Characteristics analysis for clinical study design relating to COVID-19 based on the database of ClinicalTrials.gov

Background and Objective The outbreak of the novel coronavirus disease (COVID-19) is currently ravaging worldwide. A large number of studies were registered and conducted in rapid response to the epidemic, but how to choose the proper design for clinical trials still remains the main concern. This study aimed to determine fundamental characteristics of study design during the COVID-19 epidemic and provide references for other emerging infectious diseases. Methods We searched the database of ClinicalTrials.gov with the keyword 'COVID-19′ and compared them with the design features of other conventional studies except for COVID-19. Results From January 1, 2020 to September 30, 2021, 55 334 trials were registered at ClinicalTrials.gov. Of all the registered trials, 6408 were related to COVID-19(11.58%). There were significant differences in the proportion of observational studies between COVID-19 (43.48%) and others (23.27%). The completion rate of observational trials and interventional trials in COVID-19 was 29.04% and 25.84%, respectively. COVID-19 trials showed a higher rate of completion than others (P<0.01). The time distribution and trend of observational studies and interventional studies varied considerably. Conclusion Appropriately designed trials can help to improve research efficiency and reduce the possibility of research failure. In addition to randomized controlled trials, observational and single-armed studies are also worth considering.

Development and Validation of a Novel Predictive Nomogram for Disease Progression of COVID-19: A Multicenter Retrospective Cohort Study of 4,086 Cases in China (preprint)

Aim: Coronavirus disease 2019 (COVID-19) has caused an unprecedented healthcare crisis. We aim to develop and validate a nomogram for predicting disease progression based on a large cohort of hospitalized COVID-19 patients. Methods: This is a multicenter retrospective cohort study, with a total of 4,086 hospitalized COVID-19 patients enrolled from two hospitals in Wuhan, China between February 3rd and Apr 10th. Nomogram was developed based on a cohort of 3, 022 patients from one hospital, and externally validated in another cohort of 1,064 patients from the other hospital. The calibration was assessed by a calibration plot and the HL test to evaluate the goodness of fit, and the Area under the ROC Curve (AUROC) as a measure of discriminative ability.Results: Six independent predictors, including age, dyspnea, platelet count, lactate dehydrogenase, D-dimer and cardiovascular disease, were finally identified for construction of the nomogram for predicting disease progression of COVID-19 patients during hospitalization. The AUROC was 0.877 and 0.817 for development cohort and validation cohort, respectively. The calibration plots AND Hosmer-Lemeshow test showed optimal agreement between nomogram prediction and actual observation. The decision curve analysis showed the performance of the nomograms were better than all univariable models, and had greater net benefit. Next, a predictive nomogram for disease severity on admission was formulated and the six independent factors used were similar to that of the nomogram for disease progression, which indicates that those factors play important roles in determining disease severity and the risk of disease progression. Conclusion: In the current study, a nomogram was developed based on generally readily available variables at hospital admission to help predict disease progression of COVID-19.

Treatment with human umbilical cord-derived mesenchymal stem cells for COVID-19 patients with lung damage: a randomised, double-blind, placebo controlled phase 2 trial (preprint)

Objective To assess the safety and efficacy of human umbilical cord-derived MSCs (UC-MSCs) for severe COVID-19 patients with lung damage. Design, Multicentre , randomised, double-blind, placebo-controlled trial. Setting Two hospitals in Wuhan, China, 5 March 2020 to 28 March 2020. Participants 101 severe COVID-19 patients with lung damage aged between 18-74 years. Intervention Patients were randomly assigned at a 2:1 ratio to receive either UC-MSCs (40 million cells per infusion) or placebo on days 0, 3, and 6. Main outcome measures The primary endpoints were safety and an altered proportion of whole lung lesion size from baseline to day 28, measured by chest computed tomography. Secondary outcomes were reduction of consolidation lesion sizeand lung function improvement (6-minute walk test, maximum vital capacity, diffusing capacity). Primary analysis was done in the modified intention-to-treat (mITT) population and safety analysis was done in all patients who started their assigned treatment. Results 100 patients were finally recruited to receive either UC-MSCs (n = 65) or placebo (n = 35). The patients receiving UC-MSCs exhibited a trend of numerical improvement in whole lung lesion size from baseline to day 28 compared with the placebo cases (the median difference was -13.31%, 95%CI -29.14%, 2.13%, P=0.080). UC-MSCs administration significantly reduced the proportions of consolidation lesion size from baseline to day 28 compared with the placebo (median difference: -15.45%, 95% CI -30.82%, -0.39%, P=0.043). The 6-minute walk test showed an increased distance in patients treated with UC-MSCs (difference: 27.00 m, 95% CI 0.00, 57.00, P=0.057). The incidence of adverse events was similar, and no serious adverse events were observed in the two groups. Conclusions UC-MSCs treatment is a safe and potentially effective therapeutic approach for COVID-19 patients with lung damage. A phase 3 trial is required to evaluate effects on reducing mortality and preventing long-term pulmonary disability.

