Chandelier
Senior Member (Voting Rights)
Clinical Utility of SARS-CoV-2 Antibody Titers in the Management of Patients With Long COVID Infected With the Omicron Variant
Objectives: To investigate whether serum S- and N-antibody titers against SARS-CoV-2 spike and nucleocapsid proteins reflect the clinical features of LC.
Methods: This retrospective observational study included patients diagnosed with Omicron variant-related LC who attended a post-COVID-19 outpatient clinic between July 2023 and November 2024 and provided informed consent for antibody testing.
Results: Among 275 patients (129 men and 146 women), 57 (21%) were unvaccinated. Median S- and N-antibody titers in vaccinated versus unvaccinated patients were 20,963 U/mL and 24.8 cut-off index (COI) versus 24 U/mL and 44.5 COI, respectively.
S-antibody titers were associated with the number of vaccine doses received, whereas N-antibody titers correlated with disease severity during the acute phase of COVID-19 infection, with females having higher titers by multivariable analysis.
N-antibody titers in unvaccinated patients with LC were negatively correlated with time interval from infection to clinic visit, with an estimated daily decline of 0.34% in measured N-antibody levels.
Patients with LC having memory impairment had low S-antibody titers by multivariable logistic regression analysis, and low S-antibody levels were associated with reduced quality of life (QOL).
Additionally, N-antibody titers positively correlated with lymphocyte counts and immunoglobulin levels.
Conclusion: Serum N-antibody titers reflect immune responses to COVID-19, although they are affected by gender differences and interval between infection and evaluation.
Lower S-antibody titers were associated with brain fog symptoms and reduced QOL in patients with LC.
Web | DOI | PMC | PDF | British Journal of Biomedical Science
Kawaguchi, Marina; Sakurada, Yasue; Tokumasu, Kazuki; Otsuka, Yuki; Nakano, Yasuhiro; Matsuda, Yui; Honda, Hiroyuki; Omura, Daisuke; Matsuki, Nobuyoshi; Furukawa, Masanori; Higashikage, Akihito; Otsuka, Fumio
Abstract
Background: Long COVID (LC) presents persistent symptoms that pose a major clinical challenge. Identification of reliable biomarkers to evaluate LC pathophysiology is needed.Objectives: To investigate whether serum S- and N-antibody titers against SARS-CoV-2 spike and nucleocapsid proteins reflect the clinical features of LC.
Methods: This retrospective observational study included patients diagnosed with Omicron variant-related LC who attended a post-COVID-19 outpatient clinic between July 2023 and November 2024 and provided informed consent for antibody testing.
Results: Among 275 patients (129 men and 146 women), 57 (21%) were unvaccinated. Median S- and N-antibody titers in vaccinated versus unvaccinated patients were 20,963 U/mL and 24.8 cut-off index (COI) versus 24 U/mL and 44.5 COI, respectively.
S-antibody titers were associated with the number of vaccine doses received, whereas N-antibody titers correlated with disease severity during the acute phase of COVID-19 infection, with females having higher titers by multivariable analysis.
N-antibody titers in unvaccinated patients with LC were negatively correlated with time interval from infection to clinic visit, with an estimated daily decline of 0.34% in measured N-antibody levels.
Patients with LC having memory impairment had low S-antibody titers by multivariable logistic regression analysis, and low S-antibody levels were associated with reduced quality of life (QOL).
Additionally, N-antibody titers positively correlated with lymphocyte counts and immunoglobulin levels.
Conclusion: Serum N-antibody titers reflect immune responses to COVID-19, although they are affected by gender differences and interval between infection and evaluation.
Lower S-antibody titers were associated with brain fog symptoms and reduced QOL in patients with LC.
Web | DOI | PMC | PDF | British Journal of Biomedical Science