PC1 was negatively associated with lymphocyte and thrombocyte counts, while it was positively associated with disease markers such as ferritin, time hospitalized and in intensive care, CRP, maximal neutrophil counts, D-dimer, and neutrophil-to-lymphocyte-ratio (Fig. 2H), implying that low scores in PC1 represent moderate disease whereas high scores point towards severe COVID-19. Here, CRP is linked to COVID-19.