tetano
Editor, Senior Moderator
Balkan Med J
. 2022 Apr 5.
doi: 10.4274/balkanmedj.galenos.2022.2021-8-131. Online ahead of print.
Anti-SARS-CoV-2 IgG and Neutralizing Antibody Levels in Patients with Past COVID-19 Infection: A Longitudinal Study
Harika Öykü Dinç[SUP] 1 [/SUP], Mehmet Demirci[SUP] 2 [/SUP], Yusuf Emre Özdemir[SUP] 3 [/SUP], Serhat Sirekbasan[SUP] 4 [/SUP], Ayse Nur Aktaş[SUP] 5 [/SUP], Rıdvan Karaali[SUP] 5 [/SUP], Yeşim Tuyji Tok[SUP] 6 [/SUP], Doğukan Özbey[SUP] 6 [/SUP], Rüveyda Akçin[SUP] 6 [/SUP], Nesrin Gareayaghi[SUP] 7 [/SUP], Mert Ahmet Kuşkucu[SUP] 7 [/SUP], Kenan Midilli[SUP] 6 [/SUP], Gökhan Aygün[SUP] 6 [/SUP], Suat Sarıbaş[SUP] 6 [/SUP], Bekir Kocazeybek[SUP] 6 [/SUP]
Affiliations
Abstract
Background: Monitoring the longevity of immunoglobulin G (IgG) responses following severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infections is vital to understanding the role of antibodies in preventing infection.
Aims: To determine the quantitative IgG responses specific to the Spike-S1 (S1) receptor-binding domain (S1/RBD) region of the virus in serum samples taken between 4 weeks and 7 months after polymerase chain reaction (PCR) positivity in patients who are diagnosed with coronavirus disease-2019 (COVID-19).
Study design: A longitudinal study.
Methods: This study included 113 patients with a clinical and molecular diagnosis of COVID-19. The first and second serum samples were taken 1 and 7 months, respectively, after the PCR positivity. S1/RBD-specific IgG antibody response was assayed using anti-SARS-CoV- 2 QuantiVac ELISA (IgG) kit (Euroimmun, Lübeck, Germany). The neutralizing antibodies were investigated in 57 patients whose IgG test results were above the cut-off value.
Results: In 57 patients with SARS-CoV-2 IgG, the anti-SARS-CoV-2 IgG quantitative antibody levels significantly decreased after 7 months (Z = -2.197, p = 0.028). A correlation was detected between the anti-SARS-CoV-2 IgG and nAb percent inhibition (IH%) levels detected in 1 month (rs = 0.496, p < 0.001), but without significant correlation in serum samples taken on 7 months. The nAb IH% levels of the first and second were compared for COVID-19 severity and revealed no statistical difference (p = 0.256). In the second serum sample, the nAb IH%s of patients with moderate COVID-19 showed a statistically significant difference from patients with mild COVID-19 (p = 0.018), but without significant differences between severe and moderate or mild COVID-19.
Conclusion: SARS-CoV-2 quantitative IgG antibody titers are significantly reduced at long-term follow-up (>6 months). Due to the limited information on seroconversion, comprehensive studies should be conducted for long-term follow-up of the immune response against SARS-CoV-2.
. 2022 Apr 5.
doi: 10.4274/balkanmedj.galenos.2022.2021-8-131. Online ahead of print.
Anti-SARS-CoV-2 IgG and Neutralizing Antibody Levels in Patients with Past COVID-19 Infection: A Longitudinal Study
Harika Öykü Dinç[SUP] 1 [/SUP], Mehmet Demirci[SUP] 2 [/SUP], Yusuf Emre Özdemir[SUP] 3 [/SUP], Serhat Sirekbasan[SUP] 4 [/SUP], Ayse Nur Aktaş[SUP] 5 [/SUP], Rıdvan Karaali[SUP] 5 [/SUP], Yeşim Tuyji Tok[SUP] 6 [/SUP], Doğukan Özbey[SUP] 6 [/SUP], Rüveyda Akçin[SUP] 6 [/SUP], Nesrin Gareayaghi[SUP] 7 [/SUP], Mert Ahmet Kuşkucu[SUP] 7 [/SUP], Kenan Midilli[SUP] 6 [/SUP], Gökhan Aygün[SUP] 6 [/SUP], Suat Sarıbaş[SUP] 6 [/SUP], Bekir Kocazeybek[SUP] 6 [/SUP]
Affiliations
- PMID: 35378574
- DOI: 10.4274/balkanmedj.galenos.2022.2021-8-131
Abstract
Background: Monitoring the longevity of immunoglobulin G (IgG) responses following severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infections is vital to understanding the role of antibodies in preventing infection.
Aims: To determine the quantitative IgG responses specific to the Spike-S1 (S1) receptor-binding domain (S1/RBD) region of the virus in serum samples taken between 4 weeks and 7 months after polymerase chain reaction (PCR) positivity in patients who are diagnosed with coronavirus disease-2019 (COVID-19).
Study design: A longitudinal study.
Methods: This study included 113 patients with a clinical and molecular diagnosis of COVID-19. The first and second serum samples were taken 1 and 7 months, respectively, after the PCR positivity. S1/RBD-specific IgG antibody response was assayed using anti-SARS-CoV- 2 QuantiVac ELISA (IgG) kit (Euroimmun, Lübeck, Germany). The neutralizing antibodies were investigated in 57 patients whose IgG test results were above the cut-off value.
Results: In 57 patients with SARS-CoV-2 IgG, the anti-SARS-CoV-2 IgG quantitative antibody levels significantly decreased after 7 months (Z = -2.197, p = 0.028). A correlation was detected between the anti-SARS-CoV-2 IgG and nAb percent inhibition (IH%) levels detected in 1 month (rs = 0.496, p < 0.001), but without significant correlation in serum samples taken on 7 months. The nAb IH% levels of the first and second were compared for COVID-19 severity and revealed no statistical difference (p = 0.256). In the second serum sample, the nAb IH%s of patients with moderate COVID-19 showed a statistically significant difference from patients with mild COVID-19 (p = 0.018), but without significant differences between severe and moderate or mild COVID-19.
Conclusion: SARS-CoV-2 quantitative IgG antibody titers are significantly reduced at long-term follow-up (>6 months). Due to the limited information on seroconversion, comprehensive studies should be conducted for long-term follow-up of the immune response against SARS-CoV-2.