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

A 17 year old male suffered from iron deficiency of undetermined cause for 2 years. Iron substitution was able to correct it for short periods. With the exception of fatigue and recurring abdominal pain attributed to oral iron therapy no further symptoms were present. The physical status on admission was unremarkable. The laboratory detected intestinal disorders, an anemia of the chronic type without evidence for malignancy or renal failure suggested an inflammatory gastro-intestinal disorder. In spite of a twice negative noninvasive test for gluten-intolerance the clinician favored in his differential diagnosis non tropical sprue over inflammatory bowel disease (IBD, Crohn's disease, Whipple's disease). Histopathology of small bowel specimens did not indicate sprue. An ileo-colonoscopy revealed severe ulcerating ileitis and mild chronic colitis. The histologic specimen revealed a severe ileal inflammation with cosinophilia and the colon specimens epitheloid microgranuloma. These findings are highly compatible with the diagnosis of Crohn's disease. Iron deficiency anemia is common in Crohn's disease. In the current case it is due to disturbed iron uptake. Iron deficiency anemia as sole symptom of Crohn's disease is extremely rare.
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PMID:[Severe chronic iron deficiency in a 17-year-old student]. 962 33

Recombinant human erythropoietin (EPO; epoetin) has been shown to be effective in improving anemia in a proportion of cancer patients. The response rate is approximately 60%, but varies considerably according to baseline hematocrit and transfusion needs, as well as the response criteria used. Response is not greatly influenced by the type of tumor, except in situations of major marrow involvement and limited residual hematopoiesis, or in the presence of specific mechanisms of anemia, such as hemolysis, splenomegaly, bleeding, hemodilution, or ineffective erythropoiesis. Stem cell damage by previous therapy as well as marrow suppression by current intensive chemotherapy can impair response. Besides its intensity, the type of chemotherapy may not be critical, although patients undergoing platinum-based chemotherapy may respond faster than those receiving non-platinum regimens. Complications, such as infections, bleeding, or nutritional deficiencies, may have a major negative impact on outcome. An important response-limiting factor is functional iron deficiency (ie, an imbalance between iron needs in the erythropoietic marrow and iron supply), which depends on the level of iron stores and its rate of mobilization. Functional iron deficiency is best monitored by the percentage of hypochromic red blood cells, and oral or intravenous iron supplements should be given when this percentage increases above 10%. All these factors explain why the response rate to epoetin is only approximately 60%. Therefore, it would be interesting to develop models that could help predict response to epoetin to help select the most appropriate cancer patients for this therapy. Few baseline parameters have been shown to be highly predictive of response in patients with solid tumors, although most studies in patients with myeloma or lymphoma have indicated that patients with a low baseline serum EPO level will respond better. Early changes after 2 to 4 weeks of treatment are also of great interest. Among these early changes, increments of soluble transferrin receptor, reticulocytes, and hemoglobin, as well as the persistence of elevated ferritin or EPO levels, have all shown some predictive value. Combination of baseline serum EPO and the 2-week increment of soluble transferrin receptor or hemoglobin may provide the best prediction of response.
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PMID:Prediction of response to optimize outcome of treatment with erythropoietin. 967 27

The anaemia associated with cancer can be effectively treated with recombinant human erythropoietin (rHuEpo) in about 60% of the patients. However, the response rate varies according to treatment modalities as well as the response criteria used. A number of disease- or chemotherapy-related factors determines the probability of response. Several specific mechanisms of anaemia, such as haemolysis, splenomegaly, bleeding, haemodilution, or ineffective erythropoiesis can seriously interfere with response. However, the type of tumor, in particular haematologic versus non-haematologic, is not critical, except in situations of major marrow involvement and limited residual haematopoiesis. Stem cell damage by previous therapy, reflected by low platelet counts or high transfusion needs, will impair response. In addition, marrow suppression by current intensive chemotherapy will also have a negative impact. Besides its intensity, the type of chemotherapy may not be critical, although patients undergoing platinum-based chemotherapy may respond faster than those receiving non-platinum regimens. Complications such as infections, bleeding or nutritional deficiencies may have a major negative impact on outcome. An important response-limiting factor is functional iron deficiency, i.e. an imbalance between iron needs in the erythropoietic marrow and iron supply, which depends on the level of iron stores and its rate of mobilisation. Therefore, oral or preferably intravenous iron supplements should be given when serum ferritin is below 40-100 micrograms/l, reflecting the absence of iron stores, or when the percentage of hypochromic red cells rises above 10%, indicating functional iron deficiency even in the presence of adequate storage iron. Because up to 40% of the patients will not respond to rHuEpo, it is of utmost importance to develop models that could help predict response to rHuEpo and thus select the most appropriate cancer patients for this therapy. Most studies of patients with myeloma or lymphoma have indicated that patients with a low baseline serum Epo level will respond better, but this is not true of patients with solid tumors. Also of considerable interest are early changes of erythropoietic parameters after 2 to 4 weeks of treatment, including increments of serum transferrin receptor (sTfR), reticulocytes and haemoglobin, as well as the persistence of elevated ferritin or Epo levels. Combination of baseline serum Epo and the 2-week increment of sTfR or haemoglobin may provide the best prediction of response.
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PMID:Prediction of response to treatment with recombinant human erythropoietin in anaemia associated with cancer. 978 36

