Intended for healthcare professionals

Rapid response to:

Editorials

Antibody testing for coronavirus disease 2019: not ready for prime time

BMJ 2020; 370 doi: https://doi.org/10.1136/bmj.m2655 (Published 03 July 2020) Cite this as: BMJ 2020;370:m2655

Linked Research

Diagnostic accuracy of serological tests for covid-19

Read our latest coverage of the coronavirus pandemic

Rapid Response:

Re: Antibody testing for coronavirus disease 2019: not ready for prime time

Dear Editor,
In a rapid response [1] to our editorial [2], Professor Deeks states that we misrepresented the conclusion of the Cochrane review he and others recently wrote [3]. Our editorial provides our interpretation of the meta-analysis by Bastos et al. [4], as well as other available data on the performance of antibody tests for SARS-CoV-2, which includes the Cochrane report by Deeks et al. In our editorial, we referred to the Cochrane systematic review when we wrote:
“Nonetheless, the key message of the [linked] review aligns with the conclusion of another systematic review published last week: serologic assays for SARS-CoV-2 antibodies, especially point-of-care tests, are not ready for widespread use by clinicians, the general public, or policy makers.”

Deeks is concerned that the statement above misrepresents their conclusions, however, the “Authors’ conclusions” section of the lay summary of the Cochrane review states the following (emphasis added):

“The sensitivity of antibody tests is too low in the first week since symptom onset to have a primary role for the diagnosis of COVID-19, but they may still have a role complementing other testing in individuals presenting later, when RT-PCR tests are negative, or are not done. Antibody tests are likely to have a useful role for detecting previous SARS-CoV-2 infection if used 15 or more days after the onset of symptoms. However, the duration of antibody rises is currently unknown, and we found very little data beyond 35 days post-symptom onset. We are therefore uncertain about the utility of these tests for seroprevalence surveys for public health management purposes. Concerns about high risk of bias and applicability make it likely that the accuracy of tests when used in clinical care will be lower than reported in the included studies. Sensitivity has mainly been evaluated in hospitalised patients, so it is unclear whether the tests are able to detect lower antibody levels likely seen with milder and asymptomatic COVID-19 disease.
The design, execution and reporting of studies of the accuracy of COVID-19 tests requires considerable improvement. …”

To be sure, Deeks et al. do not single out point-of-care tests in their conclusion, but the text clearly lays out many caveats about serologic testing. These caveats are consistent with our interpretation that serological assays in general are not ready for widespread use because, unfortunately, they do not yet provide the type of accurate information needed by individuals and public health officials.

1. https://www.bmj.com/content/370/bmj.m2655/rapid-responses
2. Duong YT, Wright CG, Justman J. Antibody testing for coronavirus disease 2019: not ready for prime time. BMJ 2020;370:m2655
3. Deeks JJ, Dinnes J, Takwoingi Y, et al. Antibody tests for identification of current and past infection with SARS‐CoV‐2. Cochrane Database of Systematic Reviews 2020(6) doi: 10.1002/14651858.CD013652
4. Lisboa Bastos M, Tavaziva G, Abidi SK, et al. Diagnostic accuracy of serological tests for covid-19: systematic review and meta-analysis. 2020;370:m2516. doi: 10.1136/bmj.m2516 %J BMJ

Competing interests: No competing interests

14 July 2020
Jessica Justman
associate professor of medicine in epidemiology
Yen T Duong and Connor G Wright
ICAP at Columbia, Mailman School of Public Health, Columbia University
722 West 168th Street