ABSTRACT: We performed in-depth MS-based plasma-proteome profiling in 20 hospitalised patients with COVID-19 and 7 healthy controls (PCR- and sero-negative for SARS-CoV-2) by high-resolution isoelectric focusing (HiRIEF) coupled with liquid chromatography and mass-spectrometry (LC-MS/MS). The SARS‐CoV‐2 PCR‐confirmed patients from Karolinska University Hospital in Stockholm, Sweden, were included in the study in April 2020. Data from the cohort and methodology of clinical and immunological assays has been previously described in detail elsewhere (Varnaitė et al., 2020). The study was approved by the Regional Ethical Review Board in Stockholm, Sweden and by the Swedish Ethical Review Authority, and is in accordance with the Declaration of Helsinki. All COVID-19 patients and healthy controls included in this study provided written informed consent. The cohort is described in detail elsewhere (Varnaitė et al., 2020) Reference: Varnaitė, R., García, M., Glans, H., Maleki, K.T., Sandberg, J.T., Tynell, J., Christ, W., Lagerqvist, N., Asgeirsson, H., Ljunggren, H.-G., et al. (2020). Expansion of SARS-CoV-2-Specific Antibody-Secreting Cells and Generation of Neutralizing Antibodies in Hospitalized COVID-19 Patients. J. Immunol. 205, 2437–2446.