Potential viral persistence and mucosal involvement in the etiopathology of Post Acute Sequelae Covid . 2023 march


Senior Member

Both convalescent asymptomatic and PASC cases are characterised by higher CD8+ T cell percentages, however, the proportion of blood CD8+ T cells expressing the mucosal homing receptor β7 is low in PASC patients.

CD8 T cells show increased expression of PD-1, perforin and granzyme B in PASC, and the plasma levels of type I and type III (mucosal) interferons are elevated. The humoral response is characterized by higher levels of IgA against the N and S viral proteins, particularly in those individuals who had severe acute disease.
Thus, our results highlight a model in which the persistence of viral antigens in mucosa alters mucosal immune response.
This increased expression of perforin and Eomes in CD8+ T cells from PASC individuals concomitant to higher expression levels of PD-1 indicates that CD8+ T cells are activated instead of being exhausted in individuals presenting PASC.
If viral persistence is inferred by other groups as the cornerstone of PASC, treatment of this syndrome may be based on antiviral drugs, which have not yet been tested.

it may be interesting to test these markers in Long covid patients