A theory on SARS-COV-2 susceptibility: reduced TLR7-activity as a mechanistic link between men, obese and elderly.

I hypothesize that chronic stimulation of tlr7 by intrinsic substrates in old and obese people leads to a desensitization of tlr7-signalling such that upon viral infection the immune response in those patients will be delayed, allowing the virus to more easily establish itself in these at-risk patient groups. Upon severe viral infection, resensitization of tlr7-signalling occurs so as to better fight the viral infection. This, however, leads to a situation where old and obese patients develop an overwhelming tlr7-response due to the presence of not only the viral RNA, but also the intrinsic tlr7 substrates. Thus, old and obese patients with serious COVID-19 develop a state that is similar to SLE-patients and consequently should be treated in a similar manner. The theory predicts that drugs and treatment regimens that help to control SLE-flares might also help in late-stage COVID-19 patients.