ATP5MK and COVID-19: ROC curve analysis demonstrated high clinical utility of the relative reactivity of AGP glycans with SNA in differentiating between patients with severe COVID-19 and convalescents (proposed cut-off point was 0.187 AU with sensitivity 100% and specificity 86.2%), and moderate clinical utility in differentiating between patients with severe COVID-19 and healthy individuals (proposed cut-off point was 0.117 AU with sensitivity 87.7% and specificity 79.3%), as well as between convalescents and healthy individuals (proposed cut-off point was 0.503 AU with sensitivity 60.4% and specificity 90.8%).