Proteomics and Metabolomics Profiles of Unvaccinated Nonagenarian Patients with Severe SARS-CoV‑2 Infection

The mortality rate of COVID-19 increases significantly
in patients
over the age of 90, although some elderly people in this category
have experienced mild disease or have been asymptomatic. In this context,
we aim to analyze the plasma proteomic and metabolomic profiles of
unvaccinated nonagenarian patients who had severe manifestations of
COVID-19 and either recovered or died and compare them with noninfected
control subjects. Compared with healthy individuals, nonsurviving
patients showed a reduced abundance of specific lipid-related proteins
and metabolites, including APOH, APOC1, LCAT, 7-α-25-dihydroxycholesterol,
7-dehydrocholesterol, and phosphatidylethanolamine, which may serve
as indicative markers of severity. Acute phase response, complement
activation, and sphingolipids and phospholipids remain altered in
recovered patients, indicating possible persistent effects of COVID-19.
This study employs a multiomics approach to unveil key immune alterations
in unvaccinated nonagenarians, shedding light on molecular signatures
that may serve as predictive markers for disease severity and recovery
in the elderly population.