Advice to the media
Monday, August 29, 2022
What
The amount of SARS-CoV-2 antigen measured in the blood of hospitalized patients with COVID-19 is associated with disease severity and other clinical outcomes, according to a new study published in the Annals of Internal Medicine. After the ACTIV-3 trial of COVID-19 therapeutics in people hospitalized with COVID-19, researchers at the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, and their colleagues Collaborators analyzed levels of SARS-COV -2 antigen in blood samples taken from study participants and assessed the association of these levels with disease progression. Higher levels of viral antigen in the blood, which could indicate ongoing replication of SARS-CoV-2, correlate with more severe disease. The authors suggest that SARS-CoV-2 antigen levels hold promise as a biomarker or measurable substance to predict which hospitalized patients with COVID-19 are at greater risk for worse outcomes.
The ACTIV-3 trial enrolled people hospitalized with COVID-19 between August 2020 and November 2021. Participants provided a baseline blood sample and were then randomized to receive an experimental COVID-19 therapeutic or a placebo. All participants received the antiviral remdesivir unless contraindicated. In this follow-up analysis, researchers screened 2,540 baseline blood samples from participants for levels of SARS-CoV-2 antigen.
The researchers assessed the relationship between each participant’s SARS-CoV-2 blood antigen levels and their time to discharge from the hospital, as well as their lung symptoms on day five of the trial, both if they had stayed the same, if they had gotten worse or better since then. Enrolment. With all this information in hand, the researchers performed statistical analyzes to determine whether plasma antigen levels were associated with participants’ lung function when they gave the blood sample, and whether they could predict how participants would fare over time . In addition, the researchers examined the relationship between a number of viral and participant characteristics and antigen levels.
The analysis revealed a strong correlation between higher levels of SARS-CoV-2 antigen (≥1000 nanograms per liter) and worse lung function at enrollment. Importantly, participants with higher blood levels of SARS-CoV-2 antigen at the time of enrollment
they generally had decreased lung function by day five, regardless of the severity of their disease at study entry, and it took longer to be discharged from the hospital. High levels of the antigen in the blood also correlate with some known risk factors for worse diseases, such as being male. Three additional participant characteristics were found to correlate with lower antigen levels: the presence of SARS-CoV-2 antibodies, exposure to remdesivir before enrollment, and longer time in hospital before the registration Finally, participants infected with the delta variant had higher antigen levels than those infected with earlier circulating strains. The researchers concluded that antigen levels in the blood are likely a marker of ongoing viral replication and could be useful in predicting the progression of a patient’s disease and likely outcomes once admitted to the hospital. The authors note that these results suggest that a precision medicine approach could be useful in future clinical trials of antiviral therapy. For example, antigen levels could help determine those patients most likely to benefit from therapies aimed at fighting the virus.
Article
Rogers et al. The association of baseline plasma SARS-CoV-2 nucleocapsid antigen level and outcomes in hospitalized patients with COVID-19. Annals of Internal Medicine DOI: 10.7326/M22-0924 (2022).
WHO
H. Clifford Lane, MD, Assistant Director of Clinical Research and Special Projects, NIAID, is available for comment.
contact
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