Treatment with Human Umbilical Cord-Derived Mesenchymal Stem Cells for Severe COVID-19 Patients with Lung Damage: A Randomised, Double-Blind, Placebo‑Controlled Phase 2 Trial (preprint)

Background: Treatment of severe Corona Virus Disease 2019 (COVID-19) is challenging. We performed a phase 2 trial to assess the efficacy and safety of human umbilical cord-mesenchymal stem cells (UC‑MSCs) to treat patients with severe COVID-19 with lung damage, based on our phase 1 data.Methods: In this randomised, double-blind, and placebo-controlled trial, we recruited 101 eligible patients with severe COVID-19 with lung damage aged between 18–74 years from two hospitals. Enrolled patients were randomly assigned at a 2:1 ratio to receive either UC-MSCs (4 × 107 cells per infusion) or placebo on day 0, 3, and 6. We excluded patients with malignant tumours, shock, or other organ failure. The primary endpoint was an altered proportion of whole lung lesion areas from baseline to day 28, measured by chest computed tomography. Other imaging outcomes, 6-minute walk test, maximum vital capacity, diffusing capacity, plasma biomarkers, and adverse events were recorded and analysed. Primary analysis was done in the modified intention-to-treat (mITT) population and safety analysis was done in all patients who started their assigned treatment. Findings: From March 5, 2020, to March 28, 2020, 100 patients were finally enrolled and received either UC-MSCs (n = 65) or placebo (n = 35). During follow-up, the patients receiving UC-MSCs exhibited a trend of numerical improvement in whole lung lesions from baseline to day 28 compared with the placebo cases. UC-MSCs administration significantly reduced the proportions of consolidation lesions from baseline to day 28 in the treated patients compared with the placebo subjects. The 6-minute walk test showed an increased distance in patients treated with UC-MSCs. Notably, UC-MSCs delivery was well tolerated, with no serious adverse events.Interpretation: UC-MSCs treatment is a safe and potentially effective therapeutic approach for patients with severe COVID‑19. The trial suggests that UC-MSCs administration might benefit patients with COVID-19 with lung damage at the convalescent stage as well as the progression stage.Trial Registration: This trial is registered with ClinicalTrials.gov, number NCT04288102.Funding Statement: This trial was supported by The National Key R&D Program of China (2020YFC0841900, 2020YFC0844000, 2020YFC08860900); The Innovation Groups of the National Natural Science Foundation of China (81721002); The National Science and Technology Major Project (2017YFA0105703).Declaration of Interests: All authors declare no competing interests.Ethics Approval Statement: Ethical approval was obtained from the institutional review boards of each participating hospital. Written informed consent was obtained from all the enrolled patients or their legal representatives if they were unable to provide consent.

Inhalation of Heliox as a potential treatment for the ARDS caused by COVID-19 (preprint)

Corona virus disease 2019 (COVID-19) is currently a global pandemic It presents as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) due to COVID-19 infection. Despite the widespread use of symptomatic, antiviral, , and supportive treatment, the daily death toll from COVID-19 is still rising. The most common lethal complication is acute respiratory distress syndrome (ARDS). Mechanical ventilation is one of the necessary support methods of treating ARDS. Heliox (Helium-oxygen mixture) inhalation can reduce respiratory work of breathing, improve oxygenation, improve lung compliance, and effectively optimize the treatment of ARDS. Heliox also has potential anti-inflammatory, neuroprotective, and cardiac effects, and could reduce the inflammatory storm caused by SARS-CoV-2. This article reviews the properties of heliox, the therapeutic mechanism for ARDS, and the effects of heliox on inflammation, nerves, and the heart. Conclusion We suggests that heliox is a potential treatment for COVID-19.

Clinical characteristics study of elderly patients aged 75 or older with COVID-19 pneumonia in China (preprint)

