Performance of Commercial SARS-CoV-2 Ab Tests Varies
Performance highly dependent on time of sampling in head-to-head comparisons
FRIDAY, Sept. 25, 2020 (HealthDay News) -- There is considerable variation in the performance of commercial kits for detecting antibodies against SARS-CoV-2, according to a study published online Sept. 24 in PLOS Pathogens.
Suzanne Pickering, Ph.D., from King's College London, and colleagues examined the performance of various antibody testing technologies and their potential use as diagnostic tools. Highly specific enzyme-linked immunosorbent assays were developed for detection of anti-spike, -receptor binding domain, and -nucleocapsid antibodies and were used for cross-comparison of 10 commercial serological assays on an identical panel of 110 SARS-CoV-2-positive samples and 50 prepandemic negatives.
The researchers identified wide variation in the performance of different platforms, with specificity varying from 82 to 100 percent and sensitivity from 60.9 to 87.3 percent. The head-to-head comparison showed that performance was highly dependent on the time of sampling, with sensitivities of more than 95 percent in several tests when examining samples from more than 20 days after symptom onset. Clear outlying samples were identified that were negative in all tests, but these were taken from individuals with the mildest disease presentation.
"Some of the best-performing tests were rapid lateral flow immunoassays, which are affordable, quick and easy to use, and if they are deployed appropriately could have considerable utility in health care settings," the authors write.
The study was partially funded by the Anhui Deep Blue company; different companies donated test kits.