A multicenter analytical performance evaluation of a multiplexed immunoarray for the simultaneous measurement of biomarkers of micronutrient deficiency, inflammation and malarial antigenemia

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Study Justification:
– Lack of comparative data across laboratories is a barrier to the adoption of new technologies.
– Different immunoassay methods may produce incomparable data due to a lack of harmonization.
– This multicenter study aims to validate the performance of the Q-plex™ 7-plex Human Micronutrient Array, which simultaneously measures biomarkers associated with micronutrient deficiencies, inflammation, and malarial antigenemia.
Study Highlights:
– Validation experiments were conducted in a single lab to assess precision and linearity.
– Cross-laboratory comparisons were performed using identical plasma samples from pregnant women in Niger.
– Intra- and inter-assay coefficients of variation were acceptable, indicating good precision.
– Generally good agreement was observed between laboratories for all analyte results.
– The 7-plex test protocol can be implemented by users with some experience in immunoassay methods.
Study Recommendations:
– Further validation of the 7-plex performance should be conducted independently.
– Consider using plasma samples for inter-laboratory assessments.
– Implement quality control measures to ensure accurate and reliable results.
– Provide training and support to laboratorians using the 7-plex assay.
– Consider harmonization efforts to improve comparability of immunoassay data.
Key Role Players:
– Researchers and scientists involved in conducting the study
– Laboratory technicians and operators performing the assays
– Experts in immunoassay methods and data analysis
– Policy makers and stakeholders in the field of public health and nutrition
Cost Items for Planning Recommendations:
– Training and support for laboratorians
– Quality control materials and equipment
– Assay kits and reagents
– Laboratory equipment maintenance and calibration
– Data analysis software and tools
– Shipping and logistics for sample distribution
– Communication and collaboration between laboratories

The strength of evidence for this abstract is 8 out of 10.
The evidence in the abstract is strong, but there are some areas for improvement. The multicenter study design and validation experiments conducted in a single lab provide a solid foundation for assessing the performance characteristics of the Q-plex 7-plex Human Micronutrient Array. The intra- and inter-assay coefficients of variation were acceptable, indicating good precision and linearity. Cross-laboratory comparisons showed generally good agreement between laboratories. However, there were some limitations, such as marginal performance of ferritin in some tests and higher inter-assay variation for soluble transferrin receptor. To improve the evidence, it would be beneficial to address these limitations and provide more detailed information on the methods used, such as the specific assay protocol and data analysis methods. Additionally, including information on the sample size and statistical analysis methods would further strengthen the evidence.

