This gene encodes a cell surface receptor necessary for cellular iron uptake by the process of receptormediated endocytosis. Clinical utility of the soluble transferrin receptor and. Log ferritin index in differentiating between iron deficiency anemia. Soluble transferrin receptors are proteins found in blood that can be elevated with iron deficiency. Study of soluble transferrin receptor and soluble transferrin receptor. It is not a routine test but may be ordered if other tests that evaluate the amount of iron in the body do not provide conclusive.
The complex of receptor and apotransferrin then recycles to the cell surface for another round of endocytosis 2, 5, 22, 27,28. This study describes the soluble production, purification, and functional testing of an antitransferrin receptor singlechain antibody ox26 scfv using the yeast saccharomyces cerevisiae. The soluble transferrin receptor stfr test is primarily ordered to help distinguish between anemia that is caused by iron deficiency and anemia that is caused by inflammation or a chronic illness socalled anemia of chronic disease or inflammation. Levels of this receptor are increased in irondeficiency anemia. Pdf soluble transferrin receptor in complicated anemia. Currently, the brains ability to take in antibody therapies is limited by the presence of the blood brain barrier. This receptor is required for erythropoiesis and neurologic development. Transferrin synthesis by small cell lung cancer cells acts as an autocrine regulator of cellular proliferation. Soluble transferrin receptor stfr and stfrlog ferritin index for.
This receptor is a protein dimer of two identical subunits, linked together by two pairs of disulfide bonds. The method for measurement of soluble transferrin receptor stfr is immunoturbidimetry using roche kits on the hitachi 912 clinical analyzer. On the surface of hepatocytes, the receptor binds to a protein called transferrin, which transports iron through the blood to tissues throughout the body. Transferrin receptor number, synthesis, and endocytosis during erythropoietininduced maturation of friend virusinfected erythroid cells received for publication, october 30, 1985 stephen t.
The expression of transferrin receptor tfr has been identified in many malignant tumours. Serum soluble transferrin receptor increases in iron deficiency and is usually unaffected by chronic disease states. Targetspecific elisa kits are available from a variety of manufacturers and can help streamline your immunodetection experiments. Soluble transferrin receptors and iron deficiency, a step. The soluble transferrin receptor stfr concentration is increased in iron deficiency. After adding the product to the cart by clicking the button below you will see if there is a volume discount available. It is needed for the import of iron into the cell and is regulated in response to intracellular iron concentration. A second ligand, the heditary hemochromatosis protein hfe, competes for binding with transferrin for an overlapping cterminal binding site. Soluble transferrin receptor and soluble transferrin receptor ferritin index for evaluation of the iron status in elderly patients. Transferrin receptor is a nonrtk constitutively recycling receptor and thus can be used as a control to assess rtk specificity of met trafficking. Pdf the usefulness of soluble transferrin receptor stfr. Transferrin receptor number, synthesis, and endocytosis.
Soluble transferrin receptor elisa kits biocompare. Immunofluorescence analysis of transferrin receptor monoclonal antibody h68. Soluble transferrin receptor article about soluble. Proteolysis leads to the soluble form of the transferrin receptor stfr. Pmc free article wrba f, ritzinger e, reiner a, holzner jh. The main function of this protein is to help iron enter liver cells hepatocytes. Recombinant soluble transferrin receptor rstfr 1st who reference reagent type of standard. This gene encodes a singlepass type ii membrane protein, which is a member of the transferrin receptorlike family.
Soluble transferrin receptors and iron deficiency 347 the endosomes acidosomes, and the tftfr complex is returned back to the cell surface, where apotransferrin is released again 41. Pdf we evaluated the usefulness of soluble transferrin receptor stfr and of the stfrlog ferritin indexstfrlogf in the differentiation of anemia. Serum transferrin receptor levels for the assessment of iron status. Pdf the usefulness of soluble transferrin receptor stfr in. Transferrin receptor is the main receptor for transferrin and allows transferrinbound iron uptake by the cell. Is soluble transferrin receptor a good marker of iron. By continuing to use our website, you are agreeing to our use of cookies. Soluble transferrin receptor levels may be helpful in distinguishing iron deficiency from anemia of chronic inflammation in cf because, unlike serum ferritin and transferrin, soluble transferrin receptor does not appear to be an acutephase reactant. Transferrin receptor is necessary for development of erythrocytes and the nervous system by similarity. Determination of serum soluble transferrin receptor stfr has been proposed to identify irondeficiency anemia ida in patients affected by concurrent inflammatory disease that may spuriously increases ferritin concentration. Pdf soluble transferrin receptor and soluble transferrin. The tfr2 gene provides instructions for making a protein called transferrin receptor 2. Pdf the concentration of soluble transferrin receptor stfr in serum is reported to be useful in the diagnosis of iron deficiency, especially for.
