A 67-year-old woman with a medical history of hypertension developed fever and myalgia and diagnosed as COVID-19 via SARS-CoV-2 rRT-PCR on March 6. The next day, she was admitted to a local public medical center and received hydroxychloroquine 400 mg once daily and lopinavir/ritonavir 400 mg/100 mg twice daily with empirical antibiotics. However, on day 3, she was transferred to the tertiary-care hospital due to increased oxygen demand and worsening infiltrative shadows in the left lower lung. At that time, her oxygen saturation checked 93% on 4 L/min oxygen flow via nasal cannula with a respiratory rate of 24 times per minute. Routine blood tests showed mild leukocytosis (12.67 × 103/µL) with lymphopenia (0.7 × 103/µL), elevated CRP, IL-6 and LDH. (131.1 mg/L, 474.7 pg/mL, 344 IU/L, respectively) Routine chemistry, electrolyte, and blood coagulation tests showed no abnormalities. Bacterial cultures and the PCR for other respiratory viruses were all negative.