By: Christian Ramakers, PhD, ESLM, Erasmus Medical Center Rotterdam, The Netherlands As one of seven university hospitals in The Netherlands, the Erasmus MC (Fig. 1) in Rotterdam plays an important role in the tertiary care of patients. Working closely together with four regional hospitals in the greater Rotterdam area, the Erasmus MC has reserved the majority of its 850 beds solely for those patients who need complex care that cannot be provided by our regional partners. With more than 550,000 out-patient clinic visits each year, Erasmus MC is one of the biggest hospital care providers in The Netherlands. It is well known that most of the medical decisions that clinicians make, are based on lab results. In that respect the Department of Clinical Chemistry, as part of the division of Laboratory Medicine of the Erasmus MC, plays an essential supportive role. Next to our role in the care for patients this department also focuses on novel biomarker research, and participates in numerous clinical research projects in which (new) biomarkers are involved. Two examples of the latter include the FORESEEN study and the CIUM study. In short, while the FORESEEN study looks at the added diagnostic as well as prognostic value of biomarkers used in acute care patients in the Emergency Department (ED) that present with fever, the CIUM study does the same, but in ventilated ICU patients. One of the biomarkers under investigation for both studies is suPAR. Up until the SARS-COV-2 outbreak in The Netherlands, our experience with suPAR was from a retrospective research setting. Having said that, with the sharp rise in SARS-COV-2 ICU admissions in our hospital we looked at ways to help our ICU doctors in the day-to-day clinical care of SARS-COV-2 ICU patients. With the help of our diagnostic partners (i.e. Fujirebio, Roche Diagnostics and ViroGates) and in close collaboration with our ICU colleagues, we were able to quickly expand our diagnostic testing panel with three relatively new biomarkers: KL-6 (Fujirebio), NGAL (Roche Diagnostics), and suPAR (ViroGates). "The choice for including suPAR in our testing panel for our ICU patients came from the wellknown prognostic value of suPAR." Dr. Christian Ramakers The choice for including suPAR in our testing panel for our ICU patients came from the well-known prognostic value of suPAR. While normally being used as an ED triage marker, we hypothesized that suPAR could also aid in predicting the exacerbation of SARS-COV-2 patients admitted in the ICU. Because of our experience with suPAR in the mentioned studies, we had already verified the analysis of suPAR in lithium heparin plasma on our 24\/7 cobas c8000 platform. This, together with the helping hand of our hospital IT department, enabled us to quickly add suPAR to the daily lab round of our SARSCOV-2 ICU patients.https:\/\/www.virogates.com\/wp-content\/uploads\/2020\/09\/2020-09-08-15_08_10-suPAR-News-vol-3-Final.pdf-\u2013-Google-Chrome.jpgFig. 1. The Erasmus MC in Rotterdam. Running from April 11 until April 19 we were able to get 775 suPAR measurements from 150 ICU-admitted SARS-COV-2 patients (on average, 5 serial results per patient). While it is still too early to draw conclusions, preliminary result show relatively high suPAR concentrations in our patients. Overall, the suPAR concentrations averages were 13 ng\/mL (stdev 6.6 ng\/mL). And while in some patients the suPAR concentration remains relatively low (single digits), other patients were consistently leveled-off at our set linearity cut-off value of 25 ng\/mL. And next to patients showing no obvious concentration changes in time, we also saw patients with a progressive increase in suPAR over the full nine-day period covered by the protocol. In conclusion, in order to put these results in a clinical perspective, the next step now is to combine the serial suPAR results with the clinical data available in the patients\u2019 files. Not only the clinical data during admission will be considered, but even more important in light of the prospective use of suPAR, also the long-term outcome data upon discharge.