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Christine M Pfeiffer - One of the best experts on this subject based on the ideXlab platform.
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the quansys multiplex immunoassay for serum ferritin c reactive protein and α 1 acid glycoprotein showed good comparability with reference type assays but not for Soluble Transferrin Receptor and retinol binding protein
2019Co-Authors: Razieh Esmaeili, Ming Zhang, Maya R. Sternberg, Carine Mapango, Christine M PfeifferAbstract:: The Quansys multiplex (Q-Plex) measures ferritin (Fer), Soluble Transferrin Receptor (sTfR), C-reactive protein (CRP), α-1-acid glycoprotein (AGP), and retinol-binding protein (RBP). We compared Q-Plex results with reference-type assays and evaluated Q-Plex performance. Pearson correlation and Lin's concordance coefficients between the Q-Plex and reference assay were: Fer 0.98 and 0.91, sTfR 0.88 and 0.35, CRP 0.98 and 0.98, AGP 0.82 and 0.81, and RBP 0.68 and 0.31, respectively. The median relative difference between the Q-Plex and reference assay were: Fer -2.4%, sTfR 107%, CRP 0.03%, AGP -1.3%, and RBP 51%. The Q-Plex intra-assay CVs were 85% for Fer and CRP; specificity was >85% for sTfR, AGP, and RBP. Using performance criteria derived from biologic variation, Fer, CRP, and AGP met the minimum allowable imprecision (<10.7%, <31.7%, and <8.5%, respectively) and difference from the reference assay (<±7.7%, <±32.7%, and <±10.3%, respectively), while sTfR and RBP exceeded these thresholds (<8.5% and <7.8% for imprecision and <±7.7% and <±12% for difference, respectively). The Q-Plex measures multiple biomarkers simultaneously, is easy to perform, and uses small sample volumes. With some improvements in accuracy and precision (i.e., sTfR and RBP), this assay could be a useful tool for low-resource laboratories conducting micronutrient surveys for epidemiologic screening applications. These findings need to be verified using other populations, particularly those with inadequate micronutrient status.
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The Quansys multiplex immunoassay for serum ferritin, C-reactive protein, and α-1-acid glycoprotein showed good comparability with reference-type assays but not for Soluble Transferrin Receptor and retinol-binding protein
2019Co-Authors: Razieh Esmaeili, Ming Zhang, Maya R. Sternberg, Carine Mapango, Christine M PfeifferAbstract:The Quansys multiplex (Q-Plex) measures ferritin (Fer), Soluble Transferrin Receptor (sTfR), C-reactive protein (CRP), α-1-acid glycoprotein (AGP), and retinol-binding protein (RBP). We compared Q-Plex results with reference-type assays and evaluated Q-Plex performance. Pearson correlation and Lin’s concordance coefficients between the Q-Plex and reference assay were: Fer 0.98 and 0.91, sTfR 0.88 and 0.35, CRP 0.98 and 0.98, AGP 0.82 and 0.81, and RBP 0.68 and 0.31, respectively. The median relative difference between the Q-Plex and reference assay were: Fer -2.4%, sTfR 107%, CRP 0.03%, AGP -1.3%, and RBP 51%. The Q-Plex intra-assay CVs were 85% for Fer and CRP; specificity was >85% for sTfR, AGP, and RBP. Using performance criteria derived from biologic variation, Fer, CRP, and AGP met the minimum allowable imprecision (
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serum Soluble Transferrin Receptor concentrations in us preschool children and non pregnant women of childbearing age from the national health and nutrition examination survey 2003 2010
2012Co-Authors: Zuguo Mei, Christine M Pfeiffer, Anne C Looker, David A Lacher, Rafael Floresayala, Lisa B Mirel, Laurence M GrummerstrawnAbstract:Abstract Background Serum Soluble Transferrin Receptor (sTfR) is recommended as a sensitive and accurate measure of iron deficiency (ID) in populations when only a single indicator can be used. The lack of assay standardization and of representative data on the distribution of sTfR in at-risk populations currently limits its utility. Methods Using data from NHANES 2003–2010, we examined the distribution of sTfR and developed assay-specific cutoff values for defining elevated sTfR in 2 US populations groups: children aged 1–5 y ( n = 2820) and non-pregnant women aged 15–49 y ( n = 6575). Results On average, children had higher geometric mean sTfR concentrations (4.09 mg/l; 95% CI: 4.04–4.14) than non-pregnant women (3.31 mg/l; 95% CI: 3.26–3.35) ( p Conclusions A different sTfR cutoff value may be needed in children and non-pregnant women to define ID.
