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

The aims of this study were to diagnose iron-restricted erythropoiesis (functional iron deficiency) in patients with classic iron deficiency (ID), anemia of chronic disease (ACD) and the combined state of ID/ACD with the use of two hematological methods for the measurement of reticulocyte hemoglobinization. In comparison, the biochemical markers of iron status were determined. We studied 474 anemic patients admitted to hospital with a broad spectrum of diseases. We measured indicators of reticulocyte hemoglobinization. CHr was determined on an Advia 120 hematology analyzer. A Sysmex XE-2100 hematology analyzer was used to determine RET-Y, the forward scatter of fluorescence-labeled reticulocytes, which can also be expressed as the reticulocyte hemoglobin equivalent (RET-H(e)), as well as RBC-Y, the forward scatter of fluorescence-labeled erythrocytes, which can be expressed as the erythrocyte hemoglobin equivalent. Ferritin, soluble transferrin receptor (sTfR) and the sTfR/log ferritin ratio (sTfR-F index) were used as biochemical markers. The comparison of RET-Y with CHr demonstrated an excellent curvilinear relationship between the two parameters. The normal reference range for Ret-Y was 1630-1860 arbitrary units (AU); mathematical transformation to RET-H(e) gave a range of 28.2-35.7 pg. Correlations of biochemical iron markers with RET-H(e) were as weak as with CHr in patients with ACD and acute phase response. In a diagnostic plot to identify iron status, RET-H(e) could replace CHr without any loss of sensitivity or specificity. Patient mismatch analysis between RET-H(e) and CHr in the diagnostic plot demonstrated agreement for 449 of 474 patients (94.4%). Patient specific anemia mismatches were 2.9-6.2%. According to our results, the indicators of reticulocyte hemoglobinization, RET-H(e) and CHr, measure the same phenomenon. RET-H(e) is as valuable as CHr for the diagnosis of iron-restricted erythropoiesis. The combination of RET-H(e) and the sTfR-F index in a diagnostic plot offers an attractive tool for the evaluation of iron status and identification of the progression of ID.
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PMID:Reticulocyte hemoglobin measurement--comparison of two methods in the diagnosis of iron-restricted erythropoiesis. 1623 85

Soluble transferrin receptor (sTfR) is a biochemical parameter used for the detection of iron deficiency in situations where ferritin has limited diagnostic value owing to the present chronic disease. The sTfR concentration was determined in 118 patients divided according to their inflammatory status and underlying disease into groups of patients with iron-deficiency anemia (IDA), anemia of chronic disease (ACD) and patients with a coexisting state of iron deficiency and anemia of chronic disease (ID+ACD). All patients with iron deficiency had elevated sTfR levels, but ferritin concentrations were normal or increased in patients with inflammatory characteristics. Diagnostic efficiencies of sTfR, sTfR/log ferritin index (sTfR/F) and ferritin were evaluated by receiver operating characteristic curve (ROC) analysis. According to the results obtained, the best diagnostic efficiency for differential diagnosis of anemic patients with iron deficiency compared to the control group had a sTfR concentration (0.884) that was significantly higher than ferritin (0.638), but not higher than the calculated ratio sTfR/F (0.820). The cut-off value of the sTfR/F index differentiating the best control group from the IDA and ID+ACD groups was 1.30, and for differentiation of ACD from IDA and ID+ACD, the value was 0.90. Soluble transferrin receptor is an additional parameter to ferritin for the diagnosis of IDA and differential diagnosis of ID+ACD, but calculation of the sTfR/F index did not improve the diagnostic value of determining sTfR alone.
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PMID:Usefulness of soluble transferrin receptor and ferritin in iron deficiency and chronic disease. 1627 88

Recent positional cloning of the radiation-induced polycythaemia (Pcm) mutation revealed a 58-bp microdeletion in the promoter region of ferroportin 1 (Fpn1), the sole cellular iron exporter identified to date. Here we report a molecular definition of the regulatory mechanisms governing the dynamic changes in iron balance in Pcm heterozygous mice between 3 and 12 weeks of age. Hepatic and/or duodenal response patterns of iron metabolism genes, such as Trfr, cybrd1, and Slc11a2, explained the transition from early postnatal iron deficiency to iron overload by 12 weeks of age. A significant delay in developmental up-regulation of hepcidin (Hamp), the pivotal hormonal regulator of iron homeostasis, correlated with high levels of Fpn1 expression in hepatic Kupffer cells and duodenal epithelial cells at 7 weeks of age. Conversely, upon up-regulation of Hamp expression at 12 weeks of age, Fpn1 expression decreased, indicative of a Hamp-mediated homeostatic loop. Hamp regulation due to iron did not appear dependent on transcription-level changes of the murine homolog of Hemojuvelin (Rgmc). Aged cohorts of Pcm mice exhibited low levels of Fpn1 expression in the context of an iron-deficient erythropoiesis and profound iron sequestration in reticuloendothelial macrophages, duodenum, and other tissues. Thus, similar to the anemia of chronic disease, these findings demonstrate decreased iron bioavailability due to sustained down-regulation of Fpn1 levels by Hamp. We conclude that regulatory alleles, such as Pcm, with highly dynamic changes in iron balance are ideally suited to interrogate the genetic circuitry regulating iron metabolism.
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PMID:The molecular circuitry regulating the switch between iron deficiency and overload in mice. 1641 70