Cao nutrition and public health unit, faculty of medicine and health sciences, universitat rovira i virgili, reus, spain. Role of soluble transferrin receptor and transferrin receptor. Tfr is a transmembrane, disulfidelinked dimer of two identical subunits that binds and internalizes diferric transferrin, thereby delivering iron to the cell cytosol. Physiology a specialized cell or group of nerve endings that responds to sensory stimuli. Transferrin receptor testing is used to measure the level of soluble transferrin receptors, thereby aiding in the evaluation of iron deficiency and in the diagnosis of irondeficiency anemia the reference range of transferrin receptor varies by sex in adults, as follows.
Soluble transferrin receptor and risk of type 2 diabetes in the obese and nonobese jose c. Transferrin receptor tfr is a carrier protein for transferrin. Transferrin receptor protein 1 tfr1, also known as cluster of differentiation 71 cd71, is a protein that in humans is encoded by the tfrc gene. Conserved ironresponse elements in the 3untranslated region of transferrin receptor mrna enhance binding of iron regulatory proteins 1 and 2. The soluble transferrin receptor stfr blood test is primarily requested to help distinguish between anaemia that is caused by iron deficiency and anaemia that is caused by inflammation or a chronic illness socalled anaemia of chronic disease or inflammation. Soluble transferrin receptor definition of soluble. Latex bound antistfr antibodies react with the antigen in the sample to form an antigenantibody complex. Soluble transferrin receptor conventionally refers to the cleaved extracellular portion of transferrin receptor 1 that is released into serum. The soluble transferrin receptor test is not routine but may be ordered along with or in follow up to other iron tests when you have a normal or nearnormal ferritin level but iron deficiency is still suspected.
A study cohort of 436 apparently healthy children was analyzed to establish. Recombinant soluble transferrin receptor rstfr1st who. It is not a routine blood test but may be requested if other tests that evaluate the amount of iron in the body do not. Soluble transferrin receptor elisa kits the elisa enzymelinked immunosorbent assay is a widely used application for detecting and quantifying proteins and antigens from various samples. This protein mediates cellular uptake of transferrinbound iron, and may be involved in iron metabolism, hepatocyte function and erythrocyte differentiation. The developing red cells regulate their iron uptake by increasing the number of transferrin receptors on their surface, and the number of stfr in serum increases in. In lung cancer, lymphoma and breast cancer, it has been shown that the expression of tfr correlates with tumour differentiation, probably implying some prognostic value. Blood testing of the soluble transferrin receptor stfr is used as a measure of functional iron status and the. Soluble transferrin receptor is elevated in association with hyperplastic erythropoiesis, for example, in patients with haemolytic anaemia or betathalassaemia.
Transferrin transports ferric ions from the iron stores of intracellular or mucosal ferritin to bone marrow where erythrocyte precursors and other cells. Soluble transferrin receptor and risk of type 2 diabetes. Transferrin receptor trfr expression in breast carcinoma and its possible relationship to prognosis. Proteolysis leads to the soluble form of the transferrin. The existence of a receptor for transferrin iron uptake had been recognized over half a century back. Each of the monomers has an 85 kd cterminal component which can bind an ironladen transferrin molecule.
Internalization and recycling of transferrin and its receptor. Measurement of circulating levels of the receptor are very useful in the diagnosis of iron deficiency in patients who also have anemia. It may be ordered as an alternative to ferritin when you have a chronic illness andor inflammation is present or suspected. Transferrin, an iron binding protein that facilitates iron uptake in cells, is an integral part of a mechanism that may introduce antibody therapies to the central nervous system. Soluble transferrin receptor stfr conversion to nmoll. Soluble transferrin receptor, human, antibody hytest web.
