Successful Treatment of a COVID-19 Case with Pneumonia and Renal Injury Using Tocilizumab

A 49-year-old male Japanese patient was admitted to our hospital under the diagnosis of COVID-19 pneumonia. For 5 days before admission, he had experienced various symptoms, including high fever, watery diarrhea, dyspnea, and cough, and he tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleic acid. The patient is a smoker who was on medication for hypertension. A chest computed tomography scan showed bilateral multiple patchy ground-glass opacities. Despite being treated with several therapeutic agents, he still exhibited dyspnea (oxygen saturation [SpO2] in ambient air: 88%), a high fever (axillary temperature: 39 °C), and high blood pressure (148/98 mmHg). Because laboratory data revealed high levels of C-reactive protein (CRP; 2.10 mg/dL) and urinary β2-microglobulin (B2M; 33,683 µg/mL), the anti-interleukin-6 receptor antibody tocilizumab (TCZ; 400 mg) was administered intravenously. One day after injection, he was afebrile. Four days after the TCZ injection, his CRP level dropped to 0.27 mg/dL, B2M level decreased to 3817 µg/mL, and viral load became low. No adverse drug reaction due to TCZ was observed. The patient was discharged 15 days after admission. The early administration of TCZ in this patient prevented the pneumonia and kidney injury caused by COVID-19 from progressing to hyperinflammation syndrome