Correlation between lung inflammatory cells, viral load and cytokines in fatal COVID-19

Abstract

SARS-CoV2 infection induces a complex interaction between virus and host immune system, activating multiple inflammatory pathways and leading to hyperinflammation, diffuse alveolar damage (DAD), ARDS, and multiorgan failure. We aimed to correlate the quantification of viral load, inflammatory cells and cytokines in lung tissue of fatal COVID-19. We assessed inflammatory cells by multiplex immunohistochemistry, cytokines by Luminex xMAP Assay and viral load by real time PCR in autopsy lung tissue of 18 COVID-19 patients. Correlations were considered statistically significant if p<0.05. Macrophages correlated with IL-1β (r=0.54), IL-10 (r=0.5), IFN-α2 (r=0.72), IFN-γ (r=0.6), CCL20 (r=0.5), TGF-β1 (r=0.6), TGF-β2 (r=0.6). CD4+T cells correlated with CCL20 (r=0.6), MDC/CCL2 (r=0.53), CCL17 (r=0.5), IP-10 (r=0.6), CXCL9 (r=0.6). CD8+T cells correlated with IL-1β (r=0.54), IL-4 (r=0.63), IL-6 (r=0.7), IL-8 (r=0.63), IL-10 (r=0.6), TNF-α (r=0.6), IFN-γ (r=0.74), CCL20 (r=0.7), TGF-β1 (r=0.7), TGF-β2 (r=0.56), TGF-β3 (r=0.54), MDC/CCL2 (r=0.7), CCL17 (r=0.64). Langerin dendritic cells (DC) correlated with symptom onset to death interval (r=0.6), hospitalization length (r=0.65), mechanical ventilation (MV) length (r=0.6), ICU stay (r=0.6), exudative DAD (r=-0.5), viral load (r=-0.6). Myeloid DC correlated with symptom onset to death interval (r=0.8), hospitalization length (r=0.8), MV length (r=0.8), ICU stay (r=0.8), exudative DAD (r=-0.5), viral load (r=-0.7). Viral load correlated with symptom onset to death interval (r=-0.7), hospitalization length (r=-0.8), MV length (r=-0.7), ICU stay (r=-0.8), exudative DAD (r=0.6). There is a complex temporal inflammatory modulation in severe COVID-19.