Immunologic phenotype of patients with long-COVID syndrome of 1-year duration.

Background: The pathophysiology of long-COVID remains unknown, and information is particularly limited for symptoms of very long duration. We aimed to assess the serological, T-cell immune responses and ANA titers of patients with long-COVID-19 syndrome of 1-year duration.

Methods: Prospective, longitudinal study of hospitalized COVID-19 patients followed-up for 12 months.