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evaluation of an automated Soluble Transferrin Receptor stfr assay on the roche hitachi analyzer and its comparison to two elisa assays
2007Co-Authors: Christine M Pfeiffer, James D Cook, Zuguo Mei, Mary E Cogswell, Anne C Looker, David A LacherAbstract:Abstract Background Soluble Transferrin Receptor (sTfR) assays are currently not standardized. This hinders data comparison between studies and also affects the use of a recently proposed model to estimate body iron. Methods We evaluated the analytical performance of a fully automated sTfR immunoturbidimetric assay (Roche Diagnostics) and compared it with two ELISA assays (Ramco Laboratories and an in-house ELISA assay used in the body iron model). Results The Roche assay showed excellent intra- and inter-assay precision (CV 0.8); however, sTfR values by the Roche assay were on average 30% lower than values obtained with the two ELISA assays. Conclusions sTfR data measured with an immunoturbidimetric assay can be compared to a commonly used ELISA assay, and can be used in the body iron model through regression equations obtained in the present study.
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combined measurement of ferritin Soluble Transferrin Receptor retinol binding protein and c reactive protein by an inexpensive sensitive and simple sandwich enzyme linked immunosorbent assay technique
2004Co-Authors: Juergen G Erhardt, Christine M Pfeiffer, John E Estes, Hans Konrad Biesalski, Neal E CraftAbstract:The measurement of vitamin A (VA) and iron status is very important in the assessment of nutritional deficiencies. The objective of this research was to develop a sandwich ELISA technique for the simultaneous measurement of ferritin, Soluble Transferrin Receptor, retinol binding protein, and C-reactive protein (CRP) as indicators for VA and iron status. The inclusion of CRP as marker of infection allows for more accurate interpre- tation of VA and iron status. This is accomplished in a 30-L serum or plasma sample using an ELISA with different capture and detection antibodies and different dilutions of the sample. Commercially available clinical serum controls were used for calibration purposes. The developed assays were compared to commercially available traditional tests. Regression coefficients comparing both assays were better than 0.84 (P 0.001). Using a limited sample set, the sandwich ELISA assay produced very similar specificity and sensitivity compared to traditional methods when common cutoff values were applied. Intra- and interassay variability was between 5 and 14% for all tests. The cost of the materials for all 5 measurements decreases to less than $1/sample if a large number of samples is analyzed. Due to the low cost, high throughput, and comparability to traditional tests, this procedure has several advantages for assessing VA and iron status in population surveys. J. Nutr. 134: 3127-3132, 2004.
Elzbieta Packozuchowska - One of the best experts on this subject based on the ideXlab platform.
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Soluble Transferrin Receptor and Soluble Transferrin Receptor log ferritin index in diagnosis of iron deficiency anemia in pediatric inflammatory bowel disease
2019Co-Authors: Paulina Krawiec, Elzbieta PackozuchowskaAbstract:Abstract Background There is no single reliable marker of iron homeostasis in inflammatory bowel disease. Aims To determine diagnostic usefulness of Soluble Transferrin Receptor and Soluble Transferrin Receptor/log ferritin index in iron deficiency anemia in children with inflammatory bowel disease. Methods We assessed Soluble Transferrin Receptor in serum and calculated Soluble Transferrin Receptor/log ferritin index in 75 children with inflammatory bowel disease. Diagnostic ability to identify iron deficiency anemia was examined by receiver operating characteristic analysis. Results Study group comprised 27 cases of iron deficiency anemia, 6 anemia of chronic disease with iron deficiency, 5 anemia of chronic disease. Soluble Transferrin Receptor was significantly increased in children with iron deficiency anemia (median: 1.63 μg/ml) compared to non-anemic children (median: 1.02 μg/ml). Soluble Transferrin Receptor/log ferritin index was significantly higher in iron deficiency anemia (median: 1.76) than in anemia of chronic disease (median: 0.55), anemia of chronic disease with iron deficiency (median: 0.68) or patients without anemia (median: 0.72). Soluble Transferrin Receptor and its index were not correlated with disease activity or inflammatory markers. Diagnostic power for Soluble Transferrin Receptor/log ferritin index (0.864) was superior to Soluble Transferrin Receptor (0.768) in iron deficiency anemia recognition. Conclusion Soluble Transferrin Receptor/log ferritin index has better diagnostic utility than Soluble Transferrin Receptor for iron deficiency anemia detection in pediatric inflammatory bowel disease.