Iron deficiency affects approx. 20% of the world population. Due to predominantly vegetarian diets that reduce the bioavailability of food iron drastically, deficiency states are most widely distributed in developing countries. In addition, iron demand is increased by blood losses and by fast growth which increases the risk of iron deficiency in infants, young adolescents, and in menstruating and pregnant women. The symptoms of iron deficiency include impaired physical and intellectual performance. Iron supplementation may help to break the vicious cycle between inadequate nutrition and poverty. Fortification programs have to consider social and health aspects, including provision against iron overload. Excess iron stores may promote cancer and increase the cardiovascular risk, though the latter is a subject of current debate. The best approach to control such risks is individual iron supplementation geared to the demand by adequate laboratory controls. However, this approach is too costly for general application in developing countries. Food-iron fortification has successfully reduced iron deficiency in many trials and, in comparison, is much cheaper. As iron deficiency is widely distributed in most developing countries, the risk of inducing iron overload in the general population is low. Genetically determined diseases that may lead to siderosis, such as hereditary haemochromatosis or thalassaemia major, show a limited geographic and ethnic distribution. Such subgroups can be largely avoided by targeting food-iron fortification to infants, young adolescents, or pregnant women. Food vehicle and iron compound have to be matched in order to optimise iron bioavailability and to avoid rancidity in food, spoiling its taste and odour. The fortification of salt, sugar and spice mixtures or of bakery products with a short shelf-life are valid approaches to this end. Alternatively, haem iron can be used to fortify cereal-based food staples in developing countries such as tortillas or chappaties. Thus, a variety of options is available to solve the technical problems of food iron fortification. However, optimal solutions have to be tailored to the individual situation in each country.
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PMID:Iron supplementation. 985 25

Transferrin receptor is a key protein for the cellular uptake of transferrin iron. The highest number of transferrin receptors is on the surface of erythroblasts. The released iron is used for hemoglobinosynthesis. Regulation occurs at mRNA level depending on the intracellular iron concentration. The synthesis of ferritin and transferrin receptor are regulated in an opposite manner. Serum transferrin receptor is a truncated monomeric form of the cellular receptor. Most of the circulating receptors come from erythroid marrow precursors. Its level mirrors the total tissue receptor mass, it depends on the rate of erythropoiesis and on the iron status. Serum transferrin receptor is easily measured by Elisa methods but the lack of standardization triggers large differences in the results. Unlike ferritin, the concentration of serum transferrin receptors is unaffected in inflammatory diseases, infections, malignancies or cytolysis. In these conditions its measurement is particularly valuable for assessing an associated iron deficiency. It is a very useful tool for the diagnosis of different causes of anemia. In chronic renal failure serum transferrin receptor can predict whether patients will respond to rHu EPO therapy.
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PMID:[The transferrin receptor: its role in iron metabolism and its diagnosis utility]. 992 Sep 62

