TOP-Plus is a Versatile Biosensor Platform for Monitoring SARS-CoV-2 Antibody Durability.

TitleTOP-Plus is a Versatile Biosensor Platform for Monitoring SARS-CoV-2 Antibody Durability.
Publication TypeJournal Article
Year of Publication2021
AuthorsRacine-Brzostek SE, Karbaschi M, Gaebler C, Klasse PJ, Yee J, Caskey M, Yang HS, Hao Y, Chadburn A, Shi Y, Zuk R, Nussenzweig MC, Cushing MM, Zhao Z
Date Published2021 Feb 08

BACKGROUND: There is a concern that low initial SARS-CoV-2 antibody titers in individuals may drop to undetectable levels within months after infection. Although this may raise concerns over long term immunity, both the antibody levels and avidity of the antibody-antigen interaction should be examined to understand the quality of the antibody response.

METHODS: A testing-on-a-probe-plus panel (TOP-Plus) was developed, which included a newly developed avidity assay built into the previously described SARS-CoV-2 TOP assays that measured total antibody (TAb), surrogate neutralizing antibody (SNAb), IgM and IgG on a versatile biosensor platform. TAb and SNAb levels were compared with avidity in previously infected individuals at 1.3 and 6.2 months post-infection in paired samples from 80 COVID-19 patients.

RESULTS: The newly designed avidity assay in this TOP panel correlated well with a reference Bio-Layer Interferometry avidity assay (R=0.88). The imprecision of the TOP avidity assay was less than 9%. Although TAb and neutralization activity (by SNAb) decreased between 1.3 and 6.2 months post infection, the antibody avidity increased significantly (P < 0.0001).

Alternate JournalmedRxiv
PubMed ID33564790
PubMed Central IDPMC7872385
Grant ListR01 AI036082 / AI / NIAID NIH HHS / United States
Related Faculty: 
Amy Chadburn, M.D. He Sarina Yang, M.D., Ph.D. Melissa Cushing, M.D. Sabrina Racine-Brzostek, M.D., Ph.D. Zhen Zhao, Ph.D.


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