CRISPR Assays for Disease Diagnosis: Progress to and Barriers Remaining for Clinical Applications.

Numerous groups have employed the special properties of CRISPR/Cas systems to develop platforms that have broad potential applications for sensitive and specific detection of nucleic acid (NA) targets. However, few of these approaches have progressed to commercial or clinical applications. This review summarizes the properties of known CRISPR/Cas systems and their applications, challenges associated with the development of such assays, and opportunities to improve their performance or address unmet assay needs using nano-/micro-technology platforms. These include rapid and efficient sample preparation, integrated single-tube, amplification-free, quantifiable, multiplex, and non-NA assays. Finally, this review discusses the current outlook for such assays, including remaining barriers for clinical or point-of-care applications and their commercial development.

Research Advances for Virus-vectored Tuberculosis Vaccines and Latest Findings on Tuberculosis Vaccine Development.

Tuberculosis (TB), caused by respiratory infection with Mycobacterium tuberculosis, remains a major global health threat. The only licensed TB vaccine, the one-hundred-year-old Bacille Calmette-Guérin has variable efficacy and often provides poor protection against adult pulmonary TB, the transmissible form of the disease. Thus, the lack of an optimal TB vaccine is one of the key barriers to TB control. Recently, the development of highly efficacious COVID-19 vaccines within one year accelerated the vaccine development process in human use, with the notable example of mRNA vaccines and adenovirus-vectored vaccines, and increased the public acceptance of the concept of the controlled human challenge model. In the TB vaccine field, recent progress also facilitated the deployment of an effective TB vaccine. In this review, we provide an update on the current virus-vectored TB vaccine pipeline and summarize the latest findings that might facilitate TB vaccine development. In detail, on the one hand, we provide a systematic literature review of the virus-vectored TB vaccines are in clinical trials, and other promising candidate vaccines at an earlier stage of development are being evaluated in preclinical animal models. These research sharply increase the likelihood of finding a more effective TB vaccine in the near future. On the other hand, we provide an update on the latest tools and concept that facilitating TB vaccine research development. We propose that a pre-requisite for successful development may be a better understanding of both the lung-resident memory T cell-mediated mucosal immunity and the trained immunity of phagocytic cells. Such knowledge could reveal novel targets and result in the innovative vaccine designs that may be needed for a quantum leap forward in vaccine efficacy. We also summarized the research on controlled human infection and ultra-low-dose aerosol infection murine models, which may provide more realistic assessments of vaccine utility at earlier stages. In addition, we believe that the success in the ongoing efforts to identify correlates of protection would be a game-changer for streamlining the triage of multiple next-generation TB vaccine candidates. Thus, with more advanced knowledge of TB vaccine research, we remain hopeful that a more effective TB vaccine will eventually be developed in the near future.

The predictive role of lymphocyte subsets and laboratory measurements in COVID-19 disease: a retrospective study.

AIM: The aim of this study was to investigate the predictive role of lymphocyte subsets and other laboratory measurements in patients with COVID-19. METHODS: Electronic medical records of adult patients with confirmed diagnosis of COVID-19 from the Shanghai Public Health Clinical Center were reviewed retrospectively to obtain relevant data. RESULTS: The mean age of patients was 40.98 ± 15.95 years, with 58% of the patients being males. The cutoff values at the intensive care unit (ICU) admission, mechanical ventilation, and mortality were CD4+ cells (267, 198, and 405), CD8+ cells (263, 203, and 182), and CD4+ /CD8+ cells (1.4, 1.8, and 1.4). The cutoffs below these values indicate the higher chances of disease progression. Higher CD4+ cell count led to lesser chances for ICU admission [odds ratio (OR) (95% confidence interval (CI): 0.994 (0.991, 0.997); p = 0.0002] and mortality [OR (95% CI): 0.988 (0.979, 0.99); p = 0.001], higher CD8+ count was an independent risk factor for ICU admission. T-cell count positively correlated with total lymphocyte count and platelets, while negatively correlated with D-dimer and lactate dehydrogenase (LDH). Among patients with non-severe COVID-19, median CD8+ T cell, CD4+ T cell, total lymphocyte count, and platelets were 570, 362, 1.45, and 211, respectively, while median values decreased to 149, 106, 0.64, and 172, respectively, in patients with severe COVID-19. CONCLUSION: Lower T lymphocyte subsets were significantly associated with higher admission to ICU, mechanical ventilation, and mortality among patients with COVID-19. A cutoff value of ICU admission, mechanical ventilation, and mortality below CD4+ cells (267, 198, and 405), CD8+ cells (263, 203, 182), and CD4+/CD8+ cells (1.4, 1.8, 1.4) may help identify patients at high risk of disease progression. The continuous evaluation of laboratory indices may help with dismal prognosis and prompt intervention to improve outcomes.

Beneficial aspects of high dose intravenous vitamin C on patients with COVID-19 pneumonia in severe condition: a retrospective case series study.

