ABSTRACT
SARS-CoV-Z treated at 56 degrees C for 30 min can be inactivated effectively. However, the effect of heat treatment on subsequent detection of the RNA of SARS-CoV-2 by real-time reverse transcription-quantitative polymerase Chain reaction (RT-qPCR) has not been reported. We filled this knowledge gap in present study. We used five SARS'CoV-Z-positive throat swabs. Each throat swab was divided into four parts and assigned to a group: control;56 degrees C for 30 min;56 degrees C for 45 min;56 degrees C for 60 min. After heat treatment, SARS-CoV-Z RNA was extracted and detected by RT-qPCR (absolute quantitation using a standard curve). We found that SARS- CoV-Z RNA was reduced by ~40% after treatment at 56 degrees C for 30 ' 60 min. There was no significant difference (P > 0.05 for all) in the test results between the treatment groups (56 degrees C for 30 min;56 degrees C for 45 min;56 degrees C for 60 min). Our study suggested that SARS-CoV-Z specimens could be inactivated at 56 degrees C for 30 min, before RNA extraction and RT-qPCR detection, which could protect the safety of personnel and the environment during testing. Heat inactivation had a limited effect upon RT-qPCR detection but it should be used with caution if the specimen result is near the critical value.
ABSTRACT
High rate of cardiovascular disease (CVD) has been reported among patients with coronavirus disease 2019 (COVID-19). Importantly, CVD, as one of the comorbidities, could also increase the risks of the severity of COVID-19. Here we identified phospholipase A2 group VII (PLA2G7), a well-studied CVD biomarker, as a hub gene in COVID-19 though an integrated hypothesis-free genomic analysis on nasal swabs (n = 486) from patients with COVID-19. PLA2G7 was further found to be predominantly expressed by proinflammatory macrophages in lungs emerging with progression of COVID-19. In the validation stage, RNA level of PLA2G7 was identified in nasal swabs from both COVID-19 and pneumonia patients, other than health individuals. The positive rate of PLA2G7 were correlated with not only viral loads but also severity of pneumonia in non-COVID-19 patients. Serum protein levels of PLA2G7 were found to be elevated and beyond the normal limit in COVID-19 patients, especially among those re-positive patients. We identified and validated PLA2G7, a biomarker for CVD, was abnormally enhanced in COVID-19 at both nucleotide and protein aspects. These findings provided indications into the prevalence of cardiovascular involvements seen in patients with COVID-19. PLA2G7 could be a potential prognostic and therapeutic target in COVID-19.