α-synuclein seeding-aktivitet i lukteslimhinnen i COVID-19

Person living in the Tirol area

Inclusion Criteria:

1. Participants must be 18 years or older;

2. Participants are able to understand the aim of the study and the planned procedures;

3. Written informed consent form;

4. Participants fulfilling the criteria for one of the following groups:

   1. COVID-19 patients with OD:

      • Prior history of COVID-19 (clinical documentation plus corresponding positive PCR test) at least 3 months ago;
      • OD (Sniffin' sticks discrimination and identification both <13/16 items correct) persisting for at least 3 months after SARS-CoV-2 infection;
      • Negative antigen test on day of study inclusion;
      • No evidence of structural nasal pathologies possibly responsible for OD.

   2. COVID-19 patients without OD:

      • Prior history of COVID-19 (clinical documentation plus corresponding positive PCR test) at least 3 months ago;
      • No history of/current OD (Sniffin' sticks discrimination and identification both >12/16 items correct);
      • Negative antigen test on day of study inclusion.

   3. Healthy Controls:

      • No history of COVID-19 and negative SARS-CoV-2 antibody test unless subject is vaccinated;
      • Negative antigen test on day of study inclusion;
      • No history of OD;
      • Subjective and objective normal olfactory function (Sniffin' sticks discrimination and identification both >12/16 items correct). 10 Application for Clinical Research

   4. Patients with Parkinson's disease (n = 50):

      • Confirmed diagnosis of PD according to diagnostic criteria.
      • No history of COVID-19 and negative SARS-CoV-2 antibody test unless subject is vaccinated;
      • Negative antigen test on day of study inclusion;

Exclusion Criteria:

1. Patients:

   • History of OD prior to SARS-CoV-2 infection;
   • Pre-existent relevant neurological disorder;
   • Positive SARS-CoV-2 antigen test on day of study inclusion;
   • Patients with OD only: structural pathology possibly responsible for OD.

2. Healthy controls:

   • Pre-existent relevant neurological disorder;
   • History of/presence of olfactory dysfunction (Sniffin' sticks discrimination and identification both <13/16 items correct);
   • Positive SARS-CoV-2 antigen test on day of study inclusion;
   • Positive SARS-CoV-2 antibody test unless subject is vaccinated.

3. Patients with Parkinson's disease:

   • History of COVID-19;
   • Positive SARS-CoV-2 antigen test on day of study inclusion;
   • Positive SARS-CoV-2 antibody test unless subject is vaccinated.