BACKGROUND: Coronavirus disease 2019 (COVID-19) is a global public health event without specific therapeutic agents till now. We aim to determine if high dose intravenous vitamin C (HDIVC) was effective for COVID-19 patients in severe condition. METHODS: COVID-19 patients admitted in Shanghai Public Health Clinical Center from January 22, 2020 to April 11, 2020 were retrospectively scrolled. The enrolled patients were those with confirmed diagnosis of severe or critical COVID-19 pneumonia, who received HDIVC within 24 hours after disease aggravation. Main clinical outcomes obtained from 3-5 days (day 3) and 7-10 days (day 7) after HDIVC were compared to the ones just before (day 0) HDIVC. RESULTS: Totally, twelve patients were enrolled including six severe [age of mean, 56; interquartile range (IQR), 32-65 years, 3 men] and six critical (age of mean, 63; IQR, 60-82 years, 4 men) patients. The dosage of vitamin C [median (IQR), mg/kg (body weight)/day] were [162.7 (71.1-328.6)] for severe and [178.6 (133.3-350.6)] for critical patients. By Generalized estimating equation (GEE) model, C-reactive protein (CRP) was found to decrease significantly from day 0 to 3 and 7 (severe: 59.01±37.9, 12.36±22.12, 8.95±20.4; critical: 92.5±41.21, 33.9±30.2, 59.56±41.4 mg/L). Lymphocyte and CD4+ T cell counts in severe patients reached to normal level since day 3. Similar improving trends were observed for PaO2/FiO2 (severe: 209.3±111.7, 313.4±146, 423.3±140.8; critical: 119.9±52.7, 201.8±86.64, 190.5±51.99) and sequential organ failure assessment score (severe: 2.83±1.72, 1.33±1.63, 0.67±1.03; critical: 6.67±2.34, 4.17±2.32, 3.83±2.56). Better improving effect was observed in severe than critical patients after HDIVC. CONCLUSIONS: HDIVC might be beneficial in aspects of inflammatory response, immune and organ function for aggravation of COVID-19 patients. Further clinical trials are in warrant. TRIAL REGISTRATION: This trial has been retrospectively registered in Chinese Clinical Trail Registry (ChiCTR2000032716) on May 8, 2020. http://www.chictr.org.cn/showproj.aspx?proj=53389.

COVID-19 and Tuberculosis.

On March 11, 2020, the WHO declared that coronavirus disease 2019 (COVID-19) can be characterized as a pandemic based on the alarming levels of spread and severity and on the alarming levels of inaction. COVID-19 has received worldwide attention as emergency, endangering international public health and economic development. There is a growing body of literatures regarding severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as well as COVID-19. This review will focus on the latest advance of epidemiology, pathogenesis, and clinical characteristics about COVID-19. Meanwhile, tuberculosis (TB) remains the leading representative respiratory tract communicable disease threatening public health. There are limited data on the risk of severe disease or outcomes in patients with concurrence of TB and COVID-19. Nevertheless, co-infection of some virus would aggravate TB, such as measles. And tuberculosis and influenza co-infection compared with tuberculosis single infection was associated with increased risk of death in individuals. This review will also introduce the characteristics about the concurrence of TB and emerging infectious diseases to provide a hint to manage current epidemic.

The Course of Mild and Moderate COVID-19 Infections-The Unexpected Long-Lasting Challenge.

BACKGROUND: The course of disease in mild and moderate COVID-19 has many implications for mobile patients, such as the risk of spread of the infection, precautions taken, and investigations targeted at preventing transmission. METHODS: Three hundred thirty-one adults were hospitalized from January 21 to February 22, 2020, and classified as severe (10%) or critical (4.8%) cases; 1.5% died. Two hundred eighty-two (85.2%) mild or moderate cases were admitted to regular wards. Epidemiological, demographic, clinical, chest computed tomography (CT) scan, laboratory, treatment, and outcome data from patient records were analyzed retrospectively. RESULTS: Patients were symptomatic for 9.82±5.75 (1-37) days. Pulmonary involvement was demonstrated on a chest CT scan in 97.9% of cases. It took 16.81±8.54 (3-49) days from the appearance of the first symptom until 274 patients tested virus-negative in naso- and oropharyngeal (NP) swabs, blood, urine, and stool, and 234 (83%) patients were asymptomatic for 9.09±7.82 (1-44) days. Subsequently, 131 patients were discharged. One hundred sixty-nine remained in the hospital; these patients tested virus-free and were clinically asymptomatic because of widespread persisting or increasing pulmonary infiltrates. Hospitalization took 16.24±7.57 (2-47) days; the time interval from the first symptom to discharge was 21.37±7.85 (3-52) days. CONCLUSIONS: With an asymptomatic phase, disease courses are unexpectedly long until the stage of virus negativity. NP swabs are not reliable in the later stages of COVID-19. Pneumonia outlasts virus-positive tests if sputum is not acquired. Imminent pulmonary fibrosis in high-risk groups demands follow-up examinations. Investigation of promising antiviral agents should heed the specific needs of mild and moderate COVID-19 patients.