SDC1 and COVID-19: Additionally, Syndecan-1 (SDC-1) was evaluated as a marker of possible microvascular endothelial damage, which was significantly increased in patients with COVID-19: 16.97 ± 5.6 ng/mL in the moderate group and 29.95 ± 8.67 ng/mL in the severe group, versus 10.29 ± 4.9 ng/mL in the control group; the increase was higher in severe cases.