ABSTRACT
Reactive nitrogen species (RNS) such as nitric oxide (NO) can be produced by local pulmonary cells and inflammatory cells, and they play a role in the pathogenesis of chronic pulmonary diseases and pulmonary infections. NO is an unstable compound turning to a more stable nitrite and nitrate rapidly. The objective of our study was to investigate the association between plasma nitrate+nitrite, nitrate, and nitrite levels and the severity of coronavirus disease (COVID)-19. Blood plasma samples of mild, moderate, and severe COVID-19 patients were collected from 2 different hospitals. Plasma of healthy subjects, who had never COVID-19 was used as controls (n=20 for each group). Samples were isolated by centrifugation following ultrafiltration prior to the commercial nitrate/nitrite colorimetric assay kit. Plasma nitrate+nitrite and nitrate levels, respectively, were significantly increased in severe patients (medians=34.4muM and 33.4muM), as compared to mild groups (medians=22.3muM and 20.6muM;p<0.05). In contrast, nitrite levels were significantly lower in severe patients (median= 0.8muM) than mild patients (median= 1.6muM;p<0.0001). Patients with severe disease were older (64.9 years) than the mild patients (50.6 years;p<0.05). In severe patients, age was positively correlated with nitrate+nitrite and nitrate levels, respectively (r=0.502, p=0.024;r=0.489, p=0.029). Our findings suggest that RNS may play a role in the pathogenesis of COVID-19 and that it may be considered as a marker of severity.
ABSTRACT
RATIONALE: Coronavirus disease 2019 (COVID-19), which is caused by the SARS-CoV-2, has been affecting the world since the end of 2019. Turkey is severely affected with the first case being reported on March 11th 2020. Several studies suggest an association between air pollution and the spread of the infection, and that ambient particulate matters (PM) can present a potential, as virus carriers. The aim of the present study was to investigate the presence of SARS-CoV-2 RNA on ambient PM. METHODS: Ambient PM samples in various size ranges were collected from 13 sites including urban, urban background locations and hospital gardens in 10 cities including Istanbul, Ankara, Izmir, Zonguldak, Tekirdag, Eskisehir, Bolu, Bursa, Konya, and Antalya across Turkey, between 13th of May and 14th of June, 2020. The nucleocapsid (N) 1 gene and RNA dependent RNA polymerase (RdRP) gene expressions were analyzed in PM samples for the presence of SARS-CoV-2 by applying quantitative real time-polymerase chain reaction (qRT-PCR) and three dimensional (3D)-digital PCR methods. RESULTS: A total of 155 daily samples (Total Suspended Particulate [TSP], n=80;PM2.5, n=33;PM2.5-10, n=23;PM10, n=19;and 6 size segregated, n=48) were collected using various samplers in the each city. According to RT-PCR and 3D-RT-PCR analysis, dual RdRP and N1 gene positivity were detected in 20 of the samples (9.8 %). The highest percentage of virus detection on PM samples was from hospital gardens in Tekirda Zonguldak, and Istanbul, especially in PM2.5 mode. Samples collected from two urban sites, Ankara and Eskisehir, were also positive. CONCLUSIONS: These findings suggest that SARS-CoV-2 may be transported by ambient particles, especially at sites close to the infection hot-spots such as hospital gardens. Whether this has an impact on the spread of the virus infection remains to be determined.