Clinical Validation of Automated and Rapid mariPOC SARS-CoV-2 Antigen Test

Abstract

Novel SARS coronavirus causing COVID-19 was recognized in late 2019. Diagnostics was quickly ramped up worldwide based on the detection of viral RNA. Based on the scientific knowledge for pre-existing coronaviruses, it was expected that the RNA of this novel coronavirus will be detected at significant rates from symptomatic and asymptomatic individuals due to existence of non-infectious RNA. To increase the efficacy of diagnostics, surveillance, screening and pandemic control, rapid methods, such as antigen tests, are needed for decentralized testing and to assess infectiousness. The objectives were to verify analytical sensitivity and specificity, and assess the clinical sensitivity, specificity and usability of a novel automated mariPOC SARS-CoV-2 test based on sophisticated optical laser technology detecting viral structure proteins. Analytical performance was verified using bacterial and viral preparations. Clinical performance of the test was evaluated against qRT-PCR in a retrospective study with nasopharyngeal swab specimens (N=211) collected from symptomatic patients suspected of acute SARS-CoV-2 infections. Sensitivity and specificity of the mariPOC test were 92.3% (12/13) and 100.0% (198/198), respectively. The test's limit of detection was 22 PFU/test and it had no cross-reactions with the tested respiratory microbes. Our study shows that the mariPOC can detect infectious individuals already in 20 minutes while clinical sensitivity close to qRT-PCR is achieved in two hours or less. The test targets conserved epitopes of SARS-CoV-2 nucleoprotein, making it robust against strain variations. The new test is a promising and versatile tool for syndromic testing of symptomatic cases and for high capacity infection control screening.

Clinical evaluation of an automated, rapid mariPOC® antigen test in screening of symptomatics and asymptomatics for SARS-CoV-2 infections

“…In our study, 91.4% (32/35 total mariPOC ® antigen test positives) of positive samples were positive already at 20 minutes. Our prospective evaluation results of the mariPOC ® test are well in line with those reported earlier from a retrospective study [18].…”

“…The technique of the mariPOC ® SARS-CoV-2 rapid antigen test (ArcDia International Ltd, Finland) is based on the detection of conserved SARS-CoV-2 nucleocapsid protein with specific monoclonal antibodies. Most positive test results are reported after 20 minutes and final results within 55 minutes [17,18]. The mariPOC ® platform is an automated and random access test system that enables simple and quick workflow, high capacity testing, as well as objective result readout.…”

The evaluation of an automated mariPOC SARS‐CoV‐2 antigen test compared to RT‐qPCR SARS‐CoV‐2 assay and comparison of its sensitivity in Delta‐ and Omicron‐variant samples

“…The index antigen test in the study was an automated mariPOC SARS-CoV-2 test (ArcDia International Ltd, Finland) that targets a conserved epitope in the N-protein. 13 The volume of 650 μl of VTM was diluted with 650 μl of test sample buffer, vortexed and inserted into the instrument. In the prospective part of the study, antigen test results were unknown by those interpreting RT-qPCR results.…”

Field clinical performance of SARS-CoV-2 point-of-care diagnostic tests: a living systematic review of trials up to 17th of August, 2021

“…Another example is the study by Panpradist et al 195 evaluating the Harmony COVID-19 platform. The study by Koskinen et al 196 on the MariPOC platform (ArcDia) was not included as it was conducted retrospectively with frozen samples. Some studies were excluded due to methodology. Hoehl et al 159 study using the RIDA® QUICK SARS-CoV-2 (R-Biopharm) was not included as a minimal number of samples were tested with a confirmation method, and thus false negative results could not be determined.…”

“…Another example is the study by Panpradist et al 195 evaluating the Harmony COVID-19 platform. The study by Koskinen et al 196 on the MariPOC platform (ArcDia) was not included as it was conducted retrospectively with frozen samples.…”