Anti-SARS-CoV-2 immune response and sudden death: Titin as a link

Twenty-nine pentapeptides are common to Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) spike glycoprotein (gp) and the cardiac human protein Titin, alterations of which are linked to cardiac failure and sudden death. The peptide commonality does not reflect mere peptide sharing, rather it has relevant immunological potential as nearly all of the shared sequences are present in experimentally validated SARS-CoV-2 spike gp-derived epitopes, thus supporting the possibility that anti-Titin autoimmune cross-reactions can be triggered by the virus. Moreover, contextual peptide commonality among SARS-CoV-2, human Titin, and microbial organisms to which individuals have previously been exposed, highlights the likelihood of anamnestic and extremely powerful anti-Titin immune responses that may derive from earlier immunologic imprinting. The present data may help understand, explain, and diagnose the relationship between sudden death and infections.