Plasma Proteome Profiling of COVID-19 Patients

We used publicly available data provided by the Massachusetts General Hospital (MGH) Emergency Department COVID-19 Cohort (18 (link)) (Filbin, Goldberg, Hacohen) with Olink Proteomics (https://www.olink.com/mgh-covid-study/) and call this data the MGH cohort. Patients were classified by acuity levels A1-A5 on days 1, 4, 8, and 29 (based on the World Health Organization [WHO] ordinal outcomes scale (19 ): A1, died; A2, intubated, survived; A3, hospitalized on oxygen; A4, hospitalized without oxygen; A5, discharged). Acuity_max was defined as the maximum Acuity score from day 1 through day 29. In this study, we defined “critical” patients as those with Acuity_max = A1 or A2. In total, 1472 plasma proteins, including 1463 unique proteins (Olink^® Explore 1536), were evaluated with 4 panels, including inflammation, oncology, cardiometabolic, and neurology proteins (20 ). The levels of protein were expressed as normalized protein expression value (NPX) in log2 scale. In this study, cytokines were defined as “interleukins, interferons, chemokine, colony-stimulation factors and growth factors” (21 ).