Pulmonary pathology of early-phase COVID-19 pneumonia in a patient with a benign lung lesion.

AIMS: An ongoing outbreak of 2019 novel coronavirus (CoV) disease (COVID-19), caused by severe acute respiratory syndrome (SARS) CoV-2, has been spreading in multiple countries. One of the reasons for the rapid spread is that the virus can be transmitted from infected individuals without symptoms. Revealing the pathological features of early-phase COVID-19 pneumonia is important for understanding of its pathogenesis. The aim of this study was to explore the pulmonary pathology of early-phase COVID-19 pneumonia in a patient with a benign lung lesion. METHODS AND RESULTS: We analysed the pathological changes in lung tissue from a 55-year-old female patient with early-phase SARS-CoV-2 infection. In this case, right lower lobectomy was performed for a benign pulmonary nodule. Detailed clinical, laboratory and radiological data were also examined. This patient was confirmed to have preoperative SARS-CoV-2 infection by the use of real-time reverse transcription polymerase chain reaction and RNA in-situ hybridisation on surgically removed lung tissues. Histologically, COVID-19 pneumonia was characterised by exudative inflammation. The closer to the visceral pleura, the more severe the exudation of monocytes and lymphocytes. Perivascular inflammatory infiltration, intra-alveolar multinucleated giant cells, pneumocyte hyperplasia and intracytoplasmic viral-like inclusion bodies were seen. However, fibrinous exudate and hyaline membrane formation, which were typical pulmonary features of SARS pneumonia, were not evident in this case. Immunohistochemical staining results showed an abnormal accumulation of CD4+ helper T lymphocytes and CD163+ M2 macrophages in the lung tissue. CONCLUSION: The results highlighted the pulmonary pathological changes of early-phase SARS-CoV-2 infection, and suggested a role of immune dysfunction in the pathogenesis of COVID-19 pneumonia.

Rapid and effective diagnosis of pulmonary tuberculosis with novel and sensitive loop-mediated isothermal amplification (LAMP) assay in clinical samples: a meta-analysis.

In recent years, Loop-mediated isothermal amplification (LAMP) assay has been introduced for the diagnosis of pulmonary tuberculosis (TB). We performed the meta-analysis to establish the overall accuracy of LAMP assay for diagnosing pulmonary TB. Based on comprehensive searches of the pubmed, embase and cochrane databases, we identified outcome datas from all articles estimating diagnostic accuracy with LAMP assay until 1 October 2012. A summary estimation for sensitivity, specificity, diagnostic odds ratios (DOR) and the area under the summary ROC curve (AUC) was calculated by using the bivariate random-effects approach. The meta-analysis included 10 studies (1920 suspected specimens). The summary estimate was 80.0% (95%CI, 78.0%-83.0%) for sensitivity, 96.0% (95%CI, 95.0%-97.0%) for specificity and 119.85/0.9633 for DOR/AUC in pulmonary TB. The findings in subgroup analysis were as follows: the accuracy of LAMP assay is higher in high quality level studies than moderate and low quality level studies. The pooled sensitivity for the diagnosis of pulmonary TB was 90.0% (95%CI, 86.0-93.0%) and 75.0% (95%CI, 71.0-78.0%) for high quality level studies and moderate combined low quality level studies, respectively, while the specificity was 99.0% (95%CI, 98.0-100.0%) and 91.0% (95%CI, 88.0-94.0%). Pulmonary TB can be rapidly and accurately diagnosed with LAMP assay.

Effects of Different Temperature and Time Durations of Virus Inactivation on Results of Real-time Fluorescence PCR Testing of COVID-19 Viruses.

The novel Coronavirus SARS-CoV-2 caused an outbreak of pneumonia in Wuhan, Hubei province of China in January 2020. This study aims to investigate the effects of different temperature and time durations of virus inactivation on the results of PCR testing for SARS-CoV-2. Twelve patients at the Renmin Hospital of Wuhan University suspected of being infected with SARS-CoV-2 were selected on February 13, 2020 and throat swabs were taken. The swabs were stored at room temperature (20-25°C), then divided into aliquots and subjected to different temperature for different periods in order to inactivate the viruses (56°C for 30, 45, 60 min; 65, 70, 80°C for 10, 15, 20 min). Control aliquots were stored at room temperature for 60 min. Then all aliquots were tested in a real-time fluorescence PCR using primers against SARS-CoV-2. Regardless of inactivation temperature and time, 7 of 12 cases (58.3%) tested were positive for SARS-CoV-2 by PCR, and cycle threshold values were similar. These results suggest that virus inactivation parameters exert minimal influence on PCR test results. Inactivation at 65°C for 10 min may be sufficient to ensure safe, reliable testing.