SARS-CoV-2 antigen levels linked to patient outcomes

What

According to a recent research published in the Annals of Internal Medicine, the quantity of SARS-CoV-2 antigen detected in the blood of patients hospitalized with COVID-19 is related to the severity of the disease and other clinical outcomes. Researchers from the National Institute of Allergy and Infectious Diseases (NIAID), a division of the National Institutes of Health, and their collaborators examined levels of SARS-COV-2 antigen in blood samples taken from study participants and evaluated the association of those levels with disease progression after the ACTIV-3 trial of COVID-19 therapeutics in people hospitalized with COVID-19. More severe sickness was connected with higher viral antigen levels in the blood, which may signify continuous SARS-CoV-2 replication. According to the scientists, SARS-CoV-2 antigen levels show potential as a biomarker, or quantifiable element, to identify COVID-19 hospital patients who are more likely to have negative outcomes.

People hospitalized with COVID-19 between August 2020 and November 2021 were included in the ACTIV-3 experiment. After providing a baseline blood sample, participants were randomly assigned to receive either a COVID-19 investigational treatment or a placebo. Absent medical reasons, all individuals got the antiviral remdesivir. The researchers tested 2,540 participant baseline blood samples for SARS-CoV-2 antigen levels in this follow-up study.

On day five of the trial, the researchers evaluated each participant’s pulmonary symptoms to see if they had remained the same, gotten worse, or improved since enrollment. They also looked at the relationship between each participant’s SARS-CoV-2 blood antigen levels and when they were released from the hospital. With all of this data available, the researchers ran statistical analyses to see whether plasma antigen levels were related to the patients’ pulmonary function at the time the blood sample was provided—and to see if they could forecast how the participants would perform over time. The researchers also looked at the association between a number of participant, virus, and antigen levels.

The research showed a significant connection between lower pulmonary function at the time of enrolment and higher SARS-CoV-2 antigen levels (1000 nanograms per liter). Importantly, those had higher blood levels of SARS-CoV-2 antigen upon enrolment

Regardless of the severity of their sickness at the time of study admission, patients usually had impaired lung function by day five and required longer to be discharged from the hospital. Additionally, being a man and having high blood antigen levels were also associated with recognized risk factors for more severe disease. Lower antigen levels were shown to be associated with three other participant traits, including the existence of SARS-CoV-2 antibodies, previous remdesivir exposure, and longer length of stay in the hospital. Participants who had the delta variant infection also had greater antigen levels than those who had the earlier circulating strains. The study’s authors came to the conclusion that blood antigen levels are probably a sign of continuing viral replication and may help forecast a patient’s illness course and expected consequences after hospital admission. The findings, according to the authors, point to the potential benefit of using a precision medicine strategy in upcoming antiviral medication clinical trials. For example, antigen levels might be used to identify people most likely to benefit from treatments that aim to combat the virus.

Article

Rogers et al. The association of baseline plasma SARS-CoV-2 nucleocapsid antigen level and outcomes in patients hospitalized with COVID-19. Annals of Internal Medicine DOI: 10.7326/M22-0924 (2022).

Who

H. Clifford Lane, M.D., deputy director of clinical research and special projects, NIAID, is available to comment.

Contact

To schedule interviews, please contact Elizabeth Deatrick, (301) 402-1663, NIAIDNews@niaid.nih.gov.

NIAID conducts and supports research—at NIH, throughout the United States, and worldwide—to study the causes of infectious and immune-mediated diseases, and to develop better means of preventing, diagnosing and treating these illnesses. News releases, fact sheets and other NIAID-related materials are available on the NIAID website.

About the National Institutes of Health (NIH): NIH, the nation’s medical research agency, includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic, clinical, and translational medical research, and is investigating the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit www.nih.gov.