Background The coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a global pandemic. There have been reports that long-term SARS-CoV-2 RNA shedding and re-infection of COVID-19 patients existed. However, the specific mechanism, diagnosis, and treatment of COVID-19 are still unclarified. Case presentation In this case, we reported a 64-year-old patient who had a long-term course of COVID-19 for 174 days with two retests of SARS-CoV-2 RNA positive after discharging from the hospital. The patient’s serum immunoglobulin G (IgG) of SARS-CoV-2 tested positive after the initial infection. And during treatment, the CD4 + T cell count and ratio to peripheral blood mononuclear cell (PBMC) were in dynamic change. Conclusions Our results suggested that the host immune system responded with IgG production after SARS-CoV-2 infection, but was not protective enough for the patient. The reemergence of SARS-CoV-2 could be related to the cell count and proportion of CD4 + T cells in PBMC. And the increase of CD4 + T cells after treatment may help to clear the virus.
【저자키워드】 COVID-19, SARS-CoV-2, Reemergence, RNA test, Host immune response, 【초록키워드】 Treatment, coronavirus disease, IgG, Coronavirus disease 2019, coronavirus, T cells, SARS-COV-2 infection, hospital, Infection, Diagnosis, severe acute respiratory syndrome Coronavirus, virus, Peripheral blood, global pandemic, serum, T cell, Immunoglobulin G, Immunoglobulin, Patient, Re-infection, PBMC, SARS-CoV-2 RNA, respiratory, mechanism, Protective, COVID-19 patient, the cell, mononuclear cell, during treatment, acute respiratory syndrome, treatment of COVID-19, acute respiratory syndrome coronavirus, acute respiratory syndrome coronavirus 2, help, host immune system, positive, cell count, Cell, initial, Course, tested, caused, proportion, reported, the patient, suggested, 【제목키워드】 Case report, discharged,