Soluble transferrin receptor and soluble transferrin receptorlog. Cellular uptake of iron occurs via receptormediated endocytosis of ligandoccupied transferrin receptor into specialized endosomes. In plasma, the soluble transferrin receptor is present in the form of a complex with transferrin having a molecular weight of approximately 320 kd. As the tfrtransferriniron complex reaches the cell membrane it is internalized via an endocytic vesicle. Tfr1 is required for iron import from transferrin into cells by endocytosis. Use of multiple antibiotics in patients with cf is routine. Pdf measurement of soluble transferrin receptor in serum of. In general, to increase sensitivity and specificity, the measurement of serum soluble transferrin receptor should be performed in combination with other tests of iron status, including ferritin, tibc, and serum iron refer to. Recent studies have also suggested that stfr measurements are helpful when predicting the response to erythropoietin in patients with anaemia resultant from chronic renal failure.
Haemoglobin and red cell parameters bone marrow iron staining serum iron, total iron binding capacity and transferrin saturation serum ferritin zinc protoporphyrin soluble. Scott1 soluble transferrin receptor stfr and ferritin concentrations were measured in a variety of clinical settings to. It consists of two identical subunits linked by disulfide bridges. Determination of serum soluble transferrin receptor stfr is proposed to distinguish between irondeficiency anemia and. This efficient cellular uptake pathway has been exploited for the sitespecific delivery not only of anticancer drugs and proteins, but also of therapeutic genes into proliferating malignant.
Transferrin receptor tfr is the major mediator of iron uptake by cells. Following agglutination, this is measured turbidimetrically. In the intracellular compartment, iron dissociates from tfrtransferrin complex. The investigation to diagnose iron deficiency include. Pdf analytical and clinical implications of soluble. Its expression is regulated by cellular iron requirements. Transferrin receptors, which are blood proteins, may be elevated in persons with iron deficiency. Production of soluble and active transferrin receptor. The yeast secretion apparatus was optimized by modulating expression temperature, the folding environment of the endoplasmic reticulum, and gene dosage. Recently, soluble transferrin receptor stfr levels have been shown to be a sensitive and highly quanti tative indicator of early iron deficiency. Positively regulates t and b cell proliferation through iron uptake pubmed. Clinical utility of the soluble transferrin receptor and comparison with serum ferritin in several populations alan e. Pediatric reference intervals for soluble transferrin. Soluble and cellassociated transferrin receptor in lung.
Measurement of soluble transferrin receptor in serum of healthy adults. Soluble transferrin receptorlog ferritin index was significantly higher in iron deficiency anemia median. It imports iron by internalizing the transferriniron complex through receptormediated endocytosis. Transferrin and soluble serum transferrin receptor stfr, considered early indicators of functional iron deficiency, are related to iron transport. The membrane transferrin receptormediated endocytosis or internalization of the complex of transferrin bound iron and the transferrin receptor is the major route of cellular iron uptake. This test measures the amount of soluble transferrin receptors to help detect and evaluate iron deficiency and aid in the diagnosis of iron deficiency anemia. Recent studies showing an improved diagnosis of iron deficiency id with soluble transferrin receptor stfr and stfrferritin index did not take into account the agedependency of stfr and ferritin. The transferrin receptor tfr is a homodimeric type ii membrane protein that mediates iron uptake into the cells. Transferrin receptor an overview sciencedirect topics. Soluble transferrin receptor an overview sciencedirect. Pdf soluble transferrin receptors and iron deficiency, a. Punnonen k, suominen p, kuusinen a, kuiperkramer e. The soluble transferrin receptor stfr has been introduced as a promising new diagnostic tool for differentiating between iron deficiency anemia ida and anem we use cookies to enhance your experience on our website.
317 1130 1219 211 301 454 371 145 71 1659 352 979 78 25 1243 418 380 224 1564 902 65 122 301 509 704 1449 1347 1412 1191 1041 1457 1312 824 558 724 987 154