Shankar Prem, Singh Jitendra, Joshi Ankur, Malhotra Anvita Gupta, Shrivas Arti, Goel Garima, Gupta Priyal, Yadav Jayanthi, Saigal Saurabh, Singh Sarman, Purwar Shashank
Department of Microbiology, All India Institute of Medical Sciences, Bhopal 462020, India.
Department of Translational Medicine, All India Institute of Medical Sciences, Bhopal 462020, India.
Microorganisms. 2022 Jul 1;10(7):1333. doi: 10.3390/microorganisms10071333.
Precise reasons for severe manifestation of SARS-CoV-2 remain unanswered, and efforts have been focused on respiratory system management. Demonstration of unequivocal presence of SARS-CoV-2 in vital body organs by cadaver autopsy was the only way to prove multi-organ involvement. Hence, the primary objective of the study was to determine presence of the SARS-CoV-2 in various organs of patients succumbing to SARS-CoV-2 infection. A total of 246 samples from different organs of 21 patients who died due to severe COVID-19 illness were investigated by qRT-PCR, and SARS-CoV-2 was detected in 181 (73.57%) samples and highest positivity of SARS-CoV-2 being (expectedly) found in nasopharynx (90.4%) followed by bilateral lungs (87.30%), peritoneal fluid (80%), pancreas (72.72%), bilateral kidneys (68.42%), liver (65%) and even in brain (47.2%). The deceased patients were categorized to three subgroups based upon the extent of organs in which SARS-CoV-2 was detected by qRT-PCR (high intensity ≥80%, intermediate intensity = 65-80% and low intensity ≤65% organs involvement). It was conclusively established that SARS-CoV-2 has the property of invasion beyond lungs and even crosses the blood-brain barrier, resulting in multi-system disease; this is probably the reason behind cytokine storm, though it is not clear whether organ damage is due to direct injury caused by the virus or result of inflammatory assault. Significant inverse correlation was found between the Ct value of lung samples and number of organs involved, implying that higher viral load in lungs is directly proportionate to involvement of extrapulmonary organs and patients with higher viral load in respiratory secretions should be monitored more closely for any warning signs and the treatment strategies should also address involvement of other organs for better outcome, because lungs, though the primary site of infection, are not the only organ system responsible for pathogenesis of systemic illness.
严重急性呼吸综合征冠状病毒2（SARS-CoV-2）严重表现的确切原因仍未得到解答，目前的努力主要集中在呼吸系统管理上。通过尸体解剖明确证明SARS-CoV-2在重要身体器官中的存在是证明多器官受累的唯一方法。因此，本研究的主要目的是确定死于SARS-CoV-2感染患者的各个器官中是否存在SARS-CoV-2。通过定量逆转录聚合酶链反应（qRT-PCR）对21例因严重冠状病毒病2019（COVID-19）死亡患者不同器官的246份样本进行了检测，在181份（73.57%）样本中检测到SARS-CoV-2，SARS-CoV-2阳性率最高（不出所料）的是鼻咽部（90.4%），其次是双侧肺（87.30%）、腹腔积液（80%）、胰腺（72.72%）、双侧肾脏（68.42%）、肝脏（65%），甚至在大脑中也有发现（47.2%）。根据qRT-PCR检测到SARS-CoV-2的器官范围，将死亡患者分为三个亚组（高强度≥80%、中等强度=65-80%和低强度≤65%器官受累）。最终确定SARS-CoV-2具有侵袭肺部以外器官的特性，甚至可以穿过血脑屏障，导致多系统疾病；这可能是细胞因子风暴背后的原因，不过尚不清楚器官损伤是由病毒直接损伤所致还是炎症攻击的结果。发现肺样本的Ct值与受累器官数量之间存在显著负相关，这意味着肺部较高的病毒载量与肺外器官受累直接相关，对于呼吸道分泌物中病毒载量较高的患者，应更密切地监测任何警示信号，治疗策略也应针对其他器官的受累情况，以获得更好的治疗效果，因为肺部虽然是主要感染部位，但不是导致全身疾病发病机制的唯一器官系统。
