@article{2999854,
    title = "SARS-CoV-2 antigenemia as a confounding factor in immunodiagnostic assays: A case study",
    author = "Belogiannis, K. and Florou, V.A. and Fragkou, P.C. and Ferous, S. and Chatzis, L. and Polyzou, A. and Lagopati, N. and Vassilakos, D. and Kittas, C. and Tzioufas, A.G. and Tsiodras, S. and Sourvinos, G. and Gorgoulis, V.G.",
    journal = "Virus Bulletin",
    year = "2021",
    volume = "13",
    number = "6",
    publisher = "MDPI",
    issn = "0956-9979",
    doi = "10.3390/v13061143",
    keywords = "antipyretic agent;  hematoxylin;  metformin;  monoclonal antibody;  virus antigen;  immunoglobulin G;  virus antibody;  virus antigen, adult;  antibody detection;  antibody production;  antibody response;  antigen blood level;  Article;  bioinformatics;  case report;  clinical article;  cohort analysis;  confounding variable;  controlled study;  coronavirus disease 2019;  cycle threshold value;  enzyme linked immunosorbent assay;  fever;  high throughput sequencing;  human;  human tissue;  humoral immunity;  immunohistochemistry;  male;  nasopharyngeal swab;  reverse transcription polymerase chain reaction;  RNA extraction;  sandwich ELISA;  sensitivity and specificity;  seroconversion;  serodiagnosis;  Severe acute respiratory syndrome coronavirus 2;  viremia;  virus load;  young adult;  antibody combining site;  blood;  diagnosis;  immunology;  metabolism;  virology, Antibodies, Viral;  Antigens, Viral;  Binding Sites, Antibody;  COVID-19;  COVID-19 Serological Testing;  Humans;  Immunity, Humoral;  Immunoglobulin G;  Male;  SARS-CoV-2;  Sensitivity and Specificity;  Seroconversion;  Young Adult",
    abstract = "Humoral immunity has emerged as a vital immune component against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Nevertheless, a subset of recovered Coronavirus Disease-2019 (COVID-19) paucisymptomatic/asymptomatic individuals do not generate an antibody response, constituting a paradox. We assumed that immunodiagnostic assays may operate under a competitive format within the context of antigenemia, potentially explaining this phenomenon. We present a case where persistent antigenemia/viremia was documented for at least 73 days post-symptom onset using ‘in-house’ methodology, and as it progressively declined, seroconversion took place late, around day 55, supporting our hypothesis. Thus, prolonged SARS-CoV-2 anti-genemia/viremia could mask humoral responses, rendering, in certain cases, the phenomenon of ‘non-responders’ a misnomer. © 2021 by the authors. Licensee MDPI, Basel, Switzerland."
}