ABSTRACT
COVID-19 is a respiratory-centered systemic disorder caused by SARS-CoV-2. The disease can progress into a severe form causing acute lung injury. CD48 is a co-signaling receptor, existing as both membrane-bound and soluble forms reported to be dysregulated in several inflammatory conditions. Therefore, we reasoned that CD48 could be deregulated in COVID-19 as well. Here we analyzed CD48 expression in autoptic sections and peripheral blood leukocytes and sera of COVID-19 patients by gene expression profiling (HTG(R) autoimmune panel), immunohistochemistry, flow cytometry and ELISA. Lung tissue of COVID-19 patients showed increased CD48 mRNA expression and infiltration of CD48+ lymphocytes. In the peripheral blood, mCD48 was considerably increased on all evaluated cells, and additionally, sCD48 levels were significantly higher in COVID-19 patients independently of disease severity. Considering the alterations of mCD48 and sCD48, a specific role for CD48 in COVID-19 can be assumed, suggesting it as a potential target for therapy.
ABSTRACT
BACKGROUNDAccurately identifying COVID-19 patients at-risk to deteriorate remains challenging. Tools integrating host-protein expression have proven useful in determining infection etiology and hold potential for prognosticating disease severity. METHODSAdults with COVID-19 were recruited at medical centers in Israel, Germany, and the United States. Severe outcome was defined as intensive care unit admission, non-invasive or invasive ventilation, or death. Tumor necrosis factor related apoptosis inducing ligand (TRAIL) and interferon gamma inducible protein-10 (IP-10; also known as CXCL10) and C-reactive protein (CRP) were measured using an analyzer providing values within 15 minutes. A signature indicating the likelihood of severe outcome was derived generating a score (0-100). Patients were assigned to 4 score bins. RESULTSBetween March and November 2020, 518 COVID-19 patients were enrolled, of whom 394 were eligible, 29% meeting a severe outcome. The signatures area under the receiver operating characteristic curve (AUC) was 0.86 (95% confidence interval: 0.81-0.91). Performance was not confounded by age, sex, or comorbidities and superior to IL-6 (AUC 0.77; p = 0.033) and CRP (AUC 0.78; p < 0.001). Likelihood of severe outcome increased significantly (p < 0.001) with higher scores. The signature differentiated patients who further deteriorated after meeting a severe outcome from those who improved (p = 0.004) and projected 14-day survival probabilities (p < 0.001). CONCLUSIONThe derived immune-protein signature combined with a rapid measurement platform is an accurate predictive tool for early detection of COVID-19 patients at-risk for severe outcome, facilitating timely care escalation and de-escalation and appropriate resource allocation. FUNDINGMeMed funded the study
