Dynamic changes in the immune response correlate with disease severity and outcomes during infection with SARS-CoV-2 (preprint)

Background:The coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has rapidly spread throughout China and all over the world. Little is known about the dynamic changes in the patient immune responses to SARS-CoV-2, and how different responses are correlated with disease severity and outcomes.Method:74 patients with confirmed COVID-19 were enrolled in this prospective research. The demographic information, medical history, symptoms, signs and laboratory results were analyzed and compared between severe and non-severe patients. The leukocytes, lymphocyte subsets and inflammatory cytokines were longitudinally collected.Results:Of the 74 patients included, 17 suffered from severe disease. The severe patients tended be older (65.29 ± 12.33 years vs. 45.37 ± 18.66 years), and had a greater degree of underlying disease (41.18% vs. 24.56%) , lower baseline lymphocytes counts (0.69 ± 0.36 × 10⁹ vs. 1.46 ± 0.75 × 10⁹) , higher neutrophil-lymphocyte-ratios (NLRs; 3.76 (3.15–5.51) vs. 2.07 (1.48–2.93)) and lower baseline eosinophil counts (0.01 ± 0.01 × 10⁹ vs. 0.05 ± 0.07 × 10⁹), than that in non-severe patients. The baseline helper T (Th) cells (335.47 vs. 666.46/mL), suppressor T(Ts) cells (158 vs. 334/mL), B cells (95 vs. 210/mL), and natural killer (NK) cells (52 vs. 122/mL) were significantly decreased in severe cases compared to that in non-severe cases. In addition, the baseline neutrophils and B cells were positively correlated with the severity of COVID-19 and the baseline lymphocytes and Th cells were negatively correlated with the severity of COVID-19. The dynamic change of T cells, Th cells and IFN-γ in the severe cases were parallel to the amelioration of the disease.Conclusions:Collectively, our study provides novel information on the kinetics of the immune responses in a cohort of COVID-19 patients with different disease severities. Furthermore, our study indicates that both innate and adaptive immune responses correlate with better clinical outcomes.

Nomogram Prediction of Severe Risk in Patients With COVID-19 Pneumonia: A Retrospective Study (preprint)

Background COVID-19 elicits a range of different responses in patients and can manifest into mild to very severe cases in different individuals, depending on many factors. We aimed to establish a prediction model of severe risk in COVID-19 patients, to help clinicians achieve early prevention, intervention, and aid them in choosing effective therapeutic strategy.Methods We selected confirmed COVID-19 patients who admitted to First Hospital of Changsha city between January 29 and February 15, 2020 and collected their clinical data. Multivariate logical regression was used to identify the risk factors associated with severe risk. These factors were incorporated into the nomogram to establish the model. The ROC curve, calibration plot and decision curve were used to assess the performance of model.Results 239 patients were enrolled and 45 (18.83%) patients developed severe pneumonia. Univariate and multivariate analysis showed that age, COPD, shortness of breath, fatigue, creatine kinase, D-dimer, lymphocytes and h CRP were independent risk factors for severe risk in COVID-19 patients. Incorporating these factors, the nomogram achieved good concordance indexes of 0.873 (95% CI: 0.819–0.927), and well-fitted calibration plot curves. The model provided superior net benefit when clinical decision thresholds were between 10–70% predicted risk.Conclusions Using the model, clinicians can intervene early, improve therapeutic effects and reduce the severity of COVID-19, thus ensuring more targeted and efficient use of medical resources.

Lymphopenia acted as an adverse factor for severity in patients with COVID-19: a single-centered, retrospective study (preprint)

Purpose: The outbreak of SARS-CoV-2 began in December and rapidly caused a pandemic. To investigate the significance of lymphopenia for the severity of the disease, this study was performed.Methods: 115 patients confirmed COVID-19 from a tertiary hospital in Changsha, China were enrolled. The clinical, laboratory, treatment and outcome data were collected and compared between patients with lymphopenia or not.Results: The median age was 42 years (1-75). 54 patients (47.0%) of the patients had lymphopenia on admission. In the group of lymphopenia, more patients had hypertension (30.8% vs 10.0%, P=0.006) and coronary heart disease (3.6% vs 0%, P=0.029) and more patients with leucopenia (48.1% vs 14.8%, P<0.001) and eosinophilia (92.6% vs 54.1%, P<0.001) were observed. Lymphopenia was also correlated with severity grades of pneumonia (P<0.001) and C-reactive protein (CRP) level (P=0.0014). Lymphopenia was associated with a prolonged duration of hospitalization (17.0 days vs 14.0 days, P=0.002). Moreover, the recovery of lymphocyte appeared the earliest before CRP and chest radiographs in severe cases, suggesting its predictive value for disease improvement. Conclusion: Our results showed the clinical significance of lymphopenia for predicting the severity of COVID-19 and the recovery of the disease, emphasizing the need to monitor the lymphocyte count dynamically.

Epidemiological and clinical features of 291 cases with coronavirus disease 2019 in areas adjacent to Hubei, China: a double-center observational study (preprint)

Abstract Background: The clinical outcomes of COVID-19 patients in Hubei and other areas are different. We aim to investigate the epidemiological and clinical characteristics of patient with COVID-19 in Hunan which is adjacent to Hubei. Methods: In this double-center, observational study, we recruited all consecutive patients with laboratory confirmed COVID-19 from January 23 to February 14, 2020 in two designated hospitals in Hunan province, China. Epidemiological and clinical data from patients' electronic medical records were collected and compared between mild, moderate and severe/critical group in detail. Clinical outcomes were followed up to February 20, 2020. Findings: 291 patients with COVID-19 were categorized into mild group (10.0%), moderate group (72.8%) and severe/critical group (17.2%). The median age of all patients was 46 years (49.8% were male). 86.6% patients had an indirect exposure history. The proportion of patients that had been to Wuhan in severe/critical group (48.0% vs 17.2%, p=0.006) and moderate group (43.4% vs 17.2%, p=0.007) were higher than mild group. Fever (68.7%), cough (60.5%), and fatigue (31.6%) were common symptoms especially for severe and critical patients. Typical lung imaging finding were bilateral and unilateral ground glass opacity or consolidation. Leukopenia, lymphopenia and eosinopenia occurred in 36.1%, 22.7% and 50.2% patients respectively. Increased fibrinogen was detected in 45 of 58 (77.6%) patients with available results. 29 of 44 (65.9%) or 22 of 40 (55.0%) patients were positive in Mycoplasma pneumonia or Chlamydia pneumonia antibody test respectively. Compared with mild or moderate group, severe/critical group had a relative higher level of neutrophil, Neutrophil-to-Lymphocyte Ratio, h-CRP, ESR, CK, CK-MB, LDH, D-dimer, and a lower level of lymphocyte, eosinophils, platelet, HDL and sodium (all p<0.01). Most patients received antiviral therapy and Chinese Medicine therapy. As of February 20, 2020, 159 (54.6%) patients were discharged and 2 (0.7%) patients died during hospitalization. The median length of hospital stay in discharged patients was 12 days (IQR: 10-15). Interpretation: The epidemiological and clinical characteristics of COVID-19 patients in Hunan is different from patients in Wuhan. The proportion of patients that had been to Wuhan in severe/critical group and moderate group were higher than mild group. Laboratory and imaging examination can assist in the diagnosis and classification of COVID-19 patients.