Alterations in Peripheral Lymphocyte Subsets in Early Stage of Novel Coronavirus Pneumonia

Background: Coronavirus disease 2019 (COVID-19) is currently a global public health issue. Cases of severe pneumonia caused by other coronaviruses were often associated with immunopathological events. Here, we aimed to analyze the characteristics of lymphocyte subsets and white blood cell (WBC) counts in patients with COVID-19 during the early period of infection.Methods: This was a retrospective study including patients with confirmed novel coronavirus pneumonia (NCP; 15 cases) and other viral respiratory infections (17 cases). Lymphocyte subsets were detected using flow cytometry and compared between the two groups.Findings: A total of 15 patients with NCP (male/female = 10/5) and 17 other viral respiratory infections (male/female = 8/9) were included. The WBC, neutrophil (NEUT), lymphocyte (LYMPH), eosinophil (EO), and basophil (BASO) counts were lower in the COVID-19 group, with decreased levels of CD3+, CD3+/CD4+, CD3+/CD8+, Tc, CD19+, CD19+/CD5+, CD19+/CD5-, and natural killer (NK) cells (P < 0·05). Asymptomatic patients might have noticeable changes in CT images attributed to pneumonia. T-cells exhibited decreasing changes in different grades of NCP.Interpretation: In the early stage of COVID-19 infection, WBCs, especially T-lymphocytes, might also be targeted for attack by the coronavirus. It is also possible that host-pathogen interactions might result in increased lymphocyte depletion and an excessive and prolonged cytokine/chemokine response. Clarification of the host immune system response will help further reveal the pathogenesis of this disease and facilitate its treatment or prevention.Funding Statement: This study was supported by the Natural Science Foundation of Guangdong province, China (2016A030311043 and 2017A030313691).Declaration of Interests: The authors of this study declare that they have no competing interestsEthics Approval Statement: Study was approved by Research Ethics Committee of Guangdong Provincial People’s Hospital, Guangdong Academy of Medical Sciences ( No.GDREC2020027H).