 g/dl (group B) and second assessment of Hemoglobin was done prior to delivery (ave: 6.6 weeks) showed a total rise of 3.8 g/dl (group A) and 2.4 g/dl (group B). Pre delivery mean Hemoglobin in group A and B was 11.8 g/dl and 11.3 g/dl respectively. In group C, the Hemoglobin was assessed only prior to delivery (average: 8.4 weeks from the start of therapy), and a rise of 1.4 g/dl was observed with pre delivery mean Hemoglobin of 10.2 g/dl. Target hemoglobin levels i.e. 11 g/dl was achieved by 80% in Group A, 70% in Group B and 28% in Group C by the time of delivery. Blood transfusion was not required in any group. In group A and B one patient had moderate abdominal pain, 2 had weakness and shivering and 3 had phlebitis at the site where intravenous canula was retained. None of patient discontinued the therapy due to any adverse effect. In group C majority complained of pain at injection site while 5 patients dropped out from the study due to intolerance. CONCLUSION: Intravenous iron therapy is safe, convenient and more effective then intramuscular iron therapy in treatment of iron deficiency anemia during pregnancy. The intravenous iron therapy can replace blood transfusion in antenatal period.

Adult↗

PubMed2005

[Iron concentration and acceptation of yoghurt prepared in casting iron pots (iron migration and acceptation of yogurt)].

Food fortification is an interesting strategy to treat and prevent iron anemia. This study aims to quantify the iron in yoghurt, with gelatin and sugar and without, prepared in iron and glass containers. Sensorial test was use to evaluate the acceptance and preference of the both products. The yoghurt was prepared in containers of iron and glass with UHT milk, powder milk and natural industrialized yoghurt. After fermentation, half of the product received addition of sugar and strawberry flavor gelatin. The collected samples get the total iron quantified by ICP OES. Sensorial analysis involving 105 consumers was use to determine the acceptance and preference of the products. 0,018 and 0,882mg of iron per 100g added in the natural yoghurt prepared in the glass and in the iron pots, respectively. The yoghurt with gelatin presented 0,037 and 1,302mg of iron per 100g when prepared in the glass and in the iron pots, respectively. The preference was low for the yoghurt prepared in the iron pot (29,5%), but when added strawberry gelatin it was about 51,5%. The yoghurt prepared in iron pots, is easily home made and adds important amount of iron. Add gelatin and sugar can favored its consumption.

Carbohydrates↗

PubMed1998

Iron, lactoferrin and iron regulatory protein activity in the synovium; relative importance of iron loading and the inflammatory response.

OBJECTIVES: To determine the ability of lactoferrin in rheumatoid arthritis (RA) synovial fluid to bind "free" iron, and to study the regulatory mechanisms therein that control iron homeostasis. METHODS: "Free" iron was determined by the bleomycin assay and lactoferrin concentrations by enzyme linked immunosorbent assay. The activities of iron regulatory protein (IRP) and NF-kappa B in synovial fluid cells were assayed by mobility shift assay. RESULTS: 30% of synovial fluids contained "free" iron and in these, lactoferrin concentrations were significantly lower than in those with no "free" iron (p < 0.01). Addition of exogenous lactoferrin consistently reduced the amount of "free" iron in positive synovial fluids. IRP activity in synovial cells did not correlate with synovial fluid iron concentrations but did correlate with NF-kappa B activation and with serum C reactive protein. CONCLUSION: Lactoferrin may prevent iron mediated tissue damage in RA by reducing "free" synovial iron concentration when inflammatory stimuli have disregulated IRP mediated iron homeostasis.

Adult↗

PubMed1999

Yeast mitochondrial protein, Nfs1p, coordinately regulates iron-sulfur cluster proteins, cellular iron uptake, and iron distribution.

Nfs1p is the yeast homolog of the bacterial proteins NifS and IscS, enzymes that release sulfur from cysteine for iron-sulfur cluster assembly. Here we show that the yeast mitochondrial protein Nfs1p regulates cellular and mitochondrial iron homeostasis. A strain of Saccharomyces cerevisiae, MA14, with a missense NFS1 allele (I191S) was isolated in a screen for altered iron-dependent gene regulation. This mutant exhibited constitutive up-regulation of the genes of the cellular iron uptake system, mediated through effects on the Aft1p iron-regulatory protein. Iron accumulating in the mutant cells was retained in the mitochondrial matrix while, at the same time, iron-sulfur proteins were deficient. In this work, the yeast protein was localized to mitochondria, and the gene was shown to be essential for viability. Furthermore, Nfs1p in the MA14 mutant was found to be markedly decreased, suggesting that this low protein level produced the observed regulatory effects. This hypothesis was confirmed by experiments in which expression of wild-type Nfs1p from a regulated galactose-induced promoter was turned off, leading to recapitulation of the iron regulatory phenotypes characteristic of the MA14 mutant. These phenotypes include decreases in iron-sulfur protein activities coordinated with increases in cellular iron uptake and iron distribution to mitochondria.

