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

TOMAS GRAU, RH

La Paz

Simposio; 8th CHRONIC HYPOXIA SYMPOSIUM; 2022

High Altitude Pulmonary and Pathology Institute (HAPPI-IPPA)

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and the Coronavirus Disease2019 (COVID-19) pandemic has made the serological surveillance a crucial tool for designing public health guidelines. In this context, the lack of diagnostic kits in our region motivated us to design an ELISA test to detect antibodies against the receptor binding domain (RBD) of the SARS-CoV-2 Spike glycoprotein. A robust, sensitive, cost-effective, and on-demand test was developed and 758 individuals from Tucumán, Argentina who underwent COVID-19 were studied. Results obtained showed a low correlation between anti-RBD IgG antibodies compared to those induced by virus N protein. In addition, it was detected that only 19% of the individuals developed antibody titers sufficient to be considered plasma donors. No differences in anti-RBD IgG titers were found between women and men, nor between different age groups. Analyzing a group of inhabitants of Tafí del Valle, Tucumán (located at 2014 meters above mean sea level; masl), they presented significantly higher and more persistent anti-RBD titers than the population of San Miguel de Tucumán (400 masl). These findings evidence a higher antibody response against SARS-CoV-2 in high-altitude individuals, which adds further evidence on the effect of altitude on the interaction between this new coronavirus, the immune system, and the development of infection.