Giacconi Robertina, D'Aquila Patrizia, Cardelli Maurizio, Piacenza Francesco, Pierpaoli Elisa, Sena Giada, Di Rosa Mirko, Bonfigli Anna Rita, Galeazzi Roberta, Cherubini Antonio, Fedecostante Massimiliano, Sarzani Riccardo, Di Pentima Chiara, Giordano Piero, Antonicelli Roberto, Lattanzio Fabrizia, Passarino Giuseppe, Provinciali Mauro, Bellizzi Dina
Advanced Technology Center for Aging Research, IRCCS INRCA, Ancona, Italy.
Department of Biology, Ecology and Earth Sciences, University of Calabria, 87036, Rende, Italy.
Immun Ageing. 2023 Dec 18;20(1):76. doi: 10.1186/s12979-023-00401-4.
Coronavirus disease COVID-19 is a heterogeneous condition caused by SARS-CoV-2 infection. Generally, it is characterized by interstitial pneumonia that can lead to impaired gas-exchange, acute respiratory failure, and death, although a complex disorder of multi-organ dysfunction has also been described. The pathogenesis is complex, and a variable combination of factors has been described in critically ill patients. COVID-19 is a particular risk for older persons, particularly those with frailty and comorbidities. Blood bacterial DNA has been reported in both physiological and pathological conditions and has been associated with some haematological and laboratory parameters but, to date, no study has characterized it in hospitalized old COVID-19 patients The present study aimed to establish an association between blood bacterial DNA (BB-DNA) and clinical severity in old COVID-19 patients.
BB-DNA levels were determined, by quantitative real-time PCRs targeting the 16S rRNA gene, in 149 hospitalized older patients (age range 65-99 years) with COVID-19. Clinical data, including symptoms and signs of infection, frailty status, and comorbidities, were assessed. BB-DNA was increased in deceased patients compared to discharged ones, and Cox regression analysis confirmed an association between BB-DNA and in-hospital mortality. Furthermore, BB-DNA was positively associated with the neutrophil count and negatively associated with plasma IFN-alpha. Additionally, BB-DNA was associated with diabetes.
The association of BB-DNA with mortality, immune-inflammatory parameters and diabetes in hospitalized COVID-19 patients suggests its potential role as a biomarker of unfavourable outcomes of the disease, thus it could be proposed as a novel prognostic marker in the assessment of acute COVID-19 disease.
冠状病毒病COVID-19是由严重急性呼吸综合征冠状病毒2（SARS-CoV-2）感染引起的一种异质性疾病。一般来说，其特征为间质性肺炎，可导致气体交换受损、急性呼吸衰竭和死亡，不过也有文献描述了多器官功能障碍这一复杂病症。其发病机制复杂，危重症患者中已发现多种因素的不同组合。COVID-19对老年人，尤其是身体虚弱和患有合并症的老年人来说是一种特殊风险。血液中的细菌DNA在生理和病理条件下均有报道，并且与一些血液学和实验室参数相关，但迄今为止，尚无研究对住院的老年COVID-19患者的血液细菌DNA进行特征描述。本研究旨在确定老年COVID-19患者血液细菌DNA（BB-DNA）与临床严重程度之间的关联。
通过针对16S rRNA基因的定量实时聚合酶链反应，测定了149例住院的年龄在65至99岁之间的COVID-19老年患者的BB-DNA水平。评估了包括感染症状和体征、身体虚弱状况及合并症在内的临床数据。与出院患者相比，死亡患者的BB-DNA水平升高，Cox回归分析证实BB-DNA与住院死亡率之间存在关联。此外，BB-DNA与中性粒细胞计数呈正相关，与血浆干扰素-α呈负相关。另外，BB-DNA与糖尿病有关。
住院COVID-19患者的BB-DNA与死亡率、免疫炎症参数及糖尿病之间的关联表明其可能作为该疾病不良预后的生物标志物，因此可提议将其作为评估急性COVID-19疾病的一种新型预后标志物。
