35Background: To explore the cellular immunity and cytokines status of NCP patients and to predict 36 the correlation between the cellular immunity levels, cytokines and the severity of patients. 37Methods: 123 NCP patients were divided into mild and severe groups. Peripheral blood was 38 collected, lymphocyte subsets and cytokines were detected. Correlation analysis was performed on 39 the lymphocyte subsets and cytokines, and the differences between the indexes of the two groups 40 were analyzed. 41Results: 102 mild and 21 severe patients were included. Lymphocyte subsets were reduced in two 42 groups. The proportion of CD8 + T reduction in the mild and severe group was 28.43% and 61.9%, 43 respectively; The proportion of B cell reduction was 25.49% and 28.57%; The proportion of NK 44 cell reduction was 34.31% and 47.62%; The detection value of IL-6 was 0 in 55.88% of the mild 45 group, mild group has a significantly lower proportion of patients with IL-6 higher than normal than 46 severe group; There was no significant linear correlation between the lymphocyte subsets and 47 cytokines, while significant differences were noticed between the two groups in CD4 + T, CD8 + T, 48 IL-6 and IL-10. 49Conclusions: Low levels of CD4+T and CD8+T are common in severe NCP. IL-6 and IL-10 levels 50were higher in severe patients. T cell subsets and cytokines can be used as one of the basis for 51 predicting the transition from mild to severe. Large number of samples are still needed to confirm 52 the "warning value" of CD4 + T, CD8 + T IL-6 and IL-10. 53

We explored the relationships between lymphocyte subsets, cytokines, pulmonary inflammation index (PII) and disease evolution in patients with (corona virus disease 2019) COVID-19. A total of 123 patients with COVID-19 were divided into mild and severe groups. Lymphocyte subsets and cytokines were detected on the first day of hospital admission and lung computed tomography results were quantified by PII. Difference analysis and correlation analysis were performed on the two groups. A total of 102 mild and 21 severe patients were included in the analysis. There were significant differences in cluster of differentiation 4 (CD4 + T), cluster of differentiation 8 (CD8 + T), interleukin 6 (IL-6), interleukin 10 (IL-10) and PII between the two groups. There were significant positive correlations between CD4 + T and CD8 + T, IL-6 and IL-10 in the mild group (r 2 = 0Á694, r 2 = 0Á633, respectively; P < 0Á01). After 'five-in-one' treatment, all patients were discharged with the exception of the four who died. Higher survival rates occurred in the mild group and in those with IL-6 within normal values. CD4 + T, CD8 + T, IL-6, IL-10 and PII can be used as indicators of disease evolution, and the PII can be used as an independent indicator for disease progression of COVID-19.

Objectives To investigate the clinical and chest CT characteristics of COVID-19 pneumonia and explore the radiological differences between COVID-19 and influenza. Materials and methods A total of 122 patients (61 men and 61 women, 48 ± 15 years) confirmed with COVID-19 and 48 patients (23 men and 25 women, 47 ± 19 years) confirmed with influenza were enrolled in the study. Thin-section CT was performed. The clinical data and the chest CT findings were recorded. Results The most common symptoms of COVID-19 were fever (74%) and cough (63%), and 102 patients (83%) had Wuhan contact. Pneumonia in 50 patients with COVID-19 (45%) distributed in the peripheral regions of the lung, while it showed mixed distribution in 26 patients (74%) with influenza (p = 0.022). The most common CT features of the COVID-19 group were pure ground-glass opacities (GGO, 36%), GGO with consolidation (51%), rounded opacities (35%), linear opacities (64%), bronchiolar wall thickening (49%), and interlobular septal thickening (66%). Compared with the influenza group, the COVID-19 group was more likely to have rounded opacities (35% vs. 17%, p = 0.048) and interlobular septal thickening (66% vs. 43%, p = 0.014), but less likely to have nodules (28% vs. 71%, p < 0.001), tree-in-bud sign (9% vs. 40%, p < 0.001), and pleural effusion (6% vs. 31%, p < 0.001).Conclusions There are significant differences in the CT manifestations of patients with COVID-19 and influenza. Presence of rounded opacities and interlobular septal thickening, with the absence of nodules and tree-in-bud sign, and with the typical peripheral distribution, may help us differentiate COVID-19 from influenza. Key Points • Typical CT features of COVID-19 include pure ground-glass opacities (GGO), GGO with consolidation, rounded opacities, bronchiolar wall thickening, interlobular septal thickening, and a peripheral distribution. • Presence of rounded opacities and interlobular septal thickening, with the absence of nodules and tree-in-bud sign, and with the typical peripheral distribution, may help us differentiate COVID-19 from influenza.