Comparative study of the lymphocyte change between COVID-19 and non-COVID-19 pneumonia cases suggesting uncontrolled inflammation might not be the main reason of tissue injury

Yishan Zheng; Zhen Huang; Guoping Ying; Xia Zhang; Wei Ye; Zhiliang Hu; Chunmei Hu; Hongxia Wei; Yi Zeng; Yun Chi; Cong Cheng; Feishen Lin; Hu Lu; Lingyan Xiao; Yan Song; Chunming Wang; Yongxiang Yi; Lei Dong

However, the early report about COVID-19 cases found that the profile of cytokine in the blood of patients was different from that from SARS-Cov cases: not only pro-inflammatory cytokines but also anti-inflammatory cytokines (IL-4, IL-10, etc.) increased in the COVID-19 cases. 4 Additionally, all recent reports demonstrated that high fever cases (>38 o C) were significantly fewer (even in severe cases) in COVID-19 patients than in SARS-CoV or MERS-CoV cases. 3 These features suggest that the consequences in the COVID-19 patients might not be mainly due to the inflammatory reaction, especially in the non-severe cases. Instead, the damage was likely to be caused by the virus itself. Therefore, we performed a correlation analysis between the number of lymphocyte subgroups and the biochemical indexes. We found that most of the indexes relating to organ injuries were negatively correlated with the number of lymphocytes in 2019-nCoV infected patients but not in non-2019-nCoV-infected pneumonia patients, further highlighting the virus infection -rather than the inflammatory reaction -as the possible cause of the multi-organ injury. Another supportive finding is that the difference in the number of monocytes, neutrophils, and NK cells is not significant in our analysis; while theoretically, these innate immune cells are the main player in a "cytokine storm". Interestingly, the most significant correlation happened between the injury indexes and CD4+ Th cell counts.