The Relation between Immunological Features and the Positive SARS-CoV-2 Nucleic Acid in Patients with Nonsevere COVID⁃19.

Objective. The novel coronavirus nucleic acid results are the core indicators of illness monitoring. This study aimed to evaluate the relationship between immunological features and positive SARS-CoV-2 nucleic acid by analyzing the clinical and immunological features in nonsevere COVID-19 cases. Methods. Data from nonsevere COVID-19 patients admitted to Haihe Hospital from May 2020 to June 2021 were retrospectively reviewed and analyzed. Results. (1) A total of 122 cases were reviewed in the present study, including 38 mild and 84 moderate cases. The average age of mild cases was significantly different from moderate cases (P < 0.001). Eight patients complained of hyposmia and it was more frequent in mild cases (P < 0.001). The nucleic acid positive duration (NPD) of nonsevere novel coronavirus was 20.49 (confidence interval (CI) 17.50–3.49) days. (2) The levels of specific IgM and IgG for COVID-19 were higher in mild cases than in moderate cases (P = 0.023 and P = 0.047 , respectively). (3) The correlation analysis with antibodies and T-cell subtypes showed that the lymphocyte (LYM) count, T cells, CD4⁺T cells, and CD8⁺T cells had a linear correlation with NPD. (4) Among the 93 patients monitored, 62 COVID-19 cases presented a progressive rise of specific IgM and IgG. The daily increase rates of IgM and IgG were 38.42% (CI 28.22–48.61%) and 24.90% (CI 0.23–29.58%), respectively. Conclusion. The levels and daily increase rates of specific IgM and IgG against the virus can vary between cases. The NPD presented a linear correlation with the LYM, T cells, CD4⁺T cells, and CD8+T cells. Hence, more attention should be paid to these indicators in clinical practice. [ABSTRACT FROM AUTHOR]