Abstract
The aim of this study is to assess the synthesis of kappa (κ) and lambda (λ) free light chains (FLCs) in the serum of patients with COVID-19. All the 120 serum samples were collected from patients with COVID-19 and from healthy controls (vaccinated and non-vaccinated against SARS-CoV-2). FLCs, IgG total, IgG4, IgG anti-Nucleocapsid (N), anti-spike S1 receptor binding domain (S-RBD) antibodies and IL-6 were measured according to the manufacturers’ instructions. The concentrations of anti-N IgG, IgG total, IgG4 and IL-6 were elevated in the COVID-19 group in comparison to the vaccinated and non-vaccinated controls. The levels of anti-S-RBD IgG and κFLC were increased in COVID-19 and healthy vaccinated patients when compared to non-vaccinated controls. λFLC concentration was higher in the COVID-19 group than in the non-vaccinated group. The κ:λ ratio was lower in both COVID-19 and non-vaccinated groups in comparison to vaccinated controls. κFLC correlated with all tested parameters (anti-S-RBD IgG, anti-N IgG, λFLC, κ:λ ratio, IgG total, IgG4 and IL-6) except CRP, whereas λFLC correlated with all examined parameters except IgG4. Elevated levels of FLCs in COVID-19 and healthy vaccinated against SARS-CoV-2 patients, as well as the correlation between free light chains with specific anti-SARS-CoV-2 antibodies and IL-6, reflect hyperactivation of the immune system after contact with coronavirus. Furthermore, it seems that serum levels of FLCs might be used as predictive markers of COVID-19. Our findings suggest that free light chains are involved in SARS-CoV-2 infection. However, understanding the exact mechanism requires further investigation.
Keywords: COVID-19; SARS-CoV-2; free light chain; inflammation; kappa; lambda.
【저자키워드】 COVID-19, SARS-CoV-2, Inflammation, Kappa, lambda., free light chain, 【초록키워드】 IgG, coronavirus, antibody, IL-6, SARS-COV-2 infection, CRP, immune system, Receptor binding domain, serum, anti-SARS-CoV-2 antibody, S-RBD, Patient, correlation, group, mechanism, Anti-spike, anti-N IgG, marker, SARS-CoV-2 patients, Concentration, Contact, IgG4, Predictive, Serum level, healthy control, COVID-19 group, Hyperactivation, serum sample, parameter, controls, tested, collected, examined, involved, healthy, elevated, correlated, were measured, patients with COVID-19, 【제목키워드】 response, synthesis, LIGHT, exposure to, chain, Free,