A more prominent lymphocytic infiltrate in COVID-MDR
We first investigated the histopathological features of COVID-MDR. Blinded histopathological evaluation of HE-stained sections of COVID-MDR, DRESS and MDR did not reveal a distinct histopathological pattern (Figure S1A). However, we found a more prominent lymphocytic infiltrate in COVID-MDR. Automated quantification of an anti-CD3 IHC staining confirmed that COVID-MDR yielded a higher number of T cells (CD3+) in comparison to MDR, DRESS and HC (Figure 1B, C), pointing towards T cells might playing a particular role in COVID-MDR.