SARS‐CoV‐2 antibody levels and long COVID occurrence in blood donors

Abstract

BackgroundLong COVID is a common condition lacking consensus definition; determinants remain incompletely understood. Characterizing immune profiles associated with long COVID could support the development of preventive and therapeutic strategies.MethodsWe used a survey to investigate blood donors' infection/vaccination history and acute/persistent symptoms following COVID‐19. The prevalence of long COVID was evaluated using self‐report and an adapted definition from the RECOVER study. We evaluated factors associated with long COVID, focusing on anti‐spike and anti‐nucleocapsid SARS‐CoV‐2 antibodies. Lastly, we investigated long COVID clinical subphenotypes using hierarchical clustering.ResultsOf 33,610 participants, 16,003 (48%) reported having had COVID‐19; 1853 (12%) had self‐reported long COVID, 685 (4%) met an adapted RECOVER definition, and 2050 (13%) met at least one definition. Higher anti‐nucleocapsid levels measured 12–24 weeks post‐infection were associated with higher risk of self‐reported and RECOVER long COVID. Higher anti‐spike IgG levels measured 12–24 weeks post‐infection were associated with lower risk of self‐reported long COVID. Higher total anti‐spike measured 24–48 weeks post‐infection was associated with lower risk of RECOVER long COVID. Cluster analysis identified four clinical subphenotypes; patterns included neurological and psychiatric for cluster 1; neurological and respiratory for cluster 2; multi‐systemic for cluster 3; and neurological for cluster 4.DiscussionLong COVID prevalence in blood donors varies depending on the adopted definition. Anti‐SARS‐CoV‐2 antibodies were time‐dependently associated with long COVID; higher anti‐nucleocapsid levels were associated with higher risk; and higher anti‐spike levels were associated with lower risk of long COVID. Different underlying pathophysiologic mechanisms may be associated with distinct clinical subphenotypes.