Recent studies have highlighted observations regarding re-tested positivity (RP) of SARS-CoV-2 RNA in discharged COVID-19 patients, however, the immune mechanisms underlying SARS-CoV-2 RNA RP in immunocompetent patients remain elusive. Herein, we describe the case of an immunocompetent COVID-19 patient with moderate symptoms who was twice re-tested as positive for SARS-CoV-2 RNA, and the period between first and third viral RNA positivity was 95 days, longer than previously reported (18–25 days). The chest computed tomography findings, plasma anti-SARS-CoV-2 antibody, neutralizing antibodies (NAbs) titer, and whole blood transcriptic characteristics in the viral RNA RP patient and other COVID-19 patients were analyzed. During the SARS-CoV-2 RNA RP period, new lung lesions were observed. The COVID-19 patient with viral RNA RP had delayed seroconversion of anti-spike/receptor-binding domain (RBD) IgA antibody and NAbs and were accompanied with disappearance of the lung lesions. Further experimental data validated that NAbs titer was significantly associated with anti-RBD IgA and IgG, and anti-spike IgG. The RP patient had lower interferon-, T cells- and B cell-related genes expression than non-RP patients with mild-to-moderate symptoms, and displayed lower cytokines and chemokines gene expression than severe patients. Interestingly, the RP patient had low expression of antigen presentation-related genes and low B cell counts which might have contributed to the delayed anti-RBD specific antibody and low CD8+ cell response. Collectively, delayed antigen presentation-related gene expression was found related to delayed adaptive immune response and contributed to the SARS-CoV-2 RNA RP in this described immunocompetent patient.
【저자키워드】 COVID-19, SARS-CoV-2, delayed neutralizing antibody response, delayed antigen presentation, delayed anti-RBD/anti-spike IgA conversion, re-tested positivity, 【초록키워드】 neutralizing antibody, IgG, observations, Cytokines, Gene Expression, Neutralizing antibodies, antibody, T cells, interferon, cytokine, Symptom, chemokines, Symptoms, chemokine, Antigen, RNA, B cell, Computed tomography, Chest computed tomography, Seroconversion, Viral, Characteristics, anti-SARS-CoV-2 antibody, Whole blood, anti-Spike IgG, RBD, IgA, titer, Patient, plasma, SARS-CoV-2 RNA, Viral RNA, Antigen presentation, Adaptive immune response, expression, moderate, immune mechanism, COVID-19 patients, NAb, COVID-19 patient, Mild-to-moderate, anti-RBD, moderate symptoms, lung lesion, lung lesions, T cells-, observation, severe patients, NAbs, domain, low expression, disappearance, positive, CD8+, recent, Cell, anti-RBD IgA, RBD IgA, described, analyzed, significantly, reported, contributed, discharged, accompanied, the SARS-CoV-2, 【제목키워드】 RNA, Viral, response, Innate,