Background: Coronavirus disease 2019 (COVID-19), a newly emerged respiratory disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has recently become pandemic. Clinical observation indicated that elderly patients had high incidence of severe pneumonia and poor treatment efficacy. Therefore, this study was to clarify the characteristics of elderly patients aged 75 or older with COVID-19 pneumonia in order to guide rational treatment for elderly patients. Methods: we enrolled 331 elderly patients aged 75 or older with confirmed COVID-19 in Huoshenshan hospital of Wuhan from February 3rd to March 31st. The cases were divided into general, serious and critical groups according to severity after hospitalization, and the difference among groups were compared by R package statistics software. Results: Compared with general group, serious and critical groups had more underlying comorbidities and higher incidence of cough, breath shortness and anorexia. Moreover, there existed obviously differences in many of laboratory indexes and CT images among them. serious and critical elderly patients were more likely to receive oxygen, mechanical ventilation, expectorant, corticosteroid, abidor, cephaloprin, imipenem, human serum albumin (HSA), nutrition support, anti SARS-CoV-2 positive plasma and actemra. Multivariate analysis of factors showed that male sex, hypertension, diabetes, renal diseases, breath shortness, neutrophil, platelet, creatinine, lactate dehydrogenase were the risk factor for serious and critical illness. While blood cell (WBC) was the protective factor. Conclusion: elderly patients have high incidence of severe pneumonia and poor treatment efficacy. The reasons might be that many of the elderly patients with COVID-19 pneumonia have certain chronic disease, poor immune function and a meager response to the virus. the pathogenic mechanism of SARS-CoV-2 might be involved in the cell-mediated immunity and cytokine storms by acting on lymphocytes.

Epidemiological and clinical characteristics of 47 corona virus disease 2019 non-survivors in Huoshenshan Hospital

Objective To provide a basis for further optimizing the diagnosis and treatment strategies of severe and critical corona virus disease 2019 (COVID-19) by investigating and analyzing the epidemiological and clinical characteristics of the death cases. Methods The epidemiological and clinical characteristics of 47 death cases obtained from Huoshenshan Hospital in Whuhan, Hubei Province were retrospectively analyzed. Results All the patients developed initial symptoms in Wuhan. The time from onset to admission was (12.60±5.60) days. Most of them were male (68.09%) with non-nosocomial infection (91.49%), advanced age (>60 years, 89.36%). Over half of the cases (51.06%) reported a history of contact with suspected or confirmed patients, and comorbidity of chronic diseases (70.21%). Multiple organ dysfunction syndrome (MODS) occurred in 29 cases (61.70%) with heart failure (51.06%) and renal failure (36.17%). The main clinical symptoms included fever, fatigue, dyspnea and cough. At admission,most cases were severe (55.32%) or critical (42.55%), and the in-hospital survival was longer for the severe than for the critical (P=0.02). 76.59% of the patients received invasive mechanical ventilation, and they had a longer in-hospital survival than those with non-invasive mechanical ventilation (P<0.05). Conclusions This group of cases occurred during the peak of the COVID-19 outbreak in China, characterized by male, elder and history of chronic diseases. Acute respiratory distress syndrome (ARDS) caused by COVID-19 was responsible for patients' death, and MODS manifestated by heart and kidney failure also implicated in the process. Disease severity and invasive mechanical ventilation were related to in-hospital survival.

Screening and Analysis of COVID-19 cases in non-epidemic areas: A Retrospective Study (preprint)

Objective: To compare the epidemiological and clinical characteristics of confirmed and suspected corona virus disease 2019 (COVID-19) cases via the process of “triage-screening-isolation-transfer” in the hospitals of non-epidemic areas.Methods: The general data, epidemiological history, clinical symptoms, laboratory examination, and chest computed tomography (CT) imaging characteristics of 38 patients with suspected COVID-19, admitted between January 21 and March 5, 2020, were analyzed.Results: According to the results of the novel severe acute respiratory syndrome coronavirus (SARS-CoV-2) ribonucleic acid (RNA) testing, the patients were divided into study group (RNA positive) and control group (RNA negative). Ultimately, 8 cases were RNA-positive and diagnosed as CDVID-19, and 30 cases were negative. Approximately half of the patients in the study group returned to Chongqing from Wuhan; this number was significantly larger than that of the control group (P<0.05). The number of subjects in close contact with the confirmed cases with SARS-CoV-2 RNA-positive and the incidence of aggregation was significantly larger in the study group than in the control group (both P<0.05). The clinical symptom of the study group was mainly low fever (with or without cough). The patients with decreased white blood cells (WBC) in the study group were significantly more than those in the control group (P<0.05). Both group had reduced lymphocytes (Lym) but the number of patients with increased C-reactive protein (CRP) in the study group was significantly more than that in the control group (P<0.05). There were different degrees of chest CT abnormalities in both study and control group (P > 0.05). Conclusion: The epidemiological investigations in screening for infectious diseases is crucial. The risk of infection was high from the primary epidemic area and/or in close contact with the confirmed case. The most common form of clustering occurrence was family aggregation. CDVID-19 was mainly characterized by fever and respiratory symptoms, although asymptomatic infection may also occur. Decreased WBC, decreased Lym, and increased CRP are common characteristics but can also be combined with other respiratory tract virus infections. COVID 19 screening by chest CT alone had certain limitations in non- epidemic areas.

