The
SARS-CoV-2 beta coronavirus is the etiological driver of COVID-19
disease, which is primarily characterized by shortness of breath,
persistent dry cough, and fever. Because they transport oxygen, red
blood cells (RBCs) may play a role in the severity of hypoxemia in
COVID-19 patients. The present study combines state-of-the-art metabolomics,
proteomics, and lipidomics approaches to investigate the impact of
COVID-19 on RBCs from 23 healthy subjects and 29 molecularly diagnosed
COVID-19 patients. RBCs from COVID-19 patients had increased levels
of glycolytic intermediates, accompanied by oxidation and fragmentation
of ankyrin, spectrin beta, and the N-terminal cytosolic domain of
band 3 (AE1). Significantly altered lipid metabolism was also observed,
in particular, short- and medium-chain saturated fatty acids, acyl-carnitines,
and sphingolipids. Nonetheless, there were no alterations of clinical
hematological parameters, such as RBC count, hematocrit, or mean corpuscular
hemoglobin concentration, with only minor increases in mean corpuscular
volume. Taken together, these results suggest a significant impact
of SARS-CoV-2 infection on RBC structural membrane homeostasis at
the protein and lipid levels. Increases in RBC glycolytic metabolites
are consistent with a theoretically improved capacity of hemoglobin
to off-load oxygen as a function of allosteric modulation by high-energy
phosphate compounds, perhaps to counteract COVID-19-induced hypoxia.
Conversely, because the N-terminus of AE1 stabilizes deoxyhemoglobin
and finely tunes oxygen off-loading and metabolic rewiring toward
the hexose monophosphate shunt, RBCs from COVID-19 patients may be
less capable of responding to environmental variations in hemoglobin
oxygen saturation/oxidant stress when traveling from the lungs to
peripheral capillaries and vice versa.