A lack of comparative data across laboratories is often a barrier to the uptake and adoption of new technologies. Furthermore, data generated by different immunoassay methods may be incomparable due to a lack of harmonization. In this multicenter study, we describe validation experiments conducted in a single lab and cross-lab comparisons of assay results to assess the performance characteristics of the Q-plex™ 7-plex Human Micronutrient Array (7-plex), an immunoassay that simultaneously quantifies seven biomarkers associated with micronutrient (MN) deficiencies, inflammation and malarial antigenemia using plasma or serum; alpha-1-acid glycoprotein, C-reactive protein, ferritin, histidine-rich protein 2, retinol binding protein 4, soluble transferrin receptor, and thyroglobulin. Validations included repeated testing (n = 20 separately prepared experiments on 10 assay plates) in a single lab to assess precision and linearity. Seven independent laboratories tested 76 identical heparin plasma samples collected from a cohort of pregnant women in Niger using the same 7-plex assay to assess differences in results across laboratories. In the analytical validation experiments, intra- and inter-assay coefficients of variation were acceptable at <6% and 300 μL) of plasma. Using the original 7-plex data, seventy-eight samples with concentrations representing the full range for each analyte were chosen for sub aliquoting to create 16+ identical panels consisting of 78 separate 20 μL plasma samples as follows: The frozen plasma was thawed on ice, spun briefly in a microfuge and pipetted into sterile screw cap tubes, which were then stored -80 °C (Fig 1). Two of these samples were randomly chosen from the panel and all 19 of the aliquots prepared from these samples were assessed by the 7-plex to test for tube-to-tube variability that might have been introduced during sub-aliquoting. Both samples had an intra-assay CV < 10% for each analyte (S1 Table), confirming analyte uniformity across sample tubes. The original specimen identifiers of the remaining samples were replaced with sequential numbering from 1–76, effectively blinding the labs previously involved in studies that used specimens from this panel. The samples were stored at -80 °C until shipment to the partner laboratories. In addition to the 76 member Niger heparin plasma panel samples, Quansys Biosciences prepared QC samples, named G and H, representing both high and low analyte values to be run on each plate (Fig 1). These quality controls were used to evaluate whether each plate used during this study would meet acceptance criteria ideally applied in the routine use of the kit. The controls were prepared by spiking serum with purified biomarkers as needed to reach the desired concentration of each biomarker [23]. Prior to distribution, the G and H controls were quantified by Quansys via a series of twenty independent test runs using the 7-plex to determine the expected values of all 7 biomarkers (S2 Table). Seven distinct laboratories offered to be part of the inter-laboratory performance study, each providing data from at least one, and ideally two, laboratorians per facility. Laboratories at PATH, the University of Washington, Quansys, and UC Davis had previously collaborated to develop and verify the performance of the Human Micronutrient assay [22–24] (Fig 1). Other laboratories, including ones from the US Centers for Disease Control and Prevention (CDC, GA), Eurofins Craft Technologies, Inc. (NC), Binghamton University (SUNY), and the University of British Columbia have also been independently evaluating the performance of the Human Micronutrient assay [27–30]. Once each laboratory had signed the MTA to access the samples, two complete sets of 76 heparin plasma samples and two of the G and H quality control sets, were shipped on dry ice via overnight courier. Recipients acknowledged the panels’ integrity (frozen with dry ice still in packaging) upon arrival and stored them at -80 °C until assay. The manufacturer of the assay, Quansys, was excluded from the study in order to limit bias, as their technical staff are most familiar with the platform and they manufacture and market the Human Micronutrient assay kit. Prior to performing testing, all laboratories were offered a training webinar hosted by an experienced Q-plex user (E. Brindle), to ensure that each study laboratorian was familiar with the test protocol and data analysis methods. All of the array kits used in the inter-laboratory assessment exercise were from the same manufacturing lot. Each plate image was saved and reviewed by an expert user (E. Brindle) to confirm consistency in software settings used to fit calibration curves and report results (Fig 1). To understand effects of user skills and experience and status of laboratory equipment on results, a questionnaire was distributed prior to testing to collect details from each laboratory. Each operator completed a questionnaire to determine their level of previous experience with the 7-plex, and experience with quantitative immunoassays (Fig 1). An inventory of equipment summarized maintenance histories for items necessary for use with the 7-plex, and specified the plate washing method. Experience and equipment status questionnaire results were summarized by assigning a scale value to each element, scoring each factor as follows: Lab operator experience (2 elements, 1 to 3 scale, with 3 as most experience), Quansys software experience (0 to 1 scale, 1 is experienced), automated plate washer availability (0 to 1 scale, 1 is available), and recency of calibration (2 elements, 1 to 3 scale with 3 as most recent). Scores were totaled to derive a summary score ranging from 0 (no experience, poor equipment status indicators) to 14 (extensive user experience, all equipment present and recently calibrated). Values below the lower limit of quantification (LLOQ) for each analyte were excluded from analyses. Results of the quality control samples run on every plate were evaluated to determine whether the plates would meet acceptance criteria that, for the purposes of this study, were intentionally less stringent than would generally be permitted, whereby at least one control result should have any 6 of the 7 analyte results falling within a 95% confidence interval calculated from all plates in the study. Because the intent of this exercise was to evaluate reproducibility, all plates were included nearly all subsequent analyses. The effect of excluding data from any plates meeting this rejection criteria was considered separately. Inter-assay CV’s were calculated to evaluate the performance between the 7 labs and intra-assay CV’s were calculated to evaluate the performance within each of the 7 labs. Intra-assay CVs for duplicate wells of the test samples were averaged for each analyte on each plate, and then plate averages were aggregated across analytes to summarize intra-assay CV averages by lab and by operator. Inter-assay CVs were calculated across all plates (n = 12) for each sample (n = 76); inter-assay CVs were then averaged to summarize inter-assay CV for each analyte. Agreement between results across laboratories was assessed using Lin’s concordance correlation coefficient (CCC) [31]. Results from assays conducted in the PATH and UW labs by the three operators with the most experience using the 7-Plex were averaged to create a comparison set that was compared to each of the nine remaining assay batches from five labs. Lin’s CCC was calculated using STATA version 15.1 (StataCorp, College Station, TX USA).

