TWiV 1347: No Short Answers for Long COVID

Severe COVID-19 infection triggers the reactivation of latent viruses, including herpesviruses and anelloviruses, which correlate with disease severity and specific cytokine profiles. While these viral reactivations are common in hospitalized, unvaccinated patients, their role as drivers or passengers of clinical outcomes remains unclear. Concurrently, long COVID patients with neurological symptoms demonstrate elevated autoantibodies against neural proteins, such as adrenergic receptors and the mediator complex. Passive transfer of IgG from these patients into mice induces transient pain sensitivity and fatigue-like behaviors, suggesting a potential autoimmune component to neurological long COVID symptoms. Despite these findings, the significant heterogeneity among patient cohorts and the lack of established causality necessitate further investigation to determine if these markers serve as diagnostic signatures or consequences of systemic immune dysregulation.