Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0002871 (anemia)
 52,094 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have evaluated a newly introduced immunoturbidimetric transferrin receptor assay (IdeA TfR-IT, Orion Diagnostica, Finland) in healthy subjects and in a study population consisting of patients with rheumatoid arthritis and juvenile chronic arthritis. The IdeA TfR-IT assay was found to provide reproducible results which were in good agreement with the ELISA assays from Orion Diagnostica (IDeA-ELISA, correlation R2=0.8, n=102) and R&D systems (Quantikine TfR ELISA assay, correlation R2=0.95, n=39). The analysis of the patient samples suggested that, on the basis of serum transferrin receptor and ferritin concentrations, in approximately one third of patients with rheumatoid arthritis anemia is due to the depletion of iron stores. Apparently, in all patients with rheumatoid arthritis iron deficiency must be considered as a potential cause of the anemia. Now, that assays which are suitable for automated analyzers have become available for the measurement of serum transferrin receptor, this analyte has the potential to become a part of the routine evaluation of iron status.
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PMID:Evaluation of iron status in anemic patients with rheumatoid arthritis using an automated immunoturbidimetric assay for transferrin receptor. 1120 97

Laboratory tests used in the diagnosis of iron status lack specificity in defining iron deficiency anaemia (IDA) and anaemia of inflammation (AI). The serum transferrin receptor (sTfR) may provide more information in this regard. The iron status of 561 pre-school children was determined and classified using the conventional measurements. The value of the concentration of sTfR, the ratio of sTfR (microg/ml) to LogSF (microg/l) (TfR-Index), and the Log of the ratio of sTfR (microg/l) to SF (microg/l)--(LogTfR:Fer ratio), in the classification of the iron status were determined by comparing their distributions across the classification of iron status. Although there were significant differences in sTfR and TfR-Index across the categories of iron status, there was considerable overlap. All subjects with iron deficiency had LogTfR:Fer ratio > 2.55, whereas in all subjects classified as AI it was < 2.55, thus clearly separating the two. The LogTfR:Fer ratio was not able to exclude IDA in the presence of inflammation. However, in cases of combined IDA and AI the LogTfR:Fer ratio was < 2.55 but increased to > 2.55 after resolution of the inflammation. This novel method of calculating the LogTfR:Fer ratio may provide a more precise classification of the iron status of children.
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PMID:The ratio of serum transferrin receptor and serum ferritin in the diagnosis of iron status. 1172 16

An adequate iron management is important in the treatment of anemia and in hemodialysis (HD) patients. Serum ferritin and transferrin saturation (TS) may be influenced by the presence of inflammation. Recently, the soluble transferrin receptor (s-TfR) has been advocated as a parameter of iron status in HD patients. The aim of the present study was to assess firstly the relation between serum ferritin, TS, and s-TfR in HD patients and to predict their agreement (assessed by kappa) in the diagnosis of iron deficiency, and, secondly, to assess the influence of inflammation on the relation between the parameters of iron state. Iron deficiency by either marker was respectively defined as ferritin <100 microg/l, TS <20%, or s-TfR >2.4 microg/ml. In the overall group of patients, TS and s-TfR were significantly related (r = -0.38), whereas s-TfR and serum ferritin were not. Both serum ferritin and TS were related to CRP (r = 0.50 and -0.34; p < 0.05), whereas s-TfR was not. The kappa value for agreement between serum ferritin and TS in the diagnosis of iron deficiency was 0.24 (p = 0.07), 0.12 (p = NS) for the agreement between TS and s-TfR and 0 for that between serum ferritin and s-TfR. In patients with CRP levels <or=2 mg/l (n = 16), the relation between parameters of iron state did not improve. Concluding, a large disagreement is observed between ferritin, TS and sTfR as markers of iron deficiency in HD patients, which appears to be only partly explained by the effect of inflammation.
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PMID:A comparison between the soluble transferrin receptor, transferrin saturation and serum ferritin as markers of iron state in hemodialysis patients. 1218 81