The prevalence of anaemia in patients with cancer lies between 10 and 40%, depending on the type of tumor and chemotherapy. Anaemia has a significant impact on the quality of life, along with pain or disease progression. There are multiple causes but the physiopathology resembles that of inflammatory anaemia. The following mechanisms can be distinguished: a resistance of the erythroid precursor cells (BFU-e, CFU-e) to erythropoietin, an inappropriately decreased renal erythropoietin secretion for a given haemoglobin value and alterations of the iron metabolism leading to a functional iron deficiency. Recombinant human erythropoietin (r-hu-EPO) is safe and efficient in the treatment of anaemia of chronic renal failure and rheumatoid arthritis. In oncology different phase I and II studies have demonstrated an efficacy (increase of haemoglobin, decrease of transfusion requirements) in about 50% of all adult patients. A response to a subcutaneous r-hu-EPO treatment with a relatively high posology of 150 U/kg three times a week can be expected after one to two months. No single reliable parameter will predict a response to the r-hu-EPO treatment. Several phase III studies confirm that anaemia in cancer patients undergoing chemotherapy (notably with cisplatin) can be corrected in 40 to 60% of all cases and that the haemoglobin increase improves the quality of life. Finally, recent clinical trials suggest that an early r-hu-EPO treatment might prevent the occurrence of anaemia secondary to chemotherapy. Several parameters will have to be specified such as the precise definition of the groups at risk, the appropriate haemoglobin level to initiate a r-hu-EPO treatment, its optimal posology, as well as the role of the iron substitution and its route of administration. The impact of the r-hu-EPO treatment on the quality of life of cancer patients constitutes a priority for future studies, which will have define the exact role of r-hu-EPO in oncology management.
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PMID:[Tumor anemia. Overview of the role of human recombinant erythropoietin (r-hu-EPO) in treatment of tumor anemia]. 1006 75

Iron supplementation has become an integral part of the management of patients receiving epoetin therapy, and clinicians have found it necessary to learn how and when to use it to the best advantage. Three routes of administration for iron are available: oral, intramuscular, and intravenous. Oral iron has the advantage of being simple and cheap, but it is limited by side-effects, poor compliance, poor absorption, and low efficacy. Intravenous iron is the best means of guaranteeing delivery of readily available iron to the bone marrow, but it requires greater clinical supervision. The i.v. iron preparations vary widely in their degradation kinetics, bioavailability, side-effect profiles, and maximum dose for single administration. Iron dextran is hampered by a small but significant risk of anaphylaxis, whereas all i.v. iron preparations can induce "free iron" reactions if the circulating plasma transferrin is overloaded. Intravenous iron may be given in advance of epoetin therapy, as concomitant treatment to prevent the development of iron deficiency, as treatment of absolute or functional iron deficiency, or as adjuvant therapy to enhance the response to epoetin in iron-replete patients. Markers of iron status that may indicate a need for i.v. iron include a serum ferritin of less than 100 microg/liter, a transferrin saturation of less than 20%, and a percentage of hypochromic red cells more than 10%. Various regimens are available for giving i.v. iron: low-dose administration of 20 to 60 mg every dialysis session in hemodialysis patients, medium-dose administration of 100 to 400 mg, and high-dose administration of 500 to 1000 mg. Iron sodium gluconate can only be given as a low-dose regimen because of toxicity, whereas the only preparation suitable for high-dose administration is iron dextran. Although concerns have been raised regarding iron overload and long-term toxicity with i.v. iron therapy in terms of increased risk of infections, cardiovascular disease, and malignancy, there is little evidence to substantiate this in patients receiving epoetin. Care should be taken, however, to prevent the serum ferritin rising above 800 to 1000 microg/liter and the transferrin saturation above 50%. Provided this is done, the benefits of i.v. iron almost certainly outweigh the risks in terms of optimizing the response to epoetin therapy.
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PMID:Strategies for iron supplementation: oral versus intravenous. 1008 88

