key: cord-0718511-6nlntk6y
authors: Cabrelle, Giulio; Zanon, Chiara; Crimì, Filippo; Quaia, Emilio
title: Can rapid antibody tests and chest computed tomography really substitute real‐time polymerase chain reaction in COVID‐19?
date: 2021-08-31
journal: J Med Virol
DOI: 10.1002/jmv.27295
sha: e6c1cc95304e92459a3f8d8f28ced34f15af01e3
doc_id: 718511
cord_uid: 6nlntk6y

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Can rapid antibody tests and chest computed tomography really substitute real-time polymerase chain reaction in COVID-19? Moreover, it has been previously reported that patients with a monolateral lung involvement at chest CT could have a falsely negative RT-PCR. 3 Since almost 50% of those included in this study did not show a bilateral lungs involvement at chest CT, in this group RT-PCR should have been performed on the bronchoalveolar lavage to confirm the diagnosis of COVID-19 infection.

Second, antibodies production after an infection has a variable "window period" that depends on the time required for seroconversion.

Indeed, Long et al. 4 reported that the positive rate of virus-specific immunoglobulin G reached 100% after 17-19 days after symptoms onset, and positivity of virus-specific immunoglobulin M reached a peak of 94.1% 20-22 days after symptom onset. 4 Therefore, if serum samples were collected within 0-7 days from COVID-19 diagnosis, it is reasonable that a not irrelevant part of the population was in that "window period" and, therefore, tested negative.

Finally, it is stated that chest CT was evaluated by an "infection and clinical microbiologist." In our opinion, to have a more reliable identification of radiological signs of the CT scans, images should have been reviewed by at least one radiologist expert in thoracic imaging.

In summary, while we agree with the conclusions that chest CT and rapid antibody test can be useful diagnostic tools for clinicians in the setting of the COVID-19 pandemic, it should be highlighted that the multiple biases of this retrospective study could affect the robustness of the conclusions drawn by the authors.

Evaluation of rapid antibody test and chest computed tomography results of COVID-19 patients: a retrospective study

Republic of Turkey Ministry of Health COVID-19 (SARS-CoV2 Infection) Guide

Highresolution CT features in patients with COVID-19 pneumonia and negative nasopharyngeal and oropharyngeal swabs

Antibody responses to SARS-CoV-2 in patients with COVID-19

The authors declare that there are no conflict of interests.

Filippo Crimì