Reply to Peluso et al.

To the Editor—We thank Peluso et al for their comment [1] and interest in our recent publication [2], and for providing us with the opportunity to extend the discussion regarding our observations and the potential role of autoimmunity in long COVID. There is evidence from other cohort studies that coronavirus disease 2019 (COVID-19) can induce autoimmunity and the occurrence of autoantibodies [3–5]. In our recent publication, we analyzed antinuclear antibody (ANA) titers in the acute phase, 5 and 12 months post–COVID-19 in a well-defined patient cohort and found positive ANA titers (≥1:160) in 32.4%, 40.6%, and 43.6% of analyzed patients, respectively. Our data in the acute phase of COVID-19 are in line with previously published data, which demonstrated positive ANA titers ≥1:40 in 21.3% (10/47) [6], ≥1:80 in 33.3% (11/33) [7], and ≥1:80 in 57.5% (23/40) [8]...