Rapid diagnostics for point-of-care quantification of soluble transferrin receptor

Abstract

Background Iron deficiency (ID) and anaemia are major health concerns, particularly in young children. Screening for ID based on haemoglobin (Hb) concentration alone has been shown to lack sensitivity and specificity. The American Academy of Pediatrics (AAP) recommends soluble transferrin receptor (sTfR) as a promising approach to screen for iron deficiency. However, in most settings, assessment of iron status requires access to centralized laboratories. There is an urgent need for rapid, sensitive, and affordable diagnostics for sTfR at the point-of-care. Methods An immunochromatographic assay-based point-of-care screening device was developed for rapid quantification of sTfR from a drop of serum within a few minutes. Performance optimization of the assay was done in sTfR-spiked buffer and commercially available sTfR calibrator, followed by a small-scale proof-of-concept validation with archived serum samples. Findings On preliminary testing with archived serum samples and comparison with Ramco ELISA, a correlation of 0.93 (P < 0.0001) was observed, demonstrating its potential for point-of-care assessment of iron status. Interpretation The analytical performance of the point-of-care sTfR screening device indicates the potential for application in home-use test kits and field settings, especially in low- and middle-income settings. An added advantage of sTfR quantification in combination with our previously reported serum ferritin diagnostics is in integration of Cook's equation as a quantitative and minimally-invasive indicator of total body iron stores. Fund Thrasher Research Fund (Early Career Award #13379), NIH R03 EB 023190, NSF grant #1343058, and Nutrition International (project #10-8007-CORNE-01).

The Serological Basis of the Correlation between Iron Deficiency Anemia and Thyroid Disorders in Women: A Community Based Study

“…In this research, to identify the anemic women, the iron (µg/dl) and TIBC (µg/dl) level of the patients' serum were tested quantitatively through the procedure of the Dimension® clinical chemistry system using 'Dimension®IRON Flex® reagent cartridge (DF85)' and 'Dimension®Flex® Reagent IBCT', Siemens Healthcare Diagnostics Inc., USA, respectively following their established methodology [31]. The ferritin level (ng/dl) was tested quantitatively with 'Beckman Coulter Access Ferritin Calibrators (S0-S5)' following [32].…”

The Importance of Iron Status for Young Children in Low- and Middle-Income Countries: A Narrative Review

“…The ratio between sTfR and log-ferritin (ferritin index) offers the advantage of combining two markers covering different aspects in iron depletion, generally improving sensitivity and specificity compared to their individual use [24]. Of note, paper-based smartphone-app-guided point-of-care assays for ferritin and sTfR show promise in proof-of-principle studies, suggesting field measurement of these markers in children from resource-limited settings may become feasible [97,98]. Other markers of iron-restricted erythropoiesis are zinc protoporphyrin (ZPP) and the ZPP/haem ratio in red blood cells; ZPP accumulates in the last step of haemoglobin synthesis when iron is lacking [99].…”

Quantitative Analysis of the Steroidal Calcitriol-Mediated Regulation of the Serological Components Responsible for IDA and TSH Disorders in Reproductive and Nonproductive Women

“…The iron (µg/dl) and TIBC (µg/dl) level of the patients' serum were quantitatively analyzed using 'Dimension®IRON Flex® reagent cartridge (DF85)' and 'Dimension®Flex® Reagent IBCT' (Siemens Healthcare Diagnostics Inc., USA) respectively, following the referred methodology [35,36]. The ferritin level (ng/dl) was tested quantitatively with 'Beckman Coulter Access Ferritin Calibrators (S0-S5)' considering its established protocol [36,37]. On the other hand, 'ADVIA®Centaur™ TSH-3 Kit' (Siemens, USA) and 'ADVIA®Centaur™ FT4 Kit' (Siemens, USA) were used to diagnose TSH (µIU/ml) and FT4 (ng/dl) respectively.…”