COVID-19 Priority Research Paper Volume 12, Issue 13 pp 12432—12440

Serum IgM against SARS-CoV-2 correlates with in-hospital mortality in severe/critical patients with COVID-19 in Wuhan, China

Xintian Liu1,3, *, , Xuan Zheng2, *, , Bo Liu1, , Mingxiang Wu1, , Zhenlu Zhang4, , Gangcheng Zhang2, , Xi Su1, ,

  • 1 Intensive Care Unit, Wuhan Asia General Hospital, Wuhan 430050, China
  • 2 Cardiac Center, Wuhan Asia Heart Hospital, Wuhan 430022, China
  • 3 Department of Cardiology, Wuhan Asia Heart Hospital, Wuhan 430022, China
  • 4 Department of Clinical Laboratory, Wuhan Asia General Hospital, Wuhan 430050, China
* Equal contribution and Co-first authors

Received: April 23, 2020       Accepted: May 25, 2020       Published: July 6, 2020
How to Cite

Copyright © 2020 Liu et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY 3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.


Severe/critical patients with coronavirus disease 2019 (COVID-19) have become the central issue in the current global pandemic due to their high mortality rate. However, the relationship between antibody response and clinical outcomes has not been well described in this group. We conducted a single-center, retrospective, cohort study to investigate the relationship between serum immunoglobulin G (IgG) and IgM and clinical outcomes in severe/critical patients with COVID-19. Seventy-nine severe/critical patients with COVID-19 admitted in Wuhan Asia General Hospital in Wuhan, China during January 22, 2020 to March 6, 2020 were included. Serum antibodies were measured at day 25 (SD, 7) post illness onset. The median IgG titer was 113 (IQR 81-167) AU/ml, and IgM titer was 50 (IQR, 23-105) AU/ml. Patients whose IgM titer ≥ 50 AU/ml had higher in-hospital mortality (p=0.026). IgM titer ≥ 50 AU/ml was also correlated with higher incidences of Acute Respiratory Distress Syndrome (ARDS) and sepsis shock. Antibody remeasurements were performed in 42 patients, where IgM titer declined significantly in survivors (p=0.031). Serum IgM titer changes according to the COVID-19 progression. The severe/critical patients with COVID-19 have a higher risk of clinical adverse events when IgM titer ≥ 50 AU/ml. Further decreasing of IgM could imply a better outcome in severe/critical cases.


ALT: alanine aminotransferase; ARDS: acute respiratory distress syndrome; CAD: coronary artery disease; CKD: chronic kidney disease; COPD: chronic obstructive pulmonary disease; COVID-19: coronavirus disease 2019; CLIA: chemiluminescence immunoassay; ICU: intensive care unit; IgG: immunoglobulin G; IQR: interquartile range; MERS-CoV: Middle East Respiratory Syndrome-coronavirus; NT-proBNP: N-terminal prohormone of brain natriuretic peptide; PaO2/FiO2: Alveolar oxygen partial pressure/fraction of inspiration O2; SARS-CoV-2: severe acute respiratory syndrome coronavirus 2; SD: standard deviation; WBC: white blood cell count.