Detectable serum SARS-CoV-2 viral load (RNAaemia) is closely associated with drastically elevated interleukin 6 (IL-6) level in critically ill COVID-19 patients

Xiaohua Chen; Binghong Zhao; Yueming Qu; Yurou Chen; Jie Xiong; Yong Feng; Dong Men; Qianchuan Huang; Ying Liu; Bo Yang; Jinya Ding; Feng Li

Although the detection of throat-swab rather than serum SARS-CoV-2 viral load is widely used for the COVID-19 diagnosis, an undeniable fact is that serum SARS-CoV-2 nucleic acid (RNAaemia) is detectable in part of the patients, however, in what scenario it become detectable and whether the incidence of RNAaemia could be correlated with specific type of patients is not very clear. In this study, we investigated the distribution of serum SARS-CoV-2 nucleic acid positive cases in various patients groups, and the result showed that those cases all were confirmed only in critically ill patients group. Moreover, the laboratory data analysis strongly suggest that inflammatory cytokine IL-6 level was significantly elevated in critically ill patients. More importantly, the extremely high IL-6 level was closely correlated with the incidence of RNAaemia and the mortality. Our work may provide clues for developing new COVID-19 diagnostic strategy and therapeutic targets.