Highly pathogenic coronavirus N protein aggravates lung injury by MASP-2-mediated complement over-activation

Ting Gao; Mingdong Hu; Xiaopeng Zhang; Hongzhen Li; Lin Zhu; Hainan Liu; Qincai Dong; Zhang Zhang; Zhongyi Wang; Yong Hu; Yangbo Fu; Yanwen Jin; Kaitong Li; Songtao Zhao; Yongjiu Xiao; Shuping Luo; Lufeng Li; Lingfang Zhao; Junli Liu; Huailong Zhao; Yue Liu; Weihong Yang; Jing Peng; Xiaoyu Chen; Ping Li; Yaoning Liu; Yonghong Xie; Jibo Song; Lu Zhang; Qingjun Ma; Xiuwu Bian; Wei Chen; Xuan Liu; Qing Mao; Cheng Cao

Patient #1, a 54 years old male resident in the city of Wuhan, was admitted to Dongxihu Hospital on the 4th day after the onset of symptoms (5 days of illness) with fever. Infection of SARS-CoV-2 was confirmed by rRT-PCR for SARS-CoV-2 ， and chest CT scan showed 5 bilateral opacities. The disease was getting worse from day 9 of illness, with high fever (38.7C~39.8C), SpO2 <93% on room air, pneumonia progression on CT scan, and severe hepatic damage. Prednisone (40 mg/day for 4 days) was administrated on day 10 through 13 of illness but the condition deteriorated, so the patient was transferred to Wuhan Huoshenshan Hospital, a new hospital established urgently for severe COVID-19 patients, on the day 14 of 10 illness (Fig. 5A) , and was considered as severe case in critical condition with moderate ARDS (oxygenation index <150), respiratory rate 30/min，and the Percutaneous oxygen saturation (SpO2) dropped to 77% when exposed to room air for 1 minute. Supportive care was provided， including high-flow nasal oxygen (HFNO) to target SpO2>95% (Fig. 5B, left) . He was also administrated with the antibiotics (moxifloxacin) and human serum albumin, while prednisone 15 was discontinued. Treatment with anti-C5a monoclonal antibody (BDB-001) was initiated on the morning of day 15 of illness. The antibody was given intravenously in 250 ml saline, at a dosage of 300 mg/day, on day 1, 2, 3, 5, 7, 9, 11 and 13. No adverse event was observed and the clinical condition improved in the next days, with normal body temperature in the evening of the same day (Fig. 5C, left) , increased oxygenation index (PaO 2 /FiO 2 ) (Fig. 5B, left) and lymphocyte cell 20 number (Fig. 5C, left) , decreased C reactive protein (CRP) concentration (Fig. 5C, left) , and significantly improved hepatic function (shown by decreased ALT, AST, and increased total serum protein and serum albumin concentration) (Fig. 5D, left) . The fraction of inspiration O 2 and the gas flow rate of high-flow nasal oxygen (HFNO) was eventually decreased from the highest (80%, 40 L/min to 30%, 20 L/min) to target a SpO2>95% (Fig. 5B, left) . Because the 25 high risk of taking the patient in critical condition to CT scan in the temporarily established hospital (the long distance and the cold raining weather without HFNO), no CT scan just before anti-C5a administration was available for evaluation. Nevertheless, the pneumonia 20 days after the 1st dose is observed obviously improved than 11 days after the 1st dose (Fig. S4 , upper panel). 30 Patient #2 was a 67 years old male who was admitted to the Sixth Hospital of Wuhan on the 5th day after the onset of symptoms (6 day of illness) with fever and cough. CT scan showed opacity on the superior lobe of left lung (Fig. S4) . Infection of SARS-CoV-2 was also confirmed by rRT-PCR at day 11 of illness. Anti-viral (Arbidol) and antibiotics (moxifloxacin) was administrated together with other supportive treatment. Condition was worsening by day 8 with 35 severe cough and high fever (39.7C) (Fig. 5C, right) . Methylprednisolone (40 mg/day, for 7 days from the 8th day after illness) showed little if any improvement of symptoms. The patient was transferred to Wuhan Huoshenshan Hospital on day 10 (Fig. 5A ) and the illness continued getting worse as shown by SpO2 (<90% on room air on day 14), high fever (>39C on day 10-13) (Fig. 5C, right) and pneumonia on chest CT on day 11 of illness (2 days before the 1st dose) (Fig. 40 S4, lower panel). The patients rep