Inclusion and exclusion criteria along with case versus control groups
| Inclusion criteria | Case groups |
| Age 18–90 years old | Sarcoidosis and viral illness (majority) |
| Sarcoidosis or non-sarcoidosis ILD | Non-sarcoidosis ILD and viral illness (minority) |
| Exclusion criteria | Control groups |
| Pregnant | Sarcoidosis and no viral illness |
| Imprisoned | Non-sarcoidosis ILD and no viral illness |
| Unable to consent |
ILD, interstitial lung disease.