Critically Ill COVID-19 Patients Exhibit Anti-SARS-CoV-2 Serological Responses

• Published in: Pathophysiology (Amsterdam) 2021-05, Vol.28 (2), p.212-223
• Main Authors: Fraser, Douglas D, Cepinskas, Gediminas, Slessarev, Marat, Martin, Claudio M, Daley, Mark, Patel, Maitray A, Miller, Michael R, Patterson, Eric K, O'Gorman, David B, Gill, Sean E, Higgins, Ian, John, Julius P P, Melo, Christopher, Nini, Lylia, Wang, Xiaoqin, Zeidler, Johannes, Cruz-Aguado, Jorge A
• Format: Article
• Language: English
• Subjects: COVID-19; humoral response; immunoglobulins; intensive care unit; outcome; serology
• ISSN: 1873-149X; 0928-4680; 1873-149X
• DOI: 10.3390/pathophysiology28020014

Coronavirus disease 2019 (COVID-19), caused by SARS-CoV-2, is a global health care emergency. Anti-SARS-CoV-2 serological profiling of critically ill COVID-19 patients was performed to determine their humoral response. Blood was collected from critically ill ICU patients, either COVID-19 positive (+) or COVID-19 negative (-), to measure anti-SARS-CoV-2 immunoglobulins: IgM; IgA; IgG; and Total Ig (combined IgM/IgA/IgG). Cohorts were similar, with the exception that COVID-19+ patients had a greater body mass indexes, developed bilateral pneumonias more frequently and suffered increased hypoxia when compared to COVID-19- patients ( < 0.05). The mortality rate for COVID-19+ patients was 50%. COVID-19 status could be determined by anti-SARS-CoV-2 serological responses with excellent classification accuracies on ICU day 1 (89%); ICU day 3 (96%); and ICU days 7 and 10 (100%). The importance of each Ig isotype for determining COVID-19 status on combined ICU days 1 and 3 was: Total Ig, 43%; IgM, 27%; IgA, 24% and IgG, 6%. Peak serological responses for each Ig isotype occurred on different ICU days (IgM day 13 > IgA day 17 > IgG persistently increased), with the Total Ig peaking at approximately ICU day 18. Those COVID-19+ patients who died had earlier or similar peaks in IgA and Total Ig in their ICU stay when compared to patients who survived ( < 0.005). Critically ill COVID-19 patients exhibit anti-SARS-CoV-2 serological responses, including those COVID-19 patients who ultimately died, suggesting that blunted serological responses did not contribute to mortality. Serological profiling of critically ill COVID-19 patients may aid disease surveillance, patient cohorting and help guide antibody therapies such as convalescent plasma.