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MONDAY, Oct. 26, 2020 (HealthDay News) — Sex, age, and severity of disease can predict increased antibody response in COVID-19 survivors, according to a study published recently in the Journal of Clinical Investigation<\/i>.<\/p>\n
Sabra L. Klein, Ph.D., from the Johns Hopkins Bloomberg School of Public Health in Baltimore, and colleagues evaluated humoral immune response using a severe acute respiratory syndrome coronavirus 2 virus neutralization assay, a commercial immunoglobulin G (IgG) and IgA enzyme-linked immunoassay (ELISA) to detect the spike (S) protein S1 domain; IgA, IgG, and IgM indirect ELISAs to detect the full-length S protein or S receptor-binding domain (S-RBD); and an IgG avidity assay among 126 potential convalescent plasma donors. The correlations between antibody responses and demographic and clinical characteristics were assessed.<\/p>\n
The researchers found that in the overall population, IgG titers were greater than IgM or IgA titers for S1, full-length S, and S-RBD. Eighty percent of the 126 plasma samples had detectable neutralizing antibody (nAb) titers. The IgG ELISAs confirmed 95 to 98 percent of the nAb-positive samples using nAbs as the reference; 20 to 32 percent of the nAb-negative samples were IgG ELISA-positive. Across the serological assays, increased antibody responses were seen in association with male sex, older age, and hospitalizations for COVID-19.<\/p>\n
“We found that these were significant patient characteristics that not only predicted the amount of antibody but the quality of that antibody,” Klein said in a statement.<\/p>\n