Amino Acid Sequence↗

PubMed2004

Response of soluble transferrin receptor and iron-related parameters to iron supplementation in elite, iron-depleted, nonanemic female athletes.

OBJECTIVES: To assess the effect of short-term iron supplementation on soluble transferrin receptor (sTfR) and the soluble transferrin receptor/log ferritin ratio in a group of elite, iron-depleted, nonanemic female athletes and to assess the relationship between soluble transferrin receptor and serum ferritin in a group of elite, iron-depleted female athletes. DESIGN: A prospective, interventional study and an observation at 1 point in time. The primary inclusion criteria for each component of the study was serum ferritin less than 30 ng/mL and hemoglobin greater than 12 g/dL. The exclusion criteria were use of iron supplementation within 1 month of the initial assessment, acute or chronic infectious or inflammatory disease, hematological disorders, and recent musculoskeletal injury. SETTING: The Department of Sports Medicine at the Australian Institute of Sport. SUBJECTS: For the prospective study, 51, and for the observational study, 85 elite, iron-depleted (serum ferritin <30 ng/mL), nonanemic (hemoglobin <12 g/dL for the prospective study only) female athletes. Athletes were participants at the elite level in netball, basketball, gymnastics, rowing, volleyball, track and field, soccer, sailing, and cricket. INTERVENTION: Ingestion of 1 iron tablet (325 mg dried ferrous sulfate, equivalent to 105 mg elemental iron) plus one 500-mg tablet of vitamin C each morning for 60 days. RESULTS: Following supplementation, the following changes were statistically significant. Serum ferritin increased (19.7 to 37.4 ng/mL; P < 0.00005), serum transferrin decreased (3.34 to 3.16 g/L; P = 0.023), sTfR decreased (3.46 to 3.16 mg/L; P = 0.006), and sTfR/log ferritin index decreased (1.34 to 1.00; P < 0.00005). If it is assumed that iron stores are depleted when serum ferritin is less than 12 ng/mL and that sTfR could be expected to be elevated below that level of serum ferritin, the following figures can be calculated for the value of sTfR in relation to absent iron stores: sensitivity, 33%; specificity, 96%; positive predictive value, 50%; and negative predictive value, 92%. CONCLUSIONS: Short-term iron supplementation increases iron stores and leads to reductions in sTfR and the sTfR/log ferritin index in elite female athletes. sTfR is not an accurate predictor of serum ferritin less than 12 ng/mL in this group.

Adolescent↗

PubMed1999

Low-dose oral iron absorption test in anaemic patients with and without iron deficiency determined by bone marrow iron content.

The low-dose oral iron absorption test (OIAT) was performed in 85 consecutive anaemic patients referred for bone marrow examination in order to investigate the ability of the test to predict bone marrow iron stores and to differentiate between different categories of anaemia. Eight patients were excluded for technical reasons. Test results from 77 patients are presented as Cmax (micromol/l): the maximum increase in S-iron measured during a 3 h period after administration of 10 mg oral iron sulfate. Iron deficiency was defined as the absence of stainable iron in bone marrow aspirates. Cmax was higher in 46 iron deficient patients [3 (median); 0 and 13 (1st and 3rd quartiles); 0-40 (range)] than in 31 non-iron-deficient patients (0; 0 and 2; 0-4) (P<0.01). 27 patients had primary bone marrow disease, 25 patients had absent bone marrow iron stores accompanied by inflammation, 17 patients had anaemia of chronic disease (ACD) and 8 patients had uncomplicated iron deficiency anaemia (IDA). Patients with IDA had higher Cmax (15; 13 and 28; 6-40) than patients with ACD (1; 0 and 2; 0-3), and than the 69 non-IDA patients (1; 0 and 3; 0-19) (P<0.001). Cmax values above 5 micromol/l always indicated absent bone marrow iron stores.

Adult↗