Ostojić, Gordana (55553738583)Gordana (55553738583)OstojićŠupić, Gordana (26423313800)Gordana (26423313800)ŠupićKarličić, Vukoica (6506557627)Vukoica (6506557627)KarličićKarličić, Marija (57762215800)Marija (57762215800)KarličićRistanović, Elizabeta (55278691500)Elizabeta (55278691500)RistanovićKovačević, Milan (57761750000)Milan (57761750000)KovačevićAbazović, Dzihan (57200380979)Dzihan (57200380979)AbazovićGojkov, Dragana (57202433872)Dragana (57202433872)GojkovStanojević, Ivan (55798544900)Ivan (55798544900)StanojevićVukosavljević, Miroslav (24330345200)Miroslav (24330345200)VukosavljevićVojvodić, Danilo (6603787420)Danilo (6603787420)Vojvodić2025-06-122025-06-122022https://doi.org/10.2298/VSP201009129Ohttps://www.scopus.com/inward/record.uri?eid=2-s2.0-85132757838&doi=10.2298%2fVSP201009129O&partnerID=40&md5=1d35979c100a83eea7117a963a8a065chttps://remedy.med.bg.ac.rs/handle/123456789/3757Background/Aim. Severe Acute Respiratory Syndrome Corona Virus 2 (SARS-CoV-2) 2019 infection represents a global problem. At this moment, in October 2020, there is no vaccine or efficient treatment for infected patients. Treatment with blood plasma rich with anti-SARS-CoV-2 specific antibodies might be a safe, and effective therapy for COVID-19 patients. Methods. A total of 768 patients were analyzed in this study, whose samples were collected in a time interval from May 1, 2020, till August 15, 2020. Patients were enrolled in the study from COVID-19 hospitals and out-clinics. In-house ELISA tests were developed to measure the concentration of anti-S1S2 spike and anti-nucleoprotein (np) (IgG, IgA, IgM) SARS-CoV-2 antibodies. Blood convalescent plasma was selectively collected from recovered patients according to specific antibodies concentration. Results. The highest concentrations of anti-S1S2 spike or anti-np specific IgG antibodies were detected in patients with the moderate/heavy clinical form of the infection. An extremely high concentration of anti-S1S2 spike IgG and anti-np IgG was demonstrated in 3% and 6% of patients who recovered from severe COVID-19, respectively. Of tested hospitalized patients, 63% and 51% had modest levels of anti-S1S2 spike and anti-np, respectively. After 60 days, in our selected donors, concentrations of antiS1S2 spike IgG and anti-np IgG antibodies increased in 67% and 58% of donors, respectively. Conclusion. In-house developed ELISA tests enable a novel protocol for selecting convalescent blood plasma donors recovered from SARS-CoV-2 infection. © 2022 Inst. Sci. inf., Univ. Defence in Belgrade. All rights reserved.antibody specificityclinical protocolscovid-19 serotherapyenzyme-linked immunosorbent assayplasmaSARS-CoV-2tissue donors