Simultaneous assessment of iodine, iron, vitamin A, malarial antigenemia, and inflammation status biomarkers via a multiplex immunoassay method on a population of pregnant women from Niger

Abstract

Deficiencies of vitamin A, iron, and iodine are major public health concerns in many low- and middle-income countries, but information on their status in populations is often lacking due to high costs and logistical challenges associated with assessing micronutrient status. Accurate, user-friendly, and low-cost analytical tools are needed to allow large-scale population surveys on micronutrient status. We present the expansion of a 7-plex protein microarray tool for the simultaneous measurement of up to seven biomarkers with relevance to the assessment of the key micronutrients iron, iodine, and vitamin A, and inflammation and malaria biomarkers: α-1-acid glycoprotein, C-reactive protein, ferritin, retinol binding protein 4, soluble transferrin receptor, thyroglobulin, and histidine-rich protein II. Assay performance was assessed using international reference standards and then verified by comparing the multiplexed and conventional immunoassay results on a training panel of plasma samples collected from US adults. These data were used to assign nominal concentrations to the calibrators of the assay to further improve performance which was then assessed by interrogating plasma samples from a cohort of pregnant women from Niger. The correlation between assays for each biomarker measured from this cohort was typically good, with the exception of thyroglobulin, and the sensitivity ranged from 74% to 93%, and specificity from 81% to 98%. The 7-Plex micronutrient assay has the potential for use as an affordable tool for population surveillance of vitamin A, iron, and iodine deficiencies as well as falciparum malarial parasitemia infectivity and inflammation. The assay is easy-to-use, requires minimal sample volume, and is scalable, rapid, and accurate—needing only a low-cost reader and basic equipment present in most reference laboratory settings and so may be employed by low and middle income countries for micronutrient surveillance to inform on status in key populations. Micronutrient deficiencies including iron, iodine, and vitamin A affect a significant portion of the world’s population. Efforts to assess the prevalence of these deficiencies in vulnerable populations are challenging, partly due to measurement tools that are inadequate for assessing multiple micronutrients in large-scale population surveys. We have developed a 7-plex immunoassay for the simultaneous measurement of seven biomarkers relevant to assessing iodine, iron, and vitamin A status, inflammation and Plasmodium falciparum parasitemia by measuring levels of thyroglobulin, ferritin, soluble transferrin receptor, retinol binding protein 4, α-1-acid glycoprotein, C-reactive protein, and histidine-rich protein II. This 7-plex immunoassay technique has potential as a rapid and effective tool for use in large-scale surveys and assessments of nutrition intervention programs in low- and middle-income countries.

Determinants of dietary practices during pregnancy: A longitudinal qualitative study in Niger

“…The financial inaccessibility of nutritious foods during pregnancy and gender norms related to household food procurement have been reported extensively in low‐ and middle‐income countries (Christian et al, ; Girard, Dzingina, Akogun, Mason, & McFarland, ; Hartini, Padmawati, Lindholm, Surjono, & Winkvist, ; Huybregts, Roberfroid, Kolsteren, & Van Camp, ; Levay, Mumtaz, Rashid, & Willows, ; Scorgie et al, ). However, documenting the impact of these social and market forces on nutritional and pregnancy outcomes has been less of a priority for research conducted in Niger, where studies measuring maternal micronutrient deficiency burdens and other pregnancy‐related outcomes dominate the current research agenda (Brindle et al, ; Kay, Idrissa, & Hampton, ; Seim et al, ).…”

“…Women described specific symptoms associated with morning sickness as constraints to a healthy prenatal diet, but these symptoms typically resulted in aversions to food overall, rather than to specific food items -as documented in other studies (Young & Pike, 2012 et al, 2015). However, documenting the impact of these social and market forces on nutritional and pregnancy outcomes has been less of a priority for research conducted in Niger, where studies measuring maternal micronutrient deficiency burdens and other pregnancy-related outcomes dominate the current research agenda (Brindle et al, 2017;Kay, Idrissa, & Hampton, 2014;Seim et al, 2014).…”

Comparison of a New Multiplex Immunoassay for Measurement of Ferritin, Soluble Transferrin Receptor, Retinol-Binding Protein, C-Reactive Protein and α1-Acid-glycoprotein Concentrations against a Widely-Used s-ELISA Method

“…The observed lack of concordance may be attributed to the sample preparation. In 2017, the Quansys assay was validated using a Nigerian cohort of heparinized plasma samples [ 15 ]. The fact that serum and capillary samples were used in this study could account for some of the observed assay differences.…”

Adjusting Haemoglobin Values for Altitude Maximizes Combined Sensitivity and Specificity to Detect Iron Deficiency among Women of Reproductive Age in Johannesburg, South Africa

“…The strength of this study was the assessment of iron status by measuring two different biomarkers (ferritin and sTfR) using a validated method [29]. However, we do acknowledge that a recent study comparing the Quansys multiplex immunoassay with reference-type assays found poor precision for sTfR in comparison with the Roche cobas 6000 clinical analyser [41].…”

“…Plasma was separated within 1 h after blood collection, and aliquots stored at −20 • C for a maximum of 14 days until transportation (on dry ice) for storage at −80 • C until analysis. For the analysis of iron status indices and the inflammation/infection markers C-reactive protein (CRP) and alpha-1-acid glycoprotein (AGP), the Q-Plex™ Human Micronutrient Array (7-plex, Quansys Bioscience, Logan, UT, USA) was used [29].…”