The transferrin receptor is an essential component of cellular uptake of iron, and it binds to serum transferrin. Recently, 2 different types of transferrin receptors have been recognized: transferrin receptor (TfR or transferrin receptor 1) and transferrin receptor 2. Most cells possess a ubiquitous system controlling the biosynthesis of TfR at the posttranscriptional level to avoid excess iron influx into the cells through TfR. During the process of recycling of transferrin receptors, some are shed and appear as soluble or serum transferrin receptors. Measurement of serum transferrin receptor is a new marker of iron metabolism that reflects body iron stores and total erythropoiesis. It has been shown that serum transferrin receptor to ferritin ratios have significant predictive value for differentiating iron deficiency anemia from non-iron deficiency anemia, such as anemia of chronic disorders, whereas serum ferritin is the only significant independent predictor of iron deficiency anemia.
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PMID:Transferrin receptor in tissue and serum: updated clinical significance of soluble receptor. 1241 31

The prevalence of iron-deficiency anemia in different regions of the world ranges from 12 to 43%. The increased iron requirement in pregnancy and the puerperium carry with it an increased susceptibility to iron deficiency and iron-deficiency anemia and perioperative or peripartal blood transfusion. Prevention and correction presuppose reliable laboratory parameters and a thorough understanding of the mechanisms of iron therapy. The Hb level alone is insufficient to guide management. A complete work-up (ferritin, transferrin saturation) is essential, preferably with hematological indices such as hypochromic and microcytic red cells and reticulocytes, classified by degree of maturity, in particular, before parenteral therapy is given. Since ferritin acts as both an iron-storage and acute-phase protein, it cannot be used to evaluate iron status in the presence of inflammation. A high ferritin level thus requires the presence of an inflammatory process to be eliminated before it can be taken at face value. If the C-reactive protein level is also raised, the soluble TfR concentration can be used, since it is unaffected by inflammation. Inadequate understanding of the complex chemistry of parenteral iron administration was previously responsible for serious side effects, such as toxic and allergic reactions, and even anaphylactic shock, in particular with dextran preparations. However, the current type II iron complexes that release iron to the endogenous iron-binding proteins with a half-life of about 6 hours are not only effective but carry a minimal risk of allergic accident and overload, especially after a comprehensive pretreatment work-up. Our departmental data collected over 8 years and backed by postmarketing experience in 25 countries indicate that iron sucrose complex therapy is a valid first-line option for the safe and rapid reversal of iron-deficiency anemia.
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PMID:Iron deficiency and anaemia in pregnancy: modern aspects of diagnosis and therapy. 1254 41

Hepcidin (hepatic bactericidal protein) is a protein synthesised by the hepatocyte belonging to the family of endogenous peptide antimicrobes. It is produced in large quantities by the liver, heart and spinal cord and then is excreted in the urine. This protein, sequenced on human chromosoma 19, can be found in 2 main forms: Hepc 20 and Hepc 25 aminoacids respectively with 8 cystein residues connected by disulphine bridges. Evidence of lipopolysaccharide hepatocyte and the high concentrations of iron tied to fransferrin are elements which stimulate the production and release of Hepcidin. The latter, interacting with beta-2microglobulin-HFE-TfR1 complex determines an iron retention within the macrophages of the entherocyte in the duodenal pit. Hepcidin is therefore an important molecule which is able to regulate iron homeostasis and play a most significant role in the etiopathogenesis of the hemochromatosis system and, as recently shown, of anemia in chronic inflammatory diseases.
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PMID:[Hepcidin: a key peptide in iron metabolism]. 1460 94

The distinction between iron deficiency anaemia (IDA) and the anaemia that accompanies infection, inflammation or malignancy, commonly termed the anaemia of chronic disease (ACD), is often difficult, as the conventional laboratory indices of iron status are often influenced by acute phase responses. In recent years, the soluble transferrin receptor (sTfR) has been introduced as a sensitive, early and highly quantitative new marker of iron depletion, increasing in proportion to tissue iron deficit. Unlike conventional laboratory tests, the sTfR is not an acute phase reactant and remains normal in patients with chronic disease. In this study TfR concentrations were compared with the gold standard of iron stores, bone marrow iron. The sTfR concentration was shown to be the most efficient test in predicting bone marrow iron stores in 20 patients with ACD (75% efficiency) and in 18 patients with rheumatoid arthritis (RA) (94% efficiency). Measurement of sTfR may be a useful addition in the differential diagnosis of ACD and IDA.
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PMID:Soluble transferrin receptor: a discriminating assay for iron deficiency. 1464 Nov 38