Based on the provided description, the innovation for improving access to maternal health is the development and validation of the Q-plex™ 7-plex Human Micronutrient Array. This immunoassay technology allows for the simultaneous measurement of seven biomarkers associated with micronutrient deficiencies, inflammation, and malarial antigenemia using plasma or serum samples. The multicenter study conducted in multiple laboratories demonstrated the performance characteristics and comparability of assay results across different labs. The assay showed acceptable precision, linearity, and agreement between laboratories, making it a promising tool for assessing maternal health and identifying potential deficiencies or health risks.
AI Innovations Description
The description provided is about a multicenter analytical performance evaluation of a multiplexed immunoarray called the Q-plex™ 7-plex Human Micronutrient Array. This immunoassay simultaneously measures seven biomarkers associated with micronutrient deficiencies, inflammation, and malarial antigenemia in plasma or serum samples. The study aimed to assess the performance characteristics of the assay across different laboratories.

The validation experiments included testing the precision and linearity of the assay in a single lab, as well as cross-laboratory comparisons of assay results using identical plasma samples from pregnant women in Niger. The results showed acceptable intra- and inter-assay coefficients of variation, indicating good precision and linearity of the assay. The cross-laboratory comparisons also demonstrated generally good agreement between laboratories for all analyte results.

To perform the assay, samples were processed following the assay protocol, which involved reconstituting lyophilized competitor mix and calibrator, preparing standard curves, and diluting samples and controls. The prepared samples, controls, and standards were added to assay plates, incubated, washed, and labeled. The chemiluminescent signal from each spot in the plates was quantified using imaging software, and the concentration of each analyte was interpolated from the pixel intensities.

The validation experiments and inter-laboratory assessment were conducted using plasma samples from a study of micronutrient status among pregnant women in Niger. The samples were stored at -80°C and shipped to the partner laboratories on dry ice. Each laboratory received two sets of samples and quality control sets. Prior to testing, a training webinar was provided to ensure familiarity with the test protocol and data analysis methods.

The results of the inter-laboratory assessment were analyzed to estimate intra- and inter-assay imprecision and linearity. Intra-assay coefficients of variation were calculated for each lab, and inter-assay coefficients of variation were averaged across all labs. The agreement between results across laboratories was assessed using Lin’s concordance correlation coefficient.

Overall, the study demonstrated that the Q-plex™ 7-plex Human Micronutrient Array can be implemented by users with some experience in immunoassay methods. The assay showed good performance characteristics and agreement between laboratories, indicating its potential for improving access to maternal health by providing a multiplexed measurement of biomarkers associated with maternal health conditions.
AI Innovations Methodology
Based on the provided description, the methodology used to simulate the impact of recommendations on improving access to maternal health can be summarized as follows:

1. Identify the recommendations: Review the existing literature and research to identify potential recommendations that can improve access to maternal health. These recommendations can include innovative approaches, technologies, or interventions that address barriers to accessing maternal health services.

2. Define the simulation model: Develop a simulation model that represents the current state of maternal health access and the potential impact of the identified recommendations. The model should include relevant variables such as geographical location, population demographics, healthcare infrastructure, and existing maternal health services.

3. Collect data: Gather data on the current state of maternal health access, including information on healthcare facilities, healthcare providers, transportation infrastructure, and socio-economic factors. This data will be used to calibrate and validate the simulation model.

4. Implement the recommendations: Introduce the identified recommendations into the simulation model. This can be done by adjusting relevant variables such as the availability of healthcare facilities, the number of healthcare providers, or the accessibility of transportation.

5. Run the simulation: Execute the simulation model to simulate the impact of the recommendations on improving access to maternal health. The simulation should consider various scenarios and factors that may influence the outcomes, such as population growth, changes in healthcare policies, or the introduction of new technologies.

6. Analyze the results: Analyze the simulation results to assess the impact of the recommendations on improving access to maternal health. Evaluate key indicators such as the number of women accessing maternal health services, the distance traveled to reach healthcare facilities, or the availability of essential maternal health resources.

7. Refine and iterate: Based on the analysis of the simulation results, refine the recommendations and the simulation model if necessary. Repeat the simulation process to further assess the impact of the refined recommendations on improving access to maternal health.

8. Communicate the findings: Present the findings of the simulation study to relevant stakeholders, such as policymakers, healthcare providers, and community organizations. Use the results to advocate for the implementation of the recommendations and to inform decision-making processes related to maternal health access.

It is important to note that the specific details and complexity of the simulation methodology may vary depending on the scope and objectives of the study.

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