Value of Increased Soluble Suppressor Tumorigenicity Biomarker 2 (sst2) on Admission As an Indicator of Severity in Patients with COVID-19.

Background: Soluble suppressor of tumorigenicity-2 (sST2) is a biomarker for heart failure and pulmonary injury. We hypothesize that sST2 could help predict severity of SARS-CoV-2 infections. Methods: sST2 was analyzed in patients consecutively admitted for SARS-CoV-2 pneumonia. Other prognostic markers were also measured. In-hospital complications were registered, including death, ICU admission, and respiratory support requirements. Results: 495 patients were studied (53% male, age: 57.6 +/- 17.6). At admission, median sST2 concentrations was 48.5ng/mL [IQR, 30.6-83.1ng/mL] and correlated with male gender, older age, comorbidities, other severity biomarkers, and respiratory support requirements. sST2 levels were higher in patients who died (n=45, 9.1%) (45.6 [28.0, 75.9]ng/mL vs. 144 [82.6, 319] ng/mL, p<0.001) and those admitted to ICU (n=46, 9.3%) (44.7 [27.5, 71.3] ng/mL vs. 125 [69.0, 262]ng/mL, p<0.001). sST2 levels>210ng/mL were a strong predictor of complicated in-hospital courses, with higher risk of death (OR, 39.3, CI95% 15.9, 103) and death/ICU (OR 38.3, CI95% 16.3-97.5) after adjusting for all other risk factors. The addition of sST2 enhanced the predictive capacity of mortality risk models. Conclusions: sST2 represents a robust severity predictor in COVID-19 and could be an important tool for identifying at-risk patients who may benefit from closer follow-up and specific therapies.