Alpha 1-Acid Glycoprotein is Involved With Neutrophil Nets in COVID-19

ABSTRACT

Introduction: Orosomucoid also named Alpha-1 Acid Glycoprotein(AGP) is a major acute-phase protein and is increased in response to systemic injury and inflammation. AGP has been described as an inhibitor of neutrophil migration on sepsis, particularly its immunomodulation effects. The AGP biological functions are not understood in Coronavirus disease 2019 (COVID-19). Hypothesis: We hypothesize that plasmatic AGP is upregulated in severe Covid-19 patients and is involved in the regulation of netosis. Therefore, we sought to investigate the role of AGP in plasmatic from COVID-19 severe infection patients and neutrophils infected with Severe Acute Respiratory Syndrome Coronavirus-2 (SarsCov-2). Method(s) Epidemiological data and AGP, interleukin-6 (IL-6), C-reactive protein (PCR), lactate, and other laboratorial parameters were measured in blood samples from 52 subjects hospitalized in the ICU with clinically SarsCov-2 infection confirmed by RT-PCR. To evaluate the role of AGP in netosis in neutrophils, blood samples from health patients (n=13) were collected, and neutrophils were separated and infected with Sars-Cov-2 (Moi=1). Those neutrophils were treated with AGP (10mug/ml) or vehicle for 18 hours and netosis was analyzed by flow cytometry (n=10) and immunofluorescence (IF;n=10). Early and late netosis, respectively, were characterized by negative or positive FVS and positive Sytox. The neutrophil extracellular traps (NETs) were investigated by myeloperoxidase (MPO), neutrophil elastase (NE), and DAPI by IF and quantified Netquant/Matlab software. This study was approved by Ethics Committee -CAAE 30816620.0.0000.5440. Result(s) AGP increased in severe Covid-19 patients (p<0.05). A positive correlation between AGP with IL-6 and C-reactive protein (respectively, p=0.005, p=0.002) and a negative correlation between AGP and lactate (p=0.004) were found it. Together, AGP treatment downregulated early (35,7%) and late (43,5%) netosis in neutrophils infected with SarsCov-2. Confocal analysis by MPO, NE e DAPI showed NETs released by neutrophils infected with Sar-Cov-2 decreased when neutrophils were treated with AGP (p<0.05). Conclusion(s) Our data showed increased AGP in COVID-19 infection and contributed to netosis regulation.