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There is a need for laboratories to participate in EQA schemes to achieve a harmonization of test results and to improve serological testing and research on COVID-19 and SARS-CoV-2. The Boditech iCHROMA point of care immunoassay analyser has a Covid-19 antibody assay for the qualitative determination of IgG antibodies in human whole blood/serum/plasma. The National Institute for Biological Standards and Control (NIBSC) in the United Kingdom has a portfolio of reference and research reagents, including reagents for EQA that are available to laboratories to help them set up and develop accurate diagnostic tests for SARS-CoV-2 assays.

Objectives:

To determine the performance of the Boditech iCHROMA Covid-19 IgG antibody assay using the external quality control material provided by the UK NIBSC (National Institute for Biological Standards and Control) .

Results:

The Boditech iCHROMA Covid-19 IgG assay using the cut off index 1.1, reported the results of the 33 positive control samples as positive with index range from 19.50 - 29.00, with a mean of 23.75 and standard deviation of SD of 2.53. It also reported the results of the 33 negative control samples as negative with an index range of 0.00 for all samples.

More Info

The performance of the Boditech iCHROMA with EQA materials from organizations such as the United Kingdom National External Quality Assessment Service (UKNEQAS) and Randox International Quality Assessment Scheme (RIQAS) has been well described with analytes such as human chorionic gonadotrophin (HCG) [7], follicle stimulating hormone (FSH) [7], leutinising hormone (LH) [7], Vitamin D [8], Prostate Specific Antigen (PSA) [9], testosterone [10], ferritin [11]. The detection of SARS-CoV-2 infection is important in the understanding of this infection and the importance of the EQA in harmonizing the various methods of detecting the antibodies is appropriate. The preparedness and implementation of EQA have been instrumental in the rapid expansion of Covid 19 testing capacity in countries like Korea [12]. In a recent pilot EQA scheme for anti-SARS-CoV-2 antibody testing laboratories, 16 laboratories using commercially available test systems were invited into the scheme and provided samples. Fourteen (14) out of the 16 laboratories (87.4%) submitted their data. All 14/14 (100%) of the laboratories submitted data on IgG, 10/14 (71.4%) on IgA and 5/14 (35.7%) on IgM. The results of the laboratories testing SARS-CoV-2 IgG had a success rate of 80% in identifying the control samples and their results were robust with regards to concordance rate and accuracy.

The laboratory uses internal control which comprises of pooled samples of Covid 19 positive patients when running samples using the iCHROMA anti-SARS-CoV-2 IgG assay, in this study, using the external quality control from NIBSC, the iCHROMA anti-SARS-CoV-2 IgG assay identified 33/33 (100%) times the positive control sample, as positive, with an index range from 19.50 - 29.00, with a mean of 23.75 and standard deviation of SD of 2.53. Whilst the Boditech iCHROMA anti-SARS-CoV-2 IgG assay identified 33/33 (100%) times the negative control sample, as negative, with a consistent index range of 00.00. The range of the index estimated in the NIBSC positive control sample was 19.50 29.00, interestingly the index range observed in patient samples was between 22.8 and 74.6, indicating that the NIBSC positive control was within the range of the lower levels seen in clinical samples [6]. In conclusion, we have previously shown that the Boditech iCHROMA Covid-19 IgG antibody assay has close agreement with Abbott Architect SARS-CoV-2 IgG antibody assay and now the performance of the Boditech iCHROMA Covid-19 IgG antibody assay using EQA material from the UK NIBSC was very good, this study confirms the precision of the Boditech iCHROMA Covid 19 IgG antibody method from material issued by an external EQA provider.