Immunoglobulin G/M and Cytokines Detections in Continuous Sera from Patients with Novel Coronaviruses (2019-nCoV) Infection

Abstract

Background: An outbreak of severe respiratory illness caused by a novel coronaviruses (2019- nCoV) in China since December 2019. This work aim to evaluate the clinical diagnostic values of the Immunoglobulin G/M’s or the inflammatory-related factor’s level in patients’ serum sample and the relationship with clinical manifestations and epidemiologic features.

Methods: A total of forty-nine patients confirmed by the nucleic acid test were enrolled in this study, the S (Spike) and N (Nucleocapsid) -based G/M neutralizing antibodies were detected in 206 continuous serum samples by using the enzyme-linked immunosorbent assay (ELISA). The inflammatory-ratelted factors, including interleukin-2 (IL-2), interleukin-4 (IL-4), interleukin6 (IL-6), interleukin-10 (IL-10), interleukin-17 (IL-17), interleukin-12p70 (IL-12p70), tumor necrosis factor-α(TNF-α) and interferon-γ(INF-γ) were determined by a flow cytometry.

Results: As regards to S-IgM, N-IgM, S-IgG and N-IgG, the detection positive rates in 49 patients were 38.8%, 51.0%,63.3% and 40.8% respectively. The median detection times for those antibodies were the 10th, 9th, 9th, or 9th days’ time point after the illness onset. The Kappa test results showed that the consistency of two IgM detection and two IgG detection are poor, the Kappa index are 0.408 and 0.344 respectively. 73.5%, 14.3% and 10.2% patients had high levels IL-6, IL-10 and INF-γ results. We also found that patients who lived in Wuhan or traveling to Wuhan in the short term had higher S-IgM (p=0.045) and N-IgM (p=0.002) concentrations than those who stayed in other cities. IL-6 concentrations had significant differences between severe patients and mild patients (p=0.0391). IL-10 concentration elevated in patients with background diseases compared with those no background diseases patients (p=0.0122).

Conclusions: N-IgM and S-IgG detection are more appropriate for use in the early patients screening than S-IgM and N-IgG. Antibodies detection has higher positive rate after 10 days illness onset. IL-6, IL-10 and INF-γ levels can be regarded as novel biomarkers for the prognostic and therapeutic effect evaluation.

Funding Statement: This work was supported by the Emergency Project for 2019-nCoV of PLA General Hospital (20EP013).

Declaration of Interests: The authors stated that there is no conflict of interest.

Ethics Approval Statement: The study procedures were approved by the ethics committee of The Fifth Medical Centre of PLA General Hospital of China.

Keywords: Novel coronaviruses (2019-nCoV); Immunoglobulin G/M detection; cytokines; cytokine storm