Serum Levels of IL-21 and IL-27 do not Reflect differential Avidity of Anti-SARS-CoV-2 IgG Antibodies in Symptomatic and Asymptomatic COVID-19 Patients
Abstract
The quantity and quality of anti-Spike (anti-S) antibodies, rapidly elicited by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), are necessary for understanding the immune response induced by infection. Antibody avidity is a good indicator of the quality of antibody response. Interleukin (IL)-21 and IL-27 are two cytokines that play vital roles in the affinity maturation process. Therefore, we decided to investigate whether there are any relationships between the avidities of antibodies against spike and nucleocapsid (N) antigens of SARS-CoV-2 and serum levels of these cytokines in symptomatic and asymptomatic coronavirus disease 2019 (COVID-19) patients.
Forty symptomatic COVID-19 patients and 40 asymptomatic carriers were enrolled. Anti-S and anti-N IgG avidity indices (AIs) were determined using a modified enzyme-linked immunosorbent assay (ELISA). Serum levels of IL-21 and IL-27 were quantified by specific ELISA kits.
AI values of both anti-S and anti-N IgG were lower in the symptomatic group compared to asymptomatic cases, while only that of anti-N IgG was statistically significant. For IL-21 and IL-27 serum levels, no significant difference between the two groups was shown. Also, we could not find any correlations between cytokine levels and antibody AI values. However, an inverse correlation between anti-S AI value and IL-27 serum level was found in asymptomatic patients.
Our study suggests that serum levels of IL-21 and IL-27 cannot predict differences in anti-S and anti-N IgG avidity between symptomatic and asymptomatic COVID-19 patients.
2. Garcia L, Woudenberg T, Rosado J, Dyer AH, Donnadieu F, Planas D, et al. Kinetics of the SARS-CoV-2 Antibody Avidity Response Following Infection and Vaccination. Viruses. 2022;14(7).
3. Nalbandian A, Sehgal K, Gupta A, Madhavan MV, McGroder C, Stevens JS, et al. Post-acute COVID-19 syndrome. Nat Med. 2021;27(4):601-15.
4. Wang Q, Zhang Y, Wu L, Niu S, Song C, Zhang Z, et al. Structural and Functional Basis of SARS-CoV-2 Entry by Using Human ACE2. Cell. 2020;181(4):894-904.e9.
5. Siracusano G, Pastori C, Lopalco L. Humoral immune responses in COVID-19 patients: a window on the state of the art. Front Immunol. 2020;11:1049.
6. Hajilooi M, Keramat F, Moazenian A, Rastegari-Pouyani M, Solgi G. The quantity and quality of anti-SARS-CoV-2 antibodies show contrariwise association with COVID-19 severity: lessons learned from IgG avidity. Med Microbiol Immunol. 2023;212(3):203-20.
7. Manuylov V, Burgasova O, Borisova O, Smetanina S, Vasina D, Grigoriev I, et al. Avidity of IgG to SARS-CoV-2 RBD as a Prognostic Factor for the Severity of COVID-19 Reinfection. Viruses. 2022;14(3).
8. Bauer G. The variability of the serological response to SARS-corona virus-2: Potential resolution of ambiguity through determination of avidity (functional affinity). J Med Virol. 2021;93(1):311-22.
9. Victora GD, Nussenzweig MC. Germinal centers. Annu Rev Immunol. 2012;30:429-57.
10. Young C, Brink R. The unique biology of germinal center
B cells. Immunity. 2021;54(8):1652-64.
11. Linterman MA, Beaton L, Yu D, Ramiscal RR, Srivastava M, Hogan JJ, et al. IL-21 acts directly on B cells to regulate Bcl-6 expression and germinal center responses. J Exp Med. 2010;207(2):353-63.
12. Vijayan D, Mohd Redzwan N, Avery DT, Wirasinha RC, Brink R, Walters G, et al. IL-27 Directly Enhances Germinal Center B Cell Activity and Potentiates Lupus in Sanroque Mice. J Immunol. 2016;197(8):3008-17.
13. Löfström E, Eringfält A, Kötz A, Wickbom F, Tham J, Lingman M, et al. Dynamics of IgG-avidity and antibody levels after Covid-19. J Clin Virol. 2021;144:104986.
14. Bauer G. The potential significance of high avidity immunoglobulin G (IgG) for protective immunity towards SARS-CoV-2. Int J Infect Dis. 2021;106:61-4.
15. Ding YX, Mao NY, Zhang Y, Lei Y, Gao ZG, Xu WB, et al. Measles Virus IgG Avidity Assay for Use in Identification of Measles Vaccine Failures in Tianjin, China. Biomed Environ Sci. 2019;32(11):804-11.
16. Acet Öztürk NA, Ursavaş A, Dilektaşlı AG, Demirdöğen E, Coşkun NF, Ediger D, et al. Interleukin-21: a potential biomarker for diagnosis and predicting prognosis in COVID-19 patients. Turk J Med Sci. 2021;51(5):2274-84.
17. Bayraktar N, Turan H, Bayraktar M, Ozturk A, Erdoğdu H. Analysis of serum cytokine and protective vitamin D levels in severe cases of COVID‐19. J Med Virol. 2022;94(1):154-60.
18. Tamayo-Velasco Á, Martínez-Paz P, Peñarrubia-Ponce MJ, de la Fuente I, Pérez-González S, Fernández I, et al. HGF, IL-1α, and IL-27 Are Robust Biomarkers in Early Severity Stratification of COVID-19 Patients. J Clin Med. 2021;10(9).
19. Klingler J, Lambert GS, Bandres JC, Emami-Gorizi R, Nádas A, Oguntuyo KY, et al. Immune profiles to distinguish hospitalized versus ambulatory COVID-19 cases in older patients. iScience. 2022;25(12):105608.
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Section | Brief Communication | |
Keywords | ||
Antibody avidity Interleukin-21 Interleukin-27 Severe acute respiratory syndrome coronavirus 2 |
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