Abstract:

Objective To investigate the predictive value of neutrophil to lymphocyte ratio on the prognosisof COVID⁃2019. Methods Twenty patients with SARS⁃coV⁃2 infection treated in Xiangyang NO.1 People′s Hospitalaffiliated to Hubei University of Medical from February 2020 to March 2020 were retrospectively analyzed. Theywere divided into moderate group（including normal and light 10 cases）and severe group（including severe andcritical 10 cases），according to clinical characteristics and conditions. Laboratory tests and flow cytometry resultswere collected on the day after admission，1 week after admission and leaving hospital，and calculated the neutro⁃phn to lymphocyte ratio（NLR），ΔNLR1（NLR of 1 week after admission⁃NLR of admission），ΔNLR2（NLR ofleaving hospital ⁃ NLR of 1 week after admission），compared the differences between the two groups. Flow cytome⁃try was used to detect the scattered distribution of lymphocytes，neutrophils and monocytes in peripheral blood ofthe two groups of patients，the positive rate of HLA⁃DR on T cells and CD15 on the surface of neutrophils as amarker of activation. Results There was a significant change in the NLR of the two groups during treatment. TheNLR of the severe group increased more significantly at 1 week of treatment. When the patients were cured anddischarged，the NLR of both groups decreased significantly. The frequency of CD15+ neutrophils in the moderategroup was relatively lower than that in the severe group，and there was no significant fluctuation during treatment.The frequency of CD15+ neutrophils in the severe group increased significantly during 1 week of treatment，anddecreased significantly when cured and discharged；The frequency of HLA⁃DR+ T cells in both groups had a dynamicand significant change during the treatment period，which increased significantly at 1 week of treatment，anddecreased significantly when cured and discharged，and there were differences between the groups at each timepoint of detection. Conclusion Dynamic monitoring of NLR，CD15+ neutrophil frequency，and HLA⁃DR+ T cellfrequency can reflect the condition and prognosis of COVID⁃2019.

Key words: COVID?19, neutrophil to lymphocyte ratio, CD15, HLA?DR