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; MALDONADO GALDEANO, CAROLINA; CHAVES, SILVINA; CAZORLA, SILVIA I; GABRIELA PERDIGÓN

FRONTIERS IN MEDICINE

FRONTIERS

Año: 2021

2296-858X

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has caused a globalpandemic with dramatic health and socioeconomic consequences. The CoronavirusDisease 2019 (COVID-19) challenges health systems to quickly respond by developingnew diagnostic strategies that contribute to identify infected individuals, monitorinfections, perform contact-tracing, and limit the spread of the virus. In this briefreport, we developed a highly sensitive, specific, and precise ?In-House? ELISA tocorrectly discriminate previously SARS-CoV-2-infected and non-infected individuals andstudy population seroprevalence. Among 758 individuals evaluated for anti-SARS-CoV-2serology in the province of Tucumán, Argentina, we found a weak correlation betweenantibodies 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 ofanti-RBD IgG antibodies in 33.6% of individuals diagnosed with COVID-19, while only19%showed sufficient antibody titers to be considered as plasma donors. No differencesin IgG anti-RBD titers were found between women and men, neither in between differentage groups ranging from 18 to 60. Surprisingly, individuals from a high altitude villagedisplayed elevated and longer lasting anti-RBD titers compared to those from a loweraltitude city. To our knowledge, this is the first report correlating altitude with increasedhumoral immune response against SARS-CoV-2 infection