Serology characteristics of SARS-CoV-2 infection since exposure and post symptom onset.
Eur Respir J. 2020 May 19;:
Authors: Lou B, Li TD, Zheng SF, Su YY, Li ZY, Liu W, Yu F, Ge SX, Zou QD, Yuan Q, Lin S, Hong CM, Yao XY, Zhang XJ, Wu DH, Zhou GL, Hou WH, Li TT, Zhang YL, Zhang SY, Fan J, Zhang J, Xia NS, Chen Y
Abstract
BACKGROUND: Timely diagnosis of SARS-CoV-2 infection is a prerequisite for treatment and prevention. The serology characteristics and complement diagnosis value of the antibody test to RNA test need to be demonstrated.
METHOD: Serial sera of 80 patients with PCR-confirmed COVID-19 were collected at the First Affiliated Hospital of Zhejiang University, China. Total antibody (Ab), IgM and IgG antibodies against SARS-CoV-2 were detected, and the antibody dynamics during the infection were described.
RESULTS: The seroconversion rates for Ab, IgM and IgG were 98.8%, 93.8% and 93.8%, respectively. The first detectible serology marker was Ab, followed by IgM and IgG, with a median seroconversion time of 15, 18 and 20 days post exposure (d.p.e) or 9, 10 and 12 days post onset (d.p.o), respectively. The antibody levels increased rapidly beginning at 6 d.p.o. and were accompanied by a decline in viral load. For patients in the early stage of illness (0-7 d.p.o), Ab showed the highest sensitivity (64.1%) compared to IgM and IgG (33.3% for both, p<0.001). The sensitivities of Ab, IgM and IgG increased to 100%, 96.7% and 93.3% 2 weeks later, respectively. When the same antibody type was detected, no significant difference was observed between enzyme-linked immunosorbent assays and other forms of immunoassays.
CONCLUSIONS: A typical acute antibody response is induced during SARS-CoV-2 infection. Serology testing provides an important complement to RNA testing in the later stages of illness for pathogenic specific diagnosis and helpful information to evaluate the adapted immunity status of patients.
PMID: 32430429 [PubMed - as supplied by publisher]