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1.
Preprint em Inglês | medRxiv | ID: ppmedrxiv-21258535

RESUMO

RationalInfection with the SARS-CoV2 virus is associated with elevated neutrophil counts. Evidence of neutrophil dysfunction in COVID-19 is based predominantly on transcriptomics or single functional assays. Cell functions are interwoven pathways, and so understanding the effect of COVID-19 across the spectrum of neutrophil function may identify tractable therapeutic targets. ObjectivesExamine neutrophil phenotype and functional capacity in COVID-19 patients versus age-matched controls (AMC) MethodsIsolated neutrophils from 41 hospitalised, non-ICU COVID-19 patients and 23 AMC underwent ex vivo analyses for migration, bacterial phagocytosis, ROS generation, NET formation (NETosis) and cell surface receptor expression. DNAse 1 activity was measured, alongside circulating levels of cfDNA, MPO, VEGF, IL-6 and sTNFRI. All measurements were correlated to clinical outcome. Serial sampling on day 3-5 post hospitalisation were also measured. ResultsCompared to AMC, COVID-19 neutrophils demonstrated elevated transmigration (p=0.0397) and NETosis (p=0.0366), but impaired phagocytosis (p=0.0236) associated with impaired ROS generation (p<0.0001). Surface expression of CD54 (p<0.0001) and CD11c (p=0.0008) was significantly increased and CD11b significantly decreased (p=0.0229) on COVID-19 patient neutrophils. COVID-19 patients showed increased systemic markers of NETosis including increased cfDNA (p=0.0153) and impaired DNAse activity (p<0.0.001). MPO (p<0.0001), VEGF (p<0.0001), TNFRI (p<0.0001) and IL-6 (p=0.009) were elevated in COVID-19, which positively correlated with disease severity by 4C score. ConclusionCOVID-19 is associated with neutrophil dysfunction across all main effector functions, with altered phenotype, elevated migration, impaired antimicrobial responses and elevated NETosis. These changes represent a clear mechanism for tissue damage and highlight that targeting neutrophil function may help modulate COVID-19 severity.

2.
Preprint em Inglês | medRxiv | ID: ppmedrxiv-20248195

RESUMO

BackgroundThe COVID-19 pandemic started a healthcare crisis and heavily impacted cancer services. MethodsData from cohort studies of COVID-19 cancer patients published up until October 23rd 2020 from PubMed, PubMed Central, medRxiv and Google Scholar were reviewed. Meta-analyses using the random effects model was performed to assess the risk of death in cancer patients with COVID-19. ResultsOur meta-analyses including up to 5,678 patients from 13 studies showed that the following were all statistically significant risk factors for death following SARS-CoV-2 infection in cancer patients: age of 65 and above, presence of co-morbidities, cardiovascular disease, chronic lung disease, diabetes and hypertension. There was no evidence that patients who had received cancer treatment within 60 days of their COVID-19 diagnosis were at a higher risk of death, including patients who had recent chemotherapy. ConclusionsCancer patients are susceptible to severe COVID-19, especially older patients and patients with co-morbidities who will require close monitoring. Our findings support the continued administration of anti-cancer therapy during the pandemic. The analysis of chemotherapy was powered at 70% to detect an effect size of 1.2 but all other anti-cancer treatments had lower power. Further studies are required to better estimate their impact on the outcome of cancer patients.

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