Iron balance is regulated by the rate of erythropoiesis and the size of the iron stores. Anemia that accompanies infection, inflammation, and cancer (anemia of chronic disease) features normal or increased iron stores, although patients may have functional iron deficiency, namely, an imbalance between iron requirements of the erythroid marrow and the actual supply. The proportion of hypochromic red cells and the hemoglobin content of reticulocytes are direct indicators of functional iron deficiency. Biochemical markers, especially the soluble transferrin receptor/log ferritin ratio (ferritin index), are useful indicators of the iron supply to erythropoiesis. The relationship between functional iron deficiency (reticulocyte hemoglobin content) and iron supply to erythropoiesis (ferritin index) can be described in a diagnostic plot. In normoproliferative and hypoproliferative erythropoiesis, the plot allows the differentiation of classic iron deficiency from anemia of chronic disease and the combined state of functional iron deficiency with anemia of chronic disease. The therapeutic implications of the plot are to differentiate patients into those who should be administered iron supplements, epoetin, or a combination of epoetin and iron. In patients receiving epoetin therapy, the plot is an important tool for monitoring erythropoietic activity, functional iron deficiency, and adequate iron stores for new red cell production. Enhanced erythropoiesis is reflected quantitatively by the ferritin index vector. A transgression of the 1.5 (3.2) cut-off value for the ferritin index indicates that extra doses of iron need to be administered to increase the body's iron stores. A lack of increase or a reticulocyte hemoglobin content below 28 picograms indicates functional iron deficiency. The diagnostic plot is a model for differentiating iron-deficient states and predicting those patients who will respond to epoetin therapy.
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PMID:The diagnostic plot: a concept for identifying different states of iron deficiency and monitoring the response to epoetin therapy. 1664 27

Hepcidin is a small cystein-rich cationic peptide produced mainly by the liver. It was initially isolated from human plasma and exhibited antimicrobial activity. Recently, several lines of evidence have suggested that hepcidin is a key regulator of iron metabolism at the whole body level and is relative to inflammation, infection, hypoxia and anemia. Hepcidin, is implicated in duodenal iron absorption and iron mobilization from reticuloendothelial macrophages. The major mechanism of hepcidin function seems to be the regulation of transmembrane iron transport. As both iron deficiency and iron excess are associated with cellular dysfunction, so hepcidin or hepcidin-related therapeutics could find a place in the treatment of various diseases such as hemochromatosis and anemia of chronic disease. To elucidate biological function of hepcidin further and use it for other research, it is necessary to produce enough hepcidin through DNA recombinant technique. As a highly successful system for the production of a variety of heterologous proteins, the methylotrophic Pichia pastoris system has the probability for a high level production of hepcidin. The subject of this paper is to summarize the regulation of hepcidin gene expression and the understanding of functions of hepcidin. At last, giving a prospect of production hepcidin by gene engineer.
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PMID:[Properties and advance of hepcidin]. 1675 11

The discovery in recent years of a plethora of new genes whose products are implicated in iron homeostasis has led to rapid expansion of our knowledge in the field of iron metabolism and its underlying complex regulation in both health and disease. Abnormalities of iron metabolism are among the most common disorders encountered in practical medicine and may have significant negative impact on physical condition and life expectancy. Basic insights into the principles of iron homeostasis and the pathophysiological and clinical consequences of iron overload, iron deficiency and misdistribution are thus of crucial importance in modern medicine. This review summarizes our current understanding of human iron metabolism and focuses on the clinically relevant features of hereditary and secondary hemochromatosis, iron deficiency anemia, anemia of chronic disease and anemia of critical illness. The interconnections between iron metabolism and immunity are also addressed, in as much as they may affect the risk and course of infections and malignancies.
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PMID:Molecular and clinical aspects of iron homeostasis: From anemia to hemochromatosis. 1695 74

