Comparison of a rapid immunochromatographic test with a chemiluminescence immunoassay for detection of anti-SARS-CoV-2 IgM and IgG.

The 2019 Coronavirus disease (COVID-19) has been characterized as a pandemic, representing a serious global public health emergency. Serological tests have been proposed as reliable tools for detecting Coronavirus SARS-CoV-2 antibodies in infected patients, especially for surveillance or epidemiological purposes. The aim of this study is to evaluate the agreement between the IgM/IgG rapid assays, based on lateral flow immunochromatographic assay, and the fully automated 2019-nCoV IgM and IgG, based on chemiluminescence immunoassay. SARS-CoV-2 antibodies were measured with the BIOSYNEX COVID-19 BSS IgM/IgG test (BIOSYNEX, Illkirch-Graffenstaden, France) and the MAGLUMI CLIA (IgM and IgG) (SNIBE - Shenzhen New Industries Biomedical Engineering, Shenzhen, China) in 70 serum samples from patients with PCR-confirmed diagnosis. The strength of the agreement of the two methods was calculated by using the Cohen Kappa index. The results showed a good grade of concordance between the two immunoassays with a Cohen's kappa coefficient of 0.71 (95%CI: 0.54-0.87) for IgG SARS-CoV-2 antibodies and 0.70 (95%CI: 0.53-0.87) for IgM SARS-CoV-2 antibodies. In addition, the rapid assays BIOSYNEX COVID-19 BSS for detecting SARS-CoV-2 antibodies showed a positive likelihood ratio (LR) of 10.63 (95%CI: 2.79-40.57) for IgG and a LR of 6.79 (95%CI: 2.93-15.69) for IgM. Our results suggest that the immunochromatographic rapid IgM/IgG test and the chemiluminescence IgM and IgG immunoassay have a good degree of concordance, suggesting that both could be considered as useful tools for epidemiologic surveillance.

Gambino CM ，Lo Sasso B ，Colomba C ，Giglio RV ，Agnello L ，Bivona G ，Ciaccio M ... -  《-》

Evaluations of the serological test in the diagnosis of 2019 novel coronavirus (SARS-CoV-2) infections during the COVID-19 outbreak.

Lin D ，Liu L ，Zhang M ，Hu Y ，Yang Q ，Guo J ，Dai Y ，Xu Y ，Cai Y ，Chen X ，Huang K ，Zhang Z ... -  《-》

Assessment of SARS-CoV-2 serological tests for the diagnosis of COVID-19 through the evaluation of three immunoassays: Two automated immunoassays (Euroimmun and Abbott) and one rapid lateral flow immunoassay (NG Biotech).

The emergence of new SARS-CoV-2 has promoted the development of new serological tests that could be complementary to RT-PCR. Nevertheless, the assessment of clinical performances of available tests is urgently required as their use has just been initiated for diagnose. The aim of this study was to assess the performance of three immunoassays for the detection of SARS-CoV-2 antibodies. Two automated immunoassays (Abbott SARS-CoV-2 CLIA IgG and Euroimmun Anti-SARS-CoV-2 ELISA IgG/IgA assays) and one lateral flow immunoassay (LFIA NG-Test® IgG-IgM COVID-19) were tested. 293 specimens were analyzed from patients with a positive RT-PCR response, from patients with symptoms consistent with COVID-19 but exhibiting a negative response to the RT-PCR detection test, and from control group specimens. Days since symptoms onset were collected from clinical information sheet associated with respiratory tract samples. Overall sensitivity for IgG was equivalent (around 80 %) for CLIA, ELISA and LFIA. Sensitivity for IgG detection, >14 days after onset of symptoms, was 100.0 % for all assays. Overall specificity for IgG was greater for CLIA and LFIA (more than 98 %) compared to ELISA (95.8 %). Specificity was significantly different between IgA ELISA (78.9 %) and IgM LFIA (95.8 %) (p < 0.05). The best agreement was observed between CLIA and LFIA assays (97 %; k = 0.936). Excellent sensitivity for IgG detection was obtained >14 days after onset of symptoms for all immunoassays. Specificity was also excellent for IgG CLIA and IgG LFIA. Our study shows that NG-Test® is reliable and accurate for routine use in clinical laboratories.

Nicol T ，Lefeuvre C ，Serri O ，Pivert A ，Joubaud F ，Dubée V ，Kouatchet A ，Ducancelle A ，Lunel-Fabiani F ，Le Guillou-Guillemette H ... -  《-》

Analytical performances of a chemiluminescence immunoassay for SARS-CoV-2 IgM/IgG and antibody kinetics.

Padoan A ，Cosma C ，Sciacovelli L ，Faggian D ，Plebani M ... -  《-》

Performance of six SARS-CoV-2 immunoassays in comparison with microneutralisation.

There is an urgent need for reliable high-throughput serological assays for the management of the ongoing COVID-19 pandemic. Preferably, the performance of serological tests for a novel virus should be determined with clinical specimens against a gold standard, i.e. virus neutralisation. We compared the performance of six commercial immunoassays for the detection of SARS-COV-2 IgG, IgA and IgM antibodies, including four automated assays [Abbott SARS-COV-2 IgG (CE marked), Diasorin Liaison® SARS-COV-2 S1/S2 IgG (research use only, RUO), and Euroimmun SARS-COV-2 IgG and IgA (CE marked)], and two rapid lateral flow (immunocromatographic) tests [Acro Biotech 2019-nCoV IgG/IgM (CE marked) and Xiamen Biotime Biotechnology SARS-COV-2 IgG/IgM (CE marked)] with a microneutralisation test (MNT). Two specimen panels from serum samples sent to Helsinki University Hospital Laboratory (HUSLAB) were compiled: the patient panel (N=70) included sera from PCR confirmed COVID-19 patients, and the negative panel (N=81) included sera sent for screening of autoimmune diseases and respiratory virus antibodies in 2018 and 2019. The MNT was carried out for all COVID-19 samples (70 serum samples, 62 individuals) and for 53 samples from the negative panel. Forty-one out of 62 COVID-19 patients showed neutralising antibodies.The specificity and sensitivity values of the commercial tests against MNT, respectively, were as follows: 95.1 %/80.5 % (Abbott Architect SARS-CoV-2 IgG), 94.9 %/43.8 % (Diasorin Liaison SARS-CoV-2 IgG; RUO), 68.3 %/87.8 % (Euroimmun SARS-CoV-2 IgA), 86.6 %/70.7 % (Euroimmun SARS-CoV-2 IgG), 74.4 %/56.1 % (Acro 2019-nCoV IgG), 69.5 %/46.3 % (Acro 2019-nCoV IgM), 97.5 %/71.9 % (Xiamen Biotime SARS-CoV-2 IgG), and 88.8 %/81.3 % (Xiamen Biotime SARS-CoV-2 IgM). This study shows variable performance values. Laboratories should carefully consider their testing process, such as a two-tier approach, in order to optimize the overall performance of SARS- CoV-2 serodiagnostics.

Jääskeläinen AJ ，Kuivanen S ，Kekäläinen E ，Ahava MJ ，Loginov R ，Kallio-Kokko H ，Vapalahti O ，Jarva H ，Kurkela S ，Lappalainen M ... -  《-》