Paula C Southwick - One of the best experts on this subject based on the ideXlab platform.
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improved differential diagnosis of anemia of chronic disease and iron deficiency anemia a prospective multicenter evaluation of Soluble Transferrin Receptor and the stfr log ferritin index
2011Co-Authors: Barry S Skikne, Kari Punnonen, Paul H Caldron, Michael T Bennett, Mari Rehu, Gail H Gasior, Janna S Chamberlin, Linda A Sullivan, Kurtis R Bray, Paula C SouthwickAbstract:Anemia of chronic disease (ACD) and iron deficiency anemia (IDA) are the most prevalent forms of anemia and often occur concurrently. Standard tests of iron status used in differential diagnosis are affected by inflammation, hindering clinical interpretation. In contrast, Soluble Transferrin Receptor (sTfR) indicates iron deficiency and is unaffected by inflammation. Objectives of this prospective multicenter clinical trial were to evaluate and compare the diagnostic accuracy of sTfR and the sTfR/log ferritin index (sTfR Index) for differential diagnosis using the automated Access(®) sTfR assay (Beckman Coulter) and sTfR Index. We consecutively enrolled 145 anemic patients with common disorders associated with IDA and ACD. Subjects with IDA or ACD + IDA had significantly higher sTfR and sTfR Index values than subjects with ACD (P < 0.0001). ROC curves produced the following cutoffs for sTfR: 21 nmol/L (or 1.55 mg/L), and the sTfR Index: 14 (using nmol/L) (or 1.03 using mg/L). The sTfR Index was superior to sTfR (AUC 0.87 vs. 0.74, P < 0.0001). Use of all three parameters in combination more than doubled the detection of IDA, from 41% (ferritin alone) to 92% (ferritin, sTfR, sTfR Index). Use of sTfR and the sTfR Index improves detection of IDA, particularly in situations where routine markers provide equivocal results. Findings demonstrate a significant advantage in the simultaneous determination of ferritin, sTfR and sTfR Index. Obtaining a ferritin level alone may delay diagnosis of combined IDA and ACD.
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improved differential diagnosis of anemia of chronic disease and iron deficiency anemia a prospective multicenter evaluation of Soluble Transferrin Receptor and the stfr log ferritin index
2011Co-Authors: Barry S Skikne, Kari Punnonen, Paul H Caldron, Michael T Bennett, Mari Rehu, Gail H Gasior, Janna S Chamberlin, Linda A Sullivan, Kurtis R Bray, Paula C SouthwickAbstract:Anemia of chronic disease (ACD) and iron deficiency anemia (IDA) are the most prevalent forms of anemia and often occur concurrently. Standard tests of iron status used in differential diagnosis are affected by inflammation, hindering clinical interpretation. In contrast, Soluble Transferrin Receptor (sTfR) indicates iron deficiency and is unaffected by inflammation. Objectives of this prospective multicenter clinical trial were to evaluate and compare the diagnostic accuracy of sTfR and the sTfR/log ferritin index (sTfR Index) for differential diagnosis using the automated Access® sTfR assay (Beckman Coulter) and sTfR Index. We consecutively enrolled 145 anemic patients with common disorders associated with IDA and ACD. Subjects with IDA or ACD + IDA had significantly higher sTfR and sTfR Index values than subjects with ACD (P < 0.0001). ROC curves produced the following cutoffs for sTfR: 21 nmol/L (or 1.55 mg/L), and the sTfR Index: 14 (using nmol/L) (or 1.03 using mg/L). The sTfR Index was superior to sTfR (AUC 0.87 vs. 0.74, P < 0.0001). Use of all three parameters in combination more than doubled the detection of IDA, from 41% (ferritin alone) to 92% (ferritin, sTfR, sTfR Index). Use of sTfR and the sTfR Index improves detection of IDA, particularly in situations where routine markers provide equivocal results. Findings demonstrate a significant advantage in the simultaneous determination of ferritin, sTfR and sTfR Index. Obtaining a ferritin level alone may delay diagnosis of combined IDA and ACD. Am. J. Hematol., 2011. © 2011 Wiley-Liss, Inc.