A poor preoperative haemoglobin (Hb) status is frequently encountered among adult patients scheduled for corrective surgery of the locomotive system, representing the main risk factor for blood transfusion. The soluble transferrin receptor (sTfR) has become a highly specific parameter for the detection of iron deficits as it can differentiate between iron deficiency anaemia and anaemia of chronic disease, because of the lack of effect by associated inflammation, unlike ferritin. The objectives of this study were to evaluate patients with the prevalence of risk for transfusion, the effect of inflammation on ferritin (F) values and functional iron deficiency in elderly patients with advanced degenerative arthropathy scheduled for hip or knee replacement. This observational, prospective study included patients over 50 years, operated for hip or knee replacements between April and June 2004. Of 218 patients studied, 87 (39%) presented with Hb levels between 10 and 13 g/dl. The prevalence of functional iron deficit was 27% (sTfR > 1.76 mg/l), while only 8.6% of patients displayed F levels below normal. As expected, C-reactive protein levels were elevated in 24.8% of patients and erythrocyte sedimentation rate was elevated in 50%. These inflammatory markers did not correlate with levels of either F or sTfR. Multiple factors can affect F levels, such as the inflammatory status of osteoarthritis in the elderly, obesity, nonsteroidal anti-inflammatory drugs therapy and low physical performance. As sTfR is not affected by inflammation, it has emerged as a primary parameter for the evaluation of iron status during preoperative assessment among patients scheduled for arthroplasty surgery. Our data strongly suggest that sTfR measurement contributes to improve patient management.
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PMID:Improved preoperative iron status assessment by soluble transferrin receptor in elderly patients undergoing knee and hip replacement. 1710 89

Anaemia is frequently diagnosed in patients with cancer, and may have a detrimental effect on quality of life (QoL). We previously conducted a systematic literature review (1996-2003) to produce evidence-based guidelines on the use of erythropoietic proteins in anaemic patients with cancer.[Bokemeyer C, Aapro MS, Courdi A, et al. EORTC guidelines for the use of erythropoietic proteins in anaemic patients with cancer. Eur J Cancer 2004;40:2201-2216.] We report here an update to these guidelines, including literature published through to November 2005. The results of this updated systematic literature review have enabled us to refine our guidelines based on the full body of data currently available. Level I evidence exists for a positive impact of erythropoietic proteins on haemoglobin (Hb) levels when administered to patients with chemotherapy-induced anaemia or anaemia of chronic disease, when used to prevent cancer anaemia, and in patients undergoing cancer surgery. The addition of further Level I studies confirms our recommendation that in cancer patients receiving chemotherapy and/or radiotherapy, treatment with erythropoietic proteins should be initiated at a Hb level of 9-11 g/dL based on anaemia-related symptoms rather than a fixed Hb concentration. Early intervention with erythropoietic proteins may be considered in asymptomatic anaemic patients with Hb levels 11.9 g/dL provided that individual factors like intensity and expected duration of chemotherapy are considered. Patients whose Hb level is below 9 g/dL should primarily be evaluated for need of transfusions potentially followed by the application of erythropoietic proteins. We do not recommend the prophylactic use of erythropoietic proteins to prevent anaemia in patients undergoing chemotherapy or radiotherapy who have normal Hb levels at the start of treatment, as the literature has not shown a benefit with this approach. The addition of further supporting studies confirms our recommendation that the target Hb concentration following treatment with erythropoietic proteins should be 12-13 g/dL. Once this level is achieved, maintenance doses should be titrated individually. There is Level I evidence that dosing of erythropoietic proteins less frequently than three times per week is efficacious when used to treat chemotherapy-induced anaemia or prevent cancer anaemia, with studies supporting the use of epoetin alfa and epoetin beta weekly and darbepoetin alfa given every week or every 3 weeks. We do not recommend the use of higher than standard initial doses of erythropoietic proteins with the aim of producing higher haematological responses, due to the limited body of evidence available. There is Level I evidence that, within reasonable limits of body weight, fixed doses of erythropoietic proteins can be used to treat patients with chemotherapy-induced anaemia. This analysis confirms that there are no baseline predictive factors of response to erythropoietic proteins that can be routinely used in clinical practice if functional iron deficiency or vitamin deficiency is ruled out; a low serum erythropoietin (EPO) level (only in haematological malignancies) appears to be the only predictive factor to be verified in Level I studies. Further studies are needed to investigate the value of hepcidin, c-reactive protein, and other measures as predictive factors. In these updated guidelines, we explored a new question of whether oral or intravenous iron supplementation increases the response rate to erythropoietic proteins. We found no evidence of increased response with the addition of oral iron supplementation, but there is Level II evidence of improved response to erythropoietic proteins with the addition of intravenous iron. However, the doses and schedules for intravenous iron supplementation are not yet well defined, and further studies in this area are warranted. The two major goals of erythropoietic protein therapy are prevention or elimination of transfusions and improvement of QoL. The total body of evidence shows that red blood cell (RBC) transfusion requirements are reduced following treatment with erythropoietic proteins. This analysis also confirms that QoL is significantly improved in patients with chemotherapy-induced anaemia and in those with anaemia of chronic disease following erythropoietic protein therapy, with more robust evidence now available that QoL was improved in studies investigating early intervention in cases of chemotherapy- or radiotherapy-induced anaemia. There is only indirect evidence that patients with chemotherapy-induced anaemia or anaemia of chronic disease initially classified as non-responders to standard doses proceed to respond to treatment following a dose increase. None of the studies addressed the question in a prospective, randomised fashion, and so the Taskforce does not recommend dose escalation as a general approach in all patients who are not responding. There is still insufficient data to determine the effect on survival following treatment with erythropoietic proteins in conjunction with chemotherapy or radiotherapy. Our analysis of survival endpoints in studies involving patients receiving radio(chemo)therapy found that most studies were inconclusive, with no clear link between the use of erythropoietic proteins and survival. Likewise, we found no clear link between erythropoietic therapy and other endpoints such as local tumour control, time to progression, and progression-free survival. There is no evidence that pure red cell aplasia occurs in cancer patients following treatment with erythropoietic proteins, and the fear of this condition developing should not lead to erythropoietic proteins being withheld in patients with cancer. There is Level I evidence that the risk of thromboembolic events and hypertension are slightly elevated in patients with chemotherapy-induced anaemia receiving erythropoietic proteins. Additional trials are warranted, especially to define the optimal doses and schedules of intravenous iron supplementation during erythropoietic therapy. While our review did not address cost benefit evaluations in detail, the consensus is that studies taking into account all real determinants of cost and benefit need to be performed prospectively.
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PMID:EORTC guidelines for the use of erythropoietic proteins in anaemic patients with cancer: 2006 update. 1718 41

