Furthermore, a positive correlation between cfDNA (Spearman r = 474, p < 0.001) and MPO-DNA complexes (Spearman r = 0.316, p = 0.002) with fibrinogen degradation products (a coagulation indicator) was observed in COVID-19 patients in a study including 19 mild and 41 severe patients (60 patients in total) [89]. Here, MPO is linked to COVID-19.