Context: The use of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) serological tests detect antibodies in the host, contributing to the identification of individuals who have been exposed to Coronavirus Disease 2019 (COVID-19).
Objective: To critically evaluate two commercially available SARS-CoV-2 serology tests.
Design: A total of 333 unique, non-duplicated serum samples obtained from COVID-19 patients (n=170) and negative controls (n=163) obtained pre-December 2019 were used in the study. Samples were tested on the Roche E411 and Abbott Architect i4000SR platforms and results were correlated to reverse transcription polymerase chain reaction (PCR) results and clinical symptoms.
Results: There was a strong level of agreement in the qualitative results between both assays with a Cohen's kappa value of 0.840, P<.001. The specificity for both Roche and Abbott were excellent at 100%. Roche exhibited marginally better performance in the ≥21 days group with a sensitivity of 90.6% (95% CI 75.8–96.8%) versus Abbott's sensitivity 84.4% (95% CI 68.3 – 93.1%) as well as the 14–20 days group with a sensitivity of 85.7% (95% CI 65.4 – 95.0%) versus Abbott sensitivity 81.0% (95% CI 60.0 – 92.3%). Less than 14 days of symptoms groups exhibited poor sensitivity at <50% for both assays. The area under curve (AUC ± standard error) for Roche (0.894 ± 0.025, P< .001) and Abbott (0.884 ± 0.026, P <.001) were very similar. Potential confounders for negative serological results include antiretroviral medication use and pauci-symptomatic patients.
Conclusions: Specificities for high throughput Roche and Abbott immunoassays are excellent but users need to be cautious to interpret serological test results after 14 days of symptoms to avoid false negatives
Dr Tambyah has received grants paid to the National University Hospital from Roche (CP40617, MV40618), Johnson & Johnson (63623872FLZ3001, 63623872FLZ2002), Sanofi Pasteur (H-030-014), GlaxoSmithKline, and Shionogi (1601T0831). The other authors have no relevant financial interest in the products or companies described in this article.