Observational Study
Copyright ©The Author(s) 2023. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Biol Chem. Mar 27, 2023; 14(2): 52-61
Published online Mar 27, 2023. doi: 10.4331/wjbc.v14.i2.52
Correlation of serum SARS-CoV-2 IgM and IgG serology and clinical outcomes in COVID-19 patients: Experience from a tertiary care centre
Mohan Suresh, Pratap Kumar, Prasan Kumar Panda, Vikram Jain, Rohit Raina, Sarama Saha, Subbiah Vivekanandhan, Balram Ji Omar
Mohan Suresh, Pratap Kumar, Prasan Kumar Panda, Vikram Jain, Rohit Raina, Department of Internal Medicine, All India Institute of Medical Sciences, Rishikesh 249203, India
Sarama Saha, Subbiah Vivekanandhan, Department of Biochemistry, All India Institute of Medical Sciences, Rishikesh 249203, India
Balram Ji Omar, Department of Microbiology, All India Institute of Medical Sciences, Rishikesh 249203, India
Author contributions: Panda PK, and Vivekanandhan V contributed to conceptualization; Panda PK contributed to methodology; Raina R contributed to software; Panda PK, Jain V, Suresh M, Omar BJ, and Kumar P contributed to validation; Raina R contributed to formal analysis; Saha S contributed to investigation; Panda PK contributed to resources; Suresh M contributed to data curation; Suresh M and Kumar P contributed to writing-original draft preparation; Panda PK and Omar BJ contributed to writing-review and editing; Panda PK contributed to visualization; Panda PK, Saha S, and Vivekanandhan V contributed to supervision; Panda PK, and Vivekanandhan V contributed to project administration; All authors have read and agreed to the published version of the manuscript.
Institutional review board statement: The Approval for this study was obtained from the institute ethics committee of All India Institute of Medical Sciences Rishikesh with approval no CTRI/2020/08/027169.
Informed consent statement: Consent is waived considering de-identification of the patient data.
Conflict-of-interest statement: We declare that we have no conflicts of interest and it’s not funded.
Data sharing statement: It will be made available to others as required upon requesting the corresponding author.
STROBE statement: The authors have read the STROBE Statement—checklist of items, and the manuscript was prepared and revised according to the STROBE Statement—checklist of items.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Prasan Kumar Panda, MBBS, MD, Associate Professor, Department of Internal Medicine, All India Institute of Medical Sciences, Rishikesh 249203, India. motherprasanna@rediffmail.com
Received: October 10, 2022
Peer-review started: October 10, 2022
First decision: January 3, 2023
Revised: January 12, 2023
Accepted: February 13, 2023
Article in press: February 13, 2023
Published online: March 27, 2023
Abstract
BACKGROUND

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus has become a pandemic for the last 2 years. Inflammatory response to the virus leads to organ dysfunction and death. Predicting the severity of inflammatory response helps in managing critical patients using serology tests IgG and IgM.

AIM

To investigate the correlation of the serology (IgM and IgG) with reverse transcriptase polymerase chain reaction (RT-PCR) status, disease severity [mild to critical], intensive care unit (ICU) admission, septic shock, acute kidney injury, and in-hospital mortality.

METHODS

We conducted a longitudinal study to correlate serum SARS-CoV-2 immunoglobulin M (IgM) and immunoglobulin G (IgG) serology with clinical outcomes in coronavirus disease 2019 (COVID-19) patients. We analyzed patient data from March to December 2020 for those who were admitted at All India Institute of Medical Sciences Rishikesh. Clinical and laboratory data of these patients were collected from the e-hospital portal and analyzed. A correlation was seen with clinical outcomes and was assessed using MS Excel 2010 and SPSS software.

RESULTS

Out of 494 patients, the mean age of patients was 48.95 ± 16.40 years and there were more male patients in the study (66.0%). The patients were classified as mild-moderate 328 (67.1%), severe 131 (26.8%), and critical 30 (6.1%). The mean duration from symptom onset to serology testing was 19.87 ± 30.53 d. In-hospital mortality was observed in 25.1% of patients. The seropositivity rate (i.e., either IgG or IgM > 10 AU) was 50%. IgM levels (AU/mL) (W = 33428.000, P ≤ 0.001) and IgG levels (AU/mL) (W = 39256.500, P ≤ 0.001), with the median IgM/ IgG levels (AU/mL), were highest in the RT-PCR-Positive group compared to RT-PCR-Negative clinical COVID-19. There was no significant difference between the two groups in terms of all other clinical outcomes (disease severity, septic shock, ICU admission, mechanical ventilation, and mortality).

CONCLUSION

The study showed that serology levels are high in RT-PCR positive group compared to clinical COVID-19. However, serology cannot be useful for the prediction of disease outcomes. The study also highlights the importance of doing serology at a particular time as antibody titers vary with the duration of the disease. In week intervals there was a significant correlation between clinical outcomes and serology on week 3.

Keywords: Inflammatory response, Reverse transcription polymerase chain reaction, SARS-CoV-2, Serology IgM and IgG

Core Tip: Coronavirus disease 2019 (COVID-19) serology levels are high in reverse transcriptase polymerase chain reaction positive group compared to clinical COVID-19. However, serology cannot be useful for the prediction of disease outcomes. The study also highlights the importance of doing serology at a particular time as antibody titres vary with the duration of the disease. In week interval there were significant correlation with clinical outcomes and serology on week 3.