Frontiers in Medicine (Oct 2021)

Elevated Humoral Immune Response to SARS-CoV-2 at High Altitudes Revealed by an Anti-RBD “In-House” ELISA

  • Rodrigo Hernán Tomas-Grau,
  • Diego Ploper,
  • César Luis Ávila,
  • Esteban Vera Pingitore,
  • Carolina Maldonado Galdeano,
  • Silvina Chaves,
  • Sergio Benjamín Socias,
  • Agustín Stagnetto,
  • Silvia Adriana Navarro,
  • Rossana Elena Chahla,
  • Mónica Aguilar López,
  • Conrado Juan Llapur,
  • Patricia Aznar,
  • María Elena Alcorta,
  • Dardo Costas,
  • Isolina Flores,
  • Dar Heinze,
  • Gabriela Apfelbaum,
  • Raul Mostoslavsky,
  • Gustavo Mostoslavsky,
  • Silvia Inés Cazorla,
  • Gabriela del Valle Perdigón,
  • Rosana Chehín

DOI
https://doi.org/10.3389/fmed.2021.720988
Journal volume & issue
Vol. 8

Abstract

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The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has caused a global pandemic with dramatic health and socioeconomic consequences. The Coronavirus Disease 2019 (COVID-19) challenges health systems to quickly respond by developing new diagnostic strategies that contribute to identify infected individuals, monitor infections, perform contact-tracing, and limit the spread of the virus. In this brief report, we developed a highly sensitive, specific, and precise “In-House” ELISA to correctly discriminate previously SARS-CoV-2-infected and non-infected individuals and study population seroprevalence. Among 758 individuals evaluated for anti-SARS-CoV-2 serology in the province of Tucumán, Argentina, we found a weak correlation between antibodies elicited against the RBD, the receptor-binding domain of the Spike protein, and the nucleocapsid (N) antigens of this virus. Additionally, we detected mild levels of anti-RBD IgG antibodies in 33.6% of individuals diagnosed with COVID-19, while only 19% showed sufficient antibody titers to be considered as plasma donors. No differences in IgG anti-RBD titers were found between women and men, neither in between different age groups ranging from 18 to 60. Surprisingly, individuals from a high altitude village displayed elevated and longer lasting anti-RBD titers compared to those from a lower altitude city. To our knowledge, this is the first report correlating altitude with increased humoral immune response against SARS-CoV-2 infection.

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