Heparin-induced thrombocytopenia is associated with a high risk of mortality in critical COVID-19 patients receiving heparin-involved treatment (preprint)

Background Coronavirus infectious disease 2019 (COVID-19) has developed into a global pandemic. It is essential to investigate the clinical characteristics of COVID-19 and uncover potential risk factors for severe disease to reduce the overall mortality rate of COVID-19. Methods Sixty-one critical COVID-19 patients admitted to the intensive care unit (ICU) and 93 severe non-ICU patients at Huoshenshan Hospital (Wuhan, China) were included in this study. Medical records, including demographic, platelet counts, heparin-involved treatments, heparin-induced thrombocytopenia-(HIT) related laboratory tests, and fatal outcomes of COVID-19 patients were analyzed and compared between survivors and nonsurvivors. Findings Sixty-one critical COVID-19 patients treated in ICU included 15 survivors and 46 nonsurvivors. Forty-one percent of them (25/61) had severe thrombocytopenia, with a platelet count (PLT) less than 50x109/L, of whom 76% (19/25) had a platelet decrease of >50% compared to baseline; 96% of these patients (24/25) had a fatal outcome. Among the 46 nonsurvivors, 52.2% (24/46) had severe thrombocytopenia, compared to 6.7% (1/15) among survivors. Moreover, continuous renal replacement therapy (CRRT) could induce a significant decrease in PLT in 81.3% of critical CRRT patients (13/16), resulting in a fatal outcome. In addition, a high level of anti-heparin-PF4 antibodies, a marker of HIT, was observed in most ICU patients. Surprisingly, HIT occurred not only in patients with heparin exposure, such as CRRT, but also in heparin-naive patients, suggesting that spontaneous HIT may occur in COVID-19. Interpretation Anti-heparin-PF4 antibodies are induced in critical COVID-19 patients, resulting in a progressive platelet decrease. Exposure to a high dose of heparin may trigger further severe thrombocytopenia with a fatal outcome. An alternative anticoagulant other than heparin should be used to treat COVID-19 patients in critical condition.

Highly pathogenic coronavirus N protein aggravates lung injury by MASP-2-mediated complement over-activation (preprint)

An excessive immune response contributes to SARS-CoV, MERS-CoV and SARS-CoV-2 pathogenesis and lethality, but the mechanism remains unclear. In this study, the N proteins of SARS-CoV, MERS-CoV and SARS-CoV-2 were found to bind to MASP-2, the key serine protease in the lectin pathway of complement activation, resulting in aberrant complement activation and aggravated inflammatory lung injury. Either blocking the N protein:MASP-2 interaction or suppressing complement activation can significantly alleviate N protein-induced complement hyper-activation and lung injury in vitro and in vivo. Complement hyper-activation was also observed in COVID-19 patients, and a promising suppressive effect was observed when the deteriorating patients were treated with anti-C5a monoclonal antibody. Complement suppression may represent a common therapeutic approach for pneumonia induced by these highly pathogenic coronaviruses.

Viral Kinetics and Antibody Responses in Patients with COVID-19 (preprint)

Background A pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been spreading over the world. However, the viral dynamics, host serologic responses, and their associations with clinical manifestations, have not been well described in prospective cohort. Methods We conducted a prospective cohort and enrolled 67 COVID-19 patients admitting between Jan 26 and Feb 5, 2020. Clinical specimens including nasopharyngeal swab, sputum, blood, urine and stool were tested periodically according to standardized case report form with final follow-up on February 27. The routes and duration of viral shedding, antibody response, and their associations with disease severity and clinical manifestations were systematically evaluated. Coronaviral particles in clinical specimens were observed by transmission electron microscopy (TEM). Results The median duration of SARS-CoV-2 RNA shedding were 12 (3-38), 19 (5-37), and 18 (7-26) days in nasopharyngeal swabs, sputum and stools, respectively. Only 13 urines (5.6%) and 12 plasmas (5.7%) were viral positive. Prolonged viral shedding was observed in severe patients than that of non-severe patients. Cough but not fever, aligned with viral shedding in clinical respiratory specimens, meanwhile the positive stool-RNA appeared to align with the proportion who concurrently had cough and sputum production, but not diarrhea. Typical coronaviral particles could be found directly in sputum by TEM. The anti-nucleocapsid-protein IgM started on day 7 and positive rate peaked on day 28, while that of IgG was on day 10 and day 49 after illness onset. IgM and IgG appear earlier, and their titers are significantly higher in severe patients than non-severe patients (p<0.05). The weak responders for IgG had a significantly higher viral clearance rate than that of strong responders (p= 0.011). Conclusions Nasopharyngeal, sputum and stools rather than blood and urine, were the major shedding routes for SARS-CoV-2, and meanwhile sputum had a prolonged viral shedding. Symptom cough seems to be aligned with viral shedding in clinical respiratory and fecal specimens. Stronger antibody response was associated with delayed viral clearance and disease severity.