Mauro Panteghini - One of the best experts on this subject based on the ideXlab platform.
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Soluble Transferrin Receptor in complicated anemia
2014Co-Authors: Federica Braga, Ilenia Infusino, A Dolci, Mauro PanteghiniAbstract:Determination of serum Soluble Transferrin Receptor (sTfR) has been proposed to identify iron-deficiency anemia (IDA) in patients affected by concurrent inflammatory disease that may spuriously increase ferritin concentration. The aim of this study was to critically review the available literature to assess the diagnostic efficacy of sTfR in complicated anemia. The criteria for study selection were: enrolment of patients with complicated anemia; bone marrow examination used as diagnostic gold standard for IDA; evaluation of sTfR vs. ferritin and binary data presentation. Six published studies met the criteria. However, the small size and wide heterogeneity of the studies did not allow us to conduct a meta-analysis. sTfR was overall more sensitive, even though it was evident that the ferritin sensitivity was influenced by selected cut-offs. Well-designed studies are still needed to define the added value, if any, of sTfR to ferritin for IDA detection in complicated anemia.
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Soluble Transferrin Receptor stfr and stfr log ferritin index for the diagnosis of iron deficiency anemia a meta analysis
2012Co-Authors: Ilenia Infusino, Federica Braga, A Dolci, Mauro PanteghiniAbstract:Determination of serum Soluble Transferrin Receptor (sTfR) is proposed to distinguish between iron-deficiency anemia and anemia of chronic disease. Here we conducted a meta-analysis of the literature to evaluate the diagnostic efficacy of sTfR and sTfR/log ferritin index. The meta-analysis included 18 sTfR and 10 sTfR index studies. Three sTfR index studies were, however, eliminated as outliers. The odds ratio was significant for both sTfR (22.9, 95% confidence interval [CI], 9.6-55.0) and sTfR index (9.5, 95% CI, 5.0-18.1) in a heterogeneous set of studies. Meta-analysis for sensitivity, specificity, and likelihood ratios (LRs) was performed only in a subset of 10 sTfR studies. The overall sensitivity, specificity, and positive and negative LRs were 86%, 75%, 3.85, and 0.19, respectively, with an area under summary receiver operating characteristic curve of 0.912 (standard error, 0.039). Additional studies are needed to define the overall diagnostic accuracy of sTfR.
Paulina Krawiec - One of the best experts on this subject based on the ideXlab platform.
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Soluble Transferrin Receptor and Soluble Transferrin Receptor log ferritin index in diagnosis of iron deficiency anemia in pediatric inflammatory bowel disease
2019Co-Authors: Paulina Krawiec, Elzbieta PackozuchowskaAbstract:Abstract Background There is no single reliable marker of iron homeostasis in inflammatory bowel disease. Aims To determine diagnostic usefulness of Soluble Transferrin Receptor and Soluble Transferrin Receptor/log ferritin index in iron deficiency anemia in children with inflammatory bowel disease. Methods We assessed Soluble Transferrin Receptor in serum and calculated Soluble Transferrin Receptor/log ferritin index in 75 children with inflammatory bowel disease. Diagnostic ability to identify iron deficiency anemia was examined by receiver operating characteristic analysis. Results Study group comprised 27 cases of iron deficiency anemia, 6 anemia of chronic disease with iron deficiency, 5 anemia of chronic disease. Soluble Transferrin Receptor was significantly increased in children with iron deficiency anemia (median: 1.63 μg/ml) compared to non-anemic children (median: 1.02 μg/ml). Soluble Transferrin Receptor/log ferritin index was significantly higher in iron deficiency anemia (median: 1.76) than in anemia of chronic disease (median: 0.55), anemia of chronic disease with iron deficiency (median: 0.68) or patients without anemia (median: 0.72). Soluble Transferrin Receptor and its index were not correlated with disease activity or inflammatory markers. Diagnostic power for Soluble Transferrin Receptor/log ferritin index (0.864) was superior to Soluble Transferrin Receptor (0.768) in iron deficiency anemia recognition. Conclusion Soluble Transferrin Receptor/log ferritin index has better diagnostic utility than Soluble Transferrin Receptor for iron deficiency anemia detection in pediatric inflammatory bowel disease.