The results of ROC curve analysis show that the expression of Lex structures in AGP glycans, has a potential as glycomarker with moderate clinical utility for differentiation severe COVID-19 patients from convalescents (proposed cut-off point was 0.129 AU with sensitivity 81.3% and specificity 58.6%) and healthy subjects (proposed cut-off point was 0.19 AU with sensitivity 75.4% and specificity 79.3%), as well as between convalescents and heathy individuals (proposed cut-off point was 0.222 AU with sensitivity 68.8% and specificity 63.1%). Here, ATP5MK is linked to COVID-19.