Iron deficiency is the most frequently encountered cause of suboptimal response to recombinant human erythropoietin (rHuEPO). Carefully assessing iron status is of paramount importance in chronic renal failure patients prior to or during rHuEPO therapy. Because there is great need for iron in the EPO-stimulated erythroid progenitors, it is essential that serum ferritin and transferrin saturation levels should be maintained over 300 microg/liter and 30%, respectively. Investigators have shown that oral iron is unlikely to keep pace with the iron demand for an optimal rHuEPO response in uremics. Therefore, patients with iron deficiency will always require intravenous iron therapy. The early and prompt iron supplementation can lead to reductions in rHuEPO dose and hence cost. After the iron deficiency has been corrected or excluded, we must remember all of the possible causes of hyporesponsiveness in every rHuEPO-treated patient. As dose requirements vary, it is not clear which dose of rHuEPO causes this hyporesponsiveness. However, if the patient with iron repletion does not respond well after the induction period, the major causes blunting the response to rHuEPO should be investigated. Most factors are reversible and remediable, except resistant anemia associated with hemoglobinopathy or bone marrow fibrosis, which requires a further increase in the rHuEPO dose. By means of early detection and correction of the possible causes, the goal of increasing therapeutic efficacy can be achieved. Iron overload may lead to an enhanced risk for infection, cardiovascular complication, and cancer. Over-treatment with iron should be avoided in dialysis patients, despite the fact that the safe upper limit of serum ferritin to avoid iron overload is not clearly defined. On the other hand, functional iron deficiency may develop even when serum ferritin levels are increased. Controversy remains as to whether intravenous iron therapy can overcome this form of hyporesponsiveness in iron-overloaded patients. Moreover, a treatment option of iron supplementation is not warranted in these patients, as the potential hazards of iron overload will be worsened. We demonstrated that the mean hematocrit significantly increased from 25.1+/-0.9% to 31+/-1.2% after eight weeks of intravenous ascorbate therapy (300 mg three times a week) in 12 hemodialysis patients with serum ferritin levels of more than 500 microg/liter. The enhanced erythropoiesis paralleled with a rise in transferrin saturation (27.8+/-2.5% vs. 44.8+/-9.5%, P < 0.05) and reductions in erythrocyte zinc protoporphyrin (130+/-32 vs. 72+/-19 micromol/mol heme, P < 0.05) and monthly rHuEPO dose (24.2+/-4.5 vs. 16.8+/-3.4 x 10(3) units, P < 0.05) at the end of study. It is speculated that ascorbate supplementation not only facilitates the iron release from storage sites and its delivery to hematopoietic tissues, but also increases iron utilization in erythroid cells. Our study provides a more complete understanding of the pathogenesis of iron overload-related anemia and the development of an adjuvant therapy, intravenous ascorbic acid, to the existing treatments.
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PMID:Erythropoietin hyporesponsiveness: from iron deficiency to iron overload. 1008 94

Anemia in cancer patients has many etiologies. Iron therapy clearly is indicated in patients whose anemias are associated with iron deficiency. However, a frequent cause of anemia in cancer is the "anemia of chronic disorders," in which, although functional iron may be low, tissue iron remains normal or high. Administration of iron with erythropoietin to such patients requires careful and frequent evaluation of hematologic and iron values. Inadvertent iron loading can contribute to deterioration of a variety of organ systems, as well as to increased proliferation of neoplastic cells.
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PMID:Iron therapy and cancer. 1008 97

The iron chelator deferoxamine mesylate has been shown to inhibit the growth of a variety of human malignant cell lines and the rat 13762NF mammary adenocarcinoma cell line. In vivo studies in mice have also demonstrated that an iron deficiency induced by either feeding a low iron diet or injecting the iron chelator deferoxamine mesylate decreases tumor growth. In this study Fisher rats were transplanted with the 13762NF mammary adenocarcinoma and divided into four groups: normal diet, normal diet plus deferoxamine mesylate treatment, low iron diet and low iron diet plus deferoxamine mesylate treatment. The measurements of tumor size and body weight were recorded weekly. We found that treatment with either deferoxamine mesylate or a low iron diet decreased rat tumor growth, but the greatest inhibitory effect on tumor growth occurred when the rats were treated with deferoxamine mesylate injections plus fed a low iron diet. These treatments did not significantly inhibit the weight gain of the rats. At the end of the experiments measurement of serum iron proved that these treatments caused iron deficiency, but there was no significant treatment related alteration in blood hematocrit. We therefore concluded that deferoxamine mesylate may be a useful chemotherapeutic agent in the treatment of breast cancer, when used in combination with standard chemotherapeutic regiments or with other agents that interfere with iron metabolism, and further that the restricting of iron intake should be considered when planning chemotherapy for all cancer patients.
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PMID:Inhibitory effect of deferoxamine mesylate and low iron diet on the 13762NF rat mammary adenocarcinoma. 1022 80


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