Anemia in celiac disease (CD) has been attributed to nutritional deficiencies; however, the clinical manifestations of CD have changed with nongastrointestinal presentations predominating. We collected hematologic parameters from a cohort of patients seen at a tertiary care center for CD to assess the characteristics of anemia in this population. Hematological parameters measured <or=3 months of diagnosis and degree of villous atrophy from 405 patients diagnosed >1995 was analyzed. Ferritin levels were compared with population controls (NHANES III). Iron deficiency was common, occurring in 33% of men and 19% of women (P < 0.001). Folate deficiency was seen in approximately 12% of the total sample and B12 deficiency in approximately 5%. Anemia was present in approximately 20% of the cohort. Among the anemic patients, ferritin was less than the 10th percentile in 45%, between the 10th and 50th percentile in 39% and greater than the 50th percentile in 13%. Ferritin > 50th percentile was more common in anemic men (24%) than in anemic women (9%; P > 0.20). Macrocytic anemia with concurrent B12 or folate deficiency was rare (3%). Elevated ESR was observed in patients with ferritin < 10th percentile and >50th. A gluten-free diet resulted in increased serum ferritin in iron-deficient patients, and decreased ferritin levels in those with high ferritin (r(2) = 0.46, P < 0.001). Although anemia is still a common presentation of celiac disease, nutritional deficiencies alone do not explain this phenomenon in all cases; inflammation appears to contribute as evidenced by the presence of anemia of chronic disease in some individuals.
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PMID:Anemia in celiac disease is multifactorial in etiology. 1763 74

Ferritin concentration, as a parameter of iron status that is commonly used in the diagnosis of iron deficiency anaemia (IDA), often has limited values if the iron deficiency is accompanied by inflammatory disease. This study evaluated the value of reticulocyte haemoglobin content (CHr) and soluble transferrin receptor-ferritin index (sTfR/F) in the diagnosis of IDA and differential diagnosis of IDA and anaemia of chronic disease. The study included 66 nonanaemic individuals as controls, 86 patients with IDA divided into noninflammatory and inflammatory subgroups, and 32 patients with anaemia of chronic disease. Blood count, iron, transferrin saturation, total iron binding capacity, ferritin, C-reactive protein, sTfR and CHr were determined. Receiver operator characteristic curve analysis showed very high discriminating power for CHr, soluble transferrin receptor (sTfR) and sTfR/F in the diagnosis of IDA. In patients with anaemia of chronic disease these parameters showed no significant difference from the control. CHr and sTfR enabled recognition of iron deficiency and were not affected by acute phase reaction. They are sensitive markers of body iron status with additional value to conventional tests for the detection of iron deficiency.
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PMID:Reticulocyte haemoglobin content vs. soluble transferrin receptor and ferritin index in iron deficiency anaemia accompanied with inflammation. 1827 24


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