Comparing biomarkers for COVID-19 disease with commonly associated preexisting conditions and complications.

Severe coronavirus disease 2019 (COVID-19) has been associated with certain preexisting health conditions and can cause respiratory failure along with other multi-organ injuries. However, the mechanism of these relationships is unclear, and prognostic biomarkers for the disease and its systemic complications are lacking. This study aims to examine the plasma protein profile of COVID-19 patients and evaluate overlapping protein modules with biomarkers of common comorbidities. Blood samples were collected from COVID-19 cases (n=307) and negative controls (n=78) among patients with acute respiratory distress. Proteins were measured by proximity extension assay utilizing next-generation sequencing technology. Its associations to COVID-19 disease characteristics were compared to that of preexisting conditions and established biomarkers for myocardial infarction (MI), stroke, hypertension, diabetes, smoking, and chronic kidney disease. Several proteins were differentially expressed in COVID-19, including multiple pro-inflammatory cytokines such as IFN-{gamma}, CXCL10, and CCL7/MCP-3. Elevated IL-6 was associated with increased severity, while baseline IL1RL1/ST2 levels were associated with a worse prognosis. Network analysis identified several protein modules associated with COVID-19 disease characteristics overlapping with processes of preexisting hypertension and impaired kidney function. BNP and NTpro-BNP, markers for MI and stroke, increased with disease progression and were positively associated with severity. MMP12 was similarly elevated and has been previously linked to smoking and inflammation in emphysema, along with increased cardiovascular disease risk. In conclusion, this study provides an overview of the systemic effects of COVID-19 and candidate biomarkers for clinical assessment of disease progression and the risk of systemic complications.