Evidence map›Paper›PMID 29966018›Full record

ArticlePloS one2018

Analysis of factors affecting the variability of a quantitative suspension bead array assay measuring IgG to multiple Plasmodium antigens.

Itziar Ubillos, Ruth Aguilar, Hector Sanz, Alfons Jiménez, Marta Vidal, Aida Valmaseda, Yan Dong, Deepak Gaur, Chetan E Chitnis, Sheetij Dutta and 6 more

Open access · goldAbstract read
In one paragraph

Article in PloS one, 2018. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 10 papers.

0numbers the graph read from it
0cells of the map it votes in
10citing papers in PubMed
2.3field-weighted citation impact, top 12% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

10 citing papers in PubMed, 17 citations in OpenAlex.

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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

16 authors at 6 institutions in 3 countries.

Itziar UbillosISGlobal, Hospital Clínic-Universitat de Barcelona, Barcelona, Catalonia, Spain.
Ruth AguilarISGlobal, Hospital Clínic-Universitat de Barcelona, Barcelona, Catalonia, Spain.
Hector SanzISGlobal, Hospital Clínic-Universitat de Barcelona, Barcelona, Catalonia, Spain.
Alfons JiménezISGlobal, Hospital Clínic-Universitat de Barcelona, Barcelona, Catalonia, Spain.
Marta VidalISGlobal, Hospital Clínic-Universitat de Barcelona, Barcelona, Catalonia, Spain.
Aida ValmasedaISGlobal, Hospital Clínic-Universitat de Barcelona, Barcelona, Catalonia, Spain.
Yan DongDepartment of Biostatistics, RM Fairbanks School of Public Health, Indianapolis, IN, United States of America.
Deepak GaurMalaria Group, International Centre for Genetic Engineering and Biotechnology (ICGEB), New Delhi, India.
Chetan E ChitnisMalaria Group, International Centre for Genetic Engineering and Biotechnology (ICGEB), New Delhi, India.
Sheetij DuttaU.S. Military Malaria Vaccine Program, Walter Reed Army Institute of Research (WRAIR), Silver Spring, Maryland, United States of America.
Evelina AngovU.S. Military Malaria Vaccine Program, Walter Reed Army Institute of Research (WRAIR), Silver Spring, Maryland, United States of America.
John J AponteISGlobal, Hospital Clínic-Universitat de Barcelona, Barcelona, Catalonia, Spain.
Joseph J CampoISGlobal, Hospital Clínic-Universitat de Barcelona, Barcelona, Catalonia, Spain.
Clarissa ValimDepartment of Osteopathic Medical Specialties, Michigan State University, East Lansing, MI, United States of America.
Jaroslaw HarezlakDepartment of Biostatistics, RM Fairbanks School of Public Health, Indianapolis, IN, United States of America.
Carlota DobañoISGlobal, Hospital Clínic-Universitat de Barcelona, Barcelona, Catalonia, Spain.ORCID 0000-0002-6751-4060
Barcelona Institute for Global Health · ESRichard M. Fairbanks Foundation · USWalter Reed Army Institute of Research · USHarvard University · USInternational Centre for Genetic Engineering and Biotechnology · INJawaharlal Nehru University · IN

Funding

Understanding RTS,S malaria vaccine-induced protection through integrated analysiR01AI095789 · NIAID · BARCELONA INTERNATIONAL HEALTH RES CTR · PI DOBANO, CARLOTA · 2012 to 2016
$3.2M
NIAID NIH HHS R01 AI095789
6 · The paper itself

Abstract

Reducing variability of quantitative suspension array assays is key for multi-center and large sero-epidemiological studies. To maximize precision and robustness of an in-house IgG multiplex assay, we analyzed the effect of several conditions on variability to find the best combination. The following assay conditions were studied through a fractional factorial design: antigen-bead coupling (stock vs. several), sample predilution (stock vs. daily), temperature of incubation of sample with antigen-bead (22°C vs. 37°C), plate washing (manual vs. automatic) and operator expertise (expert vs. apprentice). IgG levels against seven P. falciparum antigens with heterogeneous immunogenicities were measured in test samples, in a positive control and in blanks. We assessed the variability and MFI quantification range associated to each combination of conditions, and their interactions, and evaluated the minimum number of samples and blank replicates to achieve good replicability. Results showed that antigen immunogenicity and sample seroreactivity defined the optimal dilution to assess the effect of assay conditions on variability. We found that a unique antigen-bead coupling, samples prediluted daily, incubation at 22°C, and automatic washing, had lower variability. However, variability increased when performing several couplings and incubating at 22°C vs. 37°C. In addition, no effect of temperature was seen with a unique coupling. The expertise of the operator had no effect on assay variability but reduced the MFI quantification range. Finally, differences between sample replicates were minimal, and two blanks were sufficient to capture assay variability, as suggested by the constant Intraclass Correlation Coefficient of three and two blanks. To conclude, a single coupling was the variable that most consistently reduced assay variability, being clearly advisable. In addition, we suggest having more sample dilutions instead of replicates to increase the likelihood of sample MFIs falling in the linear part of the antigen-specific curve, thus increasing precision.

Indexed as

Antibodies, ProtozoanAntigens, ProtozoanEnzyme-Linked Immunosorbent AssayHumansImmunoglobulin GMalaria, FalciparumPlasmodium falciparumAntibodies, ProtozoanAntigens, ProtozoanImmunoglobulin G

Identifiers

PMID29966018
PMCPMC6028107
OpenAlexW2811246946

What OpenQuestion holds

Textmetadata
LicenceCC0
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.