Persistence of inflammatory and vascular damage mediators 5 months after acute COVID-19

Abstract

<b>Background:</b> In the acute phase, patients with severe COVID-19 exhibit pulmonary inflammation and vascular injury, as well as an exaggerated cytokine response. <b>Aim:</b> To&nbsp;describe the inflammatory cytokine and vascular injury mediator profiles in patients previously hospitalised with COVID-19, and to compare these profiles with those in healthy controls and in patients recovering from severe sepsis of other aetiology. <b>Methods:</b> Plasma levels of 28 different cytokine, chemokine, angiogenic and vascular injury markers were measured by MSD V-PLEX multiplex assays in 49 post-COVID patients 5.0±1.9 (mean±SD) months after hospitalisation with COVID-19 pneumonia, 11 post-sepsis patients (5.4±2.9 months after hospitalised non-COVID sepsis) and 18 healthy controls. Kruskal-Wallis or ANOVA were used to compare groups; false discovery rate correction (Benjamini Hochberg) allowed for multiple testing. <b>Results:</b> In the post-COVID group, IL-6, TNFα, SAA, MCP1, Tie-2, Flt1, PIGF and CRP were significantly elevated, whereas IL-7 and bFGF were significantly depressed. The differences in TNFα, SAA, MCP1, Tie-2, Flt1, IL-7 and bFGF appeared unique to the post-COVID group, but increased IL-6, PIGF and CRP levels were also seen in post-sepsis patients compared with controls. In post-COVID patients we found strong negative spearman correlations between each of IL-6 (r=-0.51) and CRP (r=-0.57) with TLCO %predicted (p&lt;0.001) and positive correlations with post-recovery CT abnormality scores: IL-6 (r=0.28) and CRP (r=0.46), p&lt;0.05. <b>Conclusion:</b> A&nbsp;unique&nbsp;signature of inflammatory and vascular damage markers&nbsp;is seen months after&nbsp;acute COVID-19 infection. Further research is needed to determine their pathophysiological significance.