Serum endocan (ESM-1) as diagnostic and prognostic biomarker in Multisystem inflammatory syndrome in children (MIS-C)

• Serum ESM-1 elevation in MIS-C patients reflects early endothelial damage. • The elevation of serum ESM-1 levels suggests that ESM-1 is part of the inflammatory milieu in MIS-C. • Higher serum ESM-1 levels are associated with an increased risk of cardiac complications in MIS-C patients. • ESM-1 is a valuable biomarker for identifying MIS-C patients at high risk of endothelial dysfunction and cardiac deterioration. Endothelial-cell-specific molecule-1 (ESM-1) also called endocan is a well-known biomarker for detecting inflammation, endothelial dysfunction (ED), and cardiovascular (CV) risk in COVID-19 patients. Upon SARS-CoV-2 infection, a small percentage of children develop Multisystem Inflammatory Syndrome in children (MIS-C). Whether endocan can be used as a biomarker of MIS-C is unknown. In this study, we assessed ESM-1 levels in MIS-C (n = 19) and healthy controls (HC; n = 17). We observed a significant increase in serum ESM-1 levels in MIS-C vs HC (p = 0.0074). In addition, ROC curve analysis demonstrated that this factor has a reasonable discriminatory power between MIS-C patients and HC (AUC of 0.7585). Notably, after one week of hospitalization and care, ESM-1 levels decreased, and this reduction was observed also for other inflammatory and pro-thrombotic markers like C-reactive protein, procalcitonin, fibrinogen, D-dimer, and ferritin, suggesting a general recovery trend in MIS-C patients. In fact, we observed that serum ESM-1 levels positively correlated with procalcitonin (PCT) (r = 0.468; p = 0.043). Finally, logistic regression analysis demonstrated an association between endocan levels and cardiac complications like myocarditis. Therefore, this study suggests that ESM-1 is a valuable diagnostic and prognostic biomarker in patients with MIS-C that may help identify those MIS-C patients at higher risk for cardiovascular complications and guide treatment strategies.