The impact of PM2.5, PM10 and NO2 on Covid-19 severity in a sample of patients with multiple sclerosis: A case-control study.

BACKGROUND: Many studies investigated the association between air pollution and Covid-19 severity but the only study focusing on patients with Multiple Sclerosis (MS) exclusively evaluated exposure to PM2.5. We aim to study, in a sample of MS patients, the impact of long-term exposure to PM2.5, PM10 and NO2 on Covid-19 severity, described as occurrence of pneumonia. METHODS: A 1:2 ratio case-control study was designed, differentiating cases and controls based on Covid-19 pneumonia. Associations between pollutants and outcome were studied using logistic regression. Weighted quantile sum (WQS) logistic regression was used to identify the individual contribution of each pollutant within the mixture; Least Absolute Shrinkage and Selection Operator (LASSO) penalized regression was performed to confirm the variable selection from WQS. All the analyses were adjusted for confounders selected a priori. RESULTS: Of the 615 eligible patients, 491 patients provided detailed place of exposure and were included in the principal analysis. Higher concentrations of air pollutants were associated with increased odds of developing Covid-19 pneumonia (PM2.5: 3rd vs 1st tercile OR(95% CI)=2.26(1.29;3.96); PM10: 3rd vs 1st tercile OR(95% CI)=2.12(1.22;3.68); NO2: 3rd vs 1st tercile OR(95% CI)=2.12(1.21;3.69)). Pollutants were highly correlated with each other; WQS index was associated to an increased risk of pneumonia (ß=0.44; p-value=0.004) and the main contributors to this association were NO2 (41%) and PM2.5 (34%). Consistently, Lasso method selected PM2.5 and NO2. CONCLUSIONS: Higher long-term exposure to PM2.5, PM10 and NO2 increased the odds of Covid-19 pneumonia among MS patients and the most dangerous pollutants were NO2 and PM2.5.

Reproducing Botryosphaeria Dieback Foliar Symptoms in a Simple Model System.

Botryosphaeria dieback is a grapevine trunk disease with a worldwide distribution associated with Diplodia seriata and Neofusicoccum parvum, among several other Botryosphaeriaceae species. The aforementioned xylem-inhabiting fungi cause wood lesions and leaf and berry symptoms, and eventually lead to the death of the plant. The aim of this work was to develop a simple model system to reproduce the foliar symptoms caused by D. seriata and N. parvum to better characterize fungal pathogenicity and determine the mechanisms involved in symptom development. Green stems of grafted 'Aragonez' grapevine cuttings were inoculated with three isolates of N. parvum and two isolates of D. seriata with different degrees of virulence and the experiment was repeated four times from 2011 to 2014. Three months after inoculation, the lesions associated with N. parvum were larger than those associated with D. seriata. Similarly, 8 months after inoculation, the percentage of plants showing foliar symptoms was greater in the N. parvum treatments than in the D. seriata treatments. During the emergence of foliar symptoms, plant stress-related responses were modulated in green stems and leaves, especially a downregulation of superoxide dismutase (SOD) and fasciclin-like arabinogalactan protein (fascAGP) and an upregulation of stilbene synthase (STS) genes with an accumulation of phenolics. In conclusion, the simple model system developed allowed a good characterization of isolate pathogenicity and correlation with foliar symptoms of Botryosphaeria dieback, namely spots on leaf margin and blade.