Iron deficiency is an important factor in the management of anemia in both dialysis and transplant patients. Serum ferritin and transferrin saturation (TS) may be influenced by the presence of inflammation. Recently, the soluble transferrin receptor (s-TfR) has been considered to be a marker of functional iron stores. In this study, parameters of the iron state were investigated in terms of agreement (assessed by kappa) with the diagnosis of iron deficiency and with inflammation. The study was performed in 38 hemodialysis, 31 continuous ambulatory peritoneal dialysis, and 21 anemic renal transplant patients. CRP and amyloid A protein (AAP) were studied as markers of inflammation. Iron deficiency was defined as ferritin <100 mg/L, TS <20%, or s-TfR >1.76 mg/mL. We observed that s-TfR levels were significantly related to both dialysis duration (r = 0.28 in dialysis and r = 0.60 in transplant patients, both P <.05) and PTH levels (r = 0.23 in dialysis and r = 0.55 in transplant patients, both P <.05). Among the transplant group, ferritin and TS, as well as TS and s-TfR were significantly related (r = 0.84 and r = -0.64, respectively), but not s-TfR and ferritin. Among the dialysis group, ferritin and TS, and also TS and s-TfR, were significantly related (r = 0.35 and r = -0.30, respectively), whereas s-TfR and ferritin were not. In the transplant group, the kappa value for agreement between ferritin and TS in the diagnosis of iron deficiency was 0.76 (P =.006), and 0.33 (P =.04), respectively. Among patients with CRP levels <0.3 mg/L or AAP levels <6.4 mg/L, the relation between parameters of iron state was more robust. The kappa value for agreement between ferritin and s-TfR was 0.49 (P =.006) in the dialysis group and 1 (P =.002) for that between ferritin and TS in the transplant group. Our results suggest that PTH levels may influence s-TfR levels. Discordance between ferritin, TS, and s-TfR as markers of iron deficiency might be explained by the effects of inflammation.
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PMID:Influence of inflammation on the relation between markers of iron deficiency in renal replacement therapy. 1501 95

The aim of this study was to evaluate erythropoiesis in 198 healthy babies aged 0-6 months by determination of their blood count, serum transferrin receptor (STfR), and ferritin levels. Anemia and microcytosis were present in 9% and 13% of the sample, respectively. Microcytosis rate was as high as 45% in 6-month-old babies. In infants with normal blood counts, the values of sTfR/ferritin and sTfR-F index were increasing with the increase of sTfR and decrease of ferritin beginning from 2 months of age. In the 5- to 6-month-old group, sTfR concentrations, sTfR/ferritin ratio, and sTfR-F index were higher in infants with anemia and microcytosis. This research showed a high frequency of iron deficiency detected in otherwise healthy babies. Only problems with early weaning practices were found to be significantly more common in babies with iron deficiency.
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PMID:Evaluation of erythropoiesis by serum transferrin receptor and ferritin in infants aged 0-6 months. 1520 91

The serum ferritin assay is the best single blood test for the diagnosis of iron deficiency. Previous studies with elderly anemic patients have suggested that ferritin level less than 45 mug/L is indicative of iron deficiency. The subjects of these studies were hospitalized patients with anemia, however. We thus conducted a prospective study to determine the normal minimum level of serum ferritin of community-dwelling older adults by assessing the ratio of serum transferrin receptor to the log ferritin level (sTfR-F index). We conducted the anemia survey between October and November 2002. A total of 1,254 apparently healthy older adults, aged between 60 and 95 years, from three urban community dwellings participated in the survey. Among these individuals, 156 subjects who were anemic or whose serum ferritin level was less than 100 microg/L were selected. The soluble transferrin receptor assay was performed and the sTfR-F index was calculated. The receiver operating characteristic curve analysis was performed. Based on the data, serum ferritin level of 22 microg/L was selected as the cutoff value for the diagnosis of iron deficiency in community-dwelling older adults. Applying the serum ferritin cutoff of 22 microg/L and the sTfR-F index cutoff of 1.5, the sensitivity of the assay was 89.5% (34 of 38) and the specificity was 89.0% (105 of 118). In conclusion, for the diagnosis of iron deficiency of community-residing older adults, we suggest the serum ferritin cutoff value of 22 microg/L obtained by use of the sTfR-F index. The value is lower than the previous value established for hospitalized and anemic older adults.
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PMID:The cutoff value of serum ferritin for the diagnosis of iron deficiency in community-residing older persons. 1578 29


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