Diagnostic value of combined nucleic acid and antibody detection in suspected COVID-19 cases. (September 2020) - Zeng, H.
Abstract: Objectives: Nucleic acid testing is the gold standard method for the diagnosis of coronavirus disease 2019 (COVID-19); however, large numbers of false-negative results have been reported. In this study, nucleic acid detection and antibody detection (IgG and IgM) were combined to improve the testing accuracy of patients with suspected COVID-19. Study design: The positive rate of nucleic acid detection and antibody detection (IgG and IgM) were compared in suspected COVID-19 patients. Methods: A total of 71 patients with suspected COVID-19 were selected to participate in this study, which included a retrospective analysis of clinical features, imaging examination, laboratory biochemical examination and nucleic acid detection and specific antibody (IgM and IgG) detection. Results: The majority of participants with suspected COVID-19 presented with fever (67.61%) and cough (54.93%), and the imaging results showed multiple small patches and ground-glass opacity in both lungs, with less common infiltration and consolidation opacity (23.94%). Routine blood tests were mostly normal (69.01%), although only a few patients had lymphopenia (4.23%) or leucopenia (12.68%). There was no statistical difference in the double-positive rate between nucleic acid detection (46.48%) and specific antibody (IgG and IgM) detection (42.25%) ( P = 0.612), both of which were also poorly consistent with each other (kappa = 0.231). The positive rate of combined nucleic acid detection and antibody detection (63.38%) was significantly increased, compared with that of nucleic acid detection (46.48%) and that of specific antibody (IgG and IgM) detection (42.25%), and the differences were statistically significant ( P = 0.043 and P = 0.012, respectively). Conclusions: Nucleic acid detection and specific antibody (IgG and IgM) detection had similar positive rates, and their combination could improve the positive rate of COVID-19 detection, which is of great significance for diagnosis and epidemic control. Highlights: Characteristics of 71 patients with suspected coronavirus disease 2019 (COVID-19) were analysed. Fever (67.61%) and cough (54.93%) were the most common symptoms at the onset of illness. No statistical difference was observed in the positive rate between nucleic acid and specific antibody detection. Combined nucleic acid and antibody detection could help to improve the positive rate of COVID-19 (63.38%) diagnosis.