Absent immune response to SARS-CoV-2 in a 3-month recurrence of coronavirus disease 2019 (COVID-19) case

Background The viral persistence in patients with Coronavirus Disease 2019 (COVID-19) remains to be investigated. Methods We investigated the viral loads, therapies, clinical features, and immune responses in a 70-year patient tested positive for SARS-CoV-2 for 3 months. Findings The patient exhibited the highest prevalence of abnormal indices of clinical features and immune responses at the first admission, including fever (38.3 ℃), decreased lymphocytes (0.83 × 109/L) and serum potassium (3.1 mmol/L), as well as elevated serum creatinine (115 µmol/L), urea (8.6 mmol/L), and C-reactive protein (80 mg/L). By contrast, at the second and the third admission, these indices were all normal. Through three admissions, IL-2 increased from 0.14 pg/mL, 0.69 pg/mL, to 0.91 pg/mL, while IL-6 decreased from 11.78 pg/mL, 1.52 pg/mL, to 0.69 pg/mL, so did IL-10 from 5.13 pg/mL, 1.85 pg/mL, to 1.75 pg/mL. The steady declining trend was also found in TNF-α (1.49, 1.15, and 0.85 pg/mL) and IFN-γ (0.64, 0.42, and 0.27 pg/mL). The threshold cycle values of RT-PCR were 26.1, 30.5, and 23.5 for ORFlab gene, and 26.2, 30.6, and 22.7 for N gene, showing the patient had higher viral loads at the first and the third admission than during the middle term of the disease. The patient also showed substantially improved acute exudative lesions on the chest CT scanning images. Conclusions The patient displayed declining immune responses in spite of the viral shedding for 3 months. We inferred the declining immune responses might result